Ovarian Intermediate Trophoblastic Tumors: Genotyping Defines a Distinct Category of Nongestational Tumors of Germ Cell Type.

Trophoblastic neoplasms involving the ovary are uncommon and include gestational tumors, which are either metastatic from the uterus or ectopic and nongestational tumors, which include those of germ cell type/origin and somatic tumors with trophoblastic differentiation; in all these types, most are pure choriocarcinoma. Intermediate trophoblastic tumors, which include placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT), are rare in the ovary, with most assumed to be gestational; this is the only category formally recognized in 2014 World Health Organization (WHO) classification, likely due to few well-documented nongestational examples. We report the clinicopathologic features of 6 ovarian intermediate trophoblastic tumors, including 3 PSTTs, 2 ETTs, and 1 ETT with choriocarcinomatous differentiation. DNA-based short tandem repeat genotyping identified 4 of these as nongestational (3 PSTTs and 1 ETT), as evidenced by sharing of alleles between tumor and normal tissue at all informative loci. Interestingly, all 3 of the nongestational PSTTs coexisted with mature cystic teratoma. The remaining 2 tumors (1 ETT and 1 ETT with some choriocarcinomatous differentiation) were gestational (likely ectopic due to lack of evidence of a uterine tumor), as evidenced by the presence of both maternal and novel/nonmaternal alleles at informative loci in tumor compared with normal tissue. It is important to recognize a distinct category of primary ovarian nongestational intermediate trophoblastic tumors of germ cell type/origin, including PSTT and ETT, in classification systems to guide clinical management, as gestational and nongestational tumors have different genetic origins and may require different therapy. Genotyping is useful for classification as nongestational versus gestational, particularly as traditional clinicopathologic findings cannot always predict the nature of a trophoblastic tumor.

Clinicopathologic analysis of choriocarcinoma as a pure or predominant component of germ cell tumor of the testis.

Although well recognized in the literature, the contemporary clinicopathologic data regarding choriocarcinoma (CC) as a pure or the predominant component of a testicular germ cell tumor (GCT) are limited. Herein, we present a series of pure CC and predominant CC in mixed GCT of the testis obtained from a single oncology institution. A comprehensive histologic review of 1010 orchiectomies from 1999 to 2011 yielded 6 (0.6%) pure CC and 9 (0.9%) mixed GCT cases with a predominant CC component. Patients' ages ranged from 20 to 39 years (median 29 y). All patients had markedly elevated serum ß-hCG levels (median 199,000 IU/mL) at presentation. All tumors were unilateral and involved the right (9/15) and left (6/15) testis. The mean tumor size was 6.5 cm (range, 1.5 to 8 cm). Histology was similar for pure CCs and the CC component of mixed GCTs. CC commonly showed expansile hemorrhagic nodular cysts surrounded by variable layers of neoplastic trophoblastic cells (mononucleated trophoblasts and syncytiotrophoblasts). The syncytiotrophoblasts usually covered columns of mononucleated trophoblasts and occasionally formed plexiform aggregates and pseudovillous protrusions. Immunohistochemical stains suggested a mixture of cytotrophoblasts (p63+, HPL_) and intermediate trophoblasts (p63-, HPL weak +/-) in the columns of mononucleated cells. In the 9 mixed GCTs, CC comprised 50% to 95% (7/9 were ≥80% CC) of the tumor; 7 were combined with 1, and 2 were combined with 2 other GCT components. The non-CC components included teratoma (5/9), seminoma (2/9), yolk sac tumor (2/9), and embryonal carcinoma (2/9). Lymphovascular invasion, spermatic cord invasion, and tunica vaginalis invasion were present in 15/15, 5/15, and 1/12 cases, respectively. In mixed GCTs, these locally aggressive features were attributed to the CC component, except in 1 tumor in which it was also exhibited by the embryonal carcinoma component. Lymphovascular invasion was multifocal to widespread in 73% of tumors. The stages of the 15 tumors were: pT2 (10), pT3 (5); NX (1), N1 (4), N2 (5), N3 (5); and M1a (2) and M1b (13). Distant organ metastasis mostly involved the lungs (11) and liver (10). Follow-up information was available in 14 patients, all of whom received cisplatin-based chemotherapy. All 6 pure CC patients were dead of disease (range, 6 to 14 mo, median 9.5 mo). Follow-up of 8 patients with predominant CC (range, 10 to 72 mo, median 27 mo) showed that 5 died of the disease, and 1 was alive with disease and 2 were alive with no evidence of disease at 60 and 72 months of follow-up, respectively; these latter 2 patients were the only ones with M1a disease on presentation. This series confirms the proclivity for high-stage presentation including presence of distant metastasis, hematogenous spread, and poor outcome of testicular CC. Mixed GCT with a predominant CC component has similar tendency for high-stage presentation, marked elevation of serum ß-hCG levels, and aggressive behavior compared with pure CC. This study also showed that distant metastasis by CC when only involving the lungs (M1a) may not be uniformly fatal with chemotherapy. The mononucleated trophoblastic columns in testicular CC appear to be a mixture of cytotrophoblasts and intermediate trophoblasts, similar to that described in gestational CC.

