Adult primary pure teratoma of the testis. The Indiana experience

Gonadal Teratomas: A State-of-the-Art Review in Pathology

Teratomas are neoplasms arising from germ cells and encompass tissues derived from two or more embryonic germ layers, including ectoderm, mesoderm, and endoderm. These tumours typically localize along the midline or in paramedian positions and can manifest as gonadal (20%) or extragonadal (80%) entities. Although gonadal teratomas are uncommon, they represent the predominant type of gonadal tumour in the paediatric population. They comprise approximately 20-25% of all ovarian tumours in females and about 3-5% of all testicular tumours in males. Ovarian teratomas exhibit a higher incidence in early childhood and adolescence, whereas testicular teratomas are more prevalent during the first three months of life and between the ages of 15 and 19. While the majority of paediatric gonadal teratomas are benign, malignant or mixed variants may also arise, necessitating more aggressive therapeutic interventions.

Survival of Testicular Pure Teratoma vs. Mixed Germ Cell Tumor Patients in Primary Tumor Specimens across All Stages

We aimed to test for survival differences between testicular pure teratoma vs. mixed germ cell tumor (GCT) patients in a stage-specific fashion. Pure teratoma and mixed GCT in primary tumor specimens were identified within the Surveillance, Epidemiology, and End Results database (2004-2019). Kaplan-Meier curves depicted five-year overall survival (OS) and subsequently, cumulative incidence plots depicted cancer-specific mortality (CSM) and other-cause mortality (OCM) in a stage-specific fashion. Multivariable competing risks regression (CRR) models were used. Of 9049 patients, 299 (3%) had pure teratoma. In stage I, II and III, five-year OS rates differed between pure teratoma and mixed GCT (stage I: 91.6 vs. 97.2%, p < 0.001; stage II: 100 vs. 95.9%, p < 0.001; stage III: 66.8 vs. 77.8%, p = 0.021). In stage I, survival differences originated from higher OCM (6.4 vs. 1.2%; p < 0.001). Conversely in stage III, survival differences originated from higher CSM (29.4 vs. 19.0%; p = 0.03). In multivariable CRR models, pure teratoma was associated with higher OCM in stage I (Hazard Ratio (HR): 4.83; p < 0.01). Conversely, in stage III, in multivariable CRR models, pure teratoma was associated with higher CSM (HR: 1.92; p = 0.04). In pure teratoma, survival disadvantage in stage I patients relates to OCM. Survival disadvantage in stage III pure teratoma originates from higher CSM.

MicroRNAs in Differentiation of Embryoid Bodies and the Teratoma Subtype of Testicular Cancer

BACKGROUND

Testicular germ cell tumours (TGCTs) are the most frequent tumour type among young, adult men. TGCTs can be efficiently treated, but metastases of the teratoma subtype, for which there are no circulating biomarkers, represent a challenge.

MATERIALS AND METHODS

Global microRNA expression in teratoma tissue and embryoid bodies was assessed using next-generation sequencing. Levels of microRNAs identified as potential biomarkers were obtained from serum of patients with teratoma and matched healthy men.

RESULTS

We identified miR-222-5p, miR-200a-5p, miR-196b-3p and miR-454-5p as biomarker candidates from the tumour tissue and embryoid body screening but the expression of these microRNAs was very low in serum and not statistically different between patients and controls. miR-375-3p was highly expressed, being highest in patients with teratoma (p=0.012) but the levels of expression in serum from these patients and healthy controls overlapped. miR-371a-3p was not expressed in serum from patients with pure teratoma, only in patients with mixed tumours.

CONCLUSION

The microRNA profiles of the teratoma subtype of TGCT and embryoid bodies were obtained and assessed for candidate circulating biomarkers, but none with high sensitivity and specificity for teratoma were identified in our study. We conclude that neither the proposed teratoma marker miR-375-3p nor miR-371a-3p are suitable as circulating teratoma markers.

Common Diagnostic Challenges and Pitfalls in Genitourinary Organs, With Emphasis on Immunohistochemical and Molecular Updates

CONTEXT.—

Lesions in the genitourinary (GU) organs, both benign and malignant, can demonstrate overlapping morphology, and practicing surgical pathologists should be aware of these potential pitfalls and consider a broad differential diagnosis for each specific type of lesion involving the GU organs. The following summary of the contents presented at the 6th Annual Chinese American Pathologists Association (CAPA) Diagnostic Course (October 10-11, 2020), supplemented with relevant literature review, exemplifies the common diagnostic challenges and pitfalls for mass lesions of the GU system of adults, including adrenal gland, with emphasis on immunohistochemical and molecular updates when relevant.

OBJECTIVE.—

To describe the common mass lesions in the GU system of adults, including adrenal gland, with emphasis on the diagnostic challenges and pitfalls that may arise in the pathologic assessment, and to highlight immunohistochemical workups and emerging molecular findings when relevant.

DATA SOURCES.—

The contents presented at the course and literature search comprise our data sources.

CONCLUSIONS.—

The diagnostic challenges and pitfalls that arise in the pathologic assessment of the mass lesions in the GU system of adults, including adrenal gland, are common. We summarize the contents presented at the course, supplemented with relevant literature review, and hope to provide a diagnostic framework to evaluate these lesions in routine clinical practice.

Retroperitoneal Lymph Node Dissection Versus Surveillance for Adult Early Stage Pure Testicular Teratoma: A Nationwide Analysis

PURPOSE

Following radical orchiectomy, surveillance and primary retroperitoneal lymph node dissection (RPLND) are acceptable options for the management of early stage pure testicular teratoma in adult patients; however, there is no uniform consensus. The aim of this study was to investigate survival outcomes of adults with early stage pure testicular teratoma based on management strategy.

METHODS

Data was extracted from the National Cancer Database (NCDB) from testicular cancer patients diagnosed with clinical stage (CS) I pure teratoma (pT1-4N0M0S0) between 2004 and 2014. Kaplan-Meier and Cox regression analyses were used to assess clinical outcomes based on management strategy.

RESULTS

Of the 61,167 patients diagnosed with testicular cancer, 692 (1.1%) had pure teratoma. Only individuals with CS I disease were considered (n = 237). The median age was 28 (23-35) years. Overall, 43 (18%) patients underwent RPLND and 194 (82%) patients were managed with surveillance. There was an increase in surveillance for CS I teratoma during the study period. Increasing distance from residence to treatment facility was an unadjusted predictor for undergoing primary RPLND (p < 0.001). Median follow-up was 54 months and there was no significant difference in overall survival between CS I teratoma patients managed with RPLND and those managed with surveillance (p = 0.13).

CONCLUSIONS

There has been a trend toward increasing adoption of surveillance for the management of early stage pure testicular teratoma in adults. Our findings suggest that surveillance provides comparable survival outcomes to primary retroperitoneal lymph node dissection in this setting.

