Aneurysmal Bone Cyst of the Distal Ulna in an Elderly Lady

Aneurysmal bone cyst (ABC) is a rare, benign, cystic, hemorrhagic expansile osteolytic lesion of unknown etiology resembling multiple intraosseous blood-filled spaces mostly seen in the first two decades of life. It accounts for <1% of all bone tumors and the usual sites are the metaphyses of the proximal and distal femur, proximal tibia, and posterior elements of the spine. Affection of other sites is unusual.

A 55-year-old female with a 5-month history of pain and swelling of distal ulna. She was operated on with curettage, bone grafting, and plating. At 1-year follow-up, she regained complete movements without any recurrence.

In this article, we present a case of a primary ABC of distal ulna in an unusual age group of 55 years in a female. The clinical presentation, diagnosis, surgical management, and clinical outcome at 1 year are described.