A 15-year-old boy with good past health presented with a 1-day history of fever, four episodes of vomiting, and lethargy. He denied diarrhoea, headache, or any neurological symptoms. On arrival, he had blood pressure 106/36 mm Hg, heart rate 127 bpm, temperature 39°C, and oxygen saturation 99% on air. He had reduced pulse volume with normal capillary refilling time. Systemic examination was otherwise unremarkable. Full blood count analysis revealed a haemoglobin level of 14.7 g/dL, white cell count of 9.31 × 10⁹/L, and platelet count of 240 × 10⁹/L. The patient’s blood test results were positive for dengue non-structural protein 1, and negative for dengue immunoglobulin M and immunoglobulin G. His renal profile was normal, with mild raised liver enzymes: alanine aminotransferase 82 U/L and aspartate aminotransferase 310 U/L.

In view of the tachycardia and reduced pulse volume, he was treated as a case of severe dengue fever with compensated shock. He was admitted to the intensive care unit and treated with fluid boluses according to standard protocol. On day 3 of illness he developed severe plasma leakage and was intubated for respiratory distress. His condition soon stabilised and he remained normotensive throughout his stay in intensive care unit. He was extubated on day 7 when he entered a recovery phase. At that time, he had a normal level of consciousness.

Three days later (day 10 of illness), he became encephalopathic, disorientated and able to obey only single step commands. Examination revealed a Glasgow Coma Scale score of E4V4M6 with normal motor power over both upper and lower limbs. A plain computed tomography (CT) brain scan showed hypodensities at bilateral occipital regions and semiovale, predominantly involving the white matter, and suggestive of posterior reversible encephalopathy syndrome (PRES) [Fig 1]. A diagnostic lumbar puncture was offered but refused by his parents. Blood and urine cultures were negative and he was prescribed a 1-week course of intravenous meropenem. He subsequently improved and was discharged well on day 16. Serum dengue polymerase chain reaction was later confirmed as DEN-2. At clinic follow-up, the patient was well and asymptomatic. Repeat CT brain at 3 months showed complete resolution of white matter oedema (Fig 2).

Dengue fever is an important public health problem in the tropics. At present, it is endemic in more than 100 countries. The World Health Organization estimates there to be around 390 million infections per year with 96 million manifesting clinically.1 The clinical features vary from those of a mild febrile illness to severe dengue with systemic complications. Systemic complications include shock, bleeding, plasma leakage, myocarditis and, in some patients, neurological complications. The latter include dengue encephalitis, dengue encephalopathy, meningitis, acute disseminated encephalomyelitis, and Guillain-Barré syndrome.2 Posterior reversible encephalopathy syndrome can occur but is rare.

Posterior reversible encephalopathy syndrome is a distinct clinicoradiological syndrome characterised by headache, seizures, altered consciousness and visual disturbances with the presence of reversible brain vasogenic oedema.3 It can be caused by acute hypertension, hypertensive disease in pregnancy, autoimmune diseases (systemic lupus erythematosus, systemic sclerosis), immunosuppressants, cytotoxic agents, renal failure, and infection. An infectious aetiology such as virus and gram-positive or gram-negative sepsis have all been associated with PRES as has dengue virus.4 5

The pathophysiology of PRES in dengue is still not fully understood. It is postulated to be related to endothelial dysfunction4 that subsequently leads to vasogenic oedema and decreased cerebral blood flow. In addition, inflammatory cytokines can increase vascular permeability with consequent interstitial brain oedema.3 Neuroimaging is essential for diagnosis with characteristics that include vasogenic oedema in the parieto-occipital region of both cerebral hemispheres. The subcortical white matter is always affected. Three primary patterns of magnetic resonance imaging (MRI) brain have been described, namely dominant parieto-occipital pattern, holohemispheric watershed pattern, and superior frontal sulcus pattern. Treatment is mainly supportive with removal of causative factors.