Primary Borderline Mucinous Testicular Tumor: A Case Report and Literature Review

Primary mucinous tumors of the testis and paratestis are very rare, with only 29 reported cases detected in a PubMed search. The histopathological characteristics of primary testicular mucinous tumors are similar to their ovarian counterparts, and the diagnosis and naming criteria refer to the criteria for female ovarian mucinous tumors. However, the clinical and imaging features of primary testicular mucinous tumors are poorly understood, and they are thus frequently undiagnosed or misdiagnosed. We present the case of a patient with a primary testicular mucinous tumor. A 52-year-old man presented with a 1-year history of painless enlargement of the left scrotum. Ultrasound examination revealed a cystic mass in the left testis, with viscous fluid areas and calcified spots, irregular solid bulges on the cyst wall, and a small blood supply. Serum alpha-fetoprotein, β-human chorionic gonadotropin, lactate dehydrogenase, renal function, inflammatory markers, and routine urine and blood examinations were all normal. The patient underwent radical resection of the left testis. Postoperative pathology showed a multilocular cystic mass, with the inner wall of the sac lined with mucous columnar epithelial cells, some with mild nuclear atypia, and no interstitial infiltration. The pathological diagnosis was testicular mucinous tumor. Postoperative abdominal and pelvic computed tomography, colonoscopy, and gastroscopy showed no suspicious lesions. The final diagnosis was primary testicular borderline mucinous tumor. The patient underwent postoperative follow-up examinations once a year for 4 years. Serum tumor markers, scrotal ultrasound, abdominal and pelvic computed tomography scans, and colonoscopy and gastroscopy revealed no evidence of metastases or other primary adenocarcinoma. This case highlights the clinical and imaging characteristics of primary testicular mucinous tumors, which might aid their differential diagnosis.

Role of primary retroperitoneal lymph node dissection in stage I and low-volume metastatic germ cell tumors

PURPOSE OF REVIEW

Early-stage testicular cancers are highly curable. Following orchidectomy, management options for stage I disease include active surveillance, nerve-sparing retroperitoneal lymph node dissection (nsRPLND) and primary chemotherapy as recommended by the current guidelines. Primary RPLND has for decades played an integral part of treatment in patients with early-stage testicular germ cell tumors (TGCT), particularly in nonseminomatous germ cell tumors (NSGCT) with focus on reducing the long-term morbidity. We review the role of RPLND in stage I NSCGT as well as stage II A/B NSGCT and as seminoma.

RECENT FINDINGS

Radiation therapy and systemic chemotherapy are established treatments for seminoma; however, long-term data has demonstrated the association of such therapies with late toxicity including secondary malignancies, hearing loss, cardiovascular disease as well as metabolic syndromes. Given the well established role of RPLND in NSGCTs, clinicians have developed an interest in utilization of surgery for low-volume retroperitoneal metastatic disease. Two prospective clinical trials (SEMS and PRIMETEST) are underway to determine the role of RPLND alone in low volume metastatic seminoma.

SUMMARY

RPLND is a highly effective treatment for early-stage germ cell tumors but represents overtreatment in low-volume stage I disease where active surveillance is recommended. RPLND has shown a promising role in low-volume stage II seminomas. Two phase II clinical trials are underway to further determine the curative potential of this approach.

Prospective molecular and morphological assessment of testicular prepubertal-type teratomas in postpubertal men

In 2016, the World Health Organization classification system of testicular tumors included the new entity prepubertal-type teratoma based on its morphological and molecular profile, and the realization that these tumors may occur in postpubertal men. For treatment and prognostic purposes, it is important to distinguish prepubertal-type teratoma from the usual postpubertal-type teratoma, because the former is benign unlike the latter. The distinction may be challenging. In this study, we investigated clinical, morphological, and molecular criteria for distinguishing prepubertal-type teratoma from postpubertal-type teratoma in a prospective series of pure testicular teratomas. All cases of pure teratoma in postpubertal men assessed at Barts Health NHS Trust or in consultation since the introduction of routine investigation of chromosome 12p status in 2010 were reviewed. Morphological features suggestive of prepubertal-type teratoma were observed in 14 out of 35 cases. All underwent molecular testing and none displayed 12p amplification. Mean tumor size was 16 mm (range 7-28 mm). None had associated germ cell neoplasia in situ or significant atrophy. Four incorporated a well-differentiated neuroendocrine tumor, 1-2 mm in size. Of the ten patients with follow-up information, none have recurred or metastasized. Twenty-one of the 35 cases were diagnosed as postpubertal-type teratoma, mean tumor size 40 mm (range 6-90 mm). One case underwent molecular testing: a tumor of pure skeletal muscle differentiation and possessed 12p amplification. Three cases presented with clinical metastases. Eight cases contained immature areas, ten cases had associated germ cell neoplasia in situ, and 17 cases had severe atrophy of the parenchyma. One case with neither germ cell neoplasia in situ nor atrophy showed necrosis. We conclude that both morphological and molecular features are of help in differentiating prepubertal-type teratoma from postpubertal-type teratoma. In nearly all postpubertal-type teratomas, molecular testing was unnecessary, and merely confirmed the morphological impression in the prepubertal-type teratomas. Our study confirmed the high incidence of well-differentiated neuroendocrine tumors in the prepubertal-type.

Germ Cell Testicular Tumors-Contemporary Diagnosis, Staging and Management of Localized and Advanced disease

Germ cell testicular tumors are the most commonly diagnosed cancer in young men, with cure rates exceeding 95%. Clinical stage 1 disease is the most common manifestation, with radical orchiectomy curing the majority of Clinical stage 1 patients, making active surveillance the treatment of choice, with a cancer specific survival nearing 100% and low relapse rates. However, in metastatic disease, chemotherapy, radiotherapy, and surgery are curative options. Chemotherapy remains the mainstay of therapy for advanced disease with surgical management of residual disease. Patients with advanced disease should be treated in high volume experienced academic centers with multidisciplinary teams. Research exploring refinement of diagnosis and treatment, and lowering treatment burden is underway.

Primary and Postchemotherapy Retroperitoneal Lymphadenectomy for Testicular Cancer

Clinical stage I (CS I) testicular non-seminomatous germ cell tumours (NSGCT) are highly curable. Following orchidectomy, a risk-adapted approach using active surveillance, nerve-sparing retroperitoneal lymph node dissection (RPLND) and primary chemotherapy is recommended by the current guidelines. CS I is defined as showing negative values for tumour markers (or values declining to their half-life following orchidectomy) and negative imaging studies of the chest, abdomen and retroperitoneum. Active surveillance can be performed in low- and high-risk NSGCT with an anticipated relapse rate of about 15% and 50%, respectively. The majority of patients will relapse with good and intermediate prognosis tumours, which have to be treated with 3 to 4 cycles of chemotherapy. About 25-30% of these patients will have to undergo postchemotherapy (PC) RPLND for residual masses. Primary chemotherapy with 1-2 cycles of cisplatin, etoposide, bleomycin (PEB) is a therapeutic option for high-risk CS I NSGCT associated with a recurrence rate of only 2-3% and a minimal acute and long-term toxicity rate. Nerve-sparing RPLND, if performed properly, will cure about 85% of all high-risk patients with CS I NSGCT without the need for chemotherapy. PC-RPLND plays an integral part of the multimodality treatment in patients with advanced testicular germ cell tumours (TGCT). According to current guidelines and recommendations, PC-RPLND in advanced seminomas with residual tumours is only indicated if a positron emission tomography scan performed 6-8 weeks after chemotherapy is positive. In non-seminomatous TGCT, PC-RPLND is indicated for all residual radiographical lesions with negative or plateauing markers. Loss of antegrade ejaculation represents the most common long-term complication, which can be prevented by a nerve-sparing or modified template resection. The relapse rate after PC-RPLND is around 12%; however, it increases significantly to about 45% in cases with redo RPLND and late relapses. Patients with increasing markers should undergo salvage chemotherapy. Only select patients with elevated markers who are thought to be chemo-refractory might undergo desperation PC-RPLND if all radiographically visible lesions are completely resectable. PC-RPLND requires a complex surgical approach and should only be performed in experienced, tertiary referral centres.

