Leydig cell tumor is a rare testicular neoplasm that can present as a non-palpable small testicular nodule. Here we present a case of a 36-year-old Filipino male who initially came in for fertility work-up. Semen analysis showed azoospermia. However, an incidental finding on ultrasound showed a well-circumscribed round tumor. The patient underwent radical orchiectomy. On histopathologic examination, a Leydig cell tumor was identified and supported by immunohistochemical staining. We discuss the clinical features pathogenesis, treatment, diagnosis and prognosis of this uncommon entity.
Leydig Cells ; Testis ; Orchiectomy ; Infertility

Experimental cryptorchidism has been produced in young rats by administration of estrogen of various doses and time to study the changes in the Leydig cells. Attempt was made to determine the number of Leydig cells in the cryptorchid and normal control to compare the results obtained with one another. Atrophic changes of Leydig cells were more prominent in the cryptorchid than the descended one and proportionate to the degrees of descending. Leydig cells were scattered, not clustered and decreased in number as a atrophic changes. These results suggest a close relation between Leydig cell and the testicular descending.
Animals ; Cryptorchidism ; Estrogens ; Leydig Cells ; Male ; Rats

Leydig cells, located in the loose interstitial tissue of seminiferous tubules, are the major site for androgen synthesis and secretion, and play an important role in the reproductively and fertility of males. The dysfunction of Leydig cells may lead to various male diseases, such as primary hypogonadism, cryptorchidism, and hypospadias. This review outlines the recent findings concerning the generation, development and regulation of Leydig cells.
Cell Differentiation ; Humans ; Leydig Cells ; cytology ; Male

Ovarian stromal tumors containing Leydig cell components are rare. Only a few cases of ovarian stromal Leydig cell tumors characterized by clusters of Leydig cells have been reported to date. Here, we present the first case report of a 65-year-old woman with a cellular fibroma of the ovary containing Leydig cell hyperplasia. Microscopic examination revealed the proliferation of spindle cells arranged in intersecting bundles with mild nuclear atypia and an average of 2-3 mitotic figures per ten high-power fields. Multifocal nests of polygonal cells with abundant eosinophilic cytoplasm and round nuclei were seen within the spindle cells. Final pathology of the tumor revealed a cellular fibroma including Leydig cell hyperplasia.
Aged ; Cellular Structures ; Cytoplasm ; Eosinophils ; Female ; Fibroma ; Humans ; Hyperplasia ; Leydig Cell Tumor ; Leydig Cells ; Male ; Ovary

For the study of the effects of aging on testis, the volumes of testis and Leydig cells, young and old aged rats were sacrificed. Twenty eight testes from the young aged rats were used as the normal control. Ten testes showing the atrophic changes and sixteen not-atrophied testes of the old rats were used. After measurements of the volume and weight of the testes they were fixed in Bouin's solution and their sections were stained by Masson's trichrome. The Leydig cells appearing at the graticuels attached to eye-piece of the light microscope were calculated under one hundred magnification. The findings were summarized as follow: 1. The atrophied testes showed degenerative changes in the seminiferous tubules and had the slightly increased amount of the interstitium in comparison with the control. 2. The weight and volume of the normal control testes were 1.24gm and 1.19ml, respectively, and the proportion and the volume of Leydig cells of it were 3.78% and 0.045ml, respectively. 3. The atrophied testis of the old aged rats showed decreased weight and volume, 0.41gm and 0.57ml, but the proportion of Leydig cells was 9.15%, and the volume of the Leydig cells 0.052ml. 4. The weight and volume of the not-atrophied testis of the old aged rats were 1.73gm and 1.71ml, respectively. The proportion and volume of Leydig cells, however, were 3.04% and 0.052ml.
Aging* ; Animals ; Leydig Cells ; Male ; Rats ; Seminiferous Tubules ; Testis