In our patient, diagnosis of PRES was based on clinical and radiological features. He developed acute onset encephalopathy coupled with typical neuroimaging features. Brain CT showed symmetrical hypodensities at bilateral occipital lobes and predominantly involving white matter, suggestive of PRES. He was treated conservatively, and he improved. Follow-up CT brain revealed complete resolution of vasogenic oedema. In terms of aetiology, our patient had no history of hypertension or autoimmune disease or recent cytotoxic agent. In addition, blood pressure remained stable throughout his hospital stay with no decompensated shock. The limitation of our case is the lack of MRI facilities. Compared with CT, MRI better delineates lesions and is preferable if available.

In terms of timing of PRES in relation to dengue fever, PRES has been reported to have occurred on day 5 to 6 of illness in one case,4 and within the non-structural protein 1 antigen positive period (first 7 days of illness) in another.5 In our case, it occurred on day 10 of illness and was considered compatible with the cases reported previously. A diagnosis of PRES secondary to dengue is one of exclusion, supported by typical imaging features and within a reasonable time frame. Alternative causes of PRES should be actively searched for and excluded in every case.

In conclusion, this case highlights PRES as an important differential diagnosis in a dengue patient with neurological deficits. It is important to differentiate PRES from other clinical syndromes since management is mainly supportive and by controlling the underlying conditions. Neuroimaging plays an important role in establishing the diagnosis in the compatible clinical context. The prognosis of PRES is usually good. However, more studies are needed to further elucidate the underlying pathophysiology of PRES in dengue.

Concept or design: SW Cheo and QJ Low.
Acquisition of data: SW Cheo and HJ Wong.
Analysis or interpretation of data: HJ Wong and EK Ng.
Drafting of the manuscript: SW Cheo and QJ Low.
Critical revision of the manuscript for important intellectual content: All authors.

All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

The authors have disclosed no conflicts of interest.

This case report received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

The patient was treated in accordance with the Declaration of Helsinki. The patient provided written informed consent for all treatments and procedures, and written consent for publication.

1. World Health Organization. Dengue and severe dengue: Fact sheet. Available from: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue.Accessed 4 Nov 2019.

2. Murthy JM. Neurological complications of dengue infection. Neurol India 2010;58:581-4. Crossref

3. Fugate JE, Rabinstein AA. Posterior reversible encephalopathy syndrome: clinical and radiological manifestations, pathophysiology, and outstanding questions. Lancet Neurol 2015;14:914-25. Crossref

4. Mai NT, Phu NH, Nghia HD, et al. Dengue-associated posterior reversible encephalopathy syndrome, Vietnam. Emerg Infect Dis 2018;24:402-4. Crossref

5. Sohoni CA. Bilateral symmetrical parieto occipital involvement in dengue infection. Ann Indian Acad Neurol 2015;18:358-9. Crossref

Ureterosciatic hernia is an extremely rare cause of ureteral obstruction. We report a patient with left pyonephrosis and obstructive uropathy caused by a ureterosciatic hernia.

A 97-year-old woman with a history of ischaemic stroke, hypertension, hyperlipidaemia, and chronic obstructive pulmonary disease attended the Accident and Emergency department of Kwong Wah Hospital in January 2020 with a 1-day history of decreased general health and vomiting. She had no urinary or bowel symptoms. Her vital signs were stable on admission and physical examination of her cardiorespiratory and abdominal systems was unremarkable.

Blood tests on admission revealed acute kidney injury with serum creatinine level of 387 μmol/L (baseline 73 μmol/L), leucocytosis (23.8 × 10⁹/L), and elevated C-reactive protein level of 287 mg/L.

Kidney, ureter, and bladder plain radiograph revealed the absence of urinary stone. Amoxicillin with clavulanic acid were administered intravenously. The following day the patient developed fever up to 40.1°C with abdominal pain. Urgent contrast computed tomography scan of the abdomen and pelvis showed moderate-to-severe left hydronephrosis (Fig 1) with hydroureter up to 1.4 cm down to the distal ureter at the level of the left greater sciatic foramen, where the ureter herniated out of the pelvis with an abrupt calibre change (Fig 2). There was reduced enhancement of the left kidney with no contrast excretion evident on the delayed phase. Retrograde ureteral stenting was performed and 30 mL pus was drained from the left kidney.

