Mesonephric adenocarcinoma of the uterine cervix: a case report with immunohistochemical and ultrastructural studies.

A very rare case of mesonephric adenocarcinoma with lobular mesonephric hyperplasia in the uterine cervix of a 46-year-old female is presented. The lesion was a 4 cm, exophytic, almost circumferential, whitish yellow, friable mass in the uterine cervix. Microscopically, the tumor was composed predominantly of atypical round to polygonal cells arranged in a ductal, tubular, or papillary pattern. The tumor involved the entire cervix with varying depths of penetration. Lobular mesonephric hyperplasia was also observed in the lateral cervical wall and adjacent to the tumor. Immunohistochemically, the tumor was positive for CAM5.2, CK7, epithelial membrane antigen, calretinin, and chromogranin A, and was negative for vimentin, carcinoembryonic antigen, estrogen and progesterone receptors, and CD10. An ultrastructural analysis showed telolysomes, which were characteristic features of mesonephric epithelium. The patient was alive without disease at 4 months after surgery.

Fine needle aspiration biopsy findings in endodermal sinus tumors. A report of four cases with cytologic, immunocytochemical and ultrastructural findings.

We present four cases of endodermal sinus tumor affecting children (median age, 20 months). Three tumors were located in the sacrococcygeal region and one in the right testicle. All cases were diagnosed by fine needle aspiration biopsy. The most characteristic features were cells arranged in a papillary-like configuration, vacuolated cytoplasm and intracellular and extracellular deposits of pink, homogeneous material. Immunocytochemical study showed alpha-fetoprotein-positive cells. Ultrastructural study showed intracytoplasmic inclusions of electron-dense material and basement membrane-like material in the intercellular spaces.

Tumor do seio endodermico do ovario / Endodermal sinus tumor of the ovary

Neste artigo, e feita uma revisao da literatura sobre o tumor do seio endodermico do ovario. Suas caracteristicas clinicas e anatomopatologicas sao comentadas e sua terapeutica e discutida.

An endodermal sinus tumor in the cerebellopontine angle.

Immunohistochemical and ultrastructural findings in a primary intracranial endodermal sinus tumor are reported in this paper. The tumor cells exhibited AFP, CEA and anti-alpha-1-trypsin positive immunoreactivity immunocytochemically. Aggregates of electron-dense material in the extra- and intracellular spaces and amorphous basement membrane-like substance were seen extracellularly by electron microscopy. The clinicopathological, immunocytochemical and ultrastructural features were consistent with the criteria for primary intracranial sinus tumor.

Effects of N-methyl-N'-nitro-N-nitrosoguanidine and deoxycholic acid on processes of tumorous transformation of rat visceral yolk sac. In vitro and in vivo studies.

The possibility to use the rat visceral yolk sac as a model for the study of processes of cell transformation was studied. Yolk sac teratocarcinomas could be induced using the method of in vitro culture of yolk sacs in a medium containing a direct carcinogen and a tumor promoter with subsequent transplantation under the renal or testicular capsule of syngeneic rats. Biochemical, electron-microscopic and immunohistochemical methods were used to study the characteristic changes that accompanied cellular transformation. It was shown that even a short-term (3 h) exposure of the yolk sac cells to N-methyl-N'-nitro-N-nitrosoguanidine with or without deoxycholic acid in vitro decreased significantly the rate of yolk sac transport and changed their developmental potential with manifestation of carcinogenic antigens (polyclonal keratins, monoclonal vimentin and smooth muscle actin). This cancerous transformation was promoted following their in vivo transplantation into special anatomic sites.

Yolk sac tumor of the liver.

A primary yolk sac tumor of the liver in a 16-mo female is presented. The fine needle aspiration biopsy (FNAB) cytology of this lesion is illustrated and discussed. This case supports continued exploration of the use of FNAB in childhood abdominal masses.

Primary pulmonary alpha-fetoprotein-producing malignant germ cell tumor.

We are reporting the clinical and pathologic features of a primary, pulmonary, malignant germ cell tumor associated with a marked elevation of serum alpha-fetoprotein (38,427 ng/mL) and lactate dehydrogenase activity (756 U/L), in a 26-year-old female. This controversial, rare neoplasm has not been extensively discussed in the pathology literature. We emphasize the clinical importance of establishing this diagnosis in view of the favorable response to chemotherapy shown by malignant germ cell tumors.

Fine-needle aspiration biopsy diagnosis of endodermal sinus tumor: histologic and ultrastructural correlations.

Fine-needle aspiration biopsies from five patients with endodermal sinus tumors (ESTs) were reviewed, and the findings were correlated with histologic and ultrastructural appearances. In the aspiration smears, two types of tumor cells were seen, forming clusters of variable sizes. Type A cells had distinct cell borders, and their cytoplasm contained only occasional vacuoles. Type B cells had ill-defined cell borders and formed syncytial clusters; their cytoplasm was characterized by large numbers of rounded vacuoles. The background contained patches of mucoid material and macrophages with foamy cytoplasm. Eosinophilic hyaline cytoplasmic bodies and irregular deposits of intercellular basement membrane-like material were recognized easily in aspiration smears. These features correlated well with histologic and ultrastructural appearances. The significance of these findings in the fine-needle aspiration biopsy diagnosis of EST and its distinction from other germ-cell and non-germ-cell tumors is discussed.

