Tumor risk in disorders of sex development (DSD).

Disorders of sex development (DSD), previously referred to as intersex disorders, comprise a variety of anomalies defined by congenital conditions in which chromosomal, gonadal, or anatomical sex is atypical. Besides issues such as gender assignment, clinical and diagnostic evaluation, surgical and psychosocial management, and sex steroid replacement, the significantly increased risk for developing specific types of malignancies is both clinically and biologically relevant. This relates to germ-cell tumors specifically in DSD patients with hypovirilization or gonadal dysgenesis. The presence of a well-defined part of the Y chromosome (known as the GBY region) is a prerequisite for malignant transformation, for which the testis-specific protein on the Y chromosome (TSPY) is a likely candidate gene. The precursor lesions of these cancers are carcinoma in situ (CIS)/intratubular germ-cell neoplasia unclassified (ITGCNU) in testicular tissue and gonadoblastoma in those without obvious testicular differentiation. Most recently, undifferentiated gonadal tissue (UGT) has been identified as the likely precursor for gonadoblastoma. The availability of markers for the different developmental stages of germ cells allows detailed investigation of the characteristics of normal and (pre)malignant germ cells. Although informative in a diagnostic setting for adult male patients, these markers - such as OCT3/4 - cannot easily distinguish (pre)malignant germ cells from germ cells showing delayed maturation. This latter phenomenon is frequently found in gonads of DSD patients, and may be related to the risk of malignant transformation. Thus, the mere application of these markers might result in over-diagnosis and unnecessary gonadectomy. It is proposed that morphological and histological evaluation of gonadal tissue, in combination with OCT3/4 and TSPY double immunohistochemistry and clinical parameters, is most informative in estimating the risk for germ-cell tumor development in the individual patient, and might in future be used to develop a decision tree for optimal management of patients with DSD.

Tumores fetales: I parte / Fetal tumors: Part I

Se presenta una revisión sistemática y resumida de los diferentes tumores fetales, haciendo énfasis en su diagnóstico prenatal y posibles tratamientos intrauterinos. En esta primera parte se introduce el tema y se analizan tumores del sistema nervioso central, cara y cuello.

Developmental expression of POU5F1 (OCT-3/4) in normal and dysgenetic human gonads.

BACKGROUND: To investigate how long fetal germ cells retain pluripotency, which may be linked to their ability to transform into histologically variable tumours, we examined the expression of OCT-3/4 (POU5F1), a transcription factor essential for the maintenance of totipotency in embryonic stem cells. METHODS: The ontogeny of expression of OCT-3/4 was studied in 74 specimens of normal human gonads during development and in 58 samples of gonads from cases with testicular dysgenesis syndrome (TDS), including disorders of sex differentiation and malignant changes. RESULTS: OCT-3/4 expression was found in primordial germ cells during migration to the gonadal ridges and in the indifferent gonad. The expression in testes gradually decreased until approximately 20 weeks of gestation, and thereafter it was more rapidly down-regulated, but persisted in a few cells until 3-4 months of postnatal age, which coincides with the final differentiation of gonocytes into infantile spermatogonia. Subsequently, OCT-3/4 was not detected in normal testes. In the ovaries, OCT-3/4 was expressed in primordial oogonia, but was down-regulated in oocytes that formed primary follicles. The pattern of expression was heterogeneous in dysgenetic and intersex cases, with OCT-3/4-positive gonocytes detected in this series until 14 months of age. Visibly neoplastic gonadoblastoma and carcinoma in situ (CIS) expressed abundant OCT-3/4 regardless of the age. CONCLUSIONS: In the human ovary, OCT-3/4 is silenced at the onset of the first meiotic prophase, whereas in the testis, down-regulation of OCT-3/4 is a gradual process associated with differentiation of gonocytes. This normal pattern of expression is disturbed in dysgenetic gonads, especially in rare intersex cases, thus increasing the risk of malignant transformation. The high abundance of OCT-3/4 in CIS cells is consistent with their early fetal origin and pluripotency.

New insights into the pathology and molecular biology of human germ cell tumors.

The group of human germ cell tumors (GCTs) is heterogeneous, and comprises neoplasms found at different anatomical locations. They are of interest not only for aspects of their tumor biology, but also from the point of view of developmental biology. GCTs show significant similarities to early germ cell development, most likely related to their cell of origin. Comparative analysis of the tumors and representative normal counterparts can therefore help to define events which are related to the pathogenesis of this cancer. Within the testis, three separate GCT entities have been identified, characterized by differing patho-biological, molecular/cytogenetic, and clinical observations, which will be described in more detail in this review. This article will highlight the most important contributions to the field in the last years. This includes the diagnostic value of OCT3/4, a transcription factor and marker for pluripotency. Furthermore, the invasive GCTs of young adults consistently show a gain of 12p-sequences, of which the exact role, including the gene(s) involved, remains to be elucidated, although interesting candidates have been identified. Finally, treatment sensitivity/resistance of GCTs most likely reflect the intrinsic characteristics of the cells of origin and their derivatives. The pluripotency of GCTs, in particular the possible loss of the embryonic characteristics and acquisition of somatic differentiation, could be a crucial phenomenon in this process.

Spectrum of germ cell tumors: from head to toe.

