Juvenile Granulosa Cell Tumors of the Testis: A Clinicopathologic Study of 70 Cases With Emphasis on Its Wide Morphologic Spectrum

Contemporary Updates on Sex Cord-stromal Tumors of the Testis

Testicular sex cord-stromal tumors (TSCSTs) are relatively rare, representing ~5% of testicular neoplasms overall. Historically, TSCSTs have been classified into 3 major entities: Leydig cell tumor, Sertoli cell tumor, and granulosa cell tumor. In recent years, immunophenotypic and molecular analyses have led to a more detailed understanding of the biological and genomic features of these neoplasms, resulting in the description of new entities, some of which have been included in the latest WHO classification. This review summarizes novel histopathologic, clinical, and molecular findings that may lead to a reappraisal of established concepts and help improve the diagnosis and clinical management of TSCSTs in the coming years.

[Fundamentals in the pathology of testicular tumours]

The most common group of testicular tumours comprises germ cell tumours. Other primary testicular tumours are rare, but it is important to be aware of the wide variety of other, much rarer testicular tumours for the differential diagnosis. These tumours include sex cord stromal tumours and testicular adnexal tumours, which must be distinguished from metastases or somatic-type malignancies in germ cell tumours. Immunohistochemical markers and molecular alterations can help to correctly diagnose these tumours.

The Application and Pitfalls of Immunohistochemical Markers in Challenging Diagnosis of Genitourinary Pathology

CONTEXT.—

The morphologic features of different entities in genitourinary pathology overlap, presenting a diagnostic challenge, especially when diagnostic materials are limited. Immunohistochemical markers are valuable when morphologic features alone are insufficient for definitive diagnosis. The World Health Organization classification of urinary and male genital tumors has been updated for 2022. An updated review of immunohistochemical markers for newly classified genitourinary neoplasms and their differential diagnosis is needed.

OBJECTIVE.—

To review immunohistochemical markers used in the diagnosis of genitourinary lesions in the kidney, bladder, prostate, and testis. We particularly emphasized difficult differential diagnosis and pitfalls in immunohistochemistry application and interpretation. New markers and new entities in the 2022 World Health Organization classifications of genitourinary tumors are reviewed. Recommended staining panels for commonly encountered difficult differential diagnoses and potential pitfalls are discussed.

DATA SOURCES.—

Review of current literature and our own experience.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool in the diagnosis of problematic lesions of the genitourinary tract. However, the immunostains must be carefully interpreted in the context of morphologic findings with a thorough knowledge of pitfalls and limitations.

Molecular Biomarkers With Potential Clinical Application in Testicular Cancer

Testicular germ cell tumors (TGCTs) and sex cord-stromal tumors (SCSTs) are the most common testicular neoplasms. The morphologic spectrum of such tumors is wide, with several histologic subtypes within each group. Testicular tumors often represent a diagnostic challenge, requiring proper identification of their biologic potential for accurate risk stratification and selection of therapy. In the era of precision medicine, molecular biomarkers are increasingly assuming a critical role in the management of patients with cancer. Given the overall rarity of certain types of testicular neoplasms, progress in biomarker research has been relatively slow. However, in recent years, we have witnessed a multitude of important contributions, including both tissue-based and liquid biopsy biomarkers, stemming from important discoveries of tumor pathobiology, accurate histopathological analysis, multi-institutional studies, and genome-wide molecular analyses of specific tumor subtypes. In this review, we provide an overview of the progress in molecular biomarkers of TGCTs and SCSTs, focusing on those with greatest potential for clinical application. In TGCTs, developmental biology has been the key to understanding these tumors and identifying clinically useful biomarkers (from classical serum tumor markers to pluripotency factors and circulating microRNAs of the 371-373 cluster). For SCSTs, studies have focused on tissue biomarkers only, and genome-wide investigations have recently contributed to a better understanding of rare phenotypes and the aggressive biological behavior of some tumors within this nosologic category. Several new biomarkers are moving toward clinical implementation in this field. Therefore, the practicing pathologist should be aware of their strengths and limitations in order to utilize them properly and maximize their clinical benefits.

Adamantinoma-like ewing sarcoma arising in the pancreatic tail: a case report of a rare entity and review of the literature

ALES is a rare subtype that demonstrates the EWSR1-FLI1 translocation characteristic of ES and demonstrates complex epithelial differentiation including diffuse cytokeratin and p40 expression. It has predominantly recognized in the head and neck and is common in middle-aged population. This case is the first case of ALES reported in the pancreatic tail, sharing some morphological characteristics with ALES in the head and neck, including monotonous cytology, infiltrative growth pattern, and complex epithelioid differentiation, but ALES in the head and neck often has high-grade histological features (e.g., necrosis, high mitotic rate, etc.), and sudden keratinization can also occur, but these features were not reflected in this primary pancreatic tail ALES. Although ALES arising in the pancreatic tail and in the head and neck sites share the immunohistochemical and molecular profile, our case can provide new ideas in differential diagnosis of ALES arising in pancreatic tail and promote increased recognition and understanding of ALES.

