Familial occurrence of Leydig cell tumors: a report of a case in a father and his adult son

Testicular Tumors: A Contemporary Update on Morphologic, Immunohistochemical and Molecular Features

Testicular tumors are incredibly diverse and one of the most challenging areas in surgical pathology. Because of the rarity and overlapping features with numerous entities occurring in the testis and paratestis, these tumors pose a diagnostic challenge even to the most experienced general pathologists. In 2016, the latest "World Health Organization (WHO) classification of testicular tumors" was released, which incorporated several updates to the previous 2004 classification system. These updates involved several entities, including germ cell tumors, sex cord-stromal tumors, tumors containing both germ cells and sex-cord stromal cells, a miscellaneous group of testicular tumors and paratesticular tumors. In addition, significant changes were also introduced in the 2018 AJCC TNM staging (8th edition) regarding testicular tumors. The germ cell tumors are divided into 2 major groups; tumors derived from germ cell neoplasia in situ (GCNIS) and those unrelated to GCNIS. The GCNIS associated tumors include seminomatous and nonseminomatous germ cell tumors, which constitute a heterogeneous group of tumors. Non-GCNIS-associated tumors include prepubertal-type teratoma, prepubertal yolk sac tumor, mixed prepubertal-type teratoma and yolk sac tumor and spermatocytic seminoma. In the sex cord-stromal category, the tumors are classified based on their cells of origin. Most are Leydig cell tumors and Sertoli cell tumors; however, several mixed and diverse entities based on cell types are included in this group. Gonadoblastoma is the only tumor in the mixed germ cell and sex cord-stromal tumor category. Because of recent advances in molecular techniques, abundant new genetic information has emerged which helped classify the tumors based on the molecular alterations and provided insights into the tumor pathogenesis. This review focused on the updates related to testicular germ cell tumors and sex cord-stromal tumors and described the morphologic, immunohistochemical and molecular characteristics with an aim to provide a practical diagnostic approach and an update on relevant recent molecular advances.

Adult leydig cell tumors of the testis caused by germline fumarate hydratase mutations

CONTEXT

Leydig cell tumors (LCTs) are the most common non-germ-cell neoplasms of the testis. LCTs are often hormonally active and can result in precocious virilization or in adult feminization. We identified an LCT in an affected individual from a kindred with hereditary leiomyomatosis and renal cell cancer (HLRCC) and a germline fumarate hydratase (FH) mutation (N64T).

OBJECTIVE

Our objective was to investigate the role of FH mutations in predisposition to LCTs.

DESIGN

We tested for pathogenic effects of the N64T mutation and screened an additional 29 unselected adult LCTs for FH alterations. We also tested these LCTs for mutations in two genes, the LH/choriogonadotropin receptor (LHCGR) and the guanine nucleotide-binding protein alpha (GNAS) that had been implicated in LCT tumorigenesis.

RESULTS

No mutations were found in GNAS, and one tumor had a LHCGR somatic substitution. In addition to the HLRCC case with the N64T germline FH mutation, we identified one other LCT with a previously unreported FH mutation (M411I). Both LCTs from these patients showed loss of the wild-type FH allele. Immunohistochemical and in situ hybridization analyses demonstrated activation of the hypoxia/angiogenesis pathway not only in the tumors belonging to the FH mutation carriers but also in several other mutation-negative LCTs.

CONCLUSIONS

Our study shows that some LCTs are caused by FH mutations and represents one of the first reports of germline mutations in any type of adult testicular tumor.

Hormonal and seminal evaluation of Leydig cell tumour patients before and after orchiectomy

Seven patients (aged 25-38 years) were admitted because of mono- or bilateral gynaecomastia. Plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, testosterone, 17-beta-estradiol, delta4-androstenedione, dehydropiandrosterone sulphate (DHEA-S) and 17-OH-progesterone were determined and semen analysis was carried out. FSH and LH levels were also measured after acute LH-RH administration (100 microg intravenously), and testosterone and 17-beta-estradiol were also evaluated after acute human chorionic gonadotrophin (hCG) administration (5000 IU intramuscularly). Testicular echography demonstrated the presence of a solid hypoechoic tumour. Therefore all patients were submitted to hemicastration by orchidofuniculotomy and a benign Leydig cell tumour was diagnosed in the removed testes. Hormonal and semen evaluations were repeated 3, 6, 9 and 12 months after surgery. The data before and after surgery were compared with a control group of 10 age-matched males. Before surgery, patients showed low FSH basal plasma levels; high levels of 17-beta-estradiol and low testosterone levels similar to those after hCG administration. A dyspermia was observed. Unilateral orchidectomy eliminated the autonomous secretion of oestrogen(s) so an increase of LH, FSH and testosterone levels, together with an improvement of spermatogenesis, were obtained.

