Testicular and paratesticular tumors and tumor-like lesions in the first 2 decades

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.

Melanotic Neuroectodermal Tumor of Infancy (MNTI) and Pineal Anlage Tumor (PAT) Harbor A Medulloblastoma Signature by DNA Methylation Profiling

Simple Summary

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor of uncertain origin, morphologically overlapping other rare neoplasms such as pineal anlage tumor (PAT) and a subset of medulloblastomas (i.e., melanotic medulloblastoma). Despite the similarities with MNTI, their possible histogenetic relationship has been traditionally disregarded based on their aggressive behavior and dismal prognosis. The aim of this study was to further characterize the molecular features of MNTI and PAT based on DNA-methylation and copy number variation profiling analysis. We found that MNTI shares a methylation profile with group 3 high-risk medulloblastoma, and potentially with PAT, suggesting a common histogenesis. Most MNTIs in our series lacked copy number variation alterations, whereas their presence in the one PAT deserves further study in larger cohorts to better determine their impact in prognosis and biologic behavior.

Abstract

MNTI is a rare tumor of indeterminate histogenesis and molecular signature. We performed methylation and copy number variation (CNV) profiles in patients with MNTI (n = 7) and PAT (n = 1) compared to the methylation brain tumor classifier v11b4 (BT-C) and the medulloblastoma (MB) classifier group 3/4 v1.0 (MB3/4-C). The patients’ mean age was 8 months (range: 4–48). The BT-C classified five MNTIs and one PAT (relapse) as class family MB-G3/G4, subclass group 3 (score: >0.9). The remaining two MNTIs and PAT (primary) were classified as class family plexus tumor, subclass pediatric (scores: >0.45). The MB3/4-C classified all MNTIs as high-risk MB-G3, Subtype II (score: >0.45). The primary PAT was classified as subtype III (score: 0.99) and its relapse as subtype II/III. MNTI and PAT clustered close to MB-G3. CNV analysis showed multiple rearrangements in one PAT and two MNTIs. The median follow-up was 54 months (four MNTIs in remission, one PAT died). In conclusion, we demonstrated that MNTI shares a homogenous methylation profile with MB-G3, and possibly with PAT. The role of a multipotent progenitor cell (i.e., early cranial neural crest cell) in their histogenesis and the influence of the anatomical site, tumor microenvironment, and other cytogenetic events in their divergent biologic behavior deserve further investigation.

Hepatoid Teratoma, Hepatoid Yolk Sac Tumor, and Hepatocellular Carcinoma: A Morphologic and Immunohistochemical Study of 30 Cases

Rare hepatoid teratomas (HTs) in testicular germ cell tumor patients mimic hepatoid yolk sac tumor (HYST) and hepatocellular carcinoma (HCC). We compared the features of 2 metastatic HTs, 12 HYSTs, and 16 HCCs. The mean ages were 36, 40, and 62.5 years, respectively. The HTs formed sheets of hepatocyte-like cells with macrovesicular fat arranged in vague lobules with intervening fibrous bands containing biliary ductule-like structures and abortive portal triads. HTs lacked basement membrane deposits, with hepatoid cells staining for glypican-3, arginase, and HepPar-1 (2/2), whereas stains for CK19 (2/2) and CK7 (1/2) highlighted ductules and for villin hepatoid cells and ductules (1/2). SALL4 and CDX2 stains were negative (0/2). HYSTs formed nests, trabeculae, cords, and occasional gland-like structures, and most (10/12; 83%) produced intercellular basement membrane. No Mallory-Denk bodies were seen. Stains for SALL4 (100%), glypican-3 (100%), CK19 (88%), CDX2 (88%), and villin (75%) were positive, whereas those for HepPar-1 highlighted rare tumor cells (70%) and for arginase were mostly negative (26%). All HCCs lacked basement membrane deposits, with Mallory-Denk bodies occurring in 50%. Stains for HepPar-1 (100%) and arginase (94%) were positive, glypican-3 infrequent (19%), and SALL4, CK19, villin, and CDX2 negative. In summary, HTs are distinguished from HYST by the formation of ductules and abortive portal tracts, lack of basement membrane deposits, more consistent staining for arginase and HepPar-1, and negativity for SALL4 and CDX2. Contrasting features of HCCs with HYSTs include negativity for SALL4, CK19, and CDX2, frequent Mallory-Denk bodies, and absence of basement membrane deposits.

Mixed germ cell-sex cord stromal tumour of the testis and ovary: comparison and contrast

Mixed germ cell-sex cord stromal tumours (MGC-SCSTs) of the testis and ovary differ significantly in their histological appearance, clinical behaviour, and molecular genetics. Until recently, the germ cells of testicular MGC-SCST were considered to be invariably histologically bland, whereas those from neoplasms that arise in the ovary have histological features characteristic of premalignancy. However, a recent histological and molecular genetic study demonstrated histological abnormalities and multiple chromosomal losses and gains in a small subset of testicular cases, thus providing the first evidence that testicular MGC-SCSTs can exceptionally show histological and molecular abnormalities. All cases of testicular MGC-SCST reported to date have been clinically benign, whereas ovarian examples are sometimes the precursor of a malignant germ cell neoplasm that can be clinically aggressive. Both genetic and epigenetic influences likely account for dissimilarities in these uncommon gonadal neoplasms.