Testicular Juvenile Granulosa Cell Tumors Demonstrate Recurrent Loss of Chromosome 10 and Absence of Molecular Alterations Described in Ovarian Counterparts

Testicular juvenile granulosa cell tumors (JGCTs) are a rare type of sex cord-stromal tumor, accounting for <5% of all neoplasms of the prepubertal testis. Previous reports have demonstrated sex chromosome anomalies in a small subset of cases, but the molecular alterations associated with JGCTs remain largely undescribed. We evaluated 18 JGCTs using massive parallel DNA and RNA sequencing panels. The median patient age was <1 month (range, newborn to 5 months). The patients presented with scrotal or intra-abdominal masses/enlargement, and all underwent radical orchiectomy (17 unilateral and 1 bilateral). The median tumor size was 1.8 cm (range, 1.3-10.5 cm). Histologically, the tumors were purely cystic/follicular or mixed (ie, solid and cystic/follicular). All cases were predominantly epithelioid, with 2 exhibiting prominent spindle cell components. Nuclear atypia was mild or absent, and the median number of mitoses was 0.4/mm2 (range, 0-10/mm2). Tumors frequently expressed SF-1 (11/12 cases, 92%), inhibin (6/7 cases, 86%), calretinin (3/4 cases, 75%), and keratins (2/4 cases, 50%). Single-nucleotide variant analysis demonstrated the absence of recurrent mutations. RNA sequencing did not detect gene fusions in 3 cases that were sequenced successfully. Recurrent monosomy 10 was identified in 8 of 14 cases (57%) with interpretable copy number variant data, and multiple whole-chromosome gains were present in the 2 cases with significant spindle cell components. This study demonstrated that testicular JGCTs harbor recurrent loss of chromosome 10 and lack the GNAS and AKT1 variants described in their ovarian counterparts.

An update on diagnostic tissue-based biomarkers in testicular tumors

Testicular cancer is rare overall but comprises the most common solid malignancy diagnosed in young men aged ∼20-40 years. Most testicular neoplasms generally fall into 2 broad categories: germ cell tumors (GCTs; ∼95%) and sex cord-stromal tumors (SCSTs ∼5%). Given the relative rarity of these tumors, diagnostic biomarkers are highly relevant for their diagnosis. Over the past several decades, diagnostic biomarkers have improved dramatically through targeted immunohistochemical and molecular characterization. Despite these recent advances, most markers are not perfectly sensitive or entirely specific. Therefore, they need to be used in combination and interpreted in context. In this review, we summarize tissue-based biomarkers relevant to the pathologist, with a focus on practical diagnostic issues that relate to testicular GCT and SCST.

Clinical challenge: a case of testicular tumor disguised as a prenatal testicular torsion

Background

Neonatal tumors account for a minority of prepubertal testicular tumors. Similarly, testicular torsion in the neonate within the intrauterine or postnatal period is a rare event with an estimated incidence of 6 per 100,000. Testicular salvage is almost never achieved in cases of prenatal testicular torsion and there is still no consensus on the ideal management.

Case presentation

A neonate with prenatal testicular torsion that underwent inguinal orchiectomy. On pathological examination, an uncharacterizable, multicystic, and well-delineated testicular tumor was identified. Although rare, testicular tumor presenting as neonatal testicular torsion should be considered in the differential diagnosis of an acute neonatal scrotum.

Conclusions

This case highlights that an inguinal approach for surgical exploration in prenatal testicular torsions may be preferred given the risk, albeit extremely low, of an underlying testicular tumour.

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.