[When is surgical resection of metastases in testicular germ cell tumors indicated and is there a scientific basis?]

Surgical resection of metastases represents an integral part of curative management in patients with testicular germ cell tumors (GCT). Primary nerve-sparing retroperitoneal lymph node dissection (nsRPLND) for low volume metastases in clinical stages I-IIB has to be differentiated from the more complex and more extensive postchemotherapeutic procedures. In Europe, primary nerve-sparing retroperitoneal lymph node dissection (nsRPLND) for clinical stage I nonseminomatous GCT (NSGCT) plays a subordinate. In clinical stage IIA/B, nsRPLND is indicated for patients with marker-negative metastases in whom cure rates of about 65% can be achieved with surgery alone. For clinical stage IIA/B seminomas, nsRPLND represents an individual, still experimental procedure with high cure rates. Postchemotherapy residual tumor resection (pRTR) for advanced seminomas is only indicated in the context of a FDG-PET/CT-positive residual mass >3 cm in diameter. For NSGCT, pRTR is indicated in patients with residual masses >1 cm and negative or plateauing tumor markers to resect persisting teratoma or vital cancer. Complete resection of all masses including resection of adjacent vascular, visceral or skeletal metastases is mandatory to achieving the highest cure rate possible. Due to the complexity and the lower rate of significant morbidity and mortality, these procedures should be done at tertiary referral centers.

Testicular cancer: The usage of central review for pathology diagnosis of orchiectomy specimens

BACKGROUND

Radical orchiectomy specimens present a unique set of challenges for pathology assessment owing to their rarity and complexity. This study compares second opinion pathology reports generated at a single, large academic institution to primary reports from outside hospitals.

METHODS

A database search was conducted for orchiectomy cases that were sent to our institution for management of testicular cancer from 2014 to 2015. Cases sent for consultation without a finalized diagnosis from the outside hospitals were excluded. A total of 221 consecutive cases were evaluated for comparison of final diagnoses between the outside institution and central pathology review.

RESULTS

This study revealed significant discrepancy involving multiple parameters between original and second opinion pathology reports. Of 221 cases of germ cell tumors assessed, 31% showed some discrepancy of histologic subtype. Overall, reporting of lymphovascular invasion changed in 22% of cases; of those, initially called positive 23% were changed to negative and of those initially called negative 12% were changed to positive. Although the overall discrepancy for spermatic cord invasion was 9%, an initial positive diagnosis was negated 35% of the time. The pathologic stage was altered in 23% of cases, mostly secondary to differences interpreting lymphovascular and spermatic cord invasion.

CONCLUSION

Pathologists evaluating orchiectomy specimens should be aware of the major pitfalls in classification and staging, many of which may affect patient management.

Tumors of the Testis: Morphologic Features and Molecular Alterations

This article reviews the most frequently encountered tumor of the testis; pure and mixed malignant testicular germ cell tumors (TGCT), with emphasis on adult (postpubertal) TGCTs and their differential diagnoses. We additionally review TGCT in the postchemotherapy setting, and findings to be integrated into the surgical pathology report, including staging of testicular tumors and other problematic issues. The clinical features, gross pathologic findings, key histologic features, common differential diagnoses, the use of immunohistochemistry, and molecular alterations in TGCTs are discussed.

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.

Risk of Recurrence for Clinical Stage I and II Patients With Teratoma Only at Primary Retroperitoneal Lymph Node Dissection

OBJECTIVE

To evaluate the oncologic outcomes of patients with retroperitoneal teratoma only at primary retroperitoneal lymph node dissection (RPLND) who did not receive adjuvant chemotherapy.

MATERIALS AND METHODS

Between 1979 and 2010, 23 patients with clinical stage (CS) I and II disease underwent primary RPLND at our institution with teratoma only in the retroperitoneum. No patient received adjuvant chemotherapy and the minimum follow-up was 2 years.

RESULTS

At the initial diagnosis, 13 patients (56.5%) had CS I disease and 10 patients (43.5%) had CS II disease. Pathologic staging demonstrated IIA in 13 patients (56.5%), IIB in 8 patients (34.8%), and IIC in 2 patients (8.7%). The 5-year disease-free survival (DFS) was 100% with a median follow-up of 5.8 years (range, 2.1-25.4). DFS was not significantly different comparing pathologic stage IIA vs IIB/IIC disease (P = .73). Two patients (14%) developed late relapses. One patient had a pelvic recurrence 11 years after primary RPLND. Final pathology from the pelvic resection demonstrated embryonal carcinoma. He remains disease free after his second surgery. The second patient had a contralateral retroperitoneal recurrence with yolk-sac tumor and teratoma 11 years after primary RPLND. He was treated with chemotherapy followed by postchemotherapy RPLND.

CONCLUSION

The relapse rate for patients with teratoma only at primary RPLND is low irrespective of PS. Adjuvant chemotherapy is therefore not recommended in the management of these patients.

Management of clinical stage I nonseminomatous germ cell tumors

Therapeutic options for clinical stage I nonseminomatous germ cell tumor include active surveillance, adjuvant chemotherapy and retroperitoneal lymph node dissection (RPLND). Lymphovascular invasion (LVI) determines risk of recurrence, as those without LVI have 15% risk of relapse on surveillance while those with LVI have a 50% risk. This stratifies patients into high risk(LVI+) and low risk(LVI-) groups which direct treatment recommendations. Surveillance is preferred for those with low risk disease, and is an option for those with high risk disease, as at least half are over-treated with other options. Adjuvant chemotherapy is an option for all patients as it can eradicate micrometastatic disease and reduce recurrence by at least 90%. RPLND benefits patients with low volume retroperitoneal disease with a cure rate of RPLND alone at approximately 70%. All three treatment modalities have similar survival rates approaching 100% but differing potential morbidities, which, along with patient preferences and compliance, should guide treatment decisions.

Late relapse of testis cancer

Most relapses of germ-cell tumors occur within 2 years of initial treatment. In 2 % to 4 % of patients, relapse may occur later. The retroperitoneum is the primary site of late relapses, and alpha-fetoprotein is the predominant marker. These tumors are highly resistant to chemotherapy. Surgical resection is the preferred treatment. If the recurrent disease is inoperable, salvage chemotherapy may be instituted, followed by resection of the residual disease.

Retroperitoneal lymphadenectomy and resection for testicular cancer: an update on best practice

Clinical stage I testicular nonseminomatous germ cell tumours (NSGCTs) are highly curable. Following orchidectomy a risk-adapted approach using active surveillance (AS), nerve-sparing retroperitoneal lymph node dissection (nsRPLND) and primary chemotherapy is recommended by the current guidelines. Clinical stage I is defined as negative or declining tumour markers to their half-life following orchidectomy and negative imaging studies of the chest, abdomen and retroperitoneum. Active surveillance can be performed in low-risk and in high-risk NSGCTs with an anticipated relapse rate of about 15% and 50%. The majority of patients will relapse with good and intermediate prognosis tumours which have to be treated with three to four cycles chemotherapy. About 25-30% of these patients will have to undergo postchemotherapy retroperitoneal lymph node dissection (PC-RPLND) for residual masses. Primary chemotherapy with one or two cycles of cisplatin (Platinol), etoposide and bleomycin (PEB) is a therapeutic option for high-risk clinical stage I NSGCT associated with a recurrence rate of only 2-3% and a minimal acute and long-term toxicity rate. nsRPLND, if performed properly, will cure about 85% of all high-risk patients with clinical stage I NSGCT without the need for chemotherapy. PC-RPLND forms an integral part of the multimodality treatment in patients with advanced testicular germ cell tumours (TGCTs). According to current guidelines and recommendations, PC-RPLND in advanced seminomas with residual tumours is only indicated if a positron emission tomography (PET) scan performed 6-8 weeks after chemotherapy is positive. In nonseminomatous TGCT, PC-RPLND is indicated for all residual radiographic lesions with negative or plateauing markers. Loss of antegrade ejaculation represents the most common long-term complication which can be prevented by a nerve-sparing or modified template resection. The relapse rate after PC-RPLND is around 12%, however it increases significantly to about 45% in cases with redo RPLND and late relapses. Patients with increasing markers should undergo salvage chemotherapy. Only select patients with elevated markers who are thought to be chemorefractory might undergo desperation PC-RPLND if all radiographically visible lesions are completely resectable. PC-RPLND requires a complex surgical approach and should be performed in experienced, tertiary referral centres only.

