Yolk Sac Tumor of the Testis in Infants and Children: A Clinicopathologic Analysis of 33 Cases

Embryoid Bodies and Related Proliferations in Ovarian Germ Cell Tumors

We investigated the frequency and associated pathology of embryoid bodies in ovarian tumors by evaluating neoplasms in which they are known to occur: 100 immature teratomas, 125 malignant mixed germ cell tumors, and 6 polyembryomas. Three immature teratomas contained a single relatively well-formed embryoid body, whereas these and 11 others showed foci we categorized as embryoid body remnants consisting of microscopic aggregates of embryonal or yolk sac-type epithelium associated with spaces consistent with yolk sac or amniotic cavity but lacking a classic embryoid body structure. Teratomas with these foci were all high grade. A well-formed embryoid body was found in only 1 malignant mixed tumor, but embryoid body remnants were present in 25%, invariably associated with foci of immature teratoma (100%) and often with yolk sac tumor (97%), embryonal carcinoma (35%), or both (32%). These foci usually took the form of round to oval aggregates, often well-circumscribed, for which the term "polyembryoma background" has been proposed. The polyembryomas were typically grossly hemorrhagic and occurred in patients from 9 to 43 years of age. The embryoid bodies in them generally grew in lobules within an edematous to occasionally myxoid stroma. Four tumors contained liver-like cells, 4 numerous glands likely recapitulating the allantois, 3 syncytiotrophoblast cells, 2 prominent cysts, and 2 striking vascular proliferations. This study indicates that (1) typical embryoid bodies are rare in immature teratomas but about 14% of them have embryoid body remnants. (2) Embryoid body remnants are seen in 25% of malignant mixed germ cell tumors with a teratomatous component and often proliferate to form yolk sac tumor and embryonal carcinoma. (3) Well-formed embryoid bodies growing in a confluent manner (polyembryoma) are rare, and minor foci of teratoma, yolk sac tumor, or embryonal carcinoma are almost always present, indicating that these are fundamentally malignant mixed germ cell tumors but the polyembryoma component is dominant and distinctive which, in our opinion, justifies its own nomenclature. (4) Embryoid bodies are not a feature of other germ cell tumors.

Growing teratoma syndrome in children and adolescents: Prevalence and surgical outcome

INTRODUCTION

Patients affected by metastatic germ cell tumors may occasionally experience enlargement of masses with concurrent normalization of tumor markers during or after chemotherapy. This phenomenon is described as growing teratoma syndrome (GTS). The aim of the pre sent study is to assess the prevalence of GTS in the pediatric population and its implications in terms of surgical outcome.

PATIENTS AND METHODS

The clinical notes of patients diagnosed with stage III and IV malignant germ cell tumors from January 2010 until December 2020 at our Institution were retrospectively reviewed. The prevalence of GTS, treatment strategies, survival, and outcome were analyzed.

RESULTS

Thirty-three patients with high-stage malignant germ cell tumors were diagnosed in our institution in the analyzed period. Nine patients (28%) had radiologic evidence of enlargement of persistent masses with normal markers after chemotherapy; these patients were classified as GTS patients. All nine patients underwent resection of metastatic lymph nodes, and six had surgery on visceral metastases. In six patients, radical excision of all metastatic sites was achieved; five patients are alive and in complete remission, while one died because of peri-operative complications. Out of the three patients who could not achieve radical excision of the metastases, two died of progressive disease, and one is alive with progressive disease.

CONCLUSIONS

Patients affected by GTS have a risk of progression of chemotherapy-resistant disease and death. Radical surgical excision is essential to achieve disease control and long-term survival.