Molecular assessment of testicular adult granulosa cell tumor demonstrates significant differences when compared to ovarian counterparts

Testicular adult granulosa cell tumor (AGCT) is a rare type of sex-cord stromal tumor that affects patients of a wide age range and has the potential for late metastasis. In the testis, the diagnosis of AGCTs often requires the exclusion of other more common types of sex-cord stromal tumors. Immunohistochemistry is of limited utility, being used mostly to confirm sex-cord lineage and to exclude other entities when morphology is not typical. Unlike ovarian AGCTs, which are molecularly homogeneous and harbor a specific activating FOXL2 mutation (c.7558C > T p.C134W) in >90% of cases, the molecular characteristics of testicular AGCTs remain largely unknown. In the current study, we analyzed 13 testicular AGCTs diagnosed at multiple institutions using massively parallel DNA sequencing to evaluate single nucleotide variants, copy number alterations, and structural variants. In all, 10/13 cases were sequenced successfully. Notably, the FOXL2 c.7558C > T (p.C134W) mutation was identified in only a single case (1/10, 10%). The remaining cases were molecularly heterogeneous, with largely nonrecurrent genetic variants. Putative driver events in individual cases included a well-characterized gain-of-function NRAS mutation, as well as inactivation of ATM and TP53, among others. The only highly recurrent finding was single copy loss of 22q (7/10 cases, 70%). Comparatively, the frequencies of FOXL2 c.7558C > T (p.C134W) and 22q loss in 12 metastatic ovarian AGCTs identified in our database were 92% (11/12) and 42% (5/12), respectively. The results of the present study suggest that testicular AGCTs are different from their ovarian counterparts in that they appear to be molecularly heterogeneous and only rarely harbor FOXL2 mutations.

Sex chromosome DSD individuals with mosaic 45,X0 and aberrant Y chromosomes in 46,XY cells: distinct gender phenotypes and germ cell tumour risks§

"Differences of Sexual Development (DSD)," individuals with rearranged Y chromosome breaks in their 46,XY cells are reported with male and female gender phenotypes and differences in germ cell tumour (GCT) risk. This raised the question of whether male or female gender and GCT risk depends on the site of the break and/or rearrangement of the individual´s Y chromosome. In this paper, we report molecular mapping of the breakpoint on the aberrant Y chromosome of 22 DSD individuals with a 45,X/46,XY karyotype reared with a different gender. Their Y chromosome breaks are found at different sites on the long and short Y arms. Our data indicate that gender rearing is, neither dependent on the site of Y breakage, nor on the amount of 45,X0 cells in the individuals' leukocytes. Most prominent are secondary rearrangements of the Y chromosome breaks forming di-centric Y-structures ("dic-Y"). Duplications of the short Y arm and the proximal part of the long Y arm are the results. A putative GCT risk has been analysed with immunohistochemical experiments on some dysgenetic gonadal tissue sections. With specific antibodies for OCT3/4 expression, we marked the pluripotent germ cell fraction being potential tumour precursor cells. With specific antibodies for DDX3Y, TSPY, and UTY we analyzed their putative Gonadoblastoma Y (GBY) tumour susceptibility function in the same specimen. We conclude GBY expression is only diagnostic for GCT development in the aberrant germ cells of these DSD individuals when strong OCT3/4 expression has marked their pluripotency.

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.

Sex Maintenance in Mammals

The crucial event in mammalian sexual differentiation occurs at the embryonic stage of sex determination, when the bipotential gonads differentiate as either testes or ovaries, according to the sex chromosome constitution of the embryo, XY or XX, respectively. Once differentiated, testes produce sexual hormones that induce the subsequent differentiation of the male reproductive tract. On the other hand, the lack of masculinizing hormones in XX embryos permits the formation of the female reproductive tract. It was long assumed that once the gonad is differentiated, this developmental decision is irreversible. However, several findings in the last decade have shown that this is not the case and that a continuous sex maintenance is needed. Deletion of Foxl2 in the adult ovary lead to ovary-to-testis transdifferentiation and deletion of either Dmrt1 or Sox9/Sox8 in the adult testis induces the opposite process. In both cases, mutant gonads were genetically reprogrammed, showing that both the male program in ovaries and the female program in testes must be actively repressed throughout the individual's life. In addition to these transcription factors, other genes and molecular pathways have also been shown to be involved in this antagonism. The aim of this review is to provide an overview of the genetic basis of sex maintenance once the gonad is already differentiated.

Testis-sparing surgery for testicular tumors in children: a 20 year single center experience and systematic review of the literature

PURPOSE

Although surgical therapy for testicular tumors (TT) is often radical orchidectomy, tumor resection with preservation of healthy testicular parenchyma has been proposed. This study herein reports a 20 year single center experience applying testicular sparing surgery (TSS) as a primary operative strategy in pediatric patients. A systematic literature review summarizes the utility and outcomes of TSS in appropriately selected patients.

METHODS

Pediatric patients with TT who underwent TSS between 1997 and 2018 were studied. TSS was indicated if patients presented evidence of adequately spared healthy testicular parenchyma on preoperative ultrasound and negative serum tumor markers. A systematic review of the literature was also performed.

