RESUMEN
OBJECTIVE: To illustrate a posttransplant lymphoproliferative lymphoma presenting as a solitary osseous lesion situated in the rib. CLINICAL FEATURES: A 53-year-old man was referred to a surgical department because of persistent local pain over the lower part of his left posterior hemithorax. Due to a previous history of chronic glomerulonephritis, a renal transplant was performed 7 years previously, followed by immunosuppressive therapy with azathioprine cyclophosphamide. INTERVENTION AND OUTCOME: Surgical removal of the rib lesion was performed because of the patient's history of the organ transplant. The histological study of the surgically removed tissue revealed diffuse infiltration of the marrow by lymphoid-like cells. There was evidence of interstitial fibrosis, and further immunohistochemical examination showed the presence of B cells in the specimen confirming the diagnosis of B-cell lymphoma. CONCLUSION: This case report discusses an unusual presentation of a lymphoma induced by immunosuppressive therapy in a patient who had received an organ transplant. Such lesions may appear in any organ or system, although this is distinctively unusual to involve the skeletal system.