Ectopic, retroperitoneal adrenocortical carcinoma in the setting of Lynch syndrome

Adrenocortical carcinoma (ACC) is rare within the adult population. Ectopic ACC proves even rarer. This variant is formed by cortical fragments arrested during embryologic migration. ACC is also known to be associated with several genetic syndromes and has recently been linked to Lynch syndrome in 3% of cases. We present the case of a 68-year-old male with a confirmed diagnosis of Lynch syndrome secondary to a germline MSH2 mismatch-repair gene-mutation who presented with 2 months history of non-specific abdominal pain. After imaging work-up, the patient was found to have a right upper quadrant, retroperitoneal mass. Biochemical tests were without any evidence of a hormonally active process. Fine needle aspiration of the mass revealed a poorly differentiated carcinoma of unknown etiology. The lesion was resected and found to be consistent with ectopic ACC with an associated MSH2 mutation.