RESULTS

12 cases met full inclusion criteria with 10 of 12 subjects in the prepubertal age group. Follow-up was 73 months (range 18-278 months). Only a single male patient (GSCCT) presented with early recurrence and orchidectomy was then performed. No cases of postoperative testicular atrophy were identified. Sexual maturation (Tanner stage) expected for age in each patient was documented. Review of the literature identified 34 published studies including 269 patients (94% prepubertal). Pathologic lesions here were mainly mature teratoma(s)-(62%) with a follow-up period of 4 years. Recurrent tumors were observed in only three patients (1.1%) notably two Leydig Cell Tumors and one Teratoma. Testicular atrophy reportedly occurred in only one single case (0.37%).

DISCUSSION

TSS is a feasible alternative to radical orchidectomy in pediatric male patients with localized TT and negative tumor markers. Long term follow-up is essential to monitor testicular growth, puberty with sexual development and psychological male health.

Immunohistochemical Characterization of 120 Testicular Sex Cord-Stromal Tumors With an Emphasis on the Diagnostic Utility of SOX9, FOXL2, and SF-1

Sex cord-stromal tumors (SCSTs) account for the second most common category of testicular neoplasms and include several entities that may show overlapping morphologies and present diagnostic challenges. We analyzed a cohort of 120 testicular SCSTs and investigated the diagnostic utility of SRY-box transcription factor 9 (SOX9), forkhead box protein L2 (FOXL2), and steroidogenic factor 1 (SF-1) immunohistochemical stains. The results were compared with the more commonly used SCST markers, inhibin α, calretinin, and Wilms' tumor 1 (WT1). SF-1 was overall the most sensitive stain (91%), followed by inhibin α (70%), calretinin (52%), FOXL2 (50%), SOX9 (47%), and WT1 (37%), but sensitivities varied by tumor type. SOX9 and calretinin were more commonly positive in sex cord elements versus stromal elements (62% vs. 27% and 47% vs. 9%, respectively), whereas FOXL2 was more commonly positive in stromal elements versus sex cord elements (100% vs. 55%) when excluding Leydig cell tumors from the stromal category. Although no individual stain was diagnostically specific, some immunophenotypic patterns were noted that may help in the subclassification of SCSTs. We conclude that SOX9, FOXL2, and SF-1 are useful immunohistochemical stains for confirming sex cord-stromal differentiation in testicular tumors and provide increased sensitivity as well as additional diagnostic information, especially when combined with the more commonly used inhibin α, calretinin, and WT1 immunostains. Although morphology is paramount for subclassification of SCSTs, knowledge of certain immunohistochemical patterns may be helpful for diagnostically challenging cases.

The role of FOXL2, SOX9, and β-catenin expression and DICER1 mutation in differentiating sex cord tumor with annular tubules from other sex cord tumors of the ovary

Sex cord tumor with annular tubules (SCTAT) is a highly rare type of ovarian sex cord-stromal tumor (SCST), the diagnosis of which remains to be challenging. The aim of this study was to scrutinize the utility of three immunohistochemical markers including Forkhead box protein 2 (FOXL2), SOX9, and β-catenin and DICER1 mutation status in distinguishing SCTATs from other ovarian SCSTs. Nine cases of SCTAT, 10 Sertoli-Leydig cell tumor (SCLT), 10 adult-type granulosa cell tumor (AGCT), and 8 juvenile-type granulosa cell tumor (JGCT) were included in the study. SCTATs were characterized by diffuse and strong expression of SOX9, focal and weak expression of FOXL2, and the absence of DICER1 mutation. However, AGCTs and JGCTs displayed strong and diffuse expression of FOXL2, focal/no immunoreaction for SOX9. SLCTs generally showed moderate intensity of FOXL2 and SOX9 expression. Nuclear β-catenin expression was observed in none of SLCT, 1/9 of SCTAT, 6/8 JGCT, and 4/10 AGCT cases, respectively. DICER1 hotspot mutation was detected in only 3 cases of SLCT and 2 cases of JGCT. We conclude that in addition to strong and diffuse SOX9 expression, weak/absent expression of FOXL2 is suggestive for the diagnosis of SCTAT. Hence, we suggest that inclusion of these two markers, SOX-9 and FOXL2, to the immunohistochemical panel helps in differentiation of SCTAT from other SCSTs in addition to morphologic findings. We also conclude that SCTATs of the ovary do not harbor DICER1 hotspot mutation.

[Juvenile granulosa cell tumor-Testicular tumor of the very young : Report of three cases and contemporary recommendations]

Der juvenile Granulosazelltumor (JGZT) des Hodens ist eine relevante Differentialdiagnose testikulärer Raumforderungen des Säuglingsalters. Es handelt sich um eine benigne Läsion, die Therapie ist rein chirurgisch. Metastasierungen oder Rezidive sind nicht bekannt. Am Beispiel von drei Kasuistiken wird das aktuelle diagnostische und therapeutische Management vorgestellt und diskutiert.

