Le séminome spermatocytaire

Pattern of placental alkaline phosphatase (PLAP) expression in human tumors: a tissue microarray study on 12,381 tumors

Placental alkaline phosphatase (PLAP) is commonly expressed at high levels in testicular germ cell tumors. PLAP immunohistochemistry (IHC) is thus often used to confirm this diagnosis, especially in cases of putative metastasis. However, other tumors can also express PLAP. To comprehensively determine PLAP expression in normal and tumor tissue, a tissue microarray containing 16,166 samples from 131 different tumor types and subtypes as well as 608 samples from 76 different normal tissue types was analyzed by IHC. Moderate to strong PLAP positivity was found in 27 (21%) of 131 different tumor types including seminoma (96%), embryonal carcinoma (85%), and yolk sac tumors of the testis (56%); endometrioid carcinoma of the endometrium (28%) and the ovary (20%); gastric adenocarcinoma (22%); serous carcinoma (not otherwise specified) of the ovary (17%) and the uterus (11%); adenocarcinoma of the ampulla of Vater (15%); carcinosarcoma of the ovary (11%) and the uterus (8%); esophageal adenocarcinoma (10%); invasive urothelial carcinoma (4%); cholangiocarcinoma (2%); and adenocarcinoma of the lung (1%). Low‐level PLAP immunostaining, often involving only a small fraction of tumor cells, was seen in 21 additional tumor entities. The clinical significance of PLAP expression may vary between tumor types as high PLAP expression was linked to advanced pathological tumor stage (p = 0.0086), nodal metastasis (p = 0.0085), and lymphatic (p = 0.0007) and blood vessel invasion (p = 0.0222) in colorectal cancer, but to low pathological tumor stage in endometrial cancer (p = 0.0043). In conclusion, our data identify several tumor entities that can show PLAP expression at comparable levels to testicular germ cell tumors. These tumor entities need to be considered in cases of PLAP‐positive metastasis. Low‐level PLAP expression can be found in various other tumor entities and should generally not be viewed as a strong argument for germ cell neoplasia.

Expression of the C-terminal region of the SSX protein is a useful diagnostic biomarker for spermatocytic tumour

AIMS

Spermatocytic tumour (ST) is a rare testicular germ cell neoplasm with few confirmatory biomarkers that can be challenging to diagnose. Like normal spermatogonia, STs are known to express SSX proteins. Recently, a novel SSX antibody directed against a conserved C-terminal region of SSX1, SSX2 and SSX4 (SSX_CT) has emerged as a reliable biomarker for these SSX proteins and synovial sarcoma. However, SSX_CT immunostaining has not been demonstrated in ST. The aim of this study was to assess the diagnostic utility of SSX_CT immunohistochemistry in ST and other tumours in the differential diagnosis with ST.

METHODS AND RESULTS

SSX_CT, OCT3/4 and c-KIT immunohistochemistry was performed on 15 STs, 38 seminomas, 13 embryonal carcinomas, 12 yolk sac tumours, six choriocarcinomas, four teratomas, seven Sertoli cell tumours, and six lymphomas. Staining was scored as negative, rare, focal, or diffuse. SSX_CT was positive in all (15/15) STs, and diffusely positive in 14 of 15 (93%). SSX_CT was positive in 22 of 38 (58%) seminomas; however, only two cases showed diffuse expression. SSX_CT was negative in all other tumours. OCT3/4 was negative in all STs, but positive in all seminomas and embryonal carcinomas. c-KIT was frequently positive in both STs (12/15; 80%) and seminomas (33/38; 87%). OCT3/4 and c-KIT were negative in all other tumours.

CONCLUSIONS

SSX_CT is a valuable and highly sensitive biomarker that supports the diagnosis of ST. Diffuse expression of SSX-CT in STs is also highly specific for ST. Nevertheless, SSX_CT is best used in combination with OCT3/4 when ST is in the differential diagnosis.