Primary hepatic choriocarcinoma in a 49-year-old man: report of a case.

We report a case of hepatic choriocarcinoma in a man diagnosed at autopsy after a rapid downhill clinical course. The patient was a 49-year-old man who presented with acute right-sided abdominal pain. There were no masses palpable on physical examination. Radiographic findings showed large multi-nodular tumors mainly in the right lobe of the liver. Fludeoxyglucose-positron emission tomography scan showed uptake only in the liver, and no uptake in the testes. We initially planned to perform a liver resection for the presumed diagnosis of intra-hepatic cholangiocarcinoma. However, the tumors grew rapidly and ruptured. Multiple lung metastases rapidly developed resulting in respiratory failure, preventing liver resection or even biopsy. He died 60 d after initial presentation with no pathological diagnosis. Postmortem studies included histopathological and immunohistological examinations which diagnosed a primary choriocarcinoma of the liver. Primary hepatic choriocarcinoma is very rare but should be considered in the differential diagnosis of a liver tumor in a middle aged man. Establishing this diagnosis may enable treatment of the choriocarcinoma. Liver biopsy and evaluation of serum human chorionic gonadotropin are recommended in these patients.

OCT4 staining in testicular tumors: a sensitive and specific marker for seminoma and embryonal carcinoma.

OCT4 (POU5F1) is a transcription factor expressed in embryonic stem and germ cells and is involved in the regulation and maintenance of pluripotency. It has been detected in primary testicular germ cell tumors with pluripotent potential, seminoma, and embryonal carcinoma. We undertook immunohistochemical staining of OCT4 in a wide variety of primary testicular neoplasms (germ cell tumors and other tumors) to assess the specificity and usefulness of this marker as a diagnostic tool. We examined histologic sections from 91 primary testicular neoplasms, including 64 cases of mixed germ cell tumors containing embryonal carcinoma (54), seminoma (51), yolk sac tumor (38), mature teratoma (31), immature teratoma (20), and choriocarcinoma (15). In addition, we examined sections from spermatocytic seminomas (5), Leydig cell tumors (8), Sertoli cell tumors (6), unclassified sex-cord stromal tumors (4), adenomatoid tumors (2), testicular tumor of adrenogenital syndrome (1), and granulosa cell tumor (1). Each tumor was examined with hematoxylin and eosin staining and with antibodies to OCT4. In all cases of mixed germ cell tumor with components of embryonal carcinoma (54) and seminoma (51), there was greater than 90% nuclear staining of the embryonal carcinoma and seminoma tumor cells with little to no background staining. In all but 1 of these cases (embryonal carcinoma), there was strong (3+) staining intensity. The other germ cell tumor components (yolk sac tumor, mature teratoma, immature teratoma, and choriocarcinoma) showed no staining. Syncytiotrophoblast cells, which were present in 15 of the cases, were also completely negative, as were all 5 of the spermatocytic seminomas. The 22 cases of non-germ cell tumors were all immunohistochemically negative for OCT4. Fifteen of the 54 germ cell tumors containing embryonal carcinoma were also examined with antibodies to CD30. These embryonal carcinoma components were all positive for CD30 with staining of greater than 90% of the tumor cells but with variable staining intensity. We conclude that immunostaining with antibodies to OCT4 is a useful diagnostic tool in the identification of primary testicular embryonal carcinomas and "usual," but not spermatocytic, seminomas. OCT4 immunostaining has comparable sensitivity but greater consistency compared with CD30 in the diagnosis of embryonal carcinoma.

Intratubular germ cell neoplasia of unclassified type occupying the whole testis accompanied by a small mature teratoma and metastatic choriocarcinoma and Sertoli cell-only tubules in the other testis.

A 19-year-old man with mild mental retardation was diagnosed as having metastatic choriocarcinoma and a testicular tumor. Histopathological examination of the resected testis revealed the presence of a small lesion of mature teratoma but no trace of choriocarcinoma. The remaining seminiferous tubules were atrophic and lined by large atypical germ cells, which were diagnosed as intratubular germ cell neoplasia of the unclassified type (IGCNU). A small area with prominent tubules was also observed. Within this lesion, the tubules were dilated and contained several layers of cells with central necrosis. Immunohistological comparison of staining for several biological markers (Ki-67, c-kit and placental alkaline phosphatase) between cells in the atrophic tubules and those in the dilated tubules indicated a progression of the latter cells to cells with a more proliferative ability. In the opposite testis, examined at autopsy after death due to metastatic choriocarcinoma, all seminiferous tubules were lined by Sertoli cells only. It was therefore assumed that the germ cell tumor of the combined histological type had primarily arisen in the background of IGCNU, and that choriocarcinoma had spontaneously regressed. The early onset of these testicular neoplastic lesions strongly indicates their occurrence under the genetic background of gonadal dysplasia, the Sertoli cell-only syndrome. The possible relation of gonadal disease to mental retardation in this patient is also discussed.