Testis and epididymis–unusual sites of metastatic gastric cancer: A case report and review of the literature

BACKGROUND: Although gastric cancer is one of the most prevalent cancers worldwide, cases of gastric cancer metastasis to the male reproductive system are rare. Here, we report a case involving testicular and epididymal gastric cancer metastases. CASE SUMMARY: A 75-year-old Chinese man complained of experiencing a palpable painful mass in the right scrotum for 6 mo. He had undergone distal gastrectomy with chemotherapy for pT3N3aMx poorly differentiated gastric adenocarcinoma 9 mo before. Physical examination revealed a moderate right hydrocele and a painful mass in the right testis and epididymis. Serum tumor biomarkers were all normal except for elevated beta-human chorionic gonadotropin levels. Computed tomography urography and B-ultrasound imaging revealed a moderate right hydrocele and a mixed solid-cystic mass in the right testicular and epididymal area. Thus, the patient underwent right radical orchiectomy. Immunohistochemical analysis revealed that the tumor cells were positive for pancytokeratins and caudal related homeodomain transcription 2. Metastatic, poorly differentiated gastric adenocarcinoma of the testis and epididymis was confirmed by pathology. He continued to undergo chemotherapy at the department of oncology of our hospital. Mesenteric lymph node metastases were found at the postoperative 1-mo follow-up. CONCLUSION: Palpable, painful scrotal mass, history of gastric cancer, and imaging features may indicate testicular and epididymal metastatic gastric cancer.