Nephrogenic rest associated with a mesoblastic nephroma--what does it tell us?

A 3-year-old girl presented with a tumor in the right kidney that was found to be a mesoblastic nephroma on histological examination. In addition, between the tumor and renal parenchyma there was a large perilobar sclerosing nephrogenic rest--a finding that has rarely been reported previously in non-Wilms renal tumors of childhood. We believe this supports the theory that both mesoblastic nephroma and Wilms tumor arise from the developing kidney but the key difference is the time point at which induction of neoplasm occurs.

[Nephrogenic adenoma of the bladder associated with urinary tuberculosis. Case report]. / L'adenoma nefrogenico della vescica associato a tubercolosi urinaria. Contributo casisitico.

Nephrogenic adenoma is an uncommon benign lesion of the urinary tract, that histologically is characterised by glandular-like aspects resembling the distal part of the nephron. It is usually associated with antecedent inflammation, surgical procedures or other injuries. Personal experience with one additional case nephrogenic adenoma of the bladder in a patient with urinary tract tuberculosis is presented.

Ectopic somatic endoderm in secondary human yolk sac.

Three secondary human yolk sacs (SHYSs) showing heterotopic endodermal tubular structures of the gut-forming type were analyzed from a series of 180 SHYSs. These structures were similar to the early somatic endoderm involved in the formation of gut and lung. They may have arisen either as sequestrations in growth-disorganized embryos or as a phenomenon of differentiation from extraembryonal endoderm, which would indicate that extraembryonal tissues such as the SHYSs retain the capacity to differentiate somatic endoderm in developmentally altered embryos. It is possible that these structures may be the precursors of placental hepatic tissue and teratomas. Their morphologic resemblance to similar structures found in glandular, polyvesicular, and intestinal human yolk sac tumors provides yet another example of the similarity between SHYSs and yolk sac tumors.

[The role of embryoid bodies in the development of germinogenous tumors of complex structure and of the teratoma]. / Rol' émbrioidnykh telets v razvitii germinogennykh opukholei slozhnogo stroeniia i teratomy.

250 germinal gonadal and extragonadal tumors were studied in children and adolescents under 16 years of age. Germinal tumours of complex structure were found in 42 patients and in 36 of them embryoid bodies of various types (full, not-full, amorphous) were distinguished. Certain features were revealed indicating the development of the immature teratoma by means of maturation of preexisting embryoid bodies. The arguments in favour of complex germinal tumour development due to the loss of maturation and differentiation capacity of one or several structural elements of the embryoid bodies are presented. The observation of mature, immature embryonal tissues and proliferating elements of the embryoid bodies in the composition of one and the same tumour may be explained by different biological potency of individual clones of atypical and primordial germinal cells which are the source of the development of these tumours.

Monosomy 12p in a radiation-induced germ cell tumor.

We report results of cytogenetic analysis of a cell line established from a radiation induced germ cell tumor. Tumors of this type are rare, and there is only one other report of chromosome analyses of solid tumors induced by radiotherapy (Cowan et al., 1990). The cells were grown for over a year, and harvested at passage 13. The karyotype was pseudodiploid, with several balanced translocations. Spontaneously occurring germ cell tumors are associated with i(12p). We did not observe an i(12p), but instead found monosomy of 12p and 7q22----q32.

Yolk-sac carcinoma develops spontaneously as a late occurrence in slow-growing teratoid tumors produced from transplanted 7-day mouse embryos.

Seven-day embryos of BALB/c mice transplanted underneath the kidney capsule of adult syngeneic recipients form either benign teratomas or teratocarcinomas, which can be distinguished from one another histologically at 8 weeks post-embryonic transplantation. Embryo-derived (ED) teratomas were allowed to remain in the host for an additional period up to 1 year after embryo transplantation, to test their malignant potential. It was found that a considerable number of slow-growing small tumors derived from embryonic transplant give rise to parietal yolk-sac carcinomas. A proportion of these tumors contained foci of visceral yolk-sac and trophoblastic differentiation, which gradually disappeared in successive transplantations. We conclude that parietal yolk-sac carcinoma develops as a late event in some ED teratomas. These malignant tumors originate either from small foci of yolk sac originally included in the grafted embryo or, more likely, from the yolk sac formed from the differentiating embryonic stem cells.