A Morphologic and Immunohistochemical Comparison of Nuclear β-Catenin Expressing Testicular Sertoli Cell Tumors and Pancreatic Solid Pseudopapillary Neoplasms Supporting Their Continued Separate Classification

Some recent reports suggested that many Sertoli cell tumors, not otherwise specified (SCTs-NOS) of the testis were analogs of the solid pseudopapillary neoplasm (SPN) of the pancreas. One of the most relied on pieces of information for this assertion was the shared occurrence in both neoplasms of exon 3 mutations of the CTNNB1 gene, which was reflected by nuclear β-catenin expression. We, therefore, compared the morphologic and immunohistochemical features of 18 SCTs-NOS with strong, diffuse nuclear β-catenin expression with 16 SPNs that also showed such positivity. Although there were clear similarities in the light microscopic features of these neoplasms, there were also significant differences that included, in SCT-NOS and SPN, respectively: hollow tubules (53% vs. 0%), sheet-like growth (44% vs. 94%), circumscription (79% vs. 25%), corded or trabecular patterns (81% vs. 31%), formation of papillae or pseudopapillae (24% vs. 69%), growth in nests or clusters (94% vs. 50%), perivascular pseudorosettes (13% vs. 56%), and rhabdoid cytology (6% vs. 50%). Commonly shared morphologic features included signet-ring cells, pale or foamy cytoplasm, myxoid stroma, cyst formation, perivascular hyalinization, and globular or band-like basement membrane deposits. On immunohistochemical study, sex cord markers were frequently positive in SCTs-NOS (steroidogenic factor-1-94%; FOXL2-87%; SOX9-69%; calretinin-60%; Wilms tumor-1-38%; inhibin-29%) whereas all of these markers were negative in the SPNs. We conclude that even though SCT-NOS and SPN share some morphologic features and nuclear immunoreactivity for β-catenin, there remain differences, both morphologically and immunohistochemically, between these neoplasms to the degree that SCT-NOS should not be equated with pancreatic SPN.

Juvenile Granulosa Cell Tumors of the Ovary

OBJECTIVE

To explore the clinical and pathologic features of ovarian juvenile granulosa cell tumors (JGCTs).

METHODS

Clinical data, histopathologic observations, immunohistochemical results, FOXL2 mutation status, and follow-up information of 7 JGCT cases were studied.

RESULTS

The patients most commonly presented with abdominal distension and pain (5 cases), followed by precocious puberty (1 case) and a pelvic mass (1 case). Six patients had stage I disease, and 1 had stage IV disease. The microscopic examinations typically showed lobular growth punctuated by variably sized and shaped follicles. Rare features included a reticular-cystic appearance mimicking a yolk sac tumor (2 cases), a lobular appearance similar to a sclerosing stromal tumor (1 case), strands and cords (1 case), pseudopapillary appearance (2 cases), spindle cell appearance (1 case), microcystic appearance (1 case), hobnail cells (1 case), and rhabdomyoid cells (1 case). No FOXL2 mutation was encountered. After a median follow-up of 53 months, only 1 patient with a strongly diffuse TP53-positive tumor died of the disease, and 2 successfully had babies.

CONCLUSIONS

JGCT is a rare neoplasm with a wide morphologic spectrum and is easily confused with other tumors. Familiarity with the characteristics, rare atypical appearances, and immunohistochemical results may aid in obtaining a correct diagnosis.

New insights into testicular granulosa cell tumors

Testicular granulosa cell tumors (TGCTs) are rare tumors of sex cord-stromal origin. TGCTs are mostly benign and can be classified into the adult type and the juvenile type. Due to the rarity of clinical cases and limited research efforts, the mechanism underpinning the development of TGCTs remains poorly understood. A landmark study has identified a forkhead box L2 mutation (C134W) in nearly all adult ovarian GCTs, but its implications in TGCTs are unclear. The present study focuses on reviewing the major signaling pathways (e.g., the transforming growth factor β signaling pathway) critical for the development of TGCTs, as revealed by genetically modified mouse models, with a goal of providing new insights into the pathogenesis of TGCTs and offering directions for future studies in this area. We posit that a comparative approach between testicular and ovarian GCTs is valuable, as granulosa cells and Sertoli cells arise from the same progenitor cells during gonadal development. Developing pre-clinical mouse models that recapitulate TGCTs will help answer the remaining questions around this type of rare tumor.