A 26-year-old woman had an ovarian Sertoli-Leydig cell tumor (SLCT) associated with an elevated level of serum alpha-fetoprotein (AFP). The tumor had a heterologous element of intestinal-type mucinous epithelium, retiform and intermediately differentiated tubules of the Sertoli cells, and AFP-producing Leydig cells. AFP was demonstrated within the Leydig cells by an immunohistochemical technique. After surgery, the serum AFP level of the patient fell to the normal range. The present case is the first documented case of AFP producing a SLCT of the ovary reported in Korea.
Adult ; alpha-Fetoproteins* ; Epithelium ; Female ; Humans ; Korea ; Leydig Cells ; Male ; Mucins ; Ovary* ; Reference Values ; Sertoli Cells ; Sertoli-Leydig Cell Tumor*

The Sertoil-Leydig cell tumor (SLCT) is gonadal tumor of sex-cord type, similar to that seen in the various phase of testicular development in the male. It is the most common type of all virilizing ovarian tumors and account for less than 0.5% of all ovarian tumors. A 26-year-old woman had an ovarian SLCT associated with an elevated level of serum AFP. The tumor had a heterologous element of intestinal-type mucinous epithelium, retiform and intermediately differentiated tubules of the Sertoli cell, and AFP-producing Leydig cells. After surgery, the serum AFP level of the patient fell to the normal range. We experienced a case of AFP producing SLCT, so we present it with a brief review of literature.
Adult ; alpha-Fetoproteins* ; Epithelium ; Female ; Gonads ; Humans ; Leydig Cells ; Male ; Mucins ; Ovarian Neoplasms ; Reference Values ; Sertoli-Leydig Cell Tumor*

Leydig cells are the primary source of testosterone. As is true for all specialized cells, Leydig cells originally arise from primitive undifferentiated stem cells, stem Leydig cells (SLCs). The huge potential of SLCs is to be used therapeutically to restore testosterone levels in males with androgen deficiency due to diverse causes. The initial paradigm for cell therapy would call for harvesting the SLCs of an androgen deficient male, amplifying these cells in vitro, inducing differentiation in vitro, and then implanting the mature Leydig cells back into the same individual.
Androgens ; deficiency ; Animals ; Cell Differentiation ; Cells, Cultured ; Humans ; Leydig Cells ; cytology ; Male ; Rats ; Stem Cells ; cytology

Descending of the testes is an important process for spermatogenesis and cryptorchidism is one of the most relevant genital defects in dogs. In a previous study, we observed abnormal morphology and proliferation of Sertoli cells in a cryptorchid testis. In the present study, we investigated the expression of estrogen and progesterone receptors in the normal and cryptorchid testis of a dog. Elective orchidectomy was performed on the dog's abdominal right testis (undescended, cryptorchid) and scrotal left testis (descended, normal). In the normal testis, estrogen receptor α immunoreactivity was detected in Leydig cells alone, while estrogen receptor α immunoreactivity in the cryptorchid testis was significantly prominent in the Sertoli cells as well. In addition, progesterone receptor immunoreactivity in the control testis was detected in the spermatids, but was not detected in the cryptorchid testis. This result suggests that unilateral cryptorchidism causes increases of estrogen receptor α expression in Sertoli cells.
Animals ; Cryptorchidism ; Dogs* ; Estrogens* ; Leydig Cells ; Male ; Orchiectomy ; Progesterone* ; Receptors, Progesterone* ; Sertoli Cells ; Spermatids ; Spermatogenesis ; Testis*

Histomorphologic study was performed on bilaterally testicular biopsies of 30 preadolescent patient with unilateral cryptorchidism so as to understand pathophysiology of the increased incidence or infertility, seen in unilateral cryptorchidism. The results demonstrated delayed and defective transformation of gonocytes to spermatogonia, delayed or failed transformation of spermatogonia to primary spermatocyte and decreased numbers of Leydig cells. These abnormalities were present in the unilaterally cryptorchid testis and their contralateral descended partners but they were more serious and earlier onset in the cryptorchid testis. That is to say, blunted surge in gonadotropins triggers atrophy of Leydig cells leading to delayed and defective maturation of germ cells leading to decreased numbers of germ cells. These findings are compatible with the hypothesis that hypo gonadotropic hypogonadism is the cause of cryptorchidism.
Atrophy ; Biopsy ; Cryptorchidism* ; Germ Cells ; Gonadotropins ; Humans ; Hypogonadism ; Incidence ; Infertility ; Leydig Cells ; Male ; Spermatocytes ; Spermatogonia ; Testis*