Difficult differential diagnoses in testicular pathology

CONTEXT

Although relatively rare, testicular cancer is the most common solid organ malignancy in young men and remains a leading cause of cancer death in this population. Different types of testicular tumors are treated differently, with an overall very high cure rate with proper management. Pathologists must, therefore, be familiar with important diagnostic pitfalls in testicular pathology, particularly those that result in different treatments or prognoses.

OBJECTIVE

To summarize key diagnostic features and useful ancillary tools for the most frequently encountered problems in testicular tumor pathology.

DATA SOURCES

Current texts, PubMed (National Library of Medicine) articles, and archives at Indiana University School of Medicine and Beth Israel Deaconess Medical Center were all reviewed.

CONCLUSIONS

Problematic differential diagnoses include seminoma versus nonseminomatous germ cell tumors, germ cell tumors versus non-germ cell tumors, intratubular germ cell neoplasia versus atypical germ cells with maturation arrest, pseudolymphovascular invasion versus real lymphovascular invasion in germ cell tumors, and macroscopic Sertoli cell nodules versus Sertoli cell tumors. In almost all cases, awareness of the differential diagnostic possibilities based on routine light microscopic features permits application of either additional, directed observations or immunohistochemical studies that lead to an accurate diagnosis.

[Comments on retroperitoneal lymphadenectomy - laparoscopic versus robotic]

Retroperitoneal lymph node dissection (RPLND) in high risk clinical stage I nonseminomatous germ cell tumors (NSGCT) plays a limited role in modern uro-oncology due to the superior therapeutic efficacy of even one cycle of PEB (cysplatin, etoposide, bleomycin) chemotherapy. There might be an indication for the rare case of pure mature teratoma with unfavorable prognostic risk factors. If RPLND is performed for clinical stage I NSGCT it always has to be performed in a nerve-sparing technique and within the well-defined boundaries of an anatomically adequate template in order to avoid unnecessary adjuvant systemic chemotherapy. In this aspect, laparoscopic RPLND is inferior to open RPLND as basically all patients with lymph node positive disease receive adjuvant chemotherapy. The evidence for robotic-assisted RPLND is too weak to draw any clinically useful conclusions. Currently, it is an experimental procedure.Postchemotherapy RPLND (PC-RPLND) remains a surgery for tertiary referral centres due to the complexity of the surgical intervention and the high probability of adjunctive visceral and/or vascular surgery. In accordance with international guidelines it remains a domain for an open surgical approach. Laparoscopic PC-RPLND is reserved for small residual masses with the option of a unilateral modified template resection in very experienced laparoscopic centres. With regard to robotic-assisted PC-RPLND there is no evidence in the literature with regard to morbidity and complications, short-term and long-term oncological results being in favor of this experimental approach.

Primary vs. post-chemotherapy retroperitoneal lymph node dissection (RPLND) in patients with presence of teratoma at orchiectomy

OBJECTIVE

The presence of teratoma in the primary orchiectomy specimen creates controversies for subsequent management. Although predominant teratoma is less likely to metastasize, teratoma in the retroperitoneum may be less amenable to chemotherapy. In order to elucidate the issues about teratoma in the primary tumor, we reviewed differences between primary retroperitoneal lymph node dissection (P-RPLND) vs. post-chemotherapy RPLND (PC-RPLND) in patients with teratoma at orchiectomy.

MATERIALS AND METHODS

Patients who had undergone RPLND at our institution from 2001 to 2008 were identified, and clinical charts reviewed. Eighty-three patients with teratoma at orchiectomy were identified and perioperative data were obtained.

RESULTS

Of the 83 patients with teratoma at orchiectomy who underwent RPLND, 44 (53%) and 39 (47%) underwent primary and PC-RPLND, respectively. Median follow-up was 1.4 years. Of the 83 patients with primary teratoma at orchiectomy, there were 7 (8%) patients with pure teratoma and 76 (92%) patients with mixed histology. Of the patients with mixed histology, 72 (87%) patients had embryonal carcinoma and 36 (43%) had LVI. There were 19 (43%) positive lymph nodes for P-RPLND, of which 13 (30%) contained teratoma. For the PC-RPLND group, 30 (77%) of lymph nodes were positive, of which 28 (72%) contained teratoma. There were 3 (4%) recurrences overall, all of which recurred in the PC-RPLND group. There were 11 (13%) perioperative complications total. There were no deaths in either group.

CONCLUSIONS

Patients with teratoma at orchiectomy were associated with other high risk features and are at significant risk for metastatic disease. Patients with post-chemotherapy retroperitoneal findings are at significant risk for viable GCT and/or teratoma and should undergo PC-RPLND.

Benign and Malignant Neoplasms of the Testis and Paratesticular Tissue

Benign and malignant tumors of the testes and paratesticular tissues present an interesting spectrum of diagnostic entities often encountered in routine surgical pathology practice. Germ cell tumors are the most common tumors of the testes and, despite a rising incidence, have excellent prognosis because of their radiosensitivity and/or effective chemotherapeutic agents. The proper classification of these tumors aids in the choice of appropriate treatment options. This article reviews benign and malignant neoplastic entities of the testes and paratesticular tissues and illustrates the classic pathologic characteristics. The differential diagnosis, along with ancillary studies, clinical significance, and presentation are discussed also.

Molecular and cell biology of testicular germ cell tumors

Although testicular germ cell tumors (TGCTs) are relatively uncommon, they are particularly important as they tend to affect children and young men, representing the most common tumor in male aged from 20 to 40years. TGCTs are a heterogeneous group of tumors, with specific peculiarities reflecting on epidemiologic distribution and clinic-pathological features. TGCTs show a high-cure rates in both seminomas and nonseminomas and represent the model of a curable neoplasia: sensitive serum tumor markers, accurate prognostic classification, contribute to a high effectiveness of cancer therapy. However, up to 30% of patients diagnosed with metastatic nonseminomas do not achieve a durable remission, and in metastatic teratomas cisplatin-based treatment resistance has been observed. These different prognostic and therapeutic features of TGCTs highlight the need for a better understanding of the molecular biology of TGCT, that could help to improve disease management and to tailor aggressiveness of treatment to the severity of the prognosis.

Retroperitoneal mature teratoma after orchidectomy for a stage IB pure embryonal testicular carcinoma

Nonseminomatous germ cell tumor of the testis stage I will relapse in approximately 30% of patients in the first year after orchidectomy. We report a 19-year-old patient on active surveillance who presented with a retroperitoneal lymph node enlargement suggestive of metastatic disease more than 1 year after the initial diagnosis of embryonal carcinoma stage IB. Complete resection of the lymph node was performed and showed the presence of mature teratoma. Our patient had an unusual case of metastasis formation of benign histology of a previously removed highly malignant primary tumor confined to the testis.