Risk factors and treatment outcomes of 239 patients with testicular granulosa cell tumors: a systematic review of published case series data

PURPOSE

Testicular granulosa cell tumors (tGrCT) are rare sex cord-stromal tumors. This review aims to synthesize the available evidence regarding the clinical presentation and clinicopathological characteristics, treatment and outcomes.

METHODS

We conducted a systematic literature search using the most important research databases. Whenever feasible, we extracted the data on individual patient level.

RESULTS

From 7863 identified records, we included 88 publications describing 239 patients with tGrCT. The majority of the cases were diagnosed with juvenile tGrCT (166/239, 69%), while 73/239 (31%) patients were diagnosed with adult tGrCT. Mean age at diagnosis was 1.5 years (± 5 SD) for juvenile tGrCT, and 42 years (± 19 SD) for adult tGrCT. Information on primary treatment was available in 231/239 (97%), of which 202/231 (87%) were treated with a radical orchiectomy and 20/231 (9%) received testis sparing surgery (TSS). Local recurrence after TSS was observed in 1/20 (5%) cases. Metastatic disease was never observed in men with juvenile tGrCT but in 7/73 (10%) men with adult tGrCT. In 5/7 men with metastatic tGrCT, metastases were diagnosed at initial staging, while 2/7 patients developed metastases after 72 and 121 months of follow-up, respectively. Primary site of metastasis is represented by the retroperitoneal lymph nodes, but other sites including lungs, liver, bone and inguinal lymph nodes can also be affected. In comparison with non-metastatic adult tGrCT, men with metastatic adult tGrCT had significantly larger primary tumors (70 vs 24 mm, p 0.001), and were more likely to present with angiolymphatic invasion (57% vs 4%, p 0.002) or gynecomastia (29% vs 3%, p 0.019). In five out of seven men with metastatic disease, resection of metastases or platinum-based chemotherapy led to complete remission.

CONCLUSION

Juvenile tGrCT represent a benign entity whereas adult tGCTs have metastatic potential. Tumor size, presence of angiolymphatic invasion or gynecomastia represent risk factors for metastatic disease. The published literature supports the use of testis sparing surgery but there is only limited experience with adjuvant therapies. In the metastatic setting, the reviewed literature suggests that aggressive surgical and systemic treatment might cure patients.

SALL4 is a useful marker for pediatric yolk sac tumors

BACKGROUND

SALL4 is a zinc finger transcription factor that exerts its physiological role during embryo-fetal development. Analyses of SALL4 expression have shown its oncogenic role in precursor B-cell lymphoblastic lymphoma, acute and chronic myeloid leukemia, gastrointestinal, breast, and lung cancers. The aim of this study was to determine the immunohistochemical profile of SALL4 in pediatric yolk sac tumors (YSTs).

METHODS AND RESULTS

Immunohistochemistry detection of SALL4 was performed in 22 cases of pediatric YSTs and 10 mature teratomas. The percentage of tumor cells stained was scored as 0, 1+ (1-30% cells), 2+ (31-60%), 3+ (61-90%), and 4+ (> 90%). To compare its sensitivity and specificity with Glypican-3 and α-fetoprotein (AFP), we also stained tumors from these cases for Glypican-3 and AFP. In contrast to AFP and glypican-3, SALL4 staining in more than 90% of the tumor cells was seen in all 22 pediatric YSTs (100% sensitivity) (P < 0.001 for both SALL4 vs. AFP and SALL4 vs. glypican-3).

CONCLUSIONS

SALL4 is a sensitive marker for pediatric YSTs and it can be used to distinguish them from mature teratomas. SALL4 is likely to become a new and valuable biomarker for the diagnosis of pediatric YST.

[Testicular tumors in prepubertal boys-organ preservation possible more often than expected]

In prepubertal boys, testicular tumors are rare with an incidence between 2 and 5/million. In contrast to testicular tumors in adolescents and adults, more than 2/3 of these tumors are benign. Unfortunately, in Germany in most cases, only malignant tumors (usually yolk sac tumors) are reported to the study center (MAKEI IV and now V). Therefore, the incidence in Germany is unknown. Since the introduction of polychemotherapy in the 1970s, the prognosis of malignant testicular tumors has improved enormously and has become a curable disease, even in the case of recurrence. Today the orchiectomy, which was usually carried out in the past, appears to be no longer justified in most prepubertal boys due to the high incidence of benign tumors. It has been shown in various studies that organ-sparing surgery in germ cell tumors (epidermoid cysts, teratoma); gonadal stoma tumors (Sertoli, Leydig and granulosa cell tumors) and cystic lesions (intratesticular cysts and tubular ectasia of the rete testis) is reliable and safe. In cases with preoperative significantly increased AFP (caution: norm values not valid in the first year of life) and a clear testicular tumor in the ultrasound (yolk sac tumor) or if no testicular parenchyma is sonographically detectable, orchiectomy can still be carried out. Today orchiectomies in prepubertal boys should be an exception and the reasons for an orchiectomy must be well documented.