Blood and urine cultures grew Escherichia coli. The patient recovered gradually with a 2-week course of antibiotics. The double-J stent was removed at the end of March (2 months after stent insertion). However, she developed another episode of urosepsis shortly afterwards and a double-J stent was re-inserted. She remained well with regular revision of double-J stent.

Ureterosciatic hernia is a rare disease with no more than 40 cases published worldwide to date.1 It occurs when the peritoneal sac and its contents (eg, ovary, small intestine, colon, greater omentum) protrude through the greater or lesser sciatic foramen.2 When the ureter becomes involved in the herniated contents, it is called ureterosciatic hernia. The sacrospinous ligament divides the sciatic notch into the greater and lesser sciatic foramina. The piriformis muscle subdivides the greater sciatic foramen into the suprapiriformis and infrapiriformis compartments. Ureterosciatic herniation commonly occurs through the suprapiriformis compartment of the greater sciatic foramen.2 Herniation of the ureter into the greater sciatic foramen often results from piriformis muscle weakening due to increased pressure in the intra-abdominal area due to pregnancy, constipation, surgery, trauma, neuromuscular diseases, or hip disease.3 It commonly develops in elderly women due to their wider pelvic bones but congenital cases have also been reported. The left ureter is affected more often than the right.4

The clinical presentation of ureterosciatic hernia varies and can range from asymptomatic to life-threatening urinary sepsis or obstructive uropathy. Patients may complain of flank or abdominal pain, nausea, and vomiting. A palpable mass over the affected area may be present.2

Since the signs and symptoms of ureterosciatic hernias are rather non-specific, the diagnosis is commonly made by radiographic studies including intravenous urogram, retrograde pyelography, and computed tomography. Obstruction of the ureter with U-shaped tortuosity into the sciatic foramina, also referred to as a “curlicue ureter” sign, is suggestive of ureterosciatic hernia.5

Treatment options include observation (mostly for asymptomatic patients), ureteral stenting, and surgical correction. Open, laparoscopic and robotic approaches have been described for reduction of the ureter and hernia repair.1 As our patient was aged 97 years with multiple co-morbidities, surgery was not considered.

Although seldom seen, ureterosciatic hernias are occasionally encountered. Diagnosis can be a challenge given its non-specific symptomatology and rarity.

Concept or design: All authors.
Acquisition of data: CYC Chan.
Analysis or interpretation of data: CYC Chan.
Drafting of the manuscript: CYC Chan and TCT Lai.
Critical revision of the manuscript for important intellectual content: CYC Chan.

All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

This case report received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

The patient was treated in accordance with the Declaration of Helsinki. The procedure was done under 2MO consent as the patient’s condition was unstable at the time. Risks of and indications for the procedure were discussed with the patient’s daughter who showed understanding and agreed to proceed. The patient provided consent for publication.

1. Kamisawa K, Ohigashi T, Omura M, Takamatsu K, Matsui Z. Ureterosciatic hernia treated with laparoscopic intraperitonization of the ureter. J Endourol Case Rep 2020;6:150-2. Crossref

2. Gandhi J, Lee MY, Joshi G, Smith NL, Khan SA. Ureterosciatic hernia: an up-to-date overview of evaluation and management. Translational Research in Anatomy 2018;11:5-9. Crossref

3. Gee J, Munson JL, Smith JJ 3rd. Laparoscopic repair of ureterosciatic hernia. Urology 1999;54:730-3. Crossref

4. Loffroy R, Bry J, Guiu B, et al. Ureterosciatic hernia: a rare cause of ureteral obstruction visualized by multislice helical computed tomography. Urology 2007;69:385.e1-3. Crossref

5. Pollack HM, Popky GL, Blumberg ML. Hernias of the ureter—an anatomic-roentgenographic study. Radiology 1975;117:275-81. Crossref

In December 2016, a 47-year-old Chinese woman was referred to our clinic for treatment of a large cystic pancreatic lesion. She presented with a 12-month history of intermittent epigastric pain associated with eating and weight loss of 5 kg. The patient had a history of uterine fibroids and underwent myomectomy 10 years previously. She was also under observation for a benign thyroid nodule. She had no family history of malignancy, denied consumption of alcohol, was a non-smoker, and lived as a housewife.

