Testicular sex cord-stromal tumors in children: clinicopathologic study of sixteen children with review of the literature

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.

Large Cell Calcifying Sertoli Cell Tumor: A Clinicopathologic Study of 18 Cases With Comprehensive Review of the Literature and Reappraisal of Prognostic Features

We present a series of 18 (8 clinically benign, 8 clinically ambiguous [ie, lacking sufficient follow-up to determine behavior], and 2 clinically malignant) large cell calcifying Sertoli cell tumors (LCCSCT) of the testis. The median patient age and size were 15.5 years and 1.9 cm for the benign tumors; 19 years and 1.6 cm for the ambiguous tumors; and 28.5 years and 2.3 cm for the malignant tumors. The most common presentation was a mass (n=12/18, 67%). Two patients (11%) had the Carney complex, and 2 had neurofibromatosis type 1. All tumors showed nodular growth with frequent lymphoid aggregates at the periphery. Within the nodules, there were nests and trabeculae of pale to eosinophilic epithelioid tumor cells with frequent cytoplasmic vacuolization interspersed with hypocellular, often myxoid stroma with conspicuous neutrophils. Spindled tumor cells were a minor component (<5%) in the clinically benign, ambiguous, and malignant tumors, except in 1 malignant tumor where they comprised 50% to 60% of the cellularity. Calcifications were noted in all but 2 benign tumors that were otherwise of typical appearance. Six tumors (3 in the clinically benign, 1 in the clinically ambiguous, and 2 in the malignant groups) were considered potentially malignant based on the presence of ≥1 adverse pathologic features previously recognized (see reference 1)-that is, size>4 cm, extratesticular growth, necrosis, significant atypia, vascular invasion, and >3 mitotic figures/10 HPFs. Of these, 3 tumors had ≥2 adverse features. One in a 7-year-old was clinically benign despite 5 "malignant" features; the remaining 2 in 27- and 30-year-olds, were clinically malignant, with both fulfilling previously suggested criteria for pathologically malignant tumors (age above 25 y and ≥2 adverse pathologic features). No clinically benign or ambiguous tumor met those same criteria. Of the adverse features, each of the 2 clinically malignant tumors showed tumor necrosis and lymphovascular invasion. All patients, except 1 with a clinically malignant tumor, were alive at a median follow-up of 33 months. In addition, in our literature review of 97 additional LCCSCTs, we identified 2 clinically malignant tumors in 42- and 45-year-old men that lacked any documented adverse pathologic criterion and 2 clinically malignant cases in patients with either the Carney complex or Peutz-Jeghers syndrome. In summary, our study and literature review support that all LCCSCTs in patients above 25 years old should be considered potentially malignant, and those in this age group with ≥2 adverse pathologic features warrant aggressive clinical management; furthermore, syndrome-associated cases are not uniformly benign. Tumor necrosis and lymphovascular invasion likely should receive greater adverse prognostic weight. LCCSCTs in young children may show benign outcomes despite several adverse pathologic features.

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.

Perspectives in Pediatric Pathology, Chapter 25. Testicular and Paratesticular Tumors in the Pediatric Age Group

Testicular tumors in the prepubertal age are relatively rare, representing only 9.4% of the total testicular and paratesticular specimens from a 20-year review performed at a large pediatric hospital [ 1 ]. They account for 1% to 2% of all solid tumors in the pediatric age group, with an annual incidence between 0.5/100 000 and 2/100 000 boys according to Coppes et al [ 2 ] and data from the Prepubertal Testicular Tumor Registry [ 3 ]. Similar to other neoplasms afflicting children, a bimodal age distribution is observed. The first peak is between birth and 3 years of age, and a second one occurs at the onset of puberty, extending to the fourth decade. Reports on their frequency vary because some investigators include the adolescent period, while others do not [ 4 ]. The vast majority of testicular tumors are germ cell neoplasms, accounting for 95% across all ages [ 5 ]. In children, germ cell tumors also predominate, representing 71% of all testicular neoplasms. These include yolk sac tumors (49%), teratomas (13%), seminomas and mixed germ cell tumors (9%), and sex-cord stromal tumors (29%). Malignant potential is significantly lower (less than 70%) in the pediatric age group compared to adults (90%) [ 6 ]. According to Pohl et al, 74% of prepubertal testicular tumors are benign [ 7 ].

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.

Overview of pediatric testicular tumors in Korea

Prepubertal testicular tumors are rare compared with postpubertal testicular tumors. The incidence of prepubertal testicular tumors peaks at 2 years of age, tapers off after 4 years of age, and then begins to rise again at puberty. Prepubertal and postpubertal testicular tumors show many differences, including the typical tumor histology, molecular biological differences, and the malignant potential of tumors at different ages. Pediatric testicular tumors are classified as benign or malignant on the basis of their clinical behavior and histologically are divided into germ cell and gonadal stromal (nongerm cell) tumors. Many histological and biological studies have further confirmed the distinct nature of prepubertal and postpubertal testicular tumors. These differences have led to various management strategies for prepubertal and postpubertal tumors. Because overall about 75% of prepubertal testicular tumors are benign, a testis-sparing approach is becoming more common in children. Orchiectomy and observation with very selective use of chemotherapy has become the standard approach when a malignant tumor is identified. Retroperitoneal lymph node dissection and radiation therapy play very limited roles.