Therapeutic strategies for uncommon testis cancer histologies: teratoma with malignant transformation and malignant testicular sex cord stromal tumors

Testicular cancer is the most common solid malignancy in male adolescents and young adults, with germ cell derived seminomas and non-seminomas being by far the most common histologies. Teratoma with somatic-type malignancy is a rare chemo-resistant phenotype of testis cancer associated with poor prognosis in patients with advanced stage disease. Malignant gonadal-stromal tumors comprise 5% of testicular neoplasms and approximately 10% are malignant and considered chemo-radiation resistant. Prognostic factors and treatment strategies for these uncommon histologies are lacking.

Testicular-sparing surgery in the pediatric population: multicenter review of practice with review of the literature

PURPOSE OF REVIEW

Pediatric testicular tumors have predominantly favorable histology, which may permit testicular sparing surgery (TSS). Limited guidance exists for TSS in adults and is absent in pediatric practice.The international survey and retrospective case series evaluated the current use of TSS in pediatric testicular tumors. Alongside the complementary literature review, the aim of this work was to provide evidence that could be used to produce a guideline document.

RECENT FINDINGS

Published evidence advocates small mass size as an indicator for TSS, this was not supported in the pediatric literature. Frozen section examination at TSS was not always performed by surgeons and yet the literature reports close to 100% specificity. Tumor markers and ultrasound findings are also used as indicators for TSS, a finding reflected in our survey results.

SUMMARY

Multiple case series are reported but no large data series exists, which will require international collaboration rather than a drive to publish the results of individual centers. Common indicators for TSS use; such as tumor markers and imaging are known but further work needs to evaluate the role of on-table histology and the risks of this not being available.

Juvenile Granulosa Cell Tumor of the Testis: Prenatal Diagnosis and Management

Prepubertal primary testicular tumors account for ∼1% of all pediatric solid tumors. We report a new case of prenatal diagnosis of juvenile-type granulosa cell tumor (JGCT). A fetal ultrasound performed at the 38th week of gestation for suspected nonvertex presentation identified a left multilocular septated cystic testicular mass, suggestive for JGCT. At birth, a painless left scrotal mass was detected. Ultrasound re-evaluation excluded torsion of the testis. Tumor markers and abdominal ultrasound were normal for age. Inguinal exploration revealed a cystic mass beneath the tunica albuginea that had replaced all the normal parenchyma. Since organ-sparing surgery was thus not feasible, an orchiectomy was performed and diagnosis of JGCT was confirmed. At 7-year follow-up, the child presented an uneventful outcome. Our case shows that neonatal JGCT, which has an intrauterine genesis, can be diagnosed prenatally by ultrasound in the last weeks of pregnancy.

Immunohistochemical Pitfalls in Genitourinary Pathology: 2018 Update

Immunohistochemistry may be a very useful adjunct to morphologic diagnosis in many areas of surgical pathology, including genitourinary pathology. In this review, we address common diagnostic dilemmas where immunophenotypic analysis may be utilized and we highlight pitfalls specific to each scenario. For prostate, we review the diagnosis of limited prostatic adenocarcinoma and the distinction of high-grade prostatic adenocarcinoma from urothelial carcinoma. We also cover markers of urothelial lineage in the diagnosis of metastatic carcinoma of unknown primary site. In the kidney, distinction of poorly differentiated renal cell carcinoma from urothelial carcinoma and epithelioid angiomyolipoma, adjuncts to the recognition of hereditary renal neoplasia, and the diagnosis of metastatic renal cell carcinoma are discussed. Finally, for testis we address distinction of germ cell tumors from sex cord-stromal tumors, as well as the diagnosis of metastatic germ cell tumors.

A rare case report of ovarian juvenile granulosa cell tumor with massive ascites as the first sign, and review of literature: Case report and review of literature

RATIONALE

Massive ascites as the first sign of ovarian juvenile granulosa cell tumor (JGCT) in an adolescent is an extremely rare, and its clinical features and treatment methods have not been well described.

PATIENT CONCERNS

The clinical characteristics, diagnosis, and treatment methods in a 19-year-old girl who presented with massive abdominal distention and ascites was retrospectively reviewed. Abdominopelvic ultrasonography showed a large amount of ascites. The nature of ascites was exudate. All tumor markers were normal, but ascites and serum tumor CA125 levels were significantly increased. Abdominal CT showed left attachment area teratoma and right attachment area capsule solid change.