The most common, clinically significant misdiagnoses in testicular tumor pathology, and how to avoid them

Testicular tumors are both increasing in frequency and disproportionately occur in young men; furthermore, different forms of neoplasm require different treatments. These considerations make the accurate diagnosis of testicular tumors especially important. Many of the critical distinctions involve the differentiation of seminoma from one or more potential mimics because seminoma is not only the most common testicular neoplasm but it is also the only malignant testicular tumor that is commonly treated with radiation, which is ineffective in other malignancies of the testis. For the most part, accurate diagnosis can be achieved by careful light microscopic evaluation, although appropriate immunostains can provide diagnostic assistance if doubt persists. This article discusses a number of clinically important differential diagnoses in the testis that are common sources of misinterpretations. These include: seminoma versus embryonal carcinoma, seminoma versus yolk sac tumor, seminoma versus Sertoli cell tumor, seminoma with syncytiotrophoblast cells versus choriocarcinoma, granulomatous seminoma versus granulomatous orchitis, intertubular seminoma versus orchitis, lymphoma versus seminoma or embryonal carcinoma, dermoid cyst versus teratoma, scar versus regressed germ cell tumor, and "anaplastic" spermatocytic seminoma versus usual seminoma or embryonal carcinoma.

An overview of testicular germ cell tumors

CONTEXT

More than 90% of testicular neoplasms originate from germ cells. Testicular germ cell tumors (GCTs) are a heterogeneous group of neoplasms with diverse histopathology and clinical behavior.

OBJECTIVE

To help the readers distinguish various subtypes of GCTs, to highlight the clinical manifestations and pathologic features of these tumors, and to review several newly developed immunohistochemical markers for GCTs.

DATA SOURCES

Review of the pertinent literature and our experience.

CONCLUSIONS

The etiology of GCTs is largely unknown. Cytogenetic studies suggest a different pathogenesis for each group of infantile/prepubertal GCTs, postpubertal GCTs, and spermatocytic seminoma. Unclassified intratubular germ cell neoplasia is the precursor of all GCTs, excluding spermatocytic seminoma and infantile/prepubertal GCTs. Seminoma, the most common GCT in adults, does not occur before 5 years of age. Spermatocytic seminoma, a tumor of elderly men, typically has an indolent clinical behavior, but rarely it undergoes sarcomatous transformation associated with an aggressive behavior. Embryonal carcinoma is the most common component in mixed GCTs. Eighty percent or more of embryonal carcinoma component and vascular invasion are recognized predictors of occult metastasis for clinical stage I mixed GCTs. Most patients with prepubertal yolk sac tumor, the most common pediatric GCT, have stage I disease at presentation. Most choriocarcinomas present with metastatic symptoms because of the propensity for rapid hematogenous dissemination. Teratomas in children regardless of maturity and dermoid cysts in adults are benign; in contrast, teratomas in adults have a malignant behavior. With appropriate therapy, the majority of testicular GCTs are curable.

Adult and Pediatric Testicular Teratoma

Although pure testicular teratomas in prepubertal boys have not been reported to metastasize, testicular teratomas in adults are associated with clinical metastases in 60% of cases. Teratoma has a diverse biological potential, with propensity for local growth, distant metastases, and transformation to somatic malignant cell types. Teratoma is frequently found associated with other nonseminomatous histologies and is present in the retroperitoneum in 40% of postchemotherapy retroperitoneal lymph node dissections. Because of the chemoresitant nature of teratomas, complete surgical resection is the treatment of choice. Since the biology of teratoma is unpredictable and it is frequently found in the retroperitoneum following chemotherapy for nonseminomatous germ-cell tumors, complete control of the retroperitoneum is advocated for all patients regardless of residual mass size.

Case series: Adult testicular dermoid tumours – mature teratoma or pre-pubertal teratoma?

Adult testicular dermoid tumours are rare tumours with no reported potential for recurrent or metastatic spread. Despite this they are currently classified as mature teratoma and managed as if they have equivalent malignant potential. This report describes two cases of adult mature teratoma of dermoid type and questions the classification and pathogenesis of this disease. In one of the cases there was a clear history of a testicular lump arising pre-pubertally, raising the possibility that some adult dermoid tumours may in fact be pre-pubertal teratomas that have persisted into adulthood. Classification as a mature teratoma carries with it a follow-up regimen that includes numerous radiological investigations with their attendant radiation exposure. A positive histological diagnosis and separate classification of adult dermoid tumours would allay clinical fears of recurrence and metastasis and negate the need for repeated radiological investigations.

Clonal Origin of Metastatic Testicular Teratomas

PURPOSE

Testicular teratomas in adult patients are histologically diverse tumors that frequently coexist with other germ cell tumor (GCT) components. These mixed GCTs often metastasize to retroperitoneal lymph nodes where multiple GCT elements are frequently present in the same metastatic lesion. Neither the genetic relationships among the different components in metastatic lesions nor the relationships between primary and metastatic GCT components have been elucidated.

EXPERIMENTAL DESIGN

We examined metastases from 31 patients who underwent primary retroperitoneal lymph node dissection for metastatic testicular GCT. All patients had metastatic mature teratoma with one or more other GCT components. This study included a total of 72 metastatic GCT components and 16 primary GCT components from 31 patients. Genomic DNA samples from each component were prepared from formalin-fixed, paraffin-embedded tissue sections using laser-assisted microdissection. Loss of heterozygosity (LOH) assays for seven microsatellite polymorphic markers on chromosomes 1p36 (D1S1646), 9p21 (D9S171 and IFNA), 9q21 (D9S303), 13q22-q31 (D13S317), 18q22 (D18S543), and 18q21 (D18S60) were done to assess clonality.

RESULTS

Twenty-nine of 31 (94%) cases showed allelic loss in one or more components of the metastatic GCTs. Twenty-nine of 31 mature teratomas showed allelic loss in at least one of seven microsatellite polymorphic markers analyzed. The frequency of allelic loss in informative cases of metastatic mature teratoma was 27% (8 of 30) with D1S1646, 34% (10 of 29) with D9S171, 37% (10 of 27) with IFNA, 27% (8 of 30) with D9S303, 46% (13 of 28) with D13S317, 26% (7 of 27) with D18S543, and 36% (10 of 28) with D18S60. Completely concordant allelic loss patterns between the mature teratoma and all of the other metastatic GCT components were seen in 26 of 29 cases in which the mature teratoma component showed LOH. Nearly identical allelic loss patterns were seen in the three remaining cases. In six cases analyzed, LOH patterns of each metastatic component were compared with each GCT component of the primary testicular tumor. In all six cases, each primary and metastatic component showed an identical pattern of allelic loss.

CONCLUSION

Our data support the common clonal origin of metastatic mature teratomas with other components of metastatic testicular GCTs and with each component of the primary tumor.