Spermatocytic Tumor With Sarcoma: A Rare Testicular Neoplasm

Spermatocytic tumor, formerly known as spermatocytic seminoma, is an uncommon testicular neoplasm which is a distinct clinicopathologic entity from classic seminoma. These tumors are not associated with germ cell neoplasia in situ, other germ cell tumors, or isochromosome 12p. Although typically, these tumors have an excellent prognosis occasional cases are associated with sarcoma and have a very poor prognosis. We present a case of spermatocytic tumor with sarcoma showing a chondrosarcomatous component, discuss the pathologic findings and differential diagnosis and provide follow-up information.

[Spermatocytic seminoma. A tumor with many faces]

Spermatocytic seminomas affect 0.3-0.8 per one million men. This tumor is not, as the name might suggest, a variant of classical seminoma but a distinct nosological entity, which differs markedly from all other germ cell tumors in its epidemiology, peculiar morphology, oncogenesis and clinical outcome. There are no racial differences in the incidence and risk factors are completely unknown. Patients are significantly older than is the case for other germ cell tumors with an average of 53.5 years; nevertheless, more than 25 % are younger than 40 years. Spermatocytic seminoma arises from differentiated spermatogonia, not from intratubular germ cell neoplasms. The tumor-specific gain of chromosome 9 seems to be the most important event in the oncogenesis. Conventional spermatocytic seminoma consists of three different cell types which give the tumor a highly aggressive appearance, although in actual fact, the tumor has a very favorable outcome, with few reported cases of general metastatic spread. Anaplastic spermatocytic seminoma, a recently described variant, also takes mostly a benign course; however, spermatocytic seminomas combined with sarcomas are extremely malignant.

Cancer testis antigen expression in testicular germ cell tumorigenesis

Cancer testis antigens are encoded by germ line-associated genes that are present in normal germ cells of testis and ovary but not in differentiated tissues. Their expression in various human cancer types has been interpreted as 're-expression' or as intratumoral progenitor cell signature. Cancer testis antigen expression patterns have not yet been studied in germ cell tumorigenesis with specific emphasis on intratubular germ cell neoplasia unclassified as a precursor lesion for testicular germ cell tumors. Immunohistochemistry was used to study MAGEA3, MAGEA4, MAGEC1, GAGE1 and CTAG1B expression in 325 primary testicular germ cell tumors, including 94 mixed germ cell tumors. Seminomatous and non-seminomatous components were separately arranged and evaluated on tissue microarrays. Spermatogonia in the normal testis were positive, whereas intratubular germ cell neoplasia unclassified was negative for all five CT antigens. Cancer testis antigen expression was only found in 3% (CTAG1B), 10% (GAGE1, MAGEA4), 33% (MAGEA3) and 40% (MAGEC1) of classic seminoma but not in non-seminomatous testicular germ cell tumors. In contrast, all spermatocytic seminomas were positive for cancer testis antigens. These data are consistent with a different cell origin in spermatocytic seminoma compared with classic seminoma and support a progression model with loss of cancer testis antigens in early tumorigenesis of testicular germ cell tumors and later re-expression in a subset of seminomas.

A rare case of bilateral sequential spermatocytic seminoma

Spermatocytic seminoma (SS) is a rare testicular neoplasm characterized by a palpable, painless, slowly enlarging mass in the testis. Even more rare is a synchronous bilateral presentation. Only eight cases of bilateral SS have been reported in the literature, of which three cases were present with synchronous testis enlargement, and five were sequential. Here, we report an additional case of synchronous bilateral SS and present a comprehensive relevant literature review concerning clinical features, histopathology, and treatment.

Spermatocytic seminoma at the National Institute of Oncology in Morocco

Background

Spermatocytic seminoma (SS) is a distinct testicular germ cell tumor, representing less than 1% of testicular cancers. The clinical features that distinguish ss from classical seminoma are an older age at presentation and a reduced propensity to metastasize. The aim of our work is to underline the epidemiological, clinical, histological, therapeutical and prognostic features of this tumor.

