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Search: Organ site Search: Tumor / Syndrome
WHO Classification of Tumours
Leydig cell tumor, NOS
Testis/Male genital organs


A testicular sex cord-stromal tumor that is predominantly or completely composed of Leydig cells which may contain crystals of Reinke. It usually presents as a painless testicular enlargement and it may be associated with gynecomastia and decreased libido. The majority of the cases have a benign clinical course. Approximately 10% of the cases have a malignant clinical course and metastasize.