A contrast-enhanced computed tomography scan of the abdomen revealed a cystic neoplasm 8 cm in diameter involving the head, neck, and body of the pancreas, with proximal dilatation of the pancreatic duct (Fig 1). Based on the patient’s symptoms and the size of the lesion, surgical resection was recommended. Preoperative laboratory test results, including full blood count, liver and renal function tests, blood glucose level, amylase, carcinoembryonic antigen, and cancer antigen 19.9, were within normal limits.

During surgery, a multiloculated cystic lesion was identified (Fig 2). The cystic content was serous. No nearby enlarged lymph nodes or tissue invasion suggestive of frank malignancy were evident. The pancreatic tail was healthy. An extended middle pancreatectomy (EMP) was performed. The patient recovered without complication and was discharged from hospital 13 days after surgery. Histological examination of the resected tissue confirmed a benign serous cystadenoma.

A bilateral subcostal incision was made. The lesser sac was entered to expose the anterior aspect of the pancreas after division of the gastrocolic ligament (Fig 2a). The gastroduodenal junction was purposefully divided to gain better exposure of the large cystic lesion and to facilitate further pancreatic dissection (Fig 2b). The posterior peritoneum along the inferior and superior margins of the pancreas was dissected. The superior mesenteric vein was identified under the neck of the pancreas. The splenic vein was carefully divided away from the gland and all the small branches of the pancreas draining into the splenic vein were ligated. The gallbladder was removed to facilitate identification and mobilisation of the common bile duct, the hepatic artery, and the portal vein from above. The involved portion of the pancreas was mobilised on both cephalic and caudal sides. The cystic tumour was resected in its entirety with a margin by scalpel and cautery. Most of the head (estimated 80%-90%), neck, and body of the pancreas were removed (Fig 2c). The remaining pancreatic head stump was carefully over-sewn with 3-O Prolene sutures (Ethicon; Cornelia [GA], United States) to avoid pancreatic leak. The pancreatic duct opening was identified and separately sutured. The stump was further re-enforced with fibrin sealant, Tisseel glue (Baxter Healthcare, Deerfield [IL], United States). The distal side stump was anastomosed into a Roux loop of jejunum using an end-to-end technique with invagination (Fig 2d). A short segment of catheter was inserted into the pancreatic duct. The gastric pylorus was then joined up to the proximal jejunum as a gastrojejunostomy and a jejunojejunostomy was fashioned to prevent bile reflux. The proximal jejunum was reconnected to the jejunal Roux loop distally. Two drainage tubes were placed close to the closed cephalic stump and the pancreaticojejunostomy anastomosis before proceeding with abdominal wound closure.

For benign or low-grade malignant lesions of the pancreatic neck and body, traditional approaches for surgical resection include a pancreaticoduodenectomy (PD) or an extended distal pancreatectomy. Enucleation is suitable only for small and superficial lesions that do not have any connection with the pancreatic duct. In 1957, Guillemin and Bessot first reported the technique of middle pancreatectomy (MP) for chronic pancreatitis and pancreatic transection injury.1 In 1982, Dagradi and Serio proposed the use of MP for resection of benign tumours or tumours with low malignant potential situated in the pancreatic neck and body.2 The technique has since gained acceptance.

In this case, the large cystadenoma involved a significant portion of the head of the pancreas in addition to the neck and the body. Traditional approaches for resection of such a lesion would involve either subtotal pancreatectomy or PD. The MP technique described in the literature has not included resection of the head of the pancreas. However, in this case, most of the pancreatic head in addition to the neck and the body of pancreas had to be resected. Therefore, the procedure is being formally named for the first time, EMP.

Extended middle pancreatectomy permits resection of a lesion that extends into the head of the pancreas while conferring similar advantages of an MP over traditional approaches. Compared with other surgical options (subtotal pancreatectomy and PD), this confers the advantage of parenchymal preservation and consequent preservation of pancreatic exocrine and endocrine functions.3 Pancreaticoduodenectomy has been associated with increased postoperative morbidity and mortality. Similarly, the inability to preserve the spleen in subtotal pancreatectomy has been associated with complications of thrombosis and susceptibility to infection. Finally, MP has been associated with a higher incidence of pancreatic fistula, compared with PD and extended distal pancreatectomy procedures.4 5 This has been attributed to the need to manage two pancreatic remnants by anastomosis or closure. However, as much less pancreatic head tissue is left behind in EMP, the risk of pancreatic leak from the proximal stump should theoretically be lower than that observed in MP.

