Case 52. Leydig Cell Tumor with Precocious Puberty

Clinical case. An 8-year-old patient who sought consultation for precocious pseudopuberty. During the physical examination, the penis was observed to have increased in size; also an increase in scrotal pigmentation and in the size and the consistency of the left testicle were verified. Serum levels of FSH and LH and adrenal androgens within normal limits. Serum testosterone levels were similar to those of an adult.

Pathological findings. A 1.1-cm oval yellowish tumor, moderately defined from the adjacent testicular parenchyma, located in the vicinity of the rete testis. It consists of polyhedral cells, eosinophilic cytoplasm with spherical nucleus, eccentric, without mitosis. Some nuclei are larger and show marginalization of the chromatin and ground-glass appearance. In the cytoplasm of some cells, we find two types of spherical, eosinophilic inclusions that correspond to concentric laminar formations of smooth and elongated endoplasmic reticulum suggesting Reinke crystals. The seminiferous tubules located around the tumor have an advanced pubertal maturation, which contrasts with the prepubertal aspect of the more distant parenchyma.

Comments. Leydig cell tumors represent between 4 and 9% of pediatric testicular tumors. They are responsible for 10% of all cases of early pseudopuberty in children. The peculiarities of this case are four: (a) the location of part of the tumor in the testicular mediastinum between the rete testis cavities, (b) the ground-glass appearance of the nuclei of some cells, (c) the spherical eosinophilic inclusions (concentric laminar smooth endoplasmic reticulum), and (d) the potential presence of Reinke crystals in a tumor at this age. The differential diagnosis that can be issued is with a tumor of the adrenogenital syndrome (see representative cases of these entities later on). To complicate the differential diagnosis, a Leydig cell tumor associated with adrenogenital syndrome has been reported. Other Leydig cell tumors are associated with acquired missense mutations in codon 578 of the gene for LHCGR and in the FH gene.

Case 53. Leydig Cell Tumor with Gynecomastia

Clinical case. A 26-year-old patient with painless enlargement of the left testicle. He presents bilateral gynecomastia and moderate elevation of estradiol levels (E2) and low testosterone levels.

Pathological findings. The testicle measured 5 × 4 × 3.5 cm. There was a well-defined, reddish lobed tumor at the upper pole. A marked varicocele was associated. The tumor is constituted by large polygonal cells, with eosinophilic and granular cytoplasm, separated by fibrous septa. The nuclei are central, spherical, and the nucleolus is prominent. The proliferation index is less than 2%. One or several optically empty rectangular formations are observed in some cytoplasms. There is neither necrosis nor vascular infiltration. The cells are positive for inhibin and Melan-A but do not express calretinin. The peripheral parenchyma shows very poor spermatogenesis and few Leydig cells.

Comments. It is a typical case of Leydig cell tumor. Leydig cell tumors incidence ranges from 1 to 3% of all adult testicular tumors. They are the most frequent neoplasms of the sex cord stromal tumor group. About 12.5% of the tumors, as in this case, present with gynecomastia or are discovered in an infertility study. Situations secondary to the hormonal production of estrogen (in this case) or androgen by the tumor cells, and the consequent inhibition of the hypothalamic-pituitary-testicular axis give rise to a certain degree of hypogonadotropic hypogonadism. The fact that only the beds of the Reinke crystals are observed and not the crystals themselves is due to formaldehyde fixation. The expression of calretinin in these tumors is very variable and positivity is usually constant for Inhibin, Melan-A, SF1, and CD 99. Ten percent of these tumors express immunostaining for chromogranin, synaptophysin, and cytokeratins. The expression of nuclear beta-catenin is absent in 100% of them.

Case 54. Leydig Cell Tumor with Infertility (Sertoli Cell-Only)

Clinical case. A 36-year-old patient of who presented with infertility (azoospermia). On physical exploration, the presence of a slightly increased right testicle size was evident. The ultrasound showed a 1.3-cm in diameter hypoechoic nodule in the upper pole. Serum tumor markers were negative.