DIAGNOSES

Histological and immunohistochemical results were compatible with JGCT. Based on the FIGO classification, the patient with only malignant ascites was categorized into stage IC.

INTERVENTIONS

The patient underwent mass resection with salpingoophorectomy. Following the operation, she received 6 courses of adjuvant chemotherapy with Nedaplatin and Paclitaxel liposome.

OUTCOMES

The patient was followed up postoperatively for 6 months to date without recurrence.

LESSONS

We should be highly vigilant the JGCT with massive ascites as the first clinical manifestation.

Juvenile Granulosa Cell Tumor of the Testicle - Report of a Neonatal Case with Positive Alpha-fetoprotein Immunohistochemical Staining

We report on a case of juvenile granulosa cell tumor of the testicle in a neonate, a rare testicular tumor in children. No genital ambiguity, anatomic abnormalities, nor sex chromosome aneuploidy was noted in this patient. In our case, despite positive staining for alpha-fetoprotein which is most consistent with yolk sac tumors, all clinical, gross anatomic, histologic, and other immunohistologic characteristics of the tumor remained consistent with the diagnosis of juvenile granulosa cell tumor. The alpha-fetoprotein positivity of the tumor remains unexplained.

The World Health Organization 2016 classification of testicular non-germ cell tumours: a review and update from the International Society of Urological Pathology Testis Consultation Panel

The World Health Organization (WHO) released a new tumour classification for the genitourinary system in early 2016 after consensus by pathologists with expertise in these organs. It utilized the framework of the 2004 classification, and incorporated the most up-to-date information concerning these tumours. In testicular tumours, the majority of the changes occurred in the nomenclature and classification of germ cell tumours; however, several modifications were also made for non-germ cell tumours. Among sex cord-stromal tumours, sclerosing Sertoli cell tumour (SCT) is no longer recognized as a separate entity but as a morphological variant of SCT not otherwise specified (NOS), as CTNNB1 gene mutations have been noted in both neoplasms but not in the other forms of SCT. Similarly, the lipid cell variant is not separately classified, but is considered to be a morphological variant of SCT NOS. Large-cell calcifying SCT is recognized as a distinct entity that occurs either sporadically or in association with Carney complex, with the latter patients having a distinct germline PRKAR1A gene mutation. Intratubular large-cell hyalinizing Sertoli cell neoplasia is also accepted as a separate entity linked with Peutz-Jeghers syndrome. The subcategories of 'mixed' and 'incompletely differentiated' forms of sex cord/gonadal stromal tumours have been replaced by 'mixed and unclassified sex cord-stromal tumours'. New entities introduced in the latest WHO revision include: myoid gonadal stromal tumour and 'undifferentiated gonadal tissue', a putative precursor lesion of gonadoblastoma, whereas juvenile xanthogranuloma and haemangioma are included in the miscellaneous category of tumours.

RNA-binding protein LIN28 is a sensitive marker of pediatric yolk sac tumors

BACKGROUND

RNA-binding protein LIN28 is involved in maintaining the pluripotency of embryonic stem cells. It has been detected in different types of testicular and ovarian germ cell tumors (GCTs), but its status in pediatric YSTs (yolk sac tumors) is still unknown. The aim of this study was to determine the immunohistochemical profile of LIN28 in pediatric YSTs.

METHODS AND RESULTS

Immunohistochemistry detection of LIN28 was performed in 22 cases of pediatric YSTs and 10 mature teratomas. The percentage of tumor cells stained was scored as 0, 1+ (1-30 % cells), 2+ (31-60 %), 3+ (61-90 %), and 4+ (>90 %). To compare its sensitive and specificity with alpha-fetoprotein (AFP), we also stained AFP in 22 cases of pediatric YSTs and 10 mature teratomas in children. LIN28 staining was high in all 22 pediatric yolk sac tumor (2+ in 1, 3+ in 1, and 4+ in 20), and weak staining of LIN28 was seen in 1 of 10 mature teratomas (1+), 9 of 10 mature teratomas were negative expression. However, the expression of AFP in pediatric YST was lower compared with Lin28 (- in 1, 1+ in 8, 2+ in 12, and 3+ in 1), and weak expression of AFP was seen in 2 of 10 mature teratomas (1+), 8 of 10 mature teratomas were negative. LIN28 had higher intensity expression than AFP in pediatric YSTs (P < 0.001).

CONCLUSIONS

LIN28 is a sensitive marker for pediatric YSTs and it can be used to distinguish them from mature teratomas. LIN28 is likely to become a new and valuable biomarker for diagnosing of pediatric YST.