[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.

Rare benign and malignant testicular lesions: histopathology and management

PURPOSE OF REVIEW

The presence of vascular solid tumors within the testicle is considered to be malignant until proven otherwise. However, it is prudent for clinicians to be aware of rare benign and malignant intratesticular lesions as management can differ from the established treatment algorithms for germ-cell tumors.

RECENT FINDINGS

Utilizing certain histopathologic findings can assist with the diagnosis of rare testis tumors. Often times the tumor subtypes are an important consideration in the grading and classification of the disease, which drives management. The multidisciplinary management of rare malignant testis tumors at an experienced center seems to provide optimal patient outcomes. Regardless of the primary treatment, prolonged follow-up for sex cord stromal tumors and other rare testis malignancies is advocated due to the delayed metastatic potential.

SUMMARY

The clinical presentation of rare benign and malignant testis tumors is often similar to that of germ-cell tumors. Likewise, imaging characteristics are also often indistinguishable. However, the management of these rare tumors is often different from the well established treatment algorithms of germ-cell tumors. To that end, it is important for the practicing urologist to be familiar with the current principles of these tumor characteristics and the management.

Appendageal tumors and tumor-like lesions of the testis and paratestis: a 32-year experience at a single institution

The testicular hilum and paratestis contain several embryologically diverse anatomic structures, including the spermatic cord, tunica vaginalis, epididymis, rete testis, and several other embryonic remnants. Several benign and malignant lesions arise from these morphologically distinct structures, and owing to their proximity, it is challenging to classify and subsequently stage these tumors. Herein, we conducted a retrospective review of the paratesticular appendageal and rete testis tumors and tumor-like lesions diagnosed at our department from 1985 to 2016. Soft-tissue lesions/tumors were excluded. A total of 146 paratesticular appendageal and rete testis tumors and tumor-like lesions were identified. Most were benign (n = 107; 73%). Adenomatoid tumor (26%) was the most common benign tumor, followed by different types of cysts (19%), mesothelial hyperplasia (18%), serous cystadenoma (5.5%), and rete testis adenoma (4%). Malignant lesions comprised 23% of the cases, with mesothelioma the most common (15%), followed by adenocarcinoma of the rete testis (4%), serous cystadenocarcinoma (2%), and papillary and clear cell adenocarcinoma of the epididymis (2%). Finally, serous borderline tumors and melanotic neuroectodermal tumor (retinal anlage tumors) comprised the remaining 4% of cases. In conclusion, a wide range of benign and malignant lesions can arise from the paratesticular region. Awareness of these lesions and their histologic spectrum is crucial to avoid diagnostic pitfalls and to allow pathologists to establish a correct diagnosis and subsequent treatment plan.

A Contemporary Review of Common Adult Non-germ Cell Tumors of the Testis and Paratestis

This article provides a comprehensive review of non-germ cell tumors of the testis and paratestis in adults, incorporating the latest 2016 World Health Organization updates. Clinical features, gross pathologic findings, key morphologic details, immunohistochemical profiles, and differential diagnoses are covered, with an emphasis on how to resolve commonly encountered, and sometimes difficult, differential diagnoses.

Paratesticular Soft-Tissue Masses in Orchiectomy Specimens: A 17-Year Survey of Primary and Incidental Cases From One Institution

The paratestis (PT) is defined by the testicular tunics, epididymis, spermatic cord, rete testis, and embryonic remnants. It gives rise to a large diversity of pathologies, including those of soft tissue, which may prompt orchiectomy. We performed a 17-year search of our database for orchiectomies for a PT soft-tissue mass. In a total of 4741 orchiectomy specimens, 138 orchiectomies were performed for primary neoplastic or nonneoplastic masses of the PT soft tissue or had an incidental PT soft-tissue mass. Of these, 65.9% were neoplastic. The mean age was 40.2 years (range: <1 to 87 years) and was similar for neoplastic and nonneoplastic lesions. The most common malignancies were rhabdomyosarcoma (31/63 malignancies), liposarcoma (19/63), and leiomyosarcoma (5/63), with the former occurring in younger patients (average: 18.3 years). No malignancies were incidental. The most common benign neoplasm was spermatic cord lipoma (24/28 of benign neoplasms); however, most were incidental. This was followed by leiomyoma (3/28) and hemangioma (1/28). The most common nonneoplastic lesions were adrenal rests (22/47 nonneoplastic cases); however, all were incidental findings. Of 47 nonneoplastic masses, 22 prompted orchiectomy, and of these, the most common diagnosis was fibrous/nodular periorchitis (11/47). Of 88 nonincidental lesions, 25 were either benign neoplasms (3/25) or nonneoplastic (22/25). These data indicate that PT soft-tissue neoplasms prompting orchiectomy are disproportionately rhabdomyosarcomas, though these are principally in young patients. In older patients, malignancies are more frequently liposarcomas. However, almost one-third of orchiectomies performed for PT soft-tissue masses yield benign lesions, indicating an opportunity to reduce unnecessary procedures.