Pathogenesis and pathobiology of testicular germ cell tumours: a view from a developmental biological perspective with guidelines for pathological diagnostics

Testicular germ cell tumours (GCT) are divided into three different subtypes (types I-III) regarding to their developmental origin, histological differences and molecular features. Type I GCT develop from disturbed primordial germ cells and most commonly occur in children and young adolescents, which is why they are referred to as prepubertal GCT. Type II GCT develop from a non-invasive germ cell neoplasia in situ (GCNIS) and show an isochromosome 12p (i12p) or gain of 12p material as a common and characteristic molecular alteration. Type III GCT originate from distorted postpubertal germ cells (e.g. spermatogonia) in adult patients and have changes on chromosome 9 with amplification of the DMRT1 gene. Type I GCT encompass prepubertal-type teratomas and yolk-sac tumours (YST). Type II GCT include seminoma, embryonal carcinoma, choriocarcinoma, postpubertal-type teratoma and postpubertal-type YST. Types I and II GCT both show similar morphology, but are separated from each other by the detection of a GCNIS and an i12p in type II GCT. For type II GCT it is especially important to detect non-seminomatous elements, as these tumours have a worse biological behaviour and need a different treatment to seminomas. In contrast to types I and II GCT, type III tumours are equivalent to spermatocytic tumours and usually occur in elderly men, with few exceptions in young adults. The development of types I and II GCT seems to depend not upon driver mutations, but rather on changes in the epigenetic landscape. Furthermore, different pluripotency associated factors (e.g. OCT3/4, SOX2, SOX17) play a crucial role in GCT development and can be used as immunohistochemical markers allowing to distinguish the different subtypes from each other in morphologically challenging tissue specimens. Especially in metastatic sites, a morphological and immunohistochemical diagnostic algorithm is important to detect small subpopulations of each non-seminomatous GCT subtype, which are associated with a poorer prognosis and need a different treatment. Furthermore, primary extragonadal GCT of the retroperitoneum or mediastinum develop from misguided germ cells during embryonic development, and might be challenging to detect in small tissue biopsies due to their rarity at corresponding sites. This review article summarises the pathobiological and developmental aspects of the three different types of testicular GCT that can be helpful in the histopathological examination of tumour specimens by pathologists.

Clinical characteristics and prognostic models of gonadal and extra-gonadal yolk sac tumors: a population-based analysis in children and adolescents

PURPOSE

Yolk sac tumors (YST) are a rare and aggressive germ cell tumor. We aimed to conduct a population-based cohort study and develop a nomogram to predict overall survival (OS) in pediatric patients with YST.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all pediatric patients with YST diagnosed between 2000 and 2018. The log-rank test was used to compare survival curves. To examine the impact of each factor on overall survival, a multivariate Cox proportional hazards model was created. Based on the results of the Cox regression model, a nomogram was constructed.

RESULTS

A total of 520 YST patients were identified. Overall survival rates for all patients were 92.2% at 3-year and 90.3% at 5-year, respectively. The outcome of Cox proportional hazard regression revealed that age, gender, primary sites, and treatment regimens were important independent predictors in this model. Based on the Cox regression model, we created a nomogram for predicting OS in pediatric YST patients. The chance of death increased with age in patients. Furthermore, patients with extra-gonadal YST have a lower survival rate than those with gonadal YST.

CONCLUSIONS

Our study revealed that age, gender, and primary site were found to be the most important predictors of the overall survival of pediatric YST, providing crucial epidemiological information for clinical management.

Pure post-pubertal yolk sac tumor of the testis: An extremely rare and aggressive entity

CONTEXT

Pure post-pubertal yolk sac tumors (YSTs) are an extremely rare type of malignant germ cell tumor (GCT) that account for <1 % of testicular GCTs. Clinically, they are more aggressive compared to the more common pre-pubertal counterpart. The aim of this study is to analyze the clinical presentation, ancillary tests and clinical outcomes in addition to presenting a spectrum of histomorphological features, in a case series along with a literature review.

DESIGN

A retrospective review of 4 cases of pure post-pubertal YST of the testis was performed. Data collected for each patient included demographics, clinical presentation, serum markers, radiology and pathologic findings, treatment, and clinical outcomes.

