Zur mikroskopischen Anatomie der sog. hypoplastischen Zonen des normal descendierten Hodens

Concretions in the human testis are derived from the basal lamina of seminiferous cords

We provide evidence that testicular concretions form exclusively in association with seminiferous cords. Testicular material obtained from 6 patients with various disorders of spermatogenesis was studied by means of light- and electron microscopy. Seminiferous cords in the testes examined form so-called hypoplastic zones. They contain immature Sertoli cells and are surrounded by an unusually thick basal lamina and one or two layers of myofibroblasts. They display extensive coiling and form ring-like structures. Concretions are located at the periphery or in the center of the cords and consist of a hyaline material with an occasional granular core. They are enveloped by Sertoli cells or myofibroblasts. Data presented indicate that concretions may develop within the above-mentioned ring-like structures or in deep indentations of the surrounding connective tissue. Computer-assisted 3-D reconstructions of a seminiferous cord based on 24 serial semithin sections revealed that the majority of concretions communicate with the interstitial tissue through a broad opening comparable to a "meso". On the basis of our observations we could demonstrate that concretions are accumulations of basal lamina that occasionally contain remnants of degenerated myofibroblasts. They form outside the cords and belong to the connective tissue compartment. As the components of the basal lamina are thought to be produced by the interaction of Sertoli cells and myofibroblasts we tentatively assume that the development of concretions reflects a disturbance in this complex interaction. We suggest that the presence of concretions refers to a developmental disorder and may be pathognomonic for the occurrence of defective seminiferous cords.

Response of the human testis to long-term estrogen treatment: morphology of Sertoli cells, Leydig cells and spermatogonial stem cells

The present investigation is concerned with the morphological changes observed in human testicular tissue following prolonged estrogen administration. Testicular material obtained from 11 transsexual patients who had been submitted to long-term estrogen treatment prior to sex-reversal surgery was studied by means of light- and electron microscopy. The testes of all patients examined present a more or less uniform appearance: There are narrow seminiferous cords surrounded by an extensively thickened lamina propria. They contain Sertoli cells and spermatogonia exclusively. There is no evidence of typical Leydig cells. The persisting spermatogonia show the characteristic features of pale type-A spermatogonia, whereas dark type-A spermatogonia are almost completely eliminated from the epithelium. In view of the fact that spermatogonia that survived radiotherapy and treatment with various noxious agents have recently been regarded as the stem cells of the human testis, it is suggested that also the majority of those spermatogonial types that are less sensitive to disturbances of the endocrine balance may consist of stem cells. The present results, therefore, corroborate the concept that the stem cells of the human testis may be derived from pale type-A spermatogonia or the variants of this cell type. Sertoli cells display two types of ovoid nuclei. In contrast to untreated material the nuclei lie adjacent to the basal lamina, and organelles and telolysosomes are confined to the apical cytoplasm. The apico-basal differentiation of mature cells, therefore, is not observed. Moreover, typical organelles and inclusions of mature cells are absent, as are the junctional specializations. Thus, Sertoli cells have transformed into immature cells, resembling precursors prior to puberty. Fibroblast-like cells in the interstitial tissue, which display strongly lobulated nuclei, a well-developed smooth endoplasmic reticulum, lipid droplets, and numerous inclusions are assumed to represent dedifferentiated Leydig cells. Since after estrogen treatment serum testosterone and gonadotropin levels are known to be reduced, it appears that the morphological changes correlate well with the endocrine status.

Seminiferous tubule degeneration in human cryptorchid testes

Two types of degenerating seminiferous tubules were found in cryptorchid testes with Sertoli cell hyperplasia of children and adults: 1) tubules with central degeneration, and 2) tubules with total degeneration. Central degeneration begins with degenerative changes in germ cells that accumulate in the lumen of the seminiferous tubule. Some Sertoli cells may also be affected. Degenerated cells finally disappear, and the remaining tubule is composed of only a cuboidal epithelium, which consists mainly of Sertoli cells and occasional germ cells surrounding a wide lumen. Total degeneration is principally seen in tubules with severe germinal hypoplasia. All the seminiferous epithelium cells degenerate and lose their characteristic distribution, forming a disorganized Sertoli cell nodule surrounded by a thickened basement membrane. Lastly, Sertoli cells disintegrate, and the seminiferous epithelium disappears. Tubular degeneration might be related to the thickening of the basement membrane, which hinders metabolic interchange between the seminiferous epithelium and the interstitium.

Ovarian sex cord tumor with annular tubules: review of 74 cases including 27 with Peutz-Jeghers syndrome and four with adenoma malignum of the cervix

The sex cord tumor with annular tubules (SCTAT) is a distinctive ovarian neoplasm the predominant component of which has morphologic features intermediate between those of the granulosa cell tumor and those of the Sertoli cell tumor; focal differentiation into either granulosa cell or Sertoli cell tumor may occur. Of the 74 cases that form the basis of this investigation 27 were associated with the Peutz-Jeghers syndrome; these tumors were all benign and were typically multifocal, bilateral, very small or even microscopical in size and calcified. Twelve of the 27 patients had symptoms suggestive of hyperestrinism attributable to the SCTAT; menstrual irregularity had occurred in eleven cases and postmenopausal bleeding in one. Four of the 27 patients had "adenoma malignum" of the cervix and two of them died of it. The 47 tumors from patients without evidence of the Peutz-Jeghers syndrome were unilateral and usually large. Twenty-five of them were accompanied by symptoms suggestive of hyperestrinism, such as menstrual irregularity, postmenopausal bleeding or sexual precocity; seven were malignant and four of these were fatal.