Ploidy of primary germ cell tumors of the testis. Pathogenetic and clinical relevance.

The ploidy of testicular germ cell tumors (GCT), a heterogeneous group of neoplasms, was studied by DNA flow cytometry. The DNA index for infantile yolk sac tumor (N = 10), seminomas (N = 20), and nonseminomas (N = 36), was: 1.91, 1.66, and 1.43, respectively. These values differed significantly one from another (p less than 0.01). The seminoma and nonseminoma components of combined tumors (N = 16) had a significantly different median DNA index of 1.61 and 1.40, respectively. Three of the 10 infantile yolk sac tumors, but only one of the 72 testicular GCT of adults were diploid. The consistent aneuploidy of testicular GCTs of adults might be helpful in the differential diagnosis of primary nongerm cell tumors of the testis, and in differentiating between metastases of testicular GCTs and primary extragonadal malignant GCTs. These data fit into a model of pathogenesis of testicular GCTs of adults in which all tumors, with the possible exception of spermatocytic seminoma, pass through a seminoma stage. Tumor evolution seems to result from net loss of chromosomes from a (near)tetraploid carcinoma in situ cell. The pathogenesis of infantile yolk sac tumor might be different from that of testicular GCTs of adults.

Endodermal sinus tumor and mucinous cystadenofibroma of the ovary. Occurrence in an 82-year-old woman.

We encountered an unusual ovarian tumor consisting of a mixture of typical endodermal sinus tumor (EST) and mucinous cystadenofibroma that occurred in the ovary of an 82-year-old female patient. The EST component showed the classic histologic features of this tumor. Serum alpha-fetoprotein (AFP) level was not determined. Tumor stains were negative for AFP but positive for alpha-1-antitrypsin. The malignant germ cell component was intimately associated with the benign mucinous component. Focal production of epithelial mucin and carcinoembryonic antigen (CEA) in the EST component suggested a probable association between the two tumor types. The tumor was confined to one ovary, and the patient is disease-free 2 years after surgical therapy. This neoplasm is unique not only for the malignant germ cell component occurring in an 82-year-old woman, but for the unusual combination of tumor types. The pathogenesis is unknown.

Absence of intratubular germ cell neoplasia in testicular yolk sac tumors in children. A histochemical and immunohistochemical study.

The majority of testicular germ cell tumors in adults are accompanied by neoplastic intratubular germ cells; these cells were uniformly absent in ten pure yolk sac tumors (endodermal sinus tumors) of the testicle in children studied morphologically and immunohistochemically. These differences may reflect divergent pathogenetic mechanisms that in turn may explain the tendency for different histologic types of testicular germ cell tumors to occur at different ages and the discordant biologic behavior between germ cell tumors of similar morphologic type in children and adults.

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.

[Intracranial tumor developing from the vitelline sac. Apropos of a case]. / Tumeur intracrânienne développée à partir du sac vitellin. A propos d'un cas.

The authors report a case of a primary intracranial yolk sac tumor which is a quite rare eventuality. The patient, an 18 months old girl was referred for severe intracranial hypertension. Neurological examination revealed a right hemiparesis, a left abducens nerve palsy and a bilateral papilledema. The serum and C.S.F. levels of alpha fetoprotein were at 2100 Ugr/l and 2500 Ugr/l, respectively. The computerized tomography showed a mass with a low density area in the left temporoparietal lobe and the carotid angiogram a highly hyper-vascular tumor. The child underwent a left temporo-parietal craniotomy and the friable vascular tumor was totally removed. A radiotherapy was associated to the surgical treatment. Histologically, glomerular like structures (Shiller Duval body), intra and extra cellular hyaline globules PAS positive were frequently seen. The tumor marker was demonstrated immunohistochemically.

Ovarian yolk sac tumor arising from an endometrioid carcinoma.

A yolk sac tumor that arose within an ovarian endometrioid adenocarcinoma in a 50-year-old woman is described. The tumor had typical microscopic features, stained immunohistochemically for alpha-fetoprotein, and was associated with an elevated serum alpha-fetoprotein level when metastases appeared. This is the fourth case in which a yolk sac tumor has been reported to develop from a somatic carcinoma and the second in which this tumor has been associated with epithelium of endometrioid type. Tumor heterogeneity or neometaplasia may account for the origin of a tumor of germ cell type from a carcinoma of somatic origin.