RESULTS

All patients presented with a testicular mass with or without associated pain and elevated serum alpha-feto protein. Mean age at presentation was 36 years (range 25-68 years). Two patients presented with metastatic disease at the time of diagnosis. Histologic patterns and features are as follows: germ cell neoplasia in-situ (n = 4), reticular/microcystic, solid, glandular, papillary, endometrioid, cystic, necrosis and angiolymphatic invasion (n = 3). Fluorescent in-situ hybridization test performed on Case 2, showed presence of isochromosome 12p and next generation sequencing showed gains of 12p. Case 1, 2 and 4 showed metastatic disease on follow-up.

CONCLUSIONS

Diagnosis of pure post-pubertal YST remains challenging due to the variety of morphologic patterns often present in these tumors. Extensive sampling along with use of ancillary tests is the key for diagnosis. In this study, 75 % of cases had metastatic disease at or after the diagnosis confirming the aggressive nature of this rare entity.

Pediatric Extracranial Germ Cell Tumors: Review of Clinics and Perspectives in Application of Autologous Stem Cell Transplantation

Pediatric extracranial germ cell tumors (GCTs) are rare, accounting for approximately 3.5% of childhood cancers. Since the introduction of platinum-based chemotherapy, the survival rate of patients has improved to more than 80%. However, poor-risk subtypes of pediatric extracranial GCTs do not respond well to chemotherapy, leading to refractory or relapsed (R/R) diseases. For example, long-term survival rates of mediastinal GCTs or choriocarcinoma are less than 50%. According to reports in recent years for adult patients with R/R GCTs, the use of high-dose chemotherapy (HDCT) combined with autologous stem cell transplantation (ASCT) has clinical advantages; however, HDCT combined with ASCT has rarely been reported in pediatric GCTs. The R/R and poor-risk groups of pediatric GCTs could benefit from HDCT and ASCT.

Develop and validate nomogram to predict cancer-specific survival for patients with testicular yolk sac tumors

Purpose

Testicular yolk sac tumor (TYST) is a rare malignant germ cell tumor that mainly occurs in young men. Due to the low incidence of yolk sac tumors, there is a lack of prospective cohort studies with large samples. We aimed to develop a nomogram to predict cancer-specific survival (CSS) in patients with TYST.

Materials and methods

Patient information was downloaded from the Surveillance, Epidemiology and End Results (SEER) database. We enrolled all patients with TYST from 2000 to 2018, and all patients were randomly divided into a training set and a validation set. Univariate and multivariate Cox proportional hazards regression models were used to identify independent risk factors for patients. We constructed a nomogram based on the multivariate Cox regression model to predict 1-, 3-, and 5-year CSS in patients with TYST. We used a series of validation methods to test the accuracy and reliability of the model, including the concordance index (C-index), calibration curve and the area under the receiver operating characteristic curve (AUC).

Results

619 patients with TYST were enrolled in the study. Univariate and multivariate Cox regression analysis showed that age, T stage, M stage and chemotherapy were independent risk factors for CSS. A nomogram was constructed to predict the patient's CSS. The C-index of the training set and the validation set were 0.901 (95%CI: 0.859-0.847) and 0.855 (95%CI: 0.865-0.845), respectively, indicating that the model had excellent discrimination. The AUC showed the same results. The calibration curve also indicated that the model had good accuracy.

Conclusions

In this study, we constructed the nomogram for the first time to predict the CSS of patients with TYST, which has good accuracy and reliability and can help doctors and patients make clinical decisions.