Pathological findings. The testicle measures 4.8 × 4 × 4 cm. The sectioned section showed a 1.5-cm in diameter poorly defined nodule in an upper pole, grayish yellow, without areas of necrosis or hemorrhage. Histologically, it is constituted by a proliferation in sheets of cells that show a great uniformity in terms of shape and size. They are cells with spherical nuclei, peripheral nucleolus, and eosinophilic cytoplasm. No mitosis is observed. Peripherally, the tumor cells infiltrate the intertubular interstitium. In the thickness of this infiltration, several seminiferous tubules similar to those of the peripheral parenchyma are recognized. Ultrastructurally, the cells show abundant lipid vacuoles and poor development of the smooth endoplasmic reticulum. Immunohistochemically, they have a strong expression for calretinin. All the testicular parenchyma presents seminiferous tubules with a Sertoli cell-only pattern.

Comments. Infertility associated with Leydig cell tumors is usually secondary to a hormonal production by the tumor; when this corrected infertility is mostly reversible once the contralateral testicle is recovered. In 81.25% of the cases of the Leydig cell tumors, the peritumoral parenchyma presents an abnormal spermatogenesis; in 50% of the cases tubules with Sertoli cell-only pattern, and in 25% hyperplasia of the Leydig cells. Poor spermatogenesis can be explained by tumor compression or abnormal estrogenic or androgenic production by the tumor cells. The other two findings, tubules with only Sertoli cells and hyperplasia of Leydig cells, are similar to those seen in the peripheral parenchyma of germ cell tumors, where they are considered to be part of the testicular or dysgenesis syndrome. Taking into account these data, it could be inferred that this testicle shows a primary anomaly. It is unknown to what extent this anomaly may justify the development of some Leydig cell tumors. This case has the peculiarity of not being associated with endocrine alterations and showing a Sertoli cell-only syndrome. As the patient continued with repeated azoospermia months after the orchiectomy, it is likely that the contralateral testicle was also a carrier of the same primary anomaly.

Case 55. Leydig Cell Tumor with Nodular and Microcystic Pattern

Clinical case. A 48-year-old patient who came to the urology office due to a several month long increase of his left testicle size. There was no gynecomastia and the testicular markers were negative.

Pathological findings. The testicle measures 5 × 4 × 4 cm. At the level of the lower pole, it showed a well-encapsulated yellowish tumor. In a large area of myxoid appearance, multiple yellowish nodules were prominent. Histologically, there is a proliferation of cells whose cytoplasm varies from eosinophilic to microvacuolated. The nuclei are spherical with a small nucleolus and the mitoses are very scarce. The cells, in zones, are arranged surrounding cystic spaces. In the myxoid zones, the cells are in small groups and show elongated cytoplasm in a loose and edematous stroma. Necrosis was not observed. Tumor infiltration was observed at the level of the tunica albuginea. The peritumoral parenchyma only shows signs of compression.

Comments. Leydig cell tumors present a wide variety of histological patterns: solid, diffuse or nodular, pseudoglandular and trabecular. They rarely have a microcystic and myxoid pattern. In these cases, it can raise a differential diagnosis with several tumors. Seminomas, spermatocytic tumor, Sertoli cell tumor, granulosa tumors both juvenile and adult-type, and yolk sac tumor may have a microcystic pattern. Fortunately, in other areas all these tumors have histologically typical areas that allow them to be easily identified. Of all of the above, it is the yolk sac tumor the one that is histologically closest. The positivity of the cells of this tumor for AFP and glypican-3 and the negative expression for inhibin and calretinin facilitates the diagnosis. An important fact of this tumor is the infiltration of the lymphatic vessels of the albuginea. This worrying data advised a study of extension and strict surveillance of the patient.

Case 56. Leydig Cell Tumor with Fatty and Osseous Metaplasia

Clinical case. A 36-year-old patient who had been studied for infertility for the last four years. Spermiogram revealed azoospermia in repeated analyses. Serum hormones showed an increase in serum estradiol and a decrease in FSH. On physical examination, a decrease in the size of the left testicle and an increase in the right one, that presents a nodule with a stony consistency, was detected. Right orchiectomy and contralateral biopsy were performed.