Analysis of ovarian teratomas for isochromosome 12p: evidence supporting a dual histogenetic pathway for teratomatous elements

Teratomas are the most common germ cell tumor (GCT) of the ovary and include several types with a range of clinical behavior. As in testicular teratomas, they may be benign, malignant or a component of a mixed GCT. In the testis, data support separate pathogeneses for prepubertal and postpubertal teratomas, with derivation of the former from a nontransformed germ cell and the latter from differentiation of a nonteratomatous, malignant GCT. The absence of cytogenetic abnormalities (including isochromosome 12p (i(12p)) in mature ovarian teratomas suggests that they may be analogous to prepubertal testicular teratomas, but there are no data regarding genetic changes in the teratomatous components of ovarian mixed GCTs. We therefore studied the teratomatous components of six mixed GCTs of the ovary using fluorescence in situ hybridization (FISH) for i(12p). Six mixed GCTs of the ovary occurred in patients 4-33 years of age; all had teratomatous and yolk sac tumor components and three also contained foci of embryonal carcinoma. Using FISH with 12p telomeric and 12 centromeric probes, five of six (83%) cases had detectable i(12p) in their nonteratomatous components, and four of six (66%) in the teratomatous component. One of the two cases without demonstrable i(12p) in the teratomatous portion of the mixed GCT also did not have identifiable 12p abnormalities in other elements of the mixed GCT. By comparison, five pure, mature ovarian teratomas and three pure, immature ovarian teratomas showed no evidence of either i(12p) or other forms of 12p amplification. These findings support that teratoma in mixed ovarian GCTs has a different pathogenesis compared to pure teratoma of the ovary. Furthermore, the findings of i(12p) in both the teratomatous and nonteratomatous components of ovarian mixed GCTs supports that the teratoma derives from other components, similar to the situation in the testis.

Germ cell tumors of the gonads: a selective review emphasizing problems in differential diagnosis, newly appreciated, and controversial issues

Gonadal germ cell tumors continue to be the cause of diverse, diagnostically challenging issues for the pathologist, and their correct resolution often has major important therapeutic and prognostic implications. They are academically interesting because of the biological diversity exhibited in the two gonads and variation in frequency of certain neoplasms. The most dramatic examples of the latter are the frequency of dermoid cyst in the ovary compared to the testis and the reverse pertaining to embryonal carcinoma. Within the teratoma group, there is strong evidence that ovarian and prepubertal testicular teratomas are derived from benign germ cells, a pathogenesis that likely applies also to the rare dermoid cysts and uncommon epidermoid cysts of the testis. In contrast, postpubertal testicular teratomas derive from malignant germ cells, specifically representing differentiation within a preexistent nonteratomatous cancer. As expected, given the foregoing, teratomas in boys are clinically benign, whereas in postpubertal males they are malignant, independent of their degree of immaturity. On the other hand, immaturity is an important finding in ovarian teratomas, irrespective of age, although its significance in children has recently been challenged. It is usually recognized on the basis of embryonic-appearing neuroepithelium, which shows mitotic activity and apoptosis in contrast to differentiated neuroepithelial tissues, which may occur in mature ovarian teratomas. Rarely it is based on the presence of cellular, mitotically active glial tissue. Fetal-type tissues alone are not sufficient for a diagnosis of immature teratoma. Further differences between the teratomatous tumors in the two gonads are the relative frequency of monodermal teratomas in the ovary in contrast to the testis, where only one subset, carcinoids, is seen with any frequency. When uncommon somatic-type malignancies (usually squamous cell carcinoma) occur in mature cystic teratomas of the ovary, this is a de novo form of malignant transformation; similar tumors in the testis, a very rare event, represent overgrowth of teratomatous elements that originated from malignant, nonteratomatous germ cell tumors and, therefore, had previously undergone malignant transformation. Germinomas may have several unusual features in each gonad; these include microcystic arrangements that suggest yolk sac tumor, tubular patterns that mimic Sertoli cell tumor, apparent increased cytological atypia that causes concern for embryonal carcinoma, and prominent syncytiotrophoblast giant cells that suggest choriocarcinoma. Awareness of these variants, good technical preparations, the retained typical cytological features of germinoma cells, and the judicious use of tailored panels of immunohistochemical stains resolve these dilemmas in virtually all instances. Two aspects of germinomas are unique to the testis. Firstly, intertubular growth of small seminomas may cause them to be overlooked. Secondly, the distinctive spermatocytic seminoma occurs only in the testis. A newly recognized aspect of this tumor is the propensity for some to be relatively monomorphic, making them apt to be mistaken for usual seminoma or embryonal carcinoma, although the characteristic polymorphic appearance in some foci, absence of intratubular germ cell neoplasia, unclassified type, and immunohistochemical stains should prevent this error. Cytoplasmic membrane immunoreactivity for placental alkaline phosphatase and CD117, with usual negativity for AE1/AE3 cytokeratins, is helpful in the diagnosis of germinoma. The recently described marker, OCT3/4, a nuclear transcription factor, is especially helpful in the differential of germinoma and embryonal carcinoma with other neoplasms. Yolk sac tumor continues to be confused occasionally with clear cell carcinoma of the ovary. Glandular ('endometrioid-like') yolk sac tumors mimic endometrioid carcinomas; predominant or pure hepatoid yolk sac tumors cause concern for metastatic hepatocellular carcinoma or, in the ovary, primary hepatoid carcinoma, and solid patterns, especially in limited samplings, may be misinterpreted as germinoma. The usually younger age of patients with yolk sac tumors helps with the differential considerations with the nongerm cell tumors, as do other clinical and microscopic features and selected immunohistochemical stains. Choriocarcinoma is rare in both gonads, and those in the ovary must be distinguished from metastatic tumors of placental origin. Syncytiotrophoblast cells alone, admixed with other forms of germ cell tumor, still are confused with choriocarcinoma, but this phenomenon, which is much more frequent than choriocarcinoma, lacks the plexiform arrangement of different trophoblast cell types that typifies the latter. Mixed germ cell tumors (which may show almost any combination of components) are common in the testis but rare in the ovary. A separately categorized, rare form of mixed germ cell tumor seen in both gonads is the polyembryoma. It is perhaps the most photogenic of all gonadal germ cell tumors and is also intriguing because of its distinctive, organized arrangement of yolk sac tumor and embryonal carcinoma elements and recapitulation of very early embryonic development, even to the extent of having in its fundamental unit, the embryoid body, a miniature yolk sac, and amniotic cavity. These tumors, which are constituted by innumerable embryoid bodies, almost always contain teratomatous glands in minor amounts, and one way of viewing the polyembryoma is to consider it the most immature form of teratoma. Embryoid bodies are also common as a minor component of many mixed germ cell tumors, particularly in the testis, and the diffuse embryoma is another variant that has a particular arrangement of yolk sac tumor and embryonal carcinoma elements. Regression of gonadal germ cell tumors is a phenomenon restricted to the testis, for unknown reasons. These so-called 'burnt-out' germ cell tumors can be recognized by a distinctive constellation of findings, including sometimes minor foci of residual recognizable germ cell neoplasia, a well-defined zone of scarring (often having residual ghost tubules), associated lymphoplasmacytic infiltrate, intratubular calcification and, in about 50%, of in situ germ cell neoplasia.

