Evaluation of Diagnostic Criteria for Leydig Cell Tumours in Adult Men Revealed by Gynaecomastia

Abstract

Gynaecomastia caused by Leydig cell tumours (LCT) in adult men may appear a long time before clinical evidence of testicular swelling. To evaluate the diagnostic criteria for LCT, hormonal status was studied in 14 cases and compared with results of a control group (CG) and 10 men with idiopathic gynaecomastia (IG). The mean plasma T level was significantly (P less than 0.005) lower in LCT (16.7 +/- 1.7 SEM nmol/l) than in CG (23.0 +/- 1.3 nmol/l). However, individual plasma T levels were in the normal range in 9/14 LCT. The mean plasma E2 level was significantly (P less than 0.001) higher in LCT (204.9 +/- 27.6 pmol/l) than in CG (87.9 +/- 7.7 pmol/l). However, individual plasma E2 levels were in the normal range in 5/14 LCT. In LCT, neither means of basal gonadotrophin levels nor the gonadotrophin responses to LHRH were different from CG. The mean of the plasma T responses to hCG did not differ between LTC, CG and IG. However the mean of E2 peak responses appeared significantly (P less than 0.005) higher in LCT (735.3 +/- 103.4 pmol/l) than in CG (420.5 +/- 40.4 pmol/l). The mean of the E2 peak responses was significantly (P less than 0.001) lower in IG (196.5 +/- 33.4 pmol/l) than in CG. Likewise the mean of plasma E2 levels, measured on day three following hCG administration, remained significantly (P less than 0.001) higher in LCT (662 +/- 94 pmol/l) than either in CG (228 +/- 14 pmol/l) or in IG (158 +/- 25 pmol/l). On day 3 following hCG administration, there was no overlap in individual plasma E2 levels between either LCT and CG or LCT and IG. In all LCT, plasma beta-hCG levels were in the normal range. A testicular echogram, performed in 12 LCT, confirmed the presence of a palpable tumour in 10 and revealed an occult tumour in two cases. We conclude that normal plasma beta-hCG levels, a prolonged plasma E2 response to hCG and testicular echogram appear to be the best criteria for early diagnosis of LCT responsible for gynaecomastia in adult men.

Cosecretion of Estrogen and Inhibin B by a Feminizing Adrenocortical Adenoma: Impact on Gonadotropin Secretion

“…Leydig cell tumors and rare adrenal feminizing tumors) are associated with a typical hormonal pattern, including 1) increased plasma levels of estrogens [17␤-E2 and/or estrone (E1)], 2) low plasma gonadotropin levels, and 3) a more or less marked reduction in plasma T levels (1)(2)(3)(4). These hormonal patterns reflect the E2-induced inhibition of gonadotropin secretion, as previously shown under physiological (5) and pathological conditions (6).…”

“…This mechanism has been observed in feminizing adrenal tumors (2) and has been recently demonstrated to be physiologically present in normal men (7). However, in feminizing tumors, FSH appeared more frequently and more strongly suppressed than LH (3,6), suggesting that tumor secretion could also directly inhibit pituitary FSH synthesis and/or secretion. In agreement with this hypothesis, it has been shown that E2, in addition to its hypothalamic action, is able to reduce FSH secretion through a direct effect on gonadotrophs (4,8).…”

Evaluation of endocrine testing of Leydig cell function using extractive and recombinant human chorionic gonadotropin and different doses of recombinant human LH in normal men

“…In normal adult men, plasma E 2 and T levels reach a peak 24 and 72 h respectively after a single i.m. injection of a pharmacological dose (1500-5000 IU) of ehCG (12,14,15,(17)(18)(19)22). The stimulating effect of ehCG, mediated through the activation of the LH/hCG receptor of the Leydig cell, involves the amplification of the enzymatic pathways of sex steroid synthesis.…”

“…The stimulating effect of ehCG, mediated through the activation of the LH/hCG receptor of the Leydig cell, involves the amplification of the enzymatic pathways of sex steroid synthesis. Furthermore, a gonadotropininduced activation of Leydig cell aromatase leads to a rise in E 2 synthesis (14,17,23). Multiple injections of ehCG give similar results as a single one (16,24,25).…”

“…For this reason, hCG was used as a treatment of various testicular diseases including cryptorchid testes (5-7), male hypogonadotropic hypogonadism (8), and in association with human menopausal gonadotropin, male infertility (9,10). On the other hand, hCG testing of Leydig cell function was of interest for the search of the presence of intra-abdominal testes in case of bilateral ectopia (6,7), for differentiating delayed puberty from hypogonadotropic hypogonadism (11)(12)(13), and for the etiological diagnosis of gynecomastia (14,15). Various modalities of testing have been proposed in terms of hCG doses, the number of injections, and times of blood drawing (3,11,13,16).…”