Leydig cell tumors of the testis. A clinicopathological analysis of 40 cases and review of the literature.

The clinical and pathological features of 40 Leydig cell tumors of the testis were analyzed. The patients ranged from 2 to 90 (average 46.5) years of age. The most common initial manifestation was testicular swelling, which was sometimes associated with gynecomastia; 15% of the patients presented because of gynecomastia and were found to have palpable testicular tumors. All three children were brought to the physician because of isosexual pseudoprecocity. The tumors, one of which was asynchronously bilateral, ranged from 0.5 to 10.0 (average 3) cm in greatest diameter. They were usually well circumscribed, but in seven of them the margin with the adjacent testis was ill-defined. On microscopic examination the most common pattern was that of diffuse sheets of neoplastic cells, but insular, trabecular, pseudotubular, and ribbon-like patterns were also encountered. The neoplastic cells were most often large and polygonal with abundant eosinophilic, slightly granular cytoplasm; occasionally the cytoplasm was abundantly vacuolated. In eight tumors some of the cells were spindle-shaped, and in six some had scanty cytoplasm. Crystalloids of Reinke were identified in 35% of the tumors. Conspicuous nuclear atypicality was present in 12 tumors and the mitotic rate ranged from less than 1 to 32/10 high-power fields. Blood vessel invasion, lymphatic invasion, or both were identified in four tumors. Follow-up of 2 months to 22 years (average 4 years) was available for 30 patients. Five of them died as a result of spread of their tumor. A comparison of the clinically malignant tumors with those associated with survival for 2 or more years postoperatively revealed that the former occurred in older patients and were accompanied by symptoms of shorter duration and an absence of endocrine manifestations. The malignant tumors were larger, often had an infiltrative margin and had spread beyond the testis, frequently exhibited blood vessel or lymphatic invasion, and had a greater degree of cellular atypia and necrosis and a higher mitotic rate than the benign tumors.