Congenital intra-abdominal bilateral juvenile granulosa cell tumors of the testis associated with constitutional loss of material from chromosome 4

Juvenile granulosa cell tumor (JGCT) is an uncommon gonadal stromal tumor that occurs rarely in the testis. We report a newborn boy with bilateral intra-abdominal JGCT presenting with abdominal distention and respiratory distress at birth. He was taken to the operating room emergently, and 2 large masses connected by gubernacula to the inguinal canals were resected. Associated abnormalities included a constitutional chromosome 4 abnormality, polymicrogyria, and renal cysts. This report describes a rare presentation of JGCT with abdominal compression and expands the literature to include bilateral testicular involvement. Additionally, it is the 1st report of JGCT associated with a chromosome 4 abnormality, highlighting a genetic region that may be important in JGCT development.

Testicular Tumors—Some New and a Few Perennial Problems

The histopathology of testicular tumors is presented, emphasizing new, unusual, or underemphasized aspects. Within the category of seminoma of the usual type, the recent literature has drawn attention to the presence in occasional tumors of solid or hollow tubules or spaces of varying sizes and shape that may result in cribriform or microcystic patterns, causing potential confusion with other neoplasms, most notably Sertoli cell tumor or yolk sac tumor. Although regions of typical neoplasia and awareness of this phenomenon usually will be diagnostic, immunohistochemistry may play a role in excluding Sertoli cell tumor or yolk sac tumor. Although immunohistochemistry can play an undoubted helpful role in this and selected other areas of testicular tumor evaluation, careful evaluation of the gross and routine microscopic features will solve the vast majority of diagnostic problems. An excellent review of immunohistochemistry in this area by R. E. Emerson, MD, and T. M. Ulbright, MD, is cited herein. Spermatocytic seminoma remains a crucial pitfall in diagnosis, and the pathologist must always be alert to the possible diagnosis when looking at a seminomatous neoplasm, particularly in an older patient, although about one third of these tumors occur in the usual seminoma age range. The embryonal carcinoma has a great diversity of patterns, which are briefly noted. The enigmatic and picturesque tumor, polyembryoma, which virtually never occurs in pure form but may be a confusing component of a variety of mixed germ cell tumors, is discussed and illustrated. The phenomenon of burnt-out germ cell neoplasia is also briefly noted and an excellent recent contribution is referred to. Within the sex cord–stromal family of neoplasms, recent contributions and elaborations of unusual morphologic features of Leydig cell tumors and Sertoli cell tumors are presented. Within the Leydig cell family, cyst formation, adipose metaplasia, calcification or ossification, and spindle cell patterns may be particularly confusing, and in the Sertoli cell family, a great array of patterns caused by differing admixtures of tubular, solid, and stromal components occur. The peculiar lesion, intratubular large cell hyalinizing Sertoli cell tumor, of young boys with Peutz-Jeghers syndrome, is briefly discussed. Some of the problems in the family of hematopoietic neoplasms are reviewed, these processes posing diverse problems in differential diagnosis and their correct recognition having crucial therapeutic implications. Although secondary tumors to the testis have not received the same attention in the literature as the similar phenomenon in the female gonad, remarkable examples of testicular spread of diverse neoplasms, usually carcinoma but rarely melanoma, are seen, and the pathologist should be alert to this possibility, particularly when examining an unusual morphology in an older patient. Finally, a few comments are made on the common paratesticular neoplasm, the adenomatoid tumor, highlighting its varied patterns and recent description of some of the issues that may arise when they undergo total or subtotal infarction.

Morphological approach to tumours of the testis and paratestis

Most neoplastic scrotal masses ultimately prove to be germ cell tumours and are recognisable with routine haematoxylin and eosin-stained sections. The differential diagnosis may be focused, even before reviewing histological sections, by knowledge of patient age, medical history, tumour site (testicular vs paratesticular) and gross findings. Some cases may prove to be diagnostically challenging, including rare tumours, a common tumour with an unusual pattern, a metastatic tumour, or a neoplasm with features that mimic another tumour. Several morphological patterns are seen with some frequency and these generate recurring sets of differential diagnostic considerations. These common patterns include testicular tumours with a predominant diffuse arrangement of cells with pale to clear cytoplasm, tumours with a glandular/tubular pattern, tumours with a microcystic pattern and tumours composed of oxyphilic cells. Intratubular proliferations of atypical cells, paratesticular glandular and/or papillary tumours, or tumours with spindle cell morphology can also be challenging to diagnose correctly. In some problematic cases, immunohistochemical staining may be useful to resolve these differential diagnoses.

A case of large cell calcifying Sertoli cell tumor in a child with a history of nasal myxoid tumor in infancy

A case of an 8-year-old Japanese boy with a testicular large cell calcifying Sertoli cell tumor (LCCSCT) is presented. This report appears to be the first Japanese case of LCCSCT. The patient presented with left testicular swelling and gynecomastia. His family history was not contributory; however, his past history was remarkable for a benign myxoid tumor in the nasal cavity, which was removed at the age of 2 months. After removal of the testicular tumor, the gynecomastia disappeared gradually and no recurrence or metastasis developed during a 15 month follow-up period. Although the tumor was initially interpreted as a Leydig cell tumor, a review of the slides after the patient's past history of nasal myxoid tumor was revealed led us to the diagnosis of LCCSCT. An accurate diagnosis of LCCSCT is crucial because this tumor is occasionally associated with Carney complex, which can comprise various pathological conditions, including cardiac myxoma, that may be life-threatening. Myxoma of Carney complex has been described to occur in the heart, skin, oral cavity and breast in a wide age range, but there have been no reports referring to nasal myxoid tumor associated with Carney complex.