Identical allelic losses in mature teratoma and other histologic components of malignant mixed germ cell tumors of the testis

Teratomas of the testis in post-pubertal patients are histologically diverse tumors that often coexist with other types of germ cell tumors. Using laser capture microdissection and loss of heterozygosity analysis, we investigated the clonality of mature teratoma and its relationship to other components of malignant mixed germ cell tumors to gain potential insight into the histogenetic relationship of teratoma with other germ cell tumor components. All 16 patients had mature teratoma as one component of their mixed germ cell tumors. The other histological subtypes included immature teratoma, seminoma, embryonal carcinoma, yolk sac tumor, and choriocarcinoma. Laser-assisted microdissection was performed on the formalin-fixed, paraffin-embedded tissue. Polymerase chain reaction was used to amplify genomic DNA at specific loci on chromosome 1p36.2 (D1S508), 2q22-32 (D2S156), 9p21-22 (D9S162), 11p13 (D11S903), 12q22-23 (D12S1051), and 18q21 (D18S46). Fourteen of 16 (88%) cases showed allelic loss in one or more components of the mixed germ cell tumors. Fourteen of 16 mature teratomas showed allelic loss in at least one of six microsatellite polymorphic markers analyzed. The frequency of allelic loss in mature teratoma was 50% (7 of 14) with D1S508, 33% (5 of 15) with D2S156, 58% (7 of 12) with D9S162, 43% (6 of 14) with D11S903, 20% (3 of 15) with D12S1051, and 33% (5 of 15) with D18S46. Completely concordant allelic loss patterns between mature teratoma and all of the other germ cell tumor components were seen in 10 of 14 tumors in which mature teratoma showed loss of heterozygosity. Our data support the common clonal origin of mature teratoma with other components of malignant mixed germ cell tumors of the testis.

Clinical outcome after retroperitoneal lymphadenectomy of patients with pure testicular teratoma

OBJECTIVES

To determine the pathologic findings and clinical outcome of patients with pure teratoma of the testis who underwent primary or postchemotherapy retroperitoneal lymphadenectomy (RPLND).

METHODS

From January 1989 to February 1998, 29 patients with pure testicular teratoma underwent primary (n = 11) or postchemotherapy (n = 18) RPLND.

RESULTS

Overall, 23 (79%) of 29 patients had retroperitoneal disease, with 18 (62%) initially presenting with advanced disease. The pathologic stage in the 11 patients undergoing primary RPLND was pN0 in 6 (55%), pN1 in 3 (27%), and pN2 in 2 (18%). Of the 7 patients with clinical Stage I undergoing primary RPLND, 1 had teratoma and 1 had seminoma in the retroperitoneum; of the 4 patients with clinical Stage IIA, 2 had teratoma and 1 had embryonal carcinoma. Four patients were lost to follow-up and the other seven had no evidence of disease (NED) at a median follow-up of 90.4 months, with no relapses. The pathologic findings in the 18 patients undergoing postchemotherapy RPLND revealed fibrosis in 8, teratoma in 9, and yolk sac tumor in 1. At last follow-up, 7 of the 9 patients with teratoma were NED, 1 was dead of disease, and 1 was dead of unknown causes. Of the 8 patients with fibrosis, 6 had NED and 2 were lost to follow-up. The patient with viable cancer had NED at last follow-up.

CONCLUSIONS

These data underscore the metastatic potential of pure testicular teratoma. A significant proportion (45%) of patients with low-stage pure testicular teratoma had retroperitoneal disease. Furthermore, a high proportion (62%) presented initially with advanced disease and demonstrated a considerable risk of relapse despite complete resection or favorable histologic features in the resected retroperitoneal specimen.

Primary mucinous tumors of the testis and paratestis: a report of nine cases

Ovarian-type surface epithelial tumors are rare in the testis and paratestis, with most reported examples being serous. There is little information on mucinous tumors, nine of which are described in this report, applying criteria and terminology used in the ovary. The patients were 44-69 years of age (median 64 years) and presented with masses in the testis (four) or paratestis (five). Eight tumors were cystic (median size, 3.5 cm) and contained gelatinous material; one (a paratesticular carcinoma) appeared as thickening of the tunica vaginalis. Two were classified as mucinous cystadenomas (both paratesticular), six as purely or predominantly borderline tumors (four, testis; two, paratestis; one had intraepithelial carcinoma and one microinvasive carcinoma) and one (paratestis) as mucinous carcinoma. The cystadenomas were composed of endocervical-like cells, but intestinal-like cells typified the borderline tumors and carcinomas. Cyst rupture with mucin dissection into the stroma, inflammation, and dystrophic calcification with ossification were common. No tumor was associated with intratubular germ cell neoplasia, unclassified type or with teratomatous elements. One patient with carcinoma died shortly after presentation with peritoneal spread; autopsy disclosed no other potential primary site. The follow-up (1.8-12 years) in all other cases was uneventful. Mucinous tumors of the testis and paratestis resemble their ovarian counterparts, exhibiting the same morphologic spectrum, from benign to borderline to malignant, and having both endocervical-like and intestinal features. These tumors may derive from mesothelium by the process of mullerian neometaplasia, from mullerian remnants or from the mucinous epithelium of a teratoma. The older age of the patients, lack of nonmucinous elements, and absence of intratubular germ cell neoplasia, unclassified type suggest that, if of teratomatous origin, the teratoma is different from the usual type. Clinical features are important to exclude metastasis, particularly in cases of carcinoma and, to a lesser extent, in tumors of borderline type.

Adult primary teratoma of the testis--report on 5 cases in clinical stage I disease

OBJECTIVES

Testis pure teratoma accounts for 2.7% to 3% of all germ cell tumors in adult where it behaves as a malignant neoplasm. Pure teratoma of the testis presents in clinical stage I disease in 44% of the patients whose risk of having pathological stage II disease is 16.7% to 19.2%. Herein we report on 5 cases of adult pure teratoma of the testis presenting itself in clinical stage I disease.

MATERIALS AND METHODS

From September 1976 to February 2000, 75 patients underwent orchidectomy for clinical stage I nonseminomatous germ cell cancer of the testis. Testis pure teratoma was detected in 5 patients (7%). Testis tumor markers were evaluated in all cases. Patients underwent imaging examination to detect the clinical stage of the disease. Treatment options after orchidectomy included retroperitoneal lymph node dissection (RPLND) in 4 patients and surveillance in 1.

RESULTS

The average age of the patients was 31 years (range 24-45). The tumor was on the left sided in 3 cases (60%) and right in 2 (40%). Tumor average size was 3.2 cm (rang 1-6). Histopathology detected the following subtypes: mature teratoma in 3 cases (60%), immature teratoma in 1 (20%) and teratoma with malignant transformation in (20%). All patients were at clinical stage I disease. Germ cell cancer microscopic metastatic disease including embryonal carcinoma was detected in I dissected lymph node of 1/4 patients (25%). Average follow up was 166 months (range 93-249). All patients were alive and disease free and no relapses were detected during the follow up period.

CONCLUSIONS

Primary pure teratoma of the testis does not respond to chemotherapy nor does it to radiation therapy. The disease treatment options after orchidectomy for patients with clinical stage I disease include RPLND or surveillance with their relative risks and benefits. RPLND is the chosen treatment because it is both staging and treating. A close a long term follow up is required since pure teratoma metastatic disease may clinically develop after more than 10 years.

Orchidectomy after chemotherapy for patients with metastatic testicular germ cell cancer

OBJECTIVE

To evaluate the contribution of routine orchidectomy in the management of patients who present with advanced, metastatic, testicular germ cell cancer and who are treated with initial chemotherapy.

PATIENTS AND METHODS

Sixty consecutive patients presenting with metastatic testicular germ cell cancer and treated with initial chemotherapy followed by orchidectomy were identified. The results from a clinical and pathological review of these patients are presented. The pathological findings at orchidectomy were compared with the pathological findings from metastatic masses resected after chemotherapy, and are reviewed with the clinical outcome.