Yolk Sac Tumor of the Ovary: A Report of 150 Cases and Review of the Literature

One hundred fifty yolk sac tumors (YSTs) of the ovary in patients from 1 to 61 (mean: 21.5) years of age are described; 75% of the patients were in the second and third decades and only 1 was above 50 years of age. The clinical manifestations were typically related to a fast-growing adnexal mass; endocrine manifestations (hirsutism) were present in only 2 cases. The tumors were all unilateral and 70% were ≥15 cm; an associated dermoid cyst was present in 20 cases. The tumors were solid and cystic in 57% of the cases, 25% were multicystic, and 18% uniformly solid. The solid tissue was typically tan to pink or yellow and often friable with hemorrhage and necrosis; smaller solid neoplasms were sometime uniformly yellow. The most common histologic pattern was reticular composed of an irregular meshwork of spaces that was conspicuous in 68% of the neoplasms but present to at least a minor degree in all of them. That appearance almost always merged with small to large cysts that were prominent in about 40% of tumors. In 25% of the tumors, cysts sometimes associated with a cellular stroma (the polyvesicular pattern), were present but conspicuous in only half these cases. One third of the tumors had a labyrinthine pattern, 22% glands, and 6% a festoon pattern. Papillae with a central blood vessel (Schiller-Duval bodies) were seen in one-third of the tumors but were numerous in only 5% of them. Nonspecific appearing papillae were seen in 10% of the tumors. A solid growth of cells with pale cytoplasm was seen in one-third of the tumors but was conspicuous in only half of that subset. The solid appearance was typically reminiscent of that of dysgerminoma, but lacked the septa and lymphocytic infiltrate of that neoplasm. Nine tumors had a component of cells with scant cytoplasm resulting in a blastema-like appearance and 3 had cells with abundant clear cytoplasm. Cords and clusters of cells were common but did not dominate the microscopic appearance. The stroma typically had a nonspecific collagenous to edematous appearance. Stromal luteinization was seen in 12 tumors; in 5 this was likely due to the patient being pregnant. Two tumors had minor foci of cells that resembled hepatocytes. Hyaline bodies were seen in most of the tumors and were often conspicuous. The neoplastic cells typically had modest amounts of lightly staining cytoplasm and only mild nuclear pleomorphism. Cells lining cysts were often flattened sometimes resulting in a deceptively innocuous appearance. Many of the tumors (mostly consultation cases), caused diagnostic difficulty; tumors in the differential diagnosis included clear cell carcinoma, embryonal carcinoma, Sertoli-Leydig cell tumor, and juvenile granulosa cell tumor. The patient age and marked elevation of the serum alpha-fetoprotein level (if measured) is helpful in many of these considerations. The overtly malignant gross appearance of most YSTs contrasts with certain other tumors in the differential and the association of some YSTs with dermoid cyst and many clear cell carcinomas with endometriosis may be helpful. The vast majority of ovarian YSTs are dominated microscopically by merging of reticular and cystic patterns which, although focally mimicked by other neoplasms, are in general characteristic, and distinctive features of other neoplasms are absent. Immunohistochemistry, particularly for alpha-fetoprotein and glypican 3, and lack of staining for various markers of other neoplasms is helpful but overlap exists and these results must be considered in the context of the overall clinical, gross, and microscopic features. YSTs dominated by hepatoid and glandular features are rare and their categorization as YSTs should be done cautiously if thoroughly sampled tumors show no evidence of classic features of YST emphasized herein and first elaborated by the Danish investigator Gunnar Teilum whose seminal observations have stood the test of time.

Ultrasonic misdiagnosis of giant pediatric testicular yolk sac tumor: A case report and literature review

BACKGROUND

Yolk sac tumor is the most common malignant nonseminomatous germ-cell tumor in children characterized by elevated level of α-fetoprotein (AFP), accounting for 70%-80% of all cases. However, giant yolk sac tumors that involve the entire testicle may be misdiagnosed by color Doppler ultrasonography as orchitis. Therefore, we described a case of a 2-year-old pediatric patient with a giant testicular yolk sac tumor that was misdiagnosed by ultrasonography as orchitis, in order to evaluate the role of measuring AFP levels in the initial diagnosis to aid in the accuracy of the definitive diagnosis of testicular yolk sac tumor.

