Gynecomastia as Unusual Presentation of Primary Choriocarcinoma of the Colon: A Case Report and Literature Review

ABSTRACT Objective: Gynecomastia is the benign enlargement of male breast tissue and is the most common breast condition in males. Beta human chorionic gonadotropin (β-hCG)-secreting tumors such as choriocarcinoma are one cause of gynecomastia. This is the first report of bilateral gynecomastia secondary to malignant β-hCG-secreting choriocarcinoma located in the colon. Methods: A 49 year-old male who presented bilateral gynecomastia was found to have a primary colonic choriocarcinoma. Results: Serum β-hCG levels were significantly high at 11.546 mIU/mL (normal range 0.01–5). A colonoscopy showed a stenosing mass in the sigmoid colon, and computed tomography revealed multiple liver metastases. The diagnosis of choriocarcinoma was confirmed by the histologic and immunohistochemical biopsy findings. Conclusion: Primary colorectal choriocarcinoma is a very rare entity that should be considered in the differential diagnosis of gynecomastia. Abbreviations: β-hCG human chorionic gonadotropin