An unusual case of posttransplant osteoid osteoma

Posttransplant tumors are one of the important long-term complications of renal transplant. However, aside from noninvasive Kaposi sarcomas, increased production of benign tumors has not been observed after renal transplantation, and to our knowledge, no cases of posttransplant osteoid osteoma have been reported so far. Osteoid osteoma is a common, benign, bone neoplasm that occurs typically in the long bones and presents with severe, intractable pain. Here, we present a 49-year-old man, who presented with increasing bone pain in the right upper arm, 7 months after a renal transplant. Despite an initial normal right humerus radiograph, a raised subperiosteal tumor was diagnosed in the medial border of the right humerus a few months later. An excisional biopsy was performed, and the pathologic report was an osteoid osteoma. The patient's pain, which had been resistant to most analgesics, completely disappeared after surgery, and he is currently devoid of any lesions, 9 months after excision of the tumor.