Leydig Cell Tumor : Intro & Clinical
Introduction: Leydig cell tumor (LCT) is the most common sex cord-stromal tumor and makes up 1-2% of all testicular tumors. It is composed of round or polygonal cells with abundant eosinophilic cytoplasm resembling normal Leydig cells. It has also been referred to as interstitial cell tumor. Clinical Features: LCT occurs over a wide age range and shows bimodal peaks. About 80% of cases are seen in adults, usually between the ages of 20 and 60 years (median age 47 yrs.). The remaining 20% of cases occur in children, usually between the ages of 4 and 10 years (peak incidence around age 5 yrs). It is rare below the age of 2 years. Most adult patients have non-functioning tumors and present with a painless testicular mass. The patients with androgen-synthesizing tumors may have feminizing characteristics, including gynecomastia, impotence, and decreased libido. This is result of peripheral conversion of excess androgens into estrogen. Rare LCT produce corticosteroids resulting in Cushing syndrome. Serum levels of testosterone, androstenedione, and dehydroepiandrosterone are frequently elevated. In some cases, there may be elevation of estrogen and estradiol levels as well. Rare cases (<5%) present with metastases. Children usually present with isosexual precocious puberty (prominent external genitalia, pubic hair growth, masculine voice, and accelerated skeletal and muscle development) due to androgen production. These changes do not reverse after treatment. About 10% of children have gynecomastia in addition to virilization. Pediatric cases may have very small or no palpable tumors since they present early due to hormonal manifestations. Case History: This orchiectomy is from an elderly male (> 70 yrs.) who was incidentally found to have elevated serum testosterone (> 1500 ng/dl; ref. range 264-916 ng/dl). Ultrasound showed a solid homogenous mass in the testis. The dark brown color is due to androgen byproducts. Histologic features were classic for a Leydig Cell Tumor.