Leydig cell tumor of the testis: a clinicopathologic, DNA content, and MIB-1 comparison of nonmetastasizing and metastasizing tumors

Leydig cell tumors of the testis are rare and account for a small proportion of testicular neoplasms. The objective of this study was to identify clinical and morphologic features predictive of metastasis in a large series of Leydig cell tumors, and to determine whether ploidy or proliferative activity were predictive of malignancy. Thirty cases of Leydig cell tumor of the testis (23 tumors that had not metastasized and 7 that had metastasized) were studied. Clinical history and follow-up were collected in all cases. The morphologic features examined included tumor size, mitotic index (mitotic figures/10 high-power fields), necrosis, angiolymphatic invasion, cell type, tumor-testicle interface, presence of extension beyond the testicular parenchyma, and presence of lipochrome and Reinke crystals. Most patients (93%) had a testicular mass. Patients with Leydig cell tumors that metastasized were diagnosed at a mean age of 62 years (range, 39-70 years) compared with 48 years (range, 9-79 years) in patients with nonmetastasizing tumors (p = 0.25). Leydig cell tumors that metastasized were significantly larger than nonmetastasizing tumors (mean, 4.7 versus 2.6 cm, respectively; p = 0.008), and had a significantly higher mitotic index (mean, 13.9 versus 1.9, respectively; p < 0.0001). Metastasizing Leydig cell tumors were significantly associated with atypical mitotic figures (p < 0.0001), nuclear variation (p = 0.0025), necrosis (p < 0.0001), angiolymphatic invasion (p = 0.009), infiltrative margins (p < 0.0001), high grade (p = 0.0004), and invasion into rete testis, epididymis, or tunica (p = 0.001) when compared with nonmetastasizing tumors. There was no significant difference between metastasizing and nonmetastasizing tumors in regard to cell type, lipochrome content, presence of Reinke crystals, or nuclear inclusions. All Leydig cell tumors that metastasized and 7 of 18 (38.9%) nonmetastasizing tumors were DNA aneuploid by static image analysis (p = 0.02). Metastasizing Leydig cell tumors had a significantly higher mean MIB-1 activity of 18.6% (range, 5.8-33.6) compared with 1.2% (range, 0.04-8.2) in nonmetastasizing tumors (p = 0.001). In this study, the presence of cytologic atypia, necrosis, angiolymphatic invasion, increased mitotic activity, atypical mitotic figures, infiltrative margins, extension beyond the testicular parenchyma, DNA aneuploidy, and increased MIB-1 activity were significantly associated with metastatic behavior in Leydig cell tumors.

Metachronous development of malignant Leydig cell tumor

Leydig cell tumor (LCT), a rare testicular tumor, is malignant in only about 10% of the cases. We report the case of a patient with bilateral malignant LCTs that developed metachronously. After undergoing a right inguinal orchiectomy for a malignant LCT at the age of 43 years, the patient was given cisplatin-based chemotherapy for suspected para-aortic lymph node metastasis. Eighteen months after the right orchiectomy, examination of a left testicular biopsy specimen showed a malignant LCT and a left inguinal orchiectomy was performed. Histologically, the initial malignant LCT exhibited a highly pleomorphic appearance with mitotic figures (58/10 HPF), whereas the second malignant LCT showed fewer mitoses (2/10 HPF). The proliferating cell nuclear antigen (PCNA)-labelling index in these tumors also differed (right-sided tumor, 50%; left-sided tumor, 28%). These findings suggest that the malignant LCT in the left testis developed as a second primary rather than as a metastatic tumor. There have been no known similar cases, although three cases of malignant LCT with contralateral metastasis have been reported.

Role of retroperitoneal lymph node dissection in clinical stage I Leydig cell tumours

Leydig Cell Tumours (LCT) account for 3% of all testicular tumours; 10% are malignant and are refractory to radio- and chemotherapy. The role of Retroperitoneal Lymph Node Dissection in clinical stage I LCT is therefore a particularly debated one. From March ‘83 to December ‘95, 10 patients with LCT were subjected to orchiectomy (1 of them bilaterally because of a metachronous tumour). In 10 out of 11 specimens the following pathological features – a) size larger than 50 mm, b) infiltration of spermatic cord, c) lymphatics and veins, d) capsule, e) necrosis, f) cellular pleomorphism, g) numerous mitoses, h) nuclear atypia – were absent. The only patient in which b) and d) were present was subjected to RPLND. After a follow-up ranging from 17 to 157 months all patients are disease-free. Abstention from RPLND in clinical stage I LCT therefore seems the more rational choice when the above- listed pathologic features are absent.

Leydig cell tumour in a man with human immunodeficiency virus

We report a case of Leydig-cell testicular tumour in a 32-year-old intravenous drug abuser bearing HIV-infection and pulmonary tuberculosis. The testicular mass was initially interpreted as genital tuberculosis and the diagnosis was made by aspiration cytology. Radical orchiectomy was performed and pathology revealed a Leydig-cell tumour. Gynecomastia was found as a possible sign of endocrine activity. Although testicular malignancies in men with human immunodeficiency virus are increasingly reported, this is the first case of Leydig-cell neoplasia associated to HIV-infection.