Findings

A retrospective analysis of patients referred to the national institute of oncology with seminoma, identified from the institutional tumor registry, between January 1996 and February 2009, was performed. Information reviewed included demographics, clinical, pathological staging, surgical management, adjuvant treatment and last follow-up. We studied four cases of spermatocytic seminoma, which represented 1% of testicular tumor and 6,4% of all seminoma treated at our institution during the study period. Median age at diagnosis was 45 years (range: 42-48). Mean delay before consulting was 9 months and the mean tumor size was 13,75 cm (10-18 cm). No patient had a history of maldescended testis. The main clinical complaint was unilateral testis mass with low progression. Pathology showed that tumors had a polymorphic appearance with small, intermediate and large cells. In all cases, the tumor was limited to the testis. immunohistochemical studies showed that tumors were negative for all the classical antibodies tested (LCA, cytokeratins, PLAP, lymphoid markers, CD117). Thoraco-abdomino-pelvic CT scan and tumor markers (AFP and hCG) were normal. All patients were Stage I. Treatment consisted on an orchidectomy associated with adjuvant radiotherapy in one patient. After a median follow-up of 6 years ranging from 2 to 15 years, we did not note any relapse or metastasis.

Conclusion

The diagnosis of spermatocytic seminoma must be considered in all patients aged of more than 50 with testicular tumor. With only three cases of metastatic disease confirmed in the literature, this is a subgroup of patients in whom radiotherapy can safely be omitted.

Review Article: Spermatocytic Seminoma: Review of the Literature and Description of a New Case of the Anaplastic Variant

The aims of this paper were to review the literature of Spermatocytic Seminoma (SS) updating its clinico-pathological features and to present a new case of the exceptionally rare variant of this tumor known as anaplastic which only five cases have been reported. Many studies have confirmed that SS is a distinct neoplasm both clinically and pathologically from classical Seminoma and it differs from the latter especially in regard to behavior, characterized by an almost complete inability to metastasize with only very few convincing examples described with metastatic behavior. There is general agreement that orchidectomy is sufficient therapy for SS and that surveillance following surgery is the preferred management option. Surprisingly, the presence of an anaplastic component does not seem to impact on this excellent prognosis. Very different is the case of sarcomatous transformation, for which further therapy after orchiectomy is advisable.

[Isolated testicular mass revealing a metastasis of prostate adenocarcinoma]

A testicular mass on a patient over 50 years should be considered as a metastasis, a lymphoma or a spermatocytic seminoma. Testicular metastases are rare, representing about 1 % of all testicular tumors. Prostate is the most common primary site, with less than 100 reported cases in the literature. They are most often incidentally discovered tumors, after bilateral orchiectomy for hormonal management of prostate carcinoma or at autopsy. Metastases revealed by a testicular mass are very rare. We report the original case of an 80-year-old patient with a left testicular mass indicating a metastasis of a prostate carcinoma diagnosed six years earlier. No other metastatic localization was found.

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.

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.

Anaplastic variant of spermatocytic seminoma

We report a case of a 56-year-old male with an anaplastic variant of spermatocytic seminoma of the left testis. Grossly, the tumor measured 10 x 7.5 x 6.5 cm and consisted of soft grayish-white tissue, which varied from fleshy to gelatinous with formation of some pseudocysts. Histologically, the tumor was composed of the areas of typical spermatocytic seminoma; however, in some areas, the intermediate and large tumor cells showed prominent nucleoli. In another part of the tumor, we noted anaplastic areas composed of sheets of tumor cells with large vesicular nuclei and prominent nucleoli. Tunical and vascular invasion as well as growth into the epididymis were noted. Immunohistochemically, the tumor cells showed only weak positivity for CD117, the other markers examined were negative.