Ultrastructure and immunohistochemistry of a fetal-type Leydig cell tumor

Large cell calcifying Sertoli cell tumor of the testis: Comparative immunohistochemical study with Leydig cell tumor

Large cell calcifying Sertoli cell tumor is a rare type of testicular tumor. Reported herein is a Japanese patient with this tumor not associated with Carney's complex. An 11-year-old boy was admitted to hospital because of left testicular enlargement, and radical orchiectomy was performed. Macroscopically, the tumor was well circumscribed and had a maximum diameter of approximately 2 cm. The cut surface showed a yellow-white solid mass. Histologically, the tumor was composed of large neoplastic cells with abundant eosinophilic cytoplasm with a tubular, trabecular, and solid arrangement and loose myxoid stroma with irregularly shaped calcification. Immunohistochemically, the tumor cells were positive for vimentin, S-100 protein, calretinin, inhibin-alpha, melan-A, and CD10, and type IV collagen and laminin were observed in the extracellular matrix around the tumor cells. The distributions of melan-A, CD10, and mitochondria were characteristically patchy; in contrast, they were diffusely distributed in the cytoplasm in a control case of Leydig cell tumor. The differences in immunostaining patterns for melan-A, CD10, and mitochondria as well as positivity for S-100 protein-beta might be useful diagnostic hallmarks of large cell calcifying Sertoli cell tumor for discrimination from Leydig cell tumor.

Utility of immunostaining for S-100 protein subunits in gonadal sex cord-stromal tumors, with emphasis on the large-cell calcifying Sertoli cell tumor of the testis

This study concerns the immunohistochemical localization of S-100 alpha, S-100 beta, and whole brain S-100 (wbS-100) in testicular large-cell calcifying Sertoli cell tumor (LCCSCT). We examined 8 LCCSCTs (7 benign and 1 malignant), 6 Sertoli cell tumors not otherwise specified (SCTs-NOS), 6 Leydig cell tumors (LCTs), 5 ovarian Sertoli-Leydig cell tumors (SLCTs), and 7 gonadoblastomas (GBLs). The 8 LCCSCTs showed immunoreactivity for S-100 alpha, S-100 beta, and wbS-100. Five of the 6 LCTs and the Leydig cell components in the ovarian SLCTs stained positively for S-100 alpha and wbS-100 but were negative for S-100 beta. SCTs-NOS and the Sertoli cell components in the SLCTs occasionally showed focal and weak/moderate positivity for S-100 alpha, S-100 beta, and wbS-100. Sex cord cells of the GBLs were positive for S-100 beta and wbS-100 and negative for S-100 alpha. Germ cell elements of the GBLs were negative for S-100 alpha, S-100 beta, and wbS-100. In nonneoplastic testicular parenchyma adjacent to the above-mentioned tumors, there was S-100 alpha reactivity in Leydig cells, rete testis, and a few Sertoli cells. S-100 beta reactivity was seen in a few Sertoli cells, Schwann cells, and some endothelial cells. WbS-100 reactivity was present in Leydig cells, a few Sertoli cells, rete testis, Schwann cells, and some endothelial cells. The results indicate that S-100 alpha and S-100 beta can potentially be used as immunohistochemical markers for LCCSCT, especially when differentiating it from LCT, which may mimic LCCSCT on routine histopathology. Although the biological significance of both S-100 subunits expression in LCCSCT remains unknown, these notable calcium-binding proteins may be associated with the characteristic calcification in LCCSCT through regulation of calcium levels in the tumor cells.