Gonadoblastoma: origin and outcome

Y Chromosome Loss and Implications for Oncology

The Y chromosome has recognized functions in promoting male sex determination and regulating aspects of fertility. However, recent work has demonstrated important roles for the Y chromosome and Y-encoded genes in multiple domains of male health, including cancer. It is well established that males experience shorter lifespans than females, and this sex bias on overall mortality is accentuated in populations with longer life expectancy, in part related to elevated rates of cancer. The majority of human malignancies exhibit a sex bias with elevated frequencies in males. For many of these cancer types, the disparity has not been explained by environmental risk factors such as tobacco use. Notably, loss of the Y chromosome (LOY) detected in blood cells, termed mosaic LOY, is a common event that is related to advancing age and is associated with a shortened lifespan. Mosaic LOY is linked to increased incidence and mortality across a range of malignancies. Furthermore, tumors arising in different anatomic sites exhibit different frequencies of partial or complete Y chromosome loss. Causal oncogenic or tumor-suppressive roles have been documented for several Y-encoded genes, such as lysine-specific demethylase 5 D, that exert pleiotropic effects on cellular functions by virtue of genome-wide regulation of gene activity. In this review, we discuss aspects of the Y chromosome relevant to oncology. The recent completion of the entire human Y-chromosome sequence provides a reference map of Y-encoded genes and regulatory elements to enable causal molecular studies that may explain and exploit the marked disparity in male cancer risk and mortality.

A Risk of Gonadoblastoma in Familial Swyer Syndrome-A Case Report and Literature Review

A complete gonadal dysgenesis (CGD) with 46,XY karyotype is known as the Swyer syndrome and belongs to the group of 46,XY differences of sex development (DSD). The main problem in patients with Swyer syndrome is the delayed puberty and primary amenorrhea. Moreover, intrabdominal dysgenetic gonads in the patient with genetic material of a Y chromosome may conduce to the development of gonadal tumors, such as gonadoblastoma or germinoma. The management of such patients is based on preventive excision of dysgenetic gonads and long-term hormonal replacement therapy. Sporadic cases are considered more common than familial cases. This paper presents two siblings with Swyer syndrome in whom gonadoblastoma was found. A thorough review of familial CGD with 46,XY DSD in the literature from the last 15 years suggests that the risk of gonadal tumors could be increased in familial compared to sporadic cases (66.6% vs. 15-45%, respectively).

Rare Case of a Turner Syndrome Patient with Metastatic Dysgerminoma and No Y-Chromosomal Material with Pathogenic Variants Found in KIT and MTOR

INTRODUCTION

The presence of Y-chromosomal material in females with Turner syndrome (TS) is a well-established risk factor for developing gonadoblastoma and malignant transformations thereof. However, these events are rarely seen in TS patients with no Y-chromosomal material. Thus, it is the current understanding that parts of the Y-chromosome are essential for the malignant transformation of gonadoblastoma in the dysgenetic gonad.

METHODS

We report a case of a TS female with an apparent 46,X,idic(Xq) karyotype, who was diagnosed with a metastatic dysgerminoma. Whole exome sequencing of the tumor and blood, along with RNA sequencing of the tumor, was performed to comprehensively search for cryptic Y-chromosomal material and pathogenic variants.

RESULTS

No Y-chromosomal material was detected in either tumor or blood. Whole exome-sequencing of DNA and RNA revealed a pathogenic somatic gain-of-function mutation in KIT and a pathogenic missense mutation in MTOR. The patient underwent total hysterectomy with bilateral salpingo-oophorectomy, followed by adjuvant chemotherapy. Unfortunately, she died due to chemotherapy-induced pneumonitis 7 months after the initial diagnosis.

CONCLUSION

Females with TS can develop metastatic dysgerminoma even in the absence of Y-chromosomal material. This questions the current understanding of Y-chromosomal material being essential for the malignant transformation of a gonadoblastoma in the dysgenetic gonad.

