Chondroblastoma of a Thumb Sesamoid: a Case Report and Review of Literature

Chondroblastomas are benign tumours commonly arising at the epiphysis of long bones such as the femur, tibia and humerus. Literature consists primarily of case reports describing chondroblastomas arising at unusual sites such as the carpus and patella. We report a yet unreported case of a chondroblastoma affecting a thumb sesamoid which was treated successfully by excision. A 27-year-old female was referred to the orthopaedic specialist service with a history of a gradually increasing swelling overlying her thumb on the volar aspect. Ultrasound examination raised a suspicion of either a ganglion cyst or a giant cell tumour. A biopsy confirmed it to be chondroblastoma. CT and MRI scans were then performed to know more about the extent of the tumour. It was confined to the sesamoid of the thumb. An excision performed under general anaesthesia proved to be curative. The patient continues to be asymptomatic 18 months after the surgery and has since returned back to her job as a waitress.