Leydig cell tumors :
Age group- 5-10 or 30-60
due to excess testosterone secreted by the tumour
Immunohistochemical markers of Leydig cell tumours include inhibin-alpha, calretinin, and melan-A.
10% bilateral of which most is Benign, malignant only 10%.
Scrotal ultrasonography is typically performed to confirm the diagnosis.
Microscopically, these tumors are composed of large, closely packed cells with eosinophilic cytoplasm, bland nuclei, and small nucleoli (see image below). Reinke crystals are pale-staining, cylindrical, rectangular, or rhomboid inclusions that are pathognomonic for Leydig cell tumors and are found in up to 30% of patients with such tumors. Microscopic features such as necrosis, marked pleomorphism, lymphovascular invasion, increased mitotic activity, and DNA aneuploidy are more consistent with a malignant variant.
No known role exists for radiation therapy in malignant Leydig cell tumors.
Leydig cell tumors have been primarily managed with surgical extirpation using radical inguinal orchiectomy.