We report, to the best of our knowledge, the first clinical case of EMP in the management of a large cystic neoplasm. This case demonstrated excellent postoperative outcomes and suggests that EMP may be considered a viable preferred surgical option in selected cases. However, the technical difficulties of this procedure should not be underestimated. The long-term functional outcomes have yet to be substantiated by further clinical experience.

All authors contributed to the concept or design of the study, acquisition of the data, analysis or interpretation of the data, drafting of the manuscript, and critical revision of the manuscript for important content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

As an Editor of the Journal, AKK Chui was not involved in the peer review process. The other authors have disclosed no conflicts of interest.

This case report received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

The patient was treated in accordance with the tenets of the Declaration of Helsinki. Patient consent was obtained.

1. Guillemin P, Bessot M. Chronic calcifying pancreatitis in renal tuberculosis: pancreatojejunostomy using an original technic [in French]. Mem Acad Chir (Paris) 1957;83:869-71.

2. Dagradi A, Serio G. Pancreatectomia intermedia. In: Enciclopedia Medica Italiana. Pancreas, vol XI. Florence: USES Ed Scientifiche; 1984: 850-1.

3. Tan Z, Chen P, Dong Z, Zhou B, Guo WD. Clinical efficacy of middle pancreatectomy contrasts distal pancreatectomy: a single-institution experience and review of literature. ANZ J Surg 2019;89:E184-9. Crossref

4. Shibata S, Sato T, Andoh H, et al. Outcomes and indications of segmental pancreatectomy. Comparison with distal pancreatectomy. Dig Surg 2004;21:48-53. Crossref

5. Du ZY, Chen S, Han BS, Shen BY, Liu YB, Peng CH. Middle segmental pancreatectomy: a safe and organ-preserving option foe benign and low-grade malignant lesions. World J Gastroenterol 2013;19:1458-65. Crossref

A 62-year-old man with no known systemic disease was brought to an emergency department by ambulance. He was found trapped in a car after colliding with a bridge and was found to have been driving under the influence of alcohol. On arrival, he complained of headache, neck pain, and chest pain. Physical examination revealed blood pressure of 133/71 mm Hg, heart rate 71 beats per minute, respiratory rate 22 breaths per minute, and oxygen saturation on air of 93%. He appeared intoxicated and was disorientated with a score of 13 (E3V4M6) on the Glasgow Coma Scale. His pupil size was 3.5 mm with bilateral normal reaction to light. A thorough neurological examination could not be performed but the patient was able to move all four limbs without limitation. Nonetheless a scalp laceration, upper back tenderness and left lower cervical crepitus were evident during palpation. Chest examination revealed bilateral equal breath sounds but some basal crackles and a left flank abrasion about 3 × 4 cm in size. Haemogram and biochemistry test results were within normal limits but serum alcohol level was elevated at 2.48 g/L. Chest radiography revealed a posterior fracture at the left fourth to sixth ribs and right ninth rib as well as left cervical subcutaneous emphysema that raised the suspicion of barotrauma associated with chest trauma (Fig 1). In view of the possibility of barotrauma and intracranial injuries, further evaluation with computed tomography (CT) of the brain and chest was arranged. The former was normal and the latter confirmed right first to second posterior ribs and left third to sixth posterior ribs fractures, as well as a small left-sided pneumothorax, bilateral pulmonary contusions, and pneumomediastinum. Notably, free air accumulated in the posterior epidural spaces of the cervical and thoracic spine as well as in the left retrospinal and paraspinal muscle layers with accompanying left second and third thoracic spine posterior neural arch fracture in cervical spine CT scan (Fig 2); these findings were compatible with epidural pneumorrhachis. Additionally, air was seen dissecting from the posterior neck into the epidural space. A neurosurgeon recommended close observation rather than surgical intervention for both the epidural pneumorrhachis and thoracic spine fracture. The patient was admitted to the thoracic surgical ward where he received conservative therapy for rib fractures, pneumothorax and pneumomediastinum including meperidine for pain control and oxygen therapy via a nasal cannula at 3 L/min. New chest radiographs were taken on day 4 after surgery. Cervical emphysema had mostly resolved but there was progression of pulmonary contusion with bilateral minimal pleural effusions. The patient also exhibited wheezing and dyspnoea that warranted inhaled bronchodilators and systemic steroid therapy. The patient was discharged on day 12 after surgery with symptom improvement; no neurological sequelae were noted during follow-up at the out-patient department.

