The Unusual Presentation of Gastric Adenocarcinoma as a Testicular Mass: A Favorable Response to Docetaxel and Cisplatin Plus Oral Tegafur/Uracil and Leucovorin

Gastric cancer is one of the most common malignancies in the world. The routes of metastasis include direct extension, lymphatics, and peritoneal or hematogenous spread. Testicular metastasis is rare. We present here a 23-year-old gastric cancer patient who first presented with right-side testis swelling and pain. Diagnosis of metastatic adenocarcinoma was made after right-side orchiectomy. Gastric adenocarcinoma with ascites and peritoneal seeding was found after esophagogastroscopy and abdominal computed tomography. The patient received chemotherapy consisting of docetaxel 36 mg/m² and cisplatin 30 mg/m² on day 1 and day 8, plus oral tegafur/uracil 300 mg/m²/day and leucovorin 90 mg/day on day 1 to day 14 in a 21-day cycle, and he had a partial response to the chemotherapy. Metastatic tumors, especially gastric adenocarcinoma, should be considered in the differential diagnosis of patients presenting with testicular mass and they may respond well to chemotherapy.