There are few case reports in the English literature concerning malignant transformation of an epidermal cyst into squamous cell carcinoma. We report a case of squamous cell carcinoma arising from a 40-year epidermal cyst in the proximal left thigh of a 74-year-old man. The epidermal cyst had increased in size in the previous 3 years. The patient presented with a discharge from the lesion. Ultrasonography and magnetic resonance imaging of the lesion suggested malignancy. An intra-operative frozen section of an incisional biopsy of the lesion found it to be an epidermal cyst with suspected malignant change, so a marginal excision of the lesion was performed. Squamous cell carcinoma arising from the epidermal cyst was confirmed histologically. A wide excision was done in order to obtain an adequate resection margin. A computed tomographic scan of the thorax and abdomen found no evidence of metastases. No evidence of recurrence was noted in the latest follow-up, 2 years postoperatively.

Gall bladder perforation is a potentially life-threatening condition. Spontaneous perforation is infrequent and rarely seen in the absence of gallstones but gall bladder perforation is an occasional complication of typhoid fever. If such perforations are not treated in time, mortality rates are very high. We report a case of gall bladder perforation complicating typhoid fever following enteric perforation of the ileum necessitating sequential laparotomies during the same admission.

Renal carcinoid tumours are uncommon. The aetiology is not yet fully understood and there is still no useful diagnostic tool for detecting them. We report our experience managing a Chinese woman with a primary renal carcinoid tumour.

Technological advances have made more options available for surgical intervention in spinal disorders. From spinal fusion to artificial disc implantation, these advancements have brought great benefits, allowing preservation of spinal motion and flexibility after intervertebral discectomy. Yet the use of artificial discs as a treatment for congenital spinal disorders has been documented in only a handful of publications. We report a case where a Bryan artificial cervical disc arthroplasty was used to maintain and preserve the mobility and function of the cervical motion segments adjacent to fused vertebral lesions in a 33-year-old woman with Klippel-Feil syndrome who presented with chronic neck pain and signs of early myelopathy. The rationales for using the Bryan disc prosthesis system in patients with Klippel-Feil syndrome and its advantages over conventional surgical interventions are discussed.

The authors report a case of Trimeresurus albolabris (white-lipped green pit viper) bite in a 6-year-old girl living in rural Yuen Long. Despite repeated use of Agkistrodon halys antivenin, the patient developed severe coagulopathy with defibrination syndrome on the fourth day of envenomation, which was also refractory to therapy with fresh frozen plasma. When treatment was switched to green pit viper antivenin, the coagulopathy resolved promptly. The case is illustrative of the potential lethality to children of snakebites in Hong Kong and suggests that the A halys antivenin may not be effective for the treatment of T albolabris bites.