Pneumorrachis (PRS) is characterised by the presence of air within the spinal canal and can be classified according to its location as subarachnoid or epidural PRS. Each is associated with different pathophysiological mechanisms and causes. It may result non-traumatically from spinal degeneration, gas-producing infections, or spontaneous pneumomediastinum in patients with asthma. Iatrogenic PRS may occur following a surgical procedure, epidural anaesthesia, or lumbar puncture but PRS following trauma is rare.1 Almost all types of PRS are found in association with air distribution in other compartments and cavities of the body. For example, PRS is observed in conjunction with pneumocephalus, pneumothorax, pneumomediastinum, pneumopericardium, or subcutaneous emphysema. Pneumorrachis following trauma is rare and arises from the presence of air in the posterior mediastinum or retropharyngeal space dissecting along the fascial planes from the posterior mediastinum or retropharyngeal space through the neural foramina into the epidural space under the driving pressure of a pneumothorax and pneumomediastinum and low resistance of loose connective tissue.2

Epidural PRS has been reported to occur most commonly secondary to traumatic pneumomediastinum. Neurological deficits have not been reported in epidural PRS secondary to trauma. In contrast, traumatic subarachnoid PRS is almost always secondary to major trauma and skull bone fractures, and indicates severe injury and possible association with complications such as tension pneumocephalus or meningitis.3 Various neurological deficits, such as acute lumbar root compression, chronic radiculopathy, and cauda equina syndrome may occur. It is therefore important to identify air in the epidural space and subarachnoid space to enable prompt and adequate management.4 The possible mechanism of PRS in our patient was air entry into the epidural space because of pneumomediastinum, left-sided pneumothorax and subcutaneous emphysema extending through the fractured neural arch of the thoracic spines into the epidural space; these conditions fulfil the criteria for benign traumatic PRS. Criteria for a diagnosis of benign traumatic epidural PRS include substantial pneumomediastinum with extensive subcutaneous emphysema due to thoracic trauma.4 There may also be incidental findings of small amounts of epidural air demonstrable only on CT and unrelated to spinal trauma. “Benign” epidural PRS can be managed conservatively with spontaneous resolution of epidural air.4 Repeat or further neuroimaging studies are not routinely provided in cases of epidural PRS, provided there is no new or progressive neurological deficit. Three cases have been reported with complete resolution of PRS on follow-up CT scan after 4 to 14 days.5 6 7

The PRS is usually asymptomatic and an accidental finding on CT images while evaluating other severe or life-threatening torso injuries. Although CT is the gold standard for diagnosis, it is difficult to differentiate epidural and subarachnoid PRS. Nonetheless in the former, air is collected at the corner or peripherally unlike subarachnoid PRS where it is distributed more centrally in the canal based on normal anatomy. Magnetic resonance imaging or intrathecal contrast CT can distinguish intradural from extradural air.7 In most cases of epidural PRS, the air reabsorbs spontaneously without recurrence and the patient can be managed conservatively.1 In subarachnoid PRS, timely consultation with a neurosurgeon for decompression of nerve root injuries, tension pneumocephalus and exploratory surgery by a chest surgeon to detect severe thoracic trauma is vital. Impressively, Avci et al5 reported a case of complete resolution of subarachnoid PRS on the fifth day of admission with recovery of neurological deficit after chest tube insertion. They concluded that the negative pressure of the chest drain to withdraw the air supported the hypothesis of a one-way valve mechanism in which high pressure air travels through fascial layers but is unable to return. The routine use of antibiotic is not recommended in either type unless meningitis develops.1

Traumatic PRS is rare and an incidental radiological finding. Epidural PRS is often self-limiting with a good prognosis. Although most patients can be managed conservatively, prompt recognition of subarachnoid PRS with neurological deficits and other concurrent life-threatening torso injuries is vital.