[Light and electron microscopic observations on endodermal sinus tumor of the ovary].

The results of light and electron microscopic studies of the endodermal sinus tumor of ovary are presented. Although histologic features of the tumors appeared to be much varied, ultrastructurally all tumor cell seemed to show changes essentially of the same nature. The histogenesis of endodermal sinus tumor production of AFP by the hyaline globule and the basement membrane-like substance present only in this type of tumor, are discussed. The results of the present study support the view that the tumor originate from the embryonal yolk sac cells.

Two human tumors with high basement-membrane-producing potential.

Two human tumors, an adenoid cystic carcinoma and a yolk sac tumor, were found by immunocytochemical, ultrastructural, and biochemical studies to contain abundant basement membrane matrix in contrast to the vast majority of human tumors which contained either an absent or scant basement membrane matrix. These tumors were established as xenografts in athymic (nude) mice. Both xenografts maintained characteristic histologic features, immunocytochemical localization of basement membrane components, and reasonable yields of native laminin and Type IV collagen throughout three successive transplant generations. Although only a small fraction of the yield of that of the murine Engelbreth-Holm, Swarm (EHS) sarcoma, the yield of the human basement membrane-producing tumors could be increased by rendering the mice lathyritic. The human basement membrane proteins so extracted were identical on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to their murine counterparts. These human tumors then represent a potential source of human basement membrane proteins.

Experimental rat model for human yolk sac tumor.

The morphological and biological characteristics of experimentally induced rat yolk sac carcinomas (ysca) are compared to those of human yolk sac tumors. It is shown that the rat ysca shares many morphological and biological properties with its human counterpart although the cellular origin is probably different. Whereas the human yolk sac tumors are believed to be of germ cell origin, the rat visceral yolk sac-derived tumors are not. The hypothesis is formulated that the rat ysca are derived from multipotential cells different from germ cells, and which originate in the extra-embryonic membrane after displacement.

The ultrastructure and histogenesis of male germ neoplasia with emphasis on seminoma with early carcinomatous features.

The range of ultrastructural morphology was studied in 107 male germ cell neoplasm to assess relationships among tumor subtypes and to consolidate diagnostic criteria. Eighty-three pure-pattern neoplasms including 47 seminomas, 26 embryonal carcinomas, 10 endodermal sinus tumors, and 24 mixed germ cell tumors were analyzed. In the seminoma category, 4 cases showing cell surface specialization in keeping with early carcinomatous transformation were noted. The finding suggested a closer link between seminoma and nonseminomatous germ cell tumors than had been traditionally recognized and was in keeping with other clinical, histologic, biochemical, and xenograft observations. Subtypes of nonseminomatous germ cell tumors also exhibited a continuum of ultrastructural morphology with some types such as embryonal carcinoma and endodermal sinus tumor often blending together. At a practical level, electron microscopy has been of value in selected differential diagnoses such as seminoma versus lymphoma.

Recent developments in the pathology of germ cell tumors.

This article describes some of the recent developments in the pathology of germ cell tumors of the testis. Many germ cell tumors show different types of differentiation. Two different explanations for this phenomenon include the differentiation of other germ cell elements from totipotential embryonal carcinoma cells or the direct differentiation of neoplasms from a malignant intratubular germ cell. Although the concept that there is a subset of seminomas having a poorer prognosis still exists, the histologic identification of such "anaplastic seminoma" remains an unachieved goal, and we, therefore, do not recommend the use of the term anaplastic seminoma at present. A recent analysis of spermatocytic seminomas has failed to demonstrate that they are capable of meiotic division. They are composed of cells differentiating in the direction of spermatocytes, but they have not achieved that stage. The prognosis, in general, remains excellent, although recently sarcomas have been reported in association with spermatocytic seminomas with metastasis of the sarcomatous elements. The presence of human chorionic gonadotropin-producing syncytiotrophoblastic giant cells in otherwise pure seminomas does not appear to adversely affect the prognosis. Yolk sac tumors have a varied histology that many pathologists do not recognize. The presence of intercellular basement membrane (parietal differentiation) is useful in the recognition of yolk sac tumor. Sometimes solid foci of yolk sac tumor may be mistaken for seminoma, and alpha-fetoprotein and cytokeratin stains may be useful in this situation, although the presence of basement membrane, hyaline globules, and focal microcysts by light microscopy may obviate the need to use them. Hepatic and enteric (or endometrioid) differentiation may occur in yolk sac tumors and cause diagnostic confusion. The development most "non-germ" cell malignancies in patients with germ cell tumors appears to occur by transformation of aneuploid teratomatous elements at the primary or metastatic site. The identification of such malignancies depends on the recognition of invasion by the elements rather than on high-grade cytologic atypia. Unusual patterns of choriocarcinoma and yolk sac tumor may be encountered following chemotherapy, and there is circumstantial evidence that some sarcomas and carcinomas occurring in patients with testis cancer may develop directly from yolk sac tumor.

