The majority of Leydig cell tumors are found in males, usually at 5–10 years of age or in middle adulthood (30–60 years). Children typically present with
precocious puberty. In men, testicular swelling is the most common presenting feature. Other symptoms depend on age and the type of tumour. If it is secreting
androgens the tumour is usually asymptomatic, but can cause
precocious puberty in pre-pubertal boys. If the tumour secretes
oestrogens it can cause feminisation in young boys. In adults, this causes a number of problems including
gynaecomastia, erectile dysfunction, infertility, feminine hair distribution, gonadogenital atrophy, and a loss of libido. In women it tends to happen after menopause, but premenopausal cases have been reported.
Sertoli–Leydig cell tumours of women tend to happen earlier, in the second or the third decade of a woman's life. Due to excess
testosterone secreted by the tumour, one-third of female patients present with a recent history of progressive
masculinization. Masculinization is preceded by
anovulation,
oligomenorrhea,
amenorrhea and
defeminization. Additional signs include
acne and
hirsutism, voice deepening,
clitoromegaly, temporal hair recession, and an increase in musculature. Serum testosterone level is high. ==Cause==