Concept or design: KH Lee.
Acquisition of data: YY Yang.
Analysis or interpretation of data: CB Chua.
Drafting of the manuscript: YY Yang and KH Lee.
Critical revision of the manuscript for important intellectual content: CW Hsu.

All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

We would like to extend our special thanks to Dr Cheng-yang Lee, Department of Medical Imaging, Chi Mei Medical Center, Tainan, Taiwan who provided insight and expertise on the image interpretation that greatly improved our manuscript.

All authors have no commercial association, such as consultancies, stock ownership or other equity interests or patent-licensing arrangements.

The patient was treated in accordance with the tenets of the Declaration of Helsinki. The patient provided written informed consent for all treatments and procedures.

1. Oertel MF, Korinth MC, Reinges MH, Krings T, Terbeck S, Gilsbach JM. Pathogenesis, diagnosis and management of pneumorrhachis. Eur Spine J 2006;15 Suppl 5:636-43. Crossref

2. Defouilloy C, Galy C, Lobjoie E, Strunski V, Ossart M. Epidurual pneumatosis: A benign complication of benign pneumomediastinum. Eur Respir J 1995;8:1806-7. Crossref

3. Goh BK, Yeo AW. Traumatic pneumorrhachis. J Trauma 2005;58:875-9. Crossref

4. Willing SJ. Epidural pneumatosis: a benign entity in trauma patients. AJNR Am J Neuroradiol 1991;12:345.

5. Avci İ, Başkurt O, Şirinoğlu D, Aydin MV. Rapid disappearance of pneumorrhachis after chest tube placement. Turk J Emerg Med 2019;19:146-8. Crossref

6. Kim SW, Seo HJ. Symptomatic epidural pneumorrhachis: a rare entity. J Korean Neurosurg Soc 2013;54:65-7. Crossref

7. Pfeifle C, Henkelmann R, von der Höh N, et al. Traumatic pneumorrhachis. Injury 2020;51:267-70. Crossref

A 61-year-old man with end-stage renal failure secondary to immunoglobulin A nephropathy underwent a cadaveric kidney transplant. His post-transplantation course was uneventful until he had very poor compliance to the immunosuppressants since May 2017 and admitted that he had stopped all immunosuppressants in February 2018. He developed acute antibody-mediated graft rejection in May 2018. His medications were adjusted, tacrolimus 4 mg/day, mycophenolate 360 mg twice daily and prednisolone were started. He developed a chest infection in October 2018. He denied any travel history or significant contact history. On physical examination he had cushingoid features and right-sided crepitation. Investigations revealed a low white cell count (1.8 × 10⁹/L) and neutrophil count (0.7 × 10⁹/L). Chest X-ray showed right basal infiltrates (Fig 1a). Blood and sputum for bacterial culture was negative, as was sputum for acid-fast bacilli. The patient’s condition deteriorated despite use of vancomycin, meropenem, azithromycin, and fluconazole. Computed tomography of the thorax revealed extensive collapse and consolidation over the right lower lobe and bilateral pleural effusions (Fig 1b). Bronchoscopy and transbronchial lung biopsy showed granulomatous inflammation, with granular eosinophilic material and narrow-based small budding yeasts grouped in clusters inside macrophages in the alveolar spaces. Both mucicarmine staining and immunohistochemical staining for Pneumocystis, Cytomegalovirus, and herpes simplex virus were negative (Fig 1d-g). In view of the histopathological findings, bronchoalveolar lavage was sent for fungal culture. After 7 days of incubation at 25°C, a tiny colony of mould was seen. 21 Days later, there was a white-coloured mould colony with a velvety texture, wrinkled surface, acquired splits on the surface with no diffusible pigment (Fig 2a and b). Lactophenol cotton blue stain of the wet mount revealed a classic floret pattern (Fig 2c and d). Subculture was performed at 35°C. After 10 days of incubation at 35°C, a 25-mm-diameter yeast colony was evident. Based on the characteristic growth morphology, infection with the thermally dimorphic fungus was established. Subsequent molecular genetic analysis by sequencing of the internal transcribed spacer and D1/D2 regions was performed and identified Emergomyces pasteurianus, a rare thermally dimorphic fungus not previously reported in our locality. Liposomal amphotericin B was commenced and continued for 8 weeks. The patient responded well both clinically and radiologically (Fig 1c) and treatment was switched to oral voriconazole 200 mg twice daily. The patient succumbed to his medical illness 10 weeks after being discharged home.