[General concepts of alpha-fetoprotein (AFP)-secreting tumors, with special reference to the histogenesis].

Recently, in addition to yolk sac tumors (YST) and hepatocellular carcinomas, many AFP-secreting tumors have been reported. A comparative morphological study of YST to the human yolk sac has revealed tumor cells mimicking the behavior of the human yolk sac endodermal cells (HYSEC). Another investigation suggests that an embryonal carcinoma (adult type), a gastric adenocarcinoma, or an ovarian adenocarcinoma, each showing no histologic features specific for YST, have a selective differentiation to HYSEC which can secrete an increased serum AFP. These tumors might well be called endodermal cell tumors. The histogenesis of AFP-secreting tumors can be attributed to the endodermal origin (or retrodifferentiation to the HYSEC).

[Morphology and histogenesis of yolk sac tumors in the testis]. / Morfologiia i gistogenez opukholei zheltochnogo meshka v iaichke.

The differentiation of yolk sac tumor cells was similar to the processes of development of embryonic and extraembryonic endoderm during the first 7 wk after cleavage. Two ways of yolk sac tumor histogenesis are discussed: differentiation of embryonal carcinoma cells, and redifferentiation of the polypotent undifferentiated anaplastic seminoma cells. Histogenesis features described may be responsible for aggressive nature and high malignancy of yolk sac tumors.

Gastric choriocarcinoma and yolk sac tumor in a man: observations about its possible origin.

The case of a 65-year-old man who had a gastric tumor with components of choriocarcinoma and yolk sac tumor is presented. The presence of a small component of adenocarcinoma in the primary tumor and the absence of any gonadal or other primary tumor at autopsy confirm its origin. Despite the common association of embryonal and trophoblastic elements in gonadal tumors, this is the first case in which such an association was clearly depicted in the stomach. This and the usual coexistence of adenocarcinoma with choriocarcinoma in the stomach suggest the possibility of a different mode of development of these tumors in the two sites: forward differentiation of neoplastic germ cells in the gonads and retrodifferentiation (opisthoplasia) of neoplastic mucosal epithelial cells in the stomach.

[Experimental induction and cytogenetic study of yolk sac tumors in Chinese hamsters].

The development of teratomas and yolk sac tumors from displaced yolk sac is well documented in rats and mice. However, precise mechanisms of induction and pathogeneses of these tumors still remain unknown. The present study was undertaken in order to elucidate whether this phenomenon is common to all rodents, to identify the origin of these tumors and to explore specific chromosomal changes in yolk sac tumors. Ten benign teratomas and two malignant tumors with teratomatous elements were obtained from 33 chinese hamsters after fetectomy, followed by displacement of yolk sac. The histological characteristics and the presence of laminin and alpha-FP suggested that the malignant tumors belonged to the category of yolk sac tumors. Similarities of electromicroscopic features observed in the tumor cells and the yolk sac of normal 12-day conceptuses suggested that the tumor originated from yolk sac cells. Chromosomal analyses of in vitro cell lines established from one of yolk sac tumors disclosed that the tumor was composed of clones with XX and XY sex chromosome constitution. The 1P+marker chromosome was identified as a consistent abnormality, which seemed to play an important role for the development of yolk sac tumors in chinese hamsters.

[Morphology and histogenesis problems in cervical cancer]. / Morfologiia i voprosy gistogeneza raka sheiki matki.

Both most common and rare varieties of uterine cervix carcinoma were studied light and electron microscopically. It is shown that tumours histologically classified as squamous-cell carcinoma originate either from the squamous epithelium of the ectocervix or from the metaplastic epithelium. Characteristic ultrastructural features of these histogenetic variants of squamous-cell carcinoma are described. The authors' and literature data are presented indicating that the great histological variety of adenocarcinomas and glandular-squamous carcinomas is due to the pluripotential properties of proliferating stem cells capable of forming glandular, solid and squamous-cell structures. The source of clear-cell adenocarcinoma may be not only Gartner's duct but the mullerian epithelium as well. The classification of uterine cervix carcinomas reflecting their histogenesis is proposed.