Pathological findings. The orchiectomy specimen shows a well-defined tumor, partially encapsulated, with small (1.3 cm in diameter) extracapsular tumor protrusions of. Microscopically, the tumor is composed of polygonal cells of eosinophilic, finely granular cytoplasm. The nuclei are round or oval with hardly any variation in size. Neither mitosis nor Reinke crystals are observed in the cytoplasm. Extensive areas of the tumor show groups of fat cells that in the periphery intermingle with the tumor cells. Irregularly distributed, several bone trabeculae stand out. The peritumoral parenchyma as well as the contralateral testicle biopsy shows tubules with marked hypospermatogenesis and Sertoli cell-only tubules.

Comments. Two facts are particularly important in this tumor. On the one hand, the clinical presentation: the patient sought consultation for infertility and not for testicular tumor. Infertility has been explained in these cases as secondary to the abnormal hormonal secretion of estrogens or androgens by Leydig tumor cells. In this case, in both testicles there is, focally, an added primary pathology, tubules with Sertoli cell-only, so the acquisition of fertility once the tumor is removed will be difficult. On the other hand, the coexistence of bone and adipose metaplasia, facts not previously observed until the publication of Santonja et al. in 1989. Bone metaplasia has only been observed in very few cases. In non-tumor pathology, it has been related to sequelae of ischemia or infection, facts not present in this case. Fatty metaplasia is common in undescended testes that are removed in the adulthood, in elderly patients, in tumors of the adrenogenital syndrome and in pediatric pathology, in the Proteus syndrome, the Cowden syndrome, and the Bannayan-Riley-Ruvalcaba syndrome. None of these situations occur in this patient, so both metaplasias are directly related to some activity of the tumor cells. These two histological findings have no prognostic value.

Case 57. Leydig Cell Tumor in Elderly Man

Clinical case. A 78-year-old patient who seeks consultation for voluminous left hydrocele. The testicle measured 2.8 × 2.6 × 2.5 cm.

Pathological findings. In the macroscopic figure, an atrophic testicle is shown longitudinally sectioned inside the vaginal sac that appears folded when the hydrocele is emptied. On the opposite side of the testicular mediastinum, the testicle presents an irregularly ovoid area, dark and 7 mm in diameter. It corresponds to a proliferation of Leydig cells that adopt a cord-like disposition associated to abundant and very congestive blood vessels. The cells have a marked anisocytosis and anisocariosis, frequent large nuclei with irregular contours, and a large nucleolus. No areas of necrosis or mitosis or vascular infiltration are observed. The tumor cells express immunostaining for CD56, calretinin, and androgen receptor.

Comments. This case has the following peculiarities: (a) It has been asymptomatic partly because of the hydrocele and partly because of its small size; (b) it concerns an atrophic testicle; (c) the advanced age of the patient: the peak of maximum incidence in adults is between 30 and 60 years; (d) the color of the tumor, that suggests more a vascular tumor or a melanoma metastasis than a Leydig cell tumor; (e) its small size, which raises the differential diagnosis with Leydig cells hyperplasia (in the hyperplasia respected tubules inside are observed), and (f) cellular pleomorphism, bizarre Leydig cells similar to those seen in some malignant tumors, that in this case probably represent only age changes.

Case 58. Bilateral Leydig Cell Tumor with Leydig Cell Hyperplasia

Clinical case. A 27-year-old patient with hypospadias, hypergonadotropic hypogonadism, and size increase of both testicles. He has a normal karyotype. Ultrasound examination revealed multiple hypoechoic lesions in both testes. The largest one, in the right testicle, measured 2 cm, and that of the left testicle measured 1.7 cm.

Pathological findings. Both testicles show similar images. A brown nodule measuring 1.8 cm in the right testicle and 1.6 cm in the left one. Both are well defined from the adjacent parenchyma. Histologically, they are formed by a proliferation in sheets of cells with a large eosinophilic cytoplasm, eccentric nuclei, one or two nucleoli without mitosis, and areas of necrosis. It is worth noting the practical absence of connective septa between the cells and those that are observed to contain vessels and are not collagenized. There is a Leydig cell hyperplasia in the parenchyma that adopts both a diffuse and nodular distribution. The seminiferous tubules show thickening of the wall and contain some spermatogonia and first-order spermatocytes.