Large Cell Calcifying Sertoli Cell Tumour of Testis-A Rare Case Report

Sertoli cell tumours of testes are classified into sertoli cell tumour NOS (not otherwise specified), sclerosing variant and large cell calcifying variant. So far, 90 cases of the large cell calcifying variant have been reported in literature. We describe a rare case of inhibin negative locally invasive large cell calcifying sertoli cell tumour of testis. A 62-year-old man presented with complaints of pain and swelling in right scrotum for 8 months. Ultrasound revealed a right testicular mass with internal vascularity and calcification. Gross examination of right inguinal orchiectomy specimen showed firm to hard mass with yellow areas and calcification seen on cut section. Microscopy revealed a tumour in the testis infiltrating the epididymis and rete testis and reaching up to the skin. Tumour cells were arranged in the form of solid nests, tubules and cords with neutrophilic stromal infiltrate and calcification. Tumour cells had abundant clear to eosinophilic cytoplasm, round nucleus with vesicular chromatin and conspicuous nucleoli. On immunohistochemistry, tumour cells were positive for pan cytokeratin, Epithelial Membrane Antigen (EMA), S-100 protein, desmin, vimentin, neuron specific enolase, and chromogranin. However, it was negative for inhibin alpha, OCT4, CD10, CD99, Melan A. Inhibin negative large cell calcifying sertoli cell tumour is a rare entity.

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

Since the last World Health Organization (WHO) classification scheme for tumours of the urinary tract and male genital organs, there have been a number of advances in the understanding, classification, immunohistochemistry and genetics of testicular germ cell tumours. The updated 2016 draft classification was discussed at an International Society of Urological Pathology Consultation on Testicular and Penile Cancer. This review addresses the main updates to germ cell tumour classification. Major changes include a pathogenetically derived classification using germ cell neoplasia in situ (GCNIS) as a new name for the precursor lesion, and the distinction of prepubertal tumours (non-GCNIS-derived) from postpubertal-type tumours (GCNIS-derived), acknowledging the existence of rare benign prepubertal-type teratomas in the postpubertal testis. Spermatocytic tumour is adopted as a replacement for spermatocytic seminoma, to avoid potential confusion with the unrelated usual seminoma. The spectrum of trophoblastic tumours arising in the setting of testicular germ cell tumour continues to expand, to include epithelioid and placental site trophoblastic tumours analogous to those of the gynaecological tract. Currently, reporting of anaplasia (seminoma or spermatocytic tumour) or immaturity (teratoma) is not required, as these do not have demonstrable prognostic importance. In contrast, overgrowth of a teratomatous component (somatic-type malignancy) and sarcomatous change in spermatocytic tumour indicate more aggressive behaviour, and should be reported.

Testicular germ cell tumors (TGCTs) in neonates and infants

Dr. Louis Dehner has contributed significantly to our understanding of testicular germ cell tumors in children. This review article considers the molecular biology, clinical attributes, pathologic findings, and prognosis of those lesions.

Benign scrotal masses in children - some new lessons learned

INTRODUCTION

A preponderance of benign intratesticular masses in pre-pubertal males encourages testicular-sparing surgery (TSS).

OBJECTIVE

To review outcome of benign testicular lumps in children managed at a tertiary pediatric center more than 7.5years.

METHODS

A retrospective review of pediatric benign testicular lesions from January 2008 to June 2015 was performed.

RESULTS

There were twelve benign intratesticular tumors. Of these, 11 were in pre-pubertal males; comprising four teratomas, two epidermoid cysts, one dermoid cyst, two cases of Leydig cell hyperplasia, one cystic dysplasia of the rete testis and one large simple intratesticular cyst. We illustrate a case of Leydig cell hyperplasia presenting with precocious puberty limited to the ipsilateral hemi-scrotum. TSS was attempted in all 11 pre-pubertal cases, but successfully performed in seven. TSS was possible for a large testicular cyst seemingly replacing the entire testis, with evidence that the testis reconstituted itself after surgery. Recurrence of an epidermoid cysts reported.

CONCLUSION

For the first time in the literature, this series reports Leydig cell hyperplasia presenting with ipsilateral hemi-scrotal changes of precocious puberty; shows evidence that the testis reconstitutes itself after TSS for a large cyst; and reports recurrence of an epidermoid cyst after TSS.

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.