RESULTS

Of the 60 orchidectomy specimens after chemotherapy, 24 (40%) contained significant histological abnormalities comprising residual invasive germ cell cancer, intratubular germ cell neoplasia and/or mature teratoma. The remaining 36 (60%) orchidectomy specimens contained fibrous scarring with or with no necrosis. Six (10%) orchidectomy specimens contained residual invasive germ cell cancer, three nonseminomatous germ cell cancer (NSGCT) and three seminoma. The patients with residual invasive NSGCT present within the testis had evidence of residual invasive NSGCT within extragonadal masses resected after chemotherapy; all three have relapsed and died from chemorefractory progressive disease.

CONCLUSION

Orchidectomy after chemotherapy is recommended in all patients undergoing primary chemotherapy, as a significant proportion (40%) are left with histological abnormalities that predispose to subsequent relapse. Persistence of invasive NSGCT at the site of the primary tumour after chemotherapy is associated with persistence of invasive disease at other metastatic sites and is a poor prognostic finding.

Dermoid cyst of the testis: a study of five postpubertal cases, including a pilomatrixoma-like variant, with evidence supporting its separate classification from mature testicular teratoma

It is controversial if the rare dermoid cyst of the testis should be classified as a variant of mature teratoma or separately. The spectrum of findings is also ill defined, as is the relationship of dermoid cyst to intratubular germ cell neoplasia of the unclassified type (IGCNU). This study therefore reports the findings in five testicular dermoid cysts that occurred in five patients, 17-42 years of age, who presented with testicular masses. Four lesions consisted of a keratin-filled cyst with a thickened wall, whereas one had islands of "shadow" squamous epithelial cells with superimposed calcification and ossification (pilomatrixoma-like variant). Hair was identified grossly in two cases. On microscopic examination, four tumors had hair follicles with sebaceous glands showing a typical, cutaneous-type orientation to an epidermal surface, although no hair shafts were present in two. In addition, the fibrous wall contained smooth muscle bundles (all tumors) and eccrine or apocrine sweat glands (4 tumors). In some cases there were also glands lined by ciliated epithelium (4 tumors, including the pilomatrixoma-like variant), intestinal mucosa (1 tumor), and bone (2 tumors). There was no cytologic atypia or apparent mitotic activity, and no case had IGCNU in the seminiferous tubules. All patients were clinical stage I and were treated by orchiectomy without adjuvant therapy. All were well on follow-up from 1.5 to 9.5 years later. This study supports that dermoid cyst may have noncutaneous teratomatous elements and that an important criterion for its diagnosis is the absence of IGCNU. It also supports that it should be categorized separately from mature testicular teratoma because of the malignant nature of the latter in postpubertal patients. These observations suggest that there are at least two pathways for testicular teratomas in postpubertal patients: the more common being through IGCNU by differentiation from an invasive malignant germ cell tumor and the less common one, taken by dermoid cyst, by direct transformation from a nonmalignant germ cell.

Stage I non-seminomatous germ-cell tumours of the testis: identification of a subgroup of patients with a very low risk of relapse

There is no consensus about a reproducible prognostic model capable of distinguishing between clinical stage I non-seminomatous germ cell tumour (NSGCT) carrying a high and low risk of relapse. The aim of this study was to assess the prognostic value of histological parameters in patients with stage I NSGCT undergoing surveillance after orchiectomy. We retrospectively evaluated tumour specimens from 88 consecutive stage I NSGCT patients undergoing surveillance in our institution between 1984 and 1996. 24 patients relapsed (27%). Multivariate analysis singled out vessel invasion (VI) (relative risk (RR)=3.8; 95% confidence interval (CI) 1.4-10.4) and the presence of mature teratoma (RR= 0.2; 95% CI 0.1-0.6) as independently correlated with relapse-free survival (RFS). Patients can be classified accordingly into three prognostic groups with a low (27 patients with mature teratoma but without VI), intermediate (34 patients with both VI and mature teratoma or with neither VI or mature teratoma) and a high risk (23 patients with VI, but without mature teratoma) of relapse. Relapse rates in these three groups were 0%, 29% (95% CI: 23-35%) and 61% (95% CI: 55-67%), respectively. This prognostic index, based on two standard pathological parameters, identified a subgroup with a very low risk of relapse that represents approximately one third of stage I patients. Patients who belong to this subgroup should be managed by surveillance only, instead of retroperitoneal lymph node dissection (RPLND) or adjuvant chemotherapy.

Testis risk and prognostic factors. The pathologist's perspective

Pathologic analysis is invaluable in defining the levels of risk for the development of a testicular tumor or for metastasis in a patient with an established testicular cancer. The identification of IGCNU in testicular biopsies defines a group of patients at high risk for subsequent invasive germ cell tumor unless they are treated by orchiectomy or radiotherapy. This method for defining the risk for the development of a testicular tumor is not effective in prepubertal patients, except for those with intersex syndromes. Pathologic analysis of testicular germ cell tumors in patients with clinical stage I disease may allow their stratification into high- and low-risk groups for occult metastases. This would provide a rational basis for recommending intervention or surveillance, respectively. The precise classification of postchemotherapy lesions permits an assessment of the patient's risk for subsequent recurrence and progressive tumor.

Role for retroperitoneal lymphadenectomy for testis cancer

There continue to be several controversies surrounding the role for retroperitoneal lymphadenectomy (RPL) in the management of patients with germ cell cancer of the testis. The initial treatment options for those with clinical stage I disease are surveillance (orchiectomy only), RPL or chemotherapy. Survival rates are similar with RPL and surveillance. Surgical morbidity has been reduced as techniques for RPL continue to improve. The likelihood of early or late (> 2 years) recurrence in the retroperitoneum is almost eliminated by RPL. Fewer follow-up computerized tomography scans of the abdomen are required and there are opportunities to reduce the duration and methods of follow-up, compared with surveillance. For patients with stage II disease, chemotherapy and RPL are equally effective initial treatment options but many patients require a combined approach. Initial RPL should be reserved for patients with smaller volume disease and possibly with lower preoperative marker levels. With RPL, patients are accurately staged and cured most of the time without double treatment. Approximately 30% of those with larger masses will have residual disease after initial chemotherapy and will require RPL as a second treatment. The third indication for RPL is to excise residual retroperitoneal masses following primary chemotherapy. Models to predict the presence of residual viable tumor, rather than necrosis only, at the time of surgery have been developed. If the orchiectomy specimen contained no teratoma, the tumor markers normalize after three or four courses of chemotherapy, and if the residual mass on computerized tomography scan is less than 2 cm in diameter, the rate of viable tumor may be low enough to omit RPL. In this way, the greater morbidity often associated with post-chemotherapy RPL may be avoided.

Significance of presence of teratomatous elements in the primary tumour of testicular cancer

To assess the tumour aggressiveness of teratoma, clinical records of patients with non-seminomatous germ cell testicular cancer were reviewed. Teratomatous elements were found in 57.8% of tumours. The rate of stage I tumours was lower in the teratoma-positive group than in the teratoma-negative group. Lymph node metastasis occurred more frequently than haematogenous metastasis in the teratoma-positive group. Tumour marker response in metastatic stage of teratoma-positive group was very excellent. Even if the radiographic response was not good, most patients were alive without disease after postchemotherapeutic salvage surgery. Furthermore, two patients with pure teratoma, who had tumour recurrence, were successfully treated with the multimodal therapy. Considering the smaller number of stage I patients in the teratoma-positive group than in the teratoma-negative group, the excellent overall response in the teratoma-positive group showed less aggressiveness of the tumour as a whole.