CASE PRESENTATION

A 2-year-old boy received outpatient visits for unintentional swelling of the right scrotum for 7 days. Physical examination showed a rubbery swelling of the right scrotum with rejective touch. Then, the patient underwent perineal color Doppler ultrasonography in outpatient visits. The result showed a right testicle size of 29 mm × 22 mm × 20 mm with heterogeneous echogenicity and abundant blood flow, supporting the initial diagnosis of orchitis. However, the initial surgeon was skeptical of the ultrasonography diagnosis. Thus, the patient was admitted to the Department of Andrology on day 2 for further serological and imaging examination. The serum AFP level on day 3 was 323.77 ng/ml. The results of CT and MRI showed a giant tumor of the right testis (26 mm × 21 mm × 29.6 mm) with multiple lymphoid hyperplasia in the inguinal region bilaterally. The patient received radical orchidectomy without lymph node dissection on day 9. The results of postoperative pathological examination confirmed giant testicular yolk sac tumor (T1N0M0S1, Stage Is) and was positive for AFP and SALL4 in immunohistochemistry staining. The patient received three courses of bleomycin-etoposide-cisplatin chemotherapy in the Department of Pediatrics after multidisciplinary team meeting on postoperative days 14, 37, and 58, respectively. During chemotherapy and follow-up, the patient's AFP and lactate dehydrogenase levels continued to decline, and eventually remained within normal range on postoperative day 84.

CONCLUSION

Measuring the AFP level was necessary for initial diagnosis and follow-up in pediatric cases of testicular enlargement. Radical orchidectomy combined with postoperative bleomycin-etoposide-cisplatin adjuvant chemotherapy was an effective treatment strategy for pediatric giant testicular yolk sac tumors.

Genitourinary Tract Tumors in Children: An Update

BACKGROUND

Genitourinary tract tumors in children are less common than in adults. Most of these tumors have different genetic backgrounds, clinical presentation, and oncologic behavior than their adult counterpart. As a result of low prevalence in children, some of the treatment approaches and recommendations are based on treatment experience in adult patients. However, thanks to scientific and technological development, survival rates have risen considerably.

OBJECTIVE

This paper presents a review of the principal features of the tumors involving the genitourinary tract in children and an update in genetic background, diagnosis, and treatment.

METHODS

A narrative review was performed on published literature about genitourinary tract tumors in pediatric patients. Papers presented in English and Spanish literature were reviewed. PubMed, Science Direct, and SciELO databases were used to collect information and present this article.

RESULTS

Kidney tumors are the most common type of genitourinary tumors in children. Among those, Wilms tumor represents the majority of cases and shows the successful work of clinical trial groups studying this tumor type. Other tumors involving the genitourinary tract in children include Rhabdomyosarcoma, Transitional cell carcinoma, Testicular, and Adrenal tumors.

CONCLUSION

Genitourinary tract tumors in children represent significant morbidity and economic burden, so awareness in early diagnosis represents improvement in treatment, clinical, and oncological outcomes.

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.

Risk-adapted treatment reduced chemotherapy exposure for clinical stage I pediatric testicular cancer

BACKGROUND

Different from adult clinical stage I (CS1) testicular cancer, surveillance has been recommended for CS1 pediatric testicular cancer. However, among high-risk children, more than 50% suffer a relapse and progression during surveillance, and adjuvant chemotherapy needs to be administered. Risk-adapted treatment might reduce chemotherapy exposure among these children.

METHODS

A decision model was designed and calculated using TreeAge Pro 2011 software. Clinical utilities such as the relapse rates of different groups during surveillance or after chemotherapy were collected from the literature. A survey of urologists was conducted to evaluate the toxicity of first-line and second-line chemotherapy. Using the decision analysis model, chemotherapy exposure of the risk-adapted treatment and surveillance strategies were compared based on this series of clinical utilities. One-way and two-way tests were applied to check the feasibility.