Thermally dimorphic fungal pathogens cause a significant human disease but are rarely reported in our locality with the exception of Talaromyces (Penicillium) marneffei. To the best of our knowledge, this is the first report of Emergomyces infection in Hong Kong. Emergomyces shares the characteristics of other thermally dimorphic fungi: filamentous forms at 25°C that becomes an invasive yeast-like form at 35°C.1 Emergomyces pasteurianus was previously known as Emmonsia pasteuriana. Emmonsia species are ubiquitous, soil-dwelling saprophytic fungi. Species such as Emmonsia crescens and Emmonsia parva may rarely cause adiaspiromycosis in rodents and humans.2 Recently, Emergomyces has been reclassified as a new genus within the family Ajellomycetaceae. Emergomyces and Emmonsia have significant differences in microbiology, epidemiology, clinical manifestations, and treatment outcomes. Microbiologically, Emergomyces is a thermally dimorphic fungus while Emmonsia does not undergo mould-to-yeast conversion at 37°C. Emmonsia is rarely cultivated from clinical specimens. Human infection with Emmonsia is relatively rare in clinical practice2 but Emergomyces can cause fatal and disseminated human infection and appropriate antifungal therapy is essential.

At the time of this report, five Emergomyces species are described. These species differ in geographic distribution. Es pasteurianus has been reported in Europe, Asia, and Africa. Emergomyces canadensis has been reported in Canada and the United States. Emergomyces africanus has been reported in South Africa, Emergomyces orientalis in China, and Emergomyces europaeus in Germany. The natural reservoir of Emergomyces is soil. Our patient presumably acquired the infection via inhalation of conidia in Hong Kong since he had no travel history outside of the region.

Emergomycosis is a multi-system disease. According to case reports, patients most often present with fever, widespread skin lesions, weight loss, and pulmonary disease.3 4 The diagnosis can be missed due to the slow-growing nature of the fungus. Histological examination of tissues can help diagnose the disease but on its own does not distinguish infection from other dimorphic fungi. Molecular diagnosis plays an important role in microbiological investigation. Using broad-range fungal polymerase chain reaction to sequence D2 large-subunit rDNA gene can help to confirm the diagnosis in a rapid, sensitive, and specific way.

There are no treatment guidelines for patients with emergomycosis. Guidelines for blastomycosis and histoplasmosis recommend liposomal amphotericin B as initial therapy followed by itraconazole (or other newer azole). Our patient responded to liposomal amphotericin B and oral voriconazole but passed away due to his medical disease.

More patients are now rendered immunosuppressed by advances in treatment for a variety of diseases. Clinicians and microbiologists should be aware of the presence of rare invasive fungal infections among these susceptible patients. Molecular techniques such as internal transcribed spacer polymerase chain reaction and sequencing can aid early and accurate identification of these rare fungal pathogens.

All authors contributed to the concept or design of the study, acquisition of the data, analysis or interpretation of the data, drafting of the manuscript, and critical revision of the manuscript for important intellectual content. All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

The authors have no conflicts of interest to disclose.

The authors would like to thank pathologist Dr WL Lam for providing the histopathology clinical photos and nephrologist Dr SK Fung and Dr HL Tang for providing clinical information.

This case report received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

This case report was approved by the Hospital Authority Kowloon West Cluster Research Ethics Committee (Ref KW/ EX-19-063(137-04)).

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