Abstract
INTRODUCTION: Pheochromocytoma is a catecholamine-producing tumor arising from the adrenal medulla. When it coexists with a tumor of different origin within the same adrenal gland, it is classified as a collision tumor involving a pheochromocytoma. CASE PRESENTATION: The left adrenal tumor was identified in an 84-year-old Japanese woman and initially considered pheochromocytoma; however, rapid growth, lymphadenopathy, reduced (123)I-MIBG uptake, and intense FDG (Fluorodeoxyglucose) accumulation raised suspicion of another tumor component. The patient received cyclophosphamide, vincristine and dacarbazine (CVD) chemotherapy followed by surgical resection. Histopathology revealed extensive necrosis in the diffuse large B-cell lymphoma (DLBCL) component, suggesting a response to chemotherapy. CONCLUSION: To the best of our knowledge, this is the fourth reported case of an adrenal collision tumor with pheochromocytoma and DLBCL, and the first treated with CVD followed by surgery. Collision tumors should be considered a differential diagnosis when adrenal masses present with atypical clinical or imaging features.