RESULTS

In the base case decision analysis of CS1 pediatric testicular cancer, risk-adapted treatment resulted in a lower exposure to chemotherapy than surveillance (average: 0.7965 cycles verse 1.3419 cycles). The sensitivity analysis demonstrated that when the relapse rate after primary chemotherapy was ≤ 0.10 and the relapse rate of the high-risk group was ≥ 0.40, risk-adapted treatment would result in a lower exposure to chemotherapy, without any association with the proportion of low-risk patients, the relapse rate of the low-risk group, the relapse rate after salvage chemotherapy or the toxicity utility of second-line chemotherapy compared to first-line chemotherapy.

CONCLUSIONS

Based on the decision analysis, risk-adapted treatment might decrease chemotherapy exposure for these high-risk patients, and an evaluation after orchiectomy was critical to this process. Additional clinical studies are needed to validate this statement.

[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.

Clinical characteristics and prognostic factors of male yolk sac tumor: a Surveillance, Epidemiology, and End Results program study

INTRODUCTION

Yolk sac tumor (YST) is a rare malignant germ cell tumor, which usually affects young males. Because of the low incidence, few studies on YST have been published. In our study, we aim to investigate the clinical characteristics, survival and risk factors of male YST patients based on the Surveillance, Epidemiology, and End Results (SEER) program.

METHODS

We identified 569 male YST patients from the SEER-18 database with additional treatment fields. Clinical characteristics, survival and prognostic factors were described in the study. Chi-square tests were applied to analyze categorical and continuous variables between different groups. Univariate and multivariate Cox proportional hazard model were performed to assess the relative impacts of risk factors on cancer-specific survival (CSS) in YST patients. Kaplan-Meier method and the log-rank test were used to analyze differences in survival that were significant.

RESULTS

The major primary sites of YST were testis (74.69%), mediastinum (15.47%), retroperitoneum (2.64%) and central nervous system (1.24%). The 3-year and 5-year CSS was 70.0%, 56.5% vs. 97.2%, 96.0% for the mediastinal and testicular YST patients, respectively (p < 0.001). Primary site of mediastinum, distant SEER Summary stage were independent factors of poor prognosis (hazard ratio (HR) = 2.010 (1.094-3.695), p = 0.025; HR = 6.501 (2.294-18.424), p < 0.001, respectively). Receiving surgery was a good prognosis factor for all patients (HR = 0.495 (0.260-0.940), p = 0.032) and for the mediastinal group (p = 0.0019). Being treated with chemotherapy indicated poor outcome in all patients (HR = 3.624 (1.050-12.507), p = 0.042) and in the localized testicular YST patients (p = 0.0077).

CONCLUSION

For the first time, our study revealed the primary site distribution of male YST, and summarized the clinical characteristics, survival and prognostic factors based on the SEER database, which provided important epidemiological evidence for clinical practice.