SIX1 as a Novel Immunohistochemical Marker in the Differential Diagnosis of Rhabdomyosarcoma

Background: Differential diagnosis of rhabdomyosarcoma (RMS) is challenging. Sineoculis homeobox homolog 1 (SIX1) is an oncogene involved in skeletal muscle differentiation. We compared protein expression patterns of SIX1 in RMS and its most common differential diagnoses. Methods: SIX1 immunohistochemistry in 36 RMS and in 33 tumors from seven differential diagnostic subtypes were evaluated. The fraction of SIX1 positive tumor cells was scored by three independent observers. Results: A majority (75%) of the evaluated RMS expressed SIX1 in at least 50% of tumor cells and all except one RMS had more than 25% positive tumor cells. Neuroblastoma had less than 1% SIX1 positive tumor cells. Gonadoblastoma, malignant rhabdoid tumor, and Ewing sarcoma had 10% or less positive tumor cells. Pleuropulmonary blastoma exhibited 26-50% positive tumor cells and synovial sarcoma >50% positive cells. Conclusion: SIX1 immunohistochemistry is positive in most RMS, and occasionally in some tumors within the differential diagnoses of RMS.

Prevalence and characteristics of gonadoblastoma in a retrospective multi-center study with follow-up investigations of 70 patients with Turner syndrome and a 45,X/46,XY karyotype

INTRODUCTION

A gonadectomy is currently recommended in patients with Turner syndrome (TS) and a 45,X/46,XY karyotype, due to a potential risk of gonadoblastoma (GB). However, the quality of evidence behind this recommendation is low.

OBJECTIVE

This study aimed to evaluate the prevalence of GB, its characteristics, as well as its risk factors, according to the type of Y chromosomal material in the karyotype.

METHODS

Our study within French rare disease centers included patients with TS and a 45,X/46,XY karyotype, without ambiguity of external genitalia. Clinical characteristics of the patients, their age at gonadectomy, and gonadal histology were recorded. The regions of the Y chromosome, the presence of TSPY regions, and the percentage of 45,X/46,XY mosaicism were evaluated.

RESULTS

A total of 70 patients were recruited, with a median age of 29.5 years (21.0-36.0) at the end of follow-up. Fifty-eight patients had a gonadectomy, at a mean age of 15 ± 8 years. GB was present in nine cases. Two were malignant, which were discovered at the age of 14 and 32 years, without metastases. Neither the percentage of XY cells within the 45,X/46,XY mosaicism nor the number of TSPY copies was statistically different in patients with or without GB (P = 0.37). However, the entire Y chromosome was frequent in patients with GB (6/9).

CONCLUSIONS

In our study, including a large number of patients with 45,X/46,XY TS, the prevalence of gonadoblastoma is 12.8%. An entire Y chromosome appears as the main risk factor of GB and should favor early gonadectomy.

SIGNIFICANT STATEMENT

About 10% of patients with TS have a karyotype containing Y chromosomal material: 45,X/46,XY. Its presence is related to the risk of GB. Therefore, a prophylactic gonadectomy is currently recommended in such patients. However, the quality of evidence is low. Our objective was to evaluate the prevalence of GB according to the type of Y-chromosomal material. We found a prevalence of GB of 12.8% in a cohort of 70 TS patients. No sign of hyperandrogenism was observed. The entire Y chromosome was the most frequent type of Y-material in patients with GB. As the prognosis of these tumors was good, a delay of surgery might be discussed.

Testicular Tumors: New Developments in Germ Cell and Sex Cord Stromal Tumors

This article reviews the recent advances and potential future changes in the classification of testicular germ cell and sex cord stromal tumors, highlighting changes in the classification system and terminology with description on newer entities. A discussion on approaching difficult areas and diagnostic pitfalls is also included along with the utility of ancillary investigations. Areas with limited knowledge are highlighted to providing direction for future studies and a bulleted summary in the form of critical care points is provided.

