A 91-year-old woman diagnosed to have an inoperable cholangiocarcinoma had an uncovered metal stent inserted for palliative drainage. About 1.5 years later, tumour ingrowth into the metal stent caused cholangitis. Intraductal radiofrequency ablation was applied to create local coagulative tumour necrosis and the necrotic tissue was removed via a balloon catheter. A plastic stent was inserted to empirically treat any ensuing potential bile duct injury. The patient was discharged without complication with good palliative drainage. Intraductal radiofrequency ablation is a new technique for the treatment of metal stent occlusion due to tumour ingrowths. This is the first case report of this relatively safe and feasible new technique for the treatment of tumour ingrowth into a metal stent used as palliation for malignant biliary obstruction.

Less than 5% of breast cancers present as metastasis, and urinary bladder secondaries were only sporadically reported in the literature. However, they may even be responsible for the initial presentation, for which reason they can pose a diagnostic challenge. We present here what we believe is the first such case in Hong Kong, with a review of this entity.

We report on a preterm male newborn with complete ectopia cordis associated with Cantrell’s syndrome. The neonate had an ectopia cordis involving defects of the lower sternum, supraumbilical abdominal wall, anterior portion of the diaphragm, and diaphragmatic portion of the pericardium associated with complex congenital heart defects. The infant died shortly after birth. We discuss this case and review the literature.

We report an uncommon mitochondrial variant in a baby girl with congenital hyperlactataemia and Leigh syndrome. The patient presented with a single episode of generalised clonic convulsion at day 19, and was found to have isolated and persistent hyperlactataemia ranging from 3.34 to 9.26 mmol/L. She had elevated serum lactate-to-pyruvate ratios of up to 35 and high plasma alanine concentration, indicative of a respiratory chain defect. At the age of 8 months, she developed evolving neurological and imaging features compatible with Leigh syndrome. Genetic testing for common mitochondrial DNA mutations, large mitochondrial DNA deletions, and selected nuclear genes was negative. Further analysis of lymphocyte mitochondrial DNA by sequencing revealed an uncommon heteroplasmic variant, NC_012920.1(MT-ND5):m.13094T>C (p.Val253Ala), which was previously shown to reduce complex I activity. In patients in whom there was a high suspicion of mitochondrial disorder, entire mitochondrial DNA analysis may be warranted if initial screening of common mitochondrial DNA mutations is negative.

A patient with chronic obstructive pulmonary disease developed a cough, loss of consciousness, and convulsions during an air flight. Chest radiography showed a large lung bulla. Computed tomography of the brain showed intraparenchymal air and bilateral cerebral infarcts. The findings were compatible with cerebral air embolism, most likely predisposed to by lung bulla and an air flight. The underlying pathology and possible treatment are discussed.