The history of urologic pathology: an overview

This article begins with the testis and a legendary figure, Sir Astley Cooper, who wrote an early text on the organ. The early 20th century saw the first major development, the description of the seminoma by the French investigator Maurice Chevassu, but the pace of knowledge did not accelerate until after World War II with a major article from the Armed Forces Institute of Pathology (AFIP) by Nathan B. Friedman and Robert A. Moore, soon followed by the first series testis fascicle by Frank J. Dixon and Moore. Other noteworthy contributions were made by two masters of gonadal pathology, Gunnar Teilum and Robert E. Scully. In the 1970s, Niels E. Skakkebaek played a seminal role in elaborating in-situ neoplasia of the testis. The school of British testicular tumour authored, in the mid-1970s, under the editorship of Roger C. B. Pugh, one of the best texts on testicular pathology. Advances in more recent years have been largely spearheaded by Thomas M. Ulbright of the Indiana University School of Medicine. Observations on the prostate gland date back to Andreas Vesalius and William Cheselden, the latter appearing to have introduced the word for the gland. Note is made of contributions on the anatomy and histology of the gland by Oswald Lowsley, L. M. Franks, and John McNeal. Diagnosing carcinoma of the prostate was brought into the modern age in a landmark 1953 article by Robert S. Totten et al. In the 1960s, Donald F. Gleason introduced a grading system that is now in use worldwide. The topic of premalignant lesions has been well established only for approximately three decades, based initially on the work of Dr McNeal and David G. Bostwick. One of the first to write a book on the bladder was the remarkable British surgeon-pathologist Sir Henry Thompson. Workers at the AFIP, including Colonel James E. Ash and Fatallah K. Mostofi, wrote many outstanding articles on bladder pathology. The roles of other institutions, such as Johns Hopkins University, the Mayo Clinic, and St Peter's Hospital Institute of Urology, London, and those who worked there are noted. Knowledge of the pathology of the urachus dates largely back to the remarkable book on the topic in 1916 by the Hopkins investigator Thomas S. Cullen. Information on renal tumours dates largely to the work of Paul Grawitz, but awareness of the many variants of renal cell carcinoma in general was slow to evolve, and has only accelerated in recent years. The AFIP group of Dr Mostofi, ably assisted by Colonel Charles J. Davis and Isabell A. Sesterhenn, has contributed to knowledge of renal neoplasia with articles of note on oncocytoma, metanephric adenoma, and medullary carcinoma. In the mid-1980s, the German workers Wolfgang Thoenes and Stephan Störkel recognised the distinctive tumour known as chromophobe renal cell carcinoma. Work on renal tumours in the young owes much to J. Bruce Beckwith. The observational talents of numerous investigators have, in just over a century, advanced our knowledge of diseases of the urinary tract and testis remarkably.

Relapse in children with clinical stage I testicular yolk sac tumors after initial orchiectomy

PURPOSE

To evaluate risk factors of relapse in pediatric patients with clinical stage I (CS1) testicular yolk sac tumors.

METHODS

With retrospective analysis, the medical records of children with pure testicular yolk sac tumors who were referred to Sun Yat-sen University Cancer Center and The First Affiliated Hospital from January 1995 to December 2015 were selected and recorded. Histopathology and staging were retrieved and multivariate analysis was performed with SPSS 20.0 software.

RESULTS

90 children with CS1 testicular yolk sac tumors were selected, and 21 of them underwent chemotherapy following initial orchiectomy. The median age of them was 17 months. With a median follow-up of 61 months (range 11-183 months), 84 patients were alive and 3 patients died, whereas the status was unknown in 3 patients. 30 patients experienced relapse within a median time of 4 months, including only 1 patient who underwent primary chemotherapy, and 28 of these patients underwent salvage chemotherapy. According to adjusted analysis, lymphovascular invasion (LVI) (P < 0.001), necrosis (P = 0.003) and primary chemotherapy (P = 0.008) were independent predictors of event-free survival. The 4-year event-free survival of high- and low-risk patients was 46.5% and 85.1%, respectively (P < 0.001).

CONCLUSIONS

LVI and necrosis were independent risk factors for relapse in pediatric patients with CS1 testicular yolk sac tumors, and primary chemotherapy was effective. Thus, individualized management might be feasible for these patients according to risk classification.

Ultrasound Appearances of Pediatric Testicular Yolk Sac Tumors: Twenty-one Cases in a Single Institution

Testicular yolk sac tumors are rare, and analyses of relevant ultrasound (US) findings are limited. We retrospectively reviewed the US features of 21 pathologically verified cases (patients aged 10-64 months). Neoplasms were unilateral and solitary, occupying part (focal) or all (diffuse) of the testis. Focal lesions (14 cases) were usually solid and ovoid, with a homogeneous echo texture or multiple random anechoic spaces, and hypervascular. Diffuse neoplasms had heterogeneous echo textures; most were hypervascular. On spectral Doppler US imaging, 11 cases had a mean peak systolic velocity of 12.9 cm/s and a mean resistive index of 0.54. Ultrasound is a useful tool for imaging pediatric testes when a yolk sac tumor is suspected.