Gonadal endodermal sinus (yolk sac) tumor with pure intestinal differentiation: a new histologic type.

We studied 3 cases of a variant of endodermal sinus tumor (EST) or yolk sac tumor (YST). Two tumors originated in the ovary and one in the testis. The patients had very high levels of serum alpha-fetoprotein (AFP). All three tumors had a characteristic histologic appearance and were composed of acinar structures lined by columnar epithelium with large, immature nuclei. Immunohistochemistry and electron microscopy, including freeze-fracture studies, confirmed that this unusual tumor is one with exclusive intestinal differentiation. We feel that this unique tumor is a pure EST (YST) with exclusive intestinal differentiation.

Poorly differentiated carcinoma of unknown primary site: correlation of light microscopic findings with response to cisplatin-based combination chemotherapy.

We have previously reported complete responses and long-term survival in patients with metastatic poorly differentiated carcinoma (PDC) of unknown primary site who received intensive cisplatin-containing chemotherapy regimens. We reviewed the light microscopic specimens from 113 patients with PDC in an attempt to identify common histopathologic features in the chemotherapy-responsive subgroup, and to rule out the presence of previously unrecognized germ cell tumors. Relatively few diagnoses more specific than PDC could be made. We could identify no histopathologic features by light microscopy that distinguished responsive from unresponsive neoplasms. Only one patient was found to have a previously unrecognized yolk sac carcinoma, and in five other patients the possibility of a germ cell neoplasm was considered in the differential diagnosis by at least one reviewer. The remaining tumors had no histologic features suggestive of germ cell neoplasms. Ninety-six patients had received combination chemotherapy (89 with cisplatin-containing regimens); 27 patients (28%) achieved complete remission, and 16 remain free of disease at a median of 65 months after completion of therapy. Patients with PDC of unknown primary site who are responsive to cisplatin-containing chemotherapy regimens cannot be reliably identified by light microscopy. At present, all such patients should be considered for an empiric trial of chemotherapy with cisplatin-based regimens, since cure is achievable in a minority.

Human testicular germ cell tumors in vitro and in athymic nude mice.

Four cell lines derived from pure and mixed types of human testicular germ cell tumors in vitro and in nude mice were examined by light and electron microscopies. The NEC8 and NEC15 cell lines in vitro were composed of embryonal carcinoma cells with potentiality of trophoblastic differentiation. All of the tumors formed in nude mice by both cell lines were pure embryonal carcinomas. On the other hand, the NEC14 and ITO-II cell lines showed morphological differentiation from embryonal carcinoma cells to trophoblastic cells and to yolk sac tumor cells in vitro. In nude mice, these cell lines formed mixed tumors which consisted of embryonal carcinoma, yolk sac tumor, immature teratoma or trophoblastic cells. Our data suggest that some embryonal carcinomas have multipotentiality of morphological differentiation but that others have little such potentiality.

Yolk sac tumors of the ovary and the human yolk sac.

In the present study a comparison was made between human yolk sacs and yolk sac tumors. Tubules surrounded by several to as many as 10 endodermal cells and intracellular tubules in one endodermal cell were frequently observed. The tubules were seen abundantly in the yolk sac of a 4-week pregnancy, and they resembled the reticular pattern of the yolk sac tumor. It was also observed that the papillary endoderm, which contained blood cells in the center and protruded into the endodermal tubules, resembled the Schiller-Duval body of yolk sac tumor. Ultrastructurally the tumor cells were similar to the yolk sac endoderm. alpha-Fetoprotein was positive in the yolk sac endoderm until approximately the seventh week of pregnancy. Yolk sac tumor was also alpha-fetoprotein-positive. In other words, our study of human yolk sacs of 4- to 11-week pregnancies presumes that the yolk sac tumor resembles the endoderm of 4- to 7-week pregnancies.

Germ cell tumors (germinoma and yolk sac tumor) in unusual sites in the brain.

This report presents three cases of primary intracranial germ cell tumor encountered in unusual sites, or essentially non-midline structures. The three provided the opportunity to examine surgically obtained tissues with the electron microscope. The histological diagnosis was initially made by light microscopic observations. The first case was a 10-year-old boy in whom the tumor occupied the right thalamic and basal ganglionic region and was diagnosed as a yolk sac tumor. The second an 11-year-old boy who presented with a mass lesion on the left thalamic and basal ganglionic region, diagnosed as germinoma. The third was a 39-year-old man who presented with multiple tumors in the ventricular system and posterior fossa, also diagnosed as germinoma. Among the three cases, neither diabetes insipidus nor ophthalmologic disorder was manifested. Extensive examination and autopsy findings indicated that these intracranial lesions had not metastasized from primary extracranial tumors, including those of the genital organs.