The 2022 revision of World Health Organization classification of tumors of the urinary system and male genital organs: advances and challenges

The fifth edition of the World Health Organization (WHO) classification of urinary and male genital organ tumors has been recently published in 2022. The application of molecular profiling has made a substantial impact on classification of urologic tumors. The new WHO classification introduces a group of molecularly well-defined renal tumor subtypes. The significant changes include addition of a category of "other oncocytic tumors" with oncocytoma/chromophobe renal cell carcinoma (chRCC)-like features, elimination of the subcategorization of type1/2 papillary RCC and inclusion of eosinophilic solid and cystic RCC as an independent tumor entity. The WHO/ISUP grading now has been recommended for all RCCs. Major nomenclature changes include replacement of histologic 'variants' by 'subtypes', 'clear cell papillary renal cell carcinoma' to 'clear cell renal cell tumor','TCEB1-mutated RCC' to 'ELOC-mutated RCC', 'hereditary leiomyomatosis and renal cell carcinoma' to 'fumarate hydratase-deficient RCC', 'RCC-Unclassified' to 'RCC-NOS', 'primitive neuroectodermal tumor' to 'embryonic neuroectodermal tumor', 'testicular carcinoid' to 'testicular neuroendocrine tumor', and 'basal cell carcinoma of the prostate' to 'adenoid-cystic (basal-cell) carcinoma of the prostate'. Metastatic, hematolymphoid, mesenchymal, melanocytic, soft tissue and neuroendocrine tumors are collectively discussed in separate chapters. It has been suggested that the morphological classification of urothelial cancer be replaced with a new molecular taxonomic classification system.

Imaging of Pediatric Testicular and Para-Testicular Tumors: A Pictural Review

Pre- and post-pubertal testicular tumors are two distinct entities in terms of epidemiology, diagnosis and treatment. Most pre-pubertal tumors are benign; the most frequent are teratomas, and the most common malignant tumors are yolk-sac tumors. Post-pubertal tumors are similar to those found in adults and are more likely to be malignant. Imaging plays a pivotal role in the diagnosis, staging and follow-up. The appearance on ultrasonography (US) is especially helpful to differentiate benign lesions that could be candidates for testis-sparing surgery from malignant ones that require radical orchidectomy. Some specific imaging patterns are described for benign lesions: epidermoid cysts, mature cystic teratomas and Leydig-cell tumors. Benign tumors tend to be well-circumscribed, with decreased Doppler flow on US, but malignancy should be suspected when US shows an inhomogeneous, not-well-described lesion with internal blood flow. Imaging features should always be interpreted in combination with clinical and biological data including serum levels of tumor markers and even intra-operative frozen sections in case of conservative surgery to raise any concerns of malignity. This review provides an overview of imaging features of the most frequent testicular and para-testicular tumor types in children and the value of imaging in disease staging and monitoring children with testicular tumors or risk factors for testicular tumors.

Malignant Gonadal Germ Cell Tumors (Other Than Pure Germinoma) in Patients With Disorders of Sex Development: A Report of 21 Cases Based Largely on the Collection of Dr Robert E. Scully, Illustrating a High Frequency of Yolk Sac Tumor With Prominent Hepatoid and Glandular Features

We describe 21 nonpure germinomatous gonadal germ cell tumors (9 with a germinoma component), all but 1 associated with gonadoblastoma, in patients with disorders of sex development who ranged from 7 to 36 years old (average, 20 y). Twenty patients were clinically described as phenotypic females with ambiguous genitalia/virilization and primary amenorrhea. The most common documented peripheral karyotype was 46,XY (10/12; 83%). Fifteen of 16 tumors with available clinicopathologic data were unilateral. They ranged from 7 to 30 cm (mean, 15.5 cm) and were solid and cystic with frequent necrosis and hemorrhage. Gonadoblastoma, in its classic (70%), dissecting (5%), or combined (25%) forms, was identified in all but 1. The malignant germ cell tumors were typically mixed except for 5 pure yolk sac tumors and 1 expansile gonadoblastoma with syncytiotrophoblast cells. When admixed, the most common component was yolk sac tumor (n=10), followed by germinoma (n=9), embryonal carcinoma (n=5), choriocarcinoma (n=4), immature teratoma (n=3), and teratoma (n=2). Typical morphologic patterns of yolk sac neoplasia, including reticular/microcystic, solid (including blastema-like), and endodermal sinus (Schiller-Duval bodies), were seen, as well as glandular (n=10) and hepatoid (n=6) differentiation, with cystically dilated glands and diffuse hepatoid morphology in 3 and 2 tumors, respectively. Two yolk sac tumors showed a sarcomatoid pattern. Somatic-type malignancies (alveolar rhabdomyosarcoma and low-grade spindle cell sarcoma, not otherwise specified) were identified in 1 case each. This is the first large series of germ cell tumors other than typical pure germinoma associated with gonadoblastoma. The high frequency of yolk sac tumor with glandular (especially cystic glandular) and hepatoid morphologies is noteworthy, and their presence should prompt further evaluation for an associated gonadoblastoma and possible disorder of sex development.

Ovarian gonadoblastoma with dysgerminoma in a girl with 46,XX karyotype 17a-hydroxylase/17, 20-lyase deficiency: A case report and literature review

17α-hydroxylase/17,20-lyase deficiency (17-OHD), caused by mutations in the gene of the cytochrome P450 family 17 subfamily A member 1 (CYP17A1), is a rare type of congenital adrenal hyperplasia (CAH), usually characterized by cortisol and sex steroid deficiency combined with excessive mineralocorticoid. Gonadoblastoma is a relatively rare ovarian tumor that is frequently seen among patients with 46,XY gonadal dysgenesis. Rarely have they been reported in female patients with normal 46,XX karyotype. Here, we report an interesting case of an 11-year-old Chinese girl who presented acute abdominal pain that was later attributed to tumor rupture of right ovarian gonadoblastoma with dysgerminoma. Further evaluations revealed hypertension and hypokalemia. Hormonal findings showed increased progesterone, hypergonadotropic hypogonadism, and low cortisol levels. Her chromosome karyotype was 46,XX without Y chromosome material detected. Genetic analysis revealed that the patient had a homozygous pathogenic variant c.985_987delTACinsAA (p.Y329Kfs*90) in exon 6 of the CYP17A1 gene and that her parents were all heterozygous carriers of this pathogenic variant. Due to the variable clinical manifestations of 17-OHD, meticulous assessment including genetic analysis is necessary. Further study is warranted to unravel the mechanism of gonadoblastoma in a patient with normal karyotypes.

EAU-ESPU pediatric urology guidelines on testicular tumors in prepubertal boys

BACKGROUND

Testicular tumors in prepubertal boys account for 1-2% of all solid pediatric tumors. They have a lower incidence, a different histologic distribution and are more often benign compared to testicular tumors in the adolescent and adult group. This fundamental difference should also lead to a different approach and treatment.

OBJECTIVE

To provide a guideline for diagnosis and treatment options in prepubertal boys with a testicular mass.

METHOD

A structured literature search and review for testicular tumors in prepubertal boys was performed. All English abstracts up to the end of 2019 were screened, and relevant papers were obtained to create the guideline.

RESULTS

A painless scrotal mass is the most common clinical presentation. For evaluation, high resolution ultrasound has a detection rate of almost 100%, alpha-fetoprotein is a tumor marker, however, is age dependent. Human chorionic gonadotropin (HCG) was not a tumor marker for testis tumors in prepubertal boys.

CONCLUSION

Based on a summary of the literature on prepubertal testis tumors, the 2021 EAU guidelines on Pediatric Urology recommend a partial orchiectomy as the primary approach in tumors with a favorable preoperative ultrasound diagnosis.

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.

Unclassified Mixed Germ Cell-Sex Cord-Stromal Tumor of the Ovary: An Unusual Case Report

Unclassified mixed germ cell-sex cord-stromal tumor (UMGC-SCST) is a rare ovarian neoplasm composed of germ cells and sex cord elements, which occurs in genetically and phenotypically normal women without the usual histological features seen in gonadoblastoma. Few cases have been reported in the literature so far. The age of presentation is more frequent in girls younger than 10 years of age, although it can also occur in adult women. It can be associated with isosexual pseudoprecocity. The preferred management is the resection of the gonad that contains the tumor and the conservation of the opposite ovary and tube. This is a case of a 14-year-old patient, with precocious puberty and normal phenotype, diagnosed with this kind of ovarian tumor. A fertility preserving surgery with the resection of the right ovarian tumor and tube was performed. The patient was classified as stage IA according to the 2014 International Federation of Gynecology and Obstetrics (FIGO). She received adjuvant chemotherapy with bleomycin-etoposide-cisplatin for three cycles. After a follow-up of 24 months, she was found to be asymptomatic and free of relapse.