Polyembryoma of the testis: a report of two cases dominant within mixed germ cell tumors and review of gonadal polyembryomas

Two testicular mixed germ cell tumors, from men of 21 and 41 years, in which polyembryoma predominated are described. A literature review uncovered an additional five testicular and nine ovarian cases. One tumor occurred in a 60-year-old man, but all others occurred within the typical age range of gonadal germ cell tumors. One male presented with gynecomastia and one female with sexual precocity, but all otherwise had standard clinical manifestations. These tumors are typically large with non-specific gross features, but a few have a prominent hemorrhagic appearance. No tumor is known to have been entirely composed of embryoid bodies, the unit upon which the diagnosis of polyembryoma is based. The most common additional germ cell tumor component is teratoma, present in the great majority of cases, with an approximately equal smaller number of tumors being associated with embryonal carcinoma and yolk-sac tumor, manifest as overgrowths of these elements, derived from the parent epithelium within the embryoid body. Rarely there is choriocarcinoma, and syncytiotrophoblast and hepatoid cells are occasionally present. The microscopic features of the tumors vary according to the arrangement of embryoid bodies with other elements, the prominence of associated typically myxoid to edematous stroma, and the degree to which embryoid bodies are perfectly or imperfectly formed. Although its presence in a gonadal mixed germ cell tumor is probably not associated with any special behavior, its unique features should result in polyembryoma being recorded, particularly when present in significant amount. Furthermore, awareness of its features may facilitate recognition, particularly when seen at metastatic sites or extra-gonadal sites of primary germ cell neoplasia. Whether polyembroma should be considered a distinctive pattern of mixed germ cell neoplasia or a particular variant of high-grade immature teratoma is considered, herein, and arguments can be made in favor of each viewpoint.

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.

Primary yolk sac tumor of the gluteus: a case report and literature review

Yolk sac tumor (YST) is a common malignant primitive germ cell tumor that often exhibits differentiation into endodermal structures. They most commonly occur in childhood and adolescence and are rare after the age of 40 years. Derived from the yolk sac during the embryonic period, YSTs can occur in the gonads and germ cells because the tumor cells migrate from the yolk sac toward the gonads. Here, we present a rare case of primary gluteus YST in a 3-year-old girl. She received BEP chemotherapy (bleomycin + etoposide + cisplatin) after surgical resection. There was no evidence of recurrence 7 months after primary treatment.

The 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours

The fourth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "blue book"), published in 2016, contains significant revisions. These revisions were performed after consideration by a large international group of pathologists with special expertise in this area. A subgroup of these persons met at the WHO Consensus Conference in Zurich, Switzerland, in 2015 to finalize the revisions. This review summarizes the most significant differences between the newly published classification and the prior version for renal, penile, and testicular tumours. Newly recognized epithelial renal tumours are hereditary leiomyomatosis and renal cell carcinoma (RCC) syndrome-associated RCC, succinate dehydrogenase-deficient RCC, tubulocystic RCC, acquired cystic disease-associated RCC, and clear cell papillary RCC. The WHO/International Society of Urological Pathology renal tumour grading system was recommended, and the definition of renal papillary adenoma was modified. The new WHO classification of penile squamous cell carcinomas is based on the presence of human papillomavirus and defines histologic subtypes accordingly. Germ cell neoplasia in situ (GCNIS) of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours, and testicular germ cell tumours are now separated into two fundamentally different groups: those derived from GCNIS and those unrelated to GCNIS. Spermatocytic seminoma has been designated as a spermatocytic tumour and placed within the group of non-GCNIS-related tumours in the 2016 WHO classification.

PATIENT SUMMARY

The 2016 World Health Organization (WHO) classification contains new renal tumour entities. The classification of penile squamous cell carcinomas is based on the presence of human papillomavirus. Germ cell neoplasia in situ of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours.