Primary carcinoid tumors of the testis: a clinicopathologic study of 29 cases.

Testicular carcinoid tumors are rare with only limited studies. We identified 29 primary testicular carcinoid cases from 7 academic institutions. Patients ranged in age from 12 to 65 years old (mean 36). The most common presenting symptom was the sole finding of either a testicular mass or swelling seen in 15/24 cases with available information. The next most common mode of presentation was as an incidental finding seen in 6 cases. Two patients had carcinoid syndrome including diarrhea, hot flashes, and palpitations. Nineteen were pure carcinoid tumors, 3 were associated with cystic teratoma, 2 with cysts lacking epithelial lining, 4 with epidermoid cyst, and 1 with dermoid cyst. The mean size was 2.5 cm. All 29 primary carcinoids lacked associated intratubular germ cell neoplasia, unclassified type. Mitotic figures were rare in primary carcinoid tumors with only 3 cases showing more than 2 per 10 HPF; necrosis was found in only 1 case. Random scattered mild to moderate nuclear atypia was seen in 12/29 cases. Of the 28 cases found premortem, treatment included focal excision in 3 patients and radical orchiectomy in 25 patients. Follow-up, available in 24 cases, ranged from 1 to 228 months (mean 52.7 mo); of the 20 patients with testicular typical carcinoid tumors found premortem, all were alive at last follow-up without recurrences or metastases. Of the 4 patients with a primary atypical carcinoid tumor, 1 at the time of diagnosis had retroperitoneal and lung metastases who after chemotherapy underwent resection of the retroperitoneal tumor showing metastatic yolk sac tumor and embryonal carcinoma. After resection, serum AFP levels remained elevated and the patient is scheduled for salvage chemotherapy and bone marrow transplant. The other 2 patients with atypical carcinoid and follow-up had no evidence of disease at 68 and 114 months. Most primary carcinoid tumors of the testis have a benign clinical course even if associated with epidermoid/dermoid cysts, or histologically mature teratoma. However, lesions with the morphology of atypical carcinoid can occasionally exhibit metastatic spread.