Comments. The first diagnosis that should be considered before a bilateral testicular tumor that looks like a Leydig cell tumor is that we are in front of a patient with congenital adrenal hyperplasia and presents tumors of the adrenogenital syndrome. For this, as in this case, the mandatory laboratory studies have to be carried out. Having ruled out this diagnosis, we are facing a Leydig cell tumor in a somewhat special patient. Three data are interesting in this case: (a) bilaterality, only present in 3% of Leydig cell tumors, (b) association with Leydig cell hyperplasia, which is observed in less than 25% of Leydig cell tumors, and (c) the presence of hypospadias, a rare occurrence in these patients. Histologically, it is necessary to clearly differentiate a tumor from a hyperplasia, especially when it is nodular. The classic criteria of a hyperplasia are still valid: multiple lesion, not encapsulated, containing germline or atrophic tubules inside. Leydig cell hyperplasia has been described in multiple situations such as in the peripheral parenchyma in germ cell tumors, cryptorchidism, testicular atrophies of inflammatory etiology, and the Klinefelter syndrome. None of these are related to the present case. The presence of hypospadias does not discard a partial androgen insensitivity syndrome, neither does it rule out in this case a congenital pathology that could be related to a testicular dysgenesis. It is debated whether Leydig cell hyperplasia could represent, in some cases, a precursor lesion of Leydig cell tumors.

Case 59. Malignant Leydig Cell Tumor

Clinical case. A 62-year-old patient seen in the urologist office due to discomfort and enlargement of the left testicle. The ultrasound showed a 6–8-cm in diameter hypoechoic tumor that takes most of the testicular parenchyma. Tumor markers were negative.

Pathological finding. A brown tumor formed by several coalescent nodules with hemorrhagic and necrotic areas that takes the entire testicular parenchyma. Histologically, it is formed by a proliferation of cells with a wide eosinophilic cytoplasm, which is arranged in sheets interrupted by fine connective septa. The cells have a high mitotic index. Focally, there is marked anisocytosis and anisocariosis. No Reinke crystals are observed. The tumor has areas of necrosis and infiltrates the adipose tissue of the paratesticular structures and the vessels of the spermatic cord. The cells strongly express calretinin and more weakly inhibin.

Comments. This case is a typical example of Leydig cell tumor of malignant behavior. It is admitted that only the presence of metastasis is the unequivocal sign of malignancy, but when Leydig cell tumors that metastasized have been reviewed, there are histological features that keep repeating: large size (>5 cm), endocrine changes, infiltration of margins, cellular pleomorphism, high mitotic index (>5 mitosis per high-power field), presence of necrosis and hemorrhage, and vascular infiltration. All these features are present in this case. Less than 10% of Leydig cell tumors have a malignant behavior. Lymph nodes, lung, liver, kidney, and bones are the most frequent sites of metastasis. Malignant tumors are frequently aneuploid and have an increased MIB1 index.

Case 60. Bilateral Sertoli Cell Adenomas with Seminoma in Complete Androgen Insensitivity Syndrome (CAIS)

Clinical case. A 65-year-old woman who consulted for abdominal tumors. Two voluminous masses of 12 cm (right) and 8 cm (left) in diameter could be seen in the laparotomy at the anatomical area of the ovaries. There was absence of both uterus and Fallopian tubes. The karyotype performed after the histological study was 46, XY. The patient was diagnosed with CAIS.

Pathological findings. When sectioning, the right gonad shows two different areas: the largest one, in the form of a crescent, is whitish and has a firm consistency, and the smallest one is rhomboidal, grayish and with a softer consistency. The left gonad looks similar to the crescent of the right gonad. Macroscopically, neither testicle nor epididymis is recognized. Histologically, the crescent of the right gonad and the entire left gonad are formed by a proliferation of solid tubules, not anastomosed, smaller than 70 μms. The tubules contain 2–10 cells per cross-section. The cells are cubic with a spherical nucleus, euchromatic with a small nucleolus. The cytoplasm is pale or slightly eosinophilic. The cells are supported by a thick basement membrane with no peritubular myoid cells. The thickness of the membrane is inversely proportional to the number of Sertoli cells. The intertubular space lacks Leydig cells. No mitosis is observed. The cells show immunoexpression for inhibin and WT1. The rhomboidal area of the right gonad was consistent with a seminoma.