Germ cell tumors (GCTs) occur most frequently in the gonads and are relatively rare in other sites, such as the pineal gland, neurohypophysis, mediastinum, and retroperitoneum. GCTs are thought to originate from primordial germ cells, which migrate to the primitive gonadal glands in the urogenital ridge. Extragonadal GCTs might also originate from these cells when the cells are sequestered during their migration. Pathologic subtypes of GCTs vary, and the prevalence of mixed tumors is high. These factors produce a diversity of radiologic findings and make prospective radiologic diagnosis difficult in many cases. However, similar radiologic findings have been observed in pathologically equivalent tumors in varying sites. Seminomas appear as uniformly solid, lobulated masses with fibrovascular septa that enhance intensely. Nonseminomatous GCTs appear as heterogeneous masses with areas of necrosis, hemorrhage, or cystic degeneration. Fat and calcifications are hallmarks of teratomas, most of which are benign. In immature teratomas, scattered fat and calcification within larger solid components are occasionally seen. These imaging characteristics reflect the pathologic features of each tumor, and histologically similar GCTs at varying sites have similar radiologic features. Knowledge of the pathologic appearances of GCTs and their corresponding radiologic appearances will allow radiologists to diagnose these tumors correctly.

129/Sv mice--a model system for studying germ cell biology and testicular cancer.

Some forms of testicular germ cell tumors (TGCTs) arise from primordial germ cells (PGCs) during fetal development. In both humans and mice, genetic control of susceptibility is complex, involving both Mendelian and polygenic factors. Identification and characterization of TGCT genes will provide insight not only into the basis for inherited susceptibility, but also into the genetic control of the development of the PGC lineage. Recent work has revealed the identity of several susceptibility genes that are inherited as Mendelian traits, the chromosomal location of yet-to-be identified TGCT susceptibility genes, as well as clues to the nature of developmental pathways involved in tumorigenesis. In this review we summarize current understanding of the biology and genetics of TGCTs in mice and discuss the relevance of this work to testicular cancer in humans.

Tumores de células germinativas / Germinative cell tumors

O trabalho aborda os tumores de células germinativas na infância, destacando sua importância, incidência, embriologia, marcadores tumorais, características clínicas nos diferentes sítios em que se localizam, estadiamento dos tumores gonadais e extragonadais e seu tratamento

So-called intracranial germ cell tumours: are they really of germ cell origin?

We have studied 139 cases of intracranial germ cell tumours up to the beginning of 1993, 63.3% of which showed monotypic histological patterns and 36.7% were shown to be mixed tumours. All these cases underwent surgery followed by radiation and/or chemotherapy. All cases of choriocarcinoma died within 2 years. Cases of yolk sac tumour (endodermal sinus tumour) and embryonal carcinoma also showed poor results. Mature teratoma had a 5-year survival rate (5 YSR) and 10-year survival rate (10 YSR) of 92.9% each. Immature teratoma and malignant teratoma showed a 5-YSR and 10-YSR of 75.0% each. Germinoma showed a 5-YSR of 94.7% and a 10-YSR of 91.2%. All these results may bring into question the validity of the germ cell theory, since germinoma, which should be the most undifferentiated according to the theory, was the most benign and choriocarcinoma and yolk sac tumour (endodermal sinus tumour) which should be the most differentiated, were the most malignant in the follow-up study. Therefore, germ cell tumours may not originate from one single type of cells (primordial germs cells), except for germinoma. The embryonic cells of various stages of embryogenesis may perhaps be misplaced in the bilaminar embryonic disc and become involved in the stream of lateral mesoderm at the time of the primitive streak formation and be carried to the future cranial area to be wrongly enfolded into the brain at the time of the neural tube formation. The following law may be propounded: Tumours composed of cells resembling the cells appearing in the earlier stages of embryogenesis (ontogenesis) are more malignant than those resembling the cells appearing in the later stages of embryogenesis (ontogenesis).

[Classification of ovarian tumors based on embryogenesis]. / Classification des tumeurs de l'ovaire basée sur l'embryogenèse.

This paper studies gonadal differentiation into the ovary from the earliest interaction between germ cells and somatic cells in the developing urogenital ridge up to the formation of primordial follicles. Granulosa cells appear to be derived from the breaking down of the cordlike arrangement of epithelial cells resulting from proliferation of surface coelomic mesothelium. Thecal cells arise from mesenchymal progenitors cells in the ovarian stroma. Based on the findings of embryology and biology, the authors then propose a classification of ovarian tumors by rearranging the WHO classification.

A fetal testis with intratubular germ cell neoplasia (ITGCN).

A fetal testis with abnormal germ cells similar to the cells of intratubular germ cell neoplasia (ITGCN) or so-called carcinoma in situ is presented. Elective abortion was performed in week 18 of the pregnancy of a 26-yr-old woman, because of 21 trisomy (Down's syndrome) at amniocentesis. At microscopical examination abnormal germ cells were found, similar to those occurring in the adult testis and with the same distribution as those described in ITGCN in children with dysgenetic gonads and with androgen insensitivity syndrome. PAS positivity and placental-like alkaline phosphatase (PLAP) was demonstrated in the abnormal germ cells. The finding indicates that the first event of germ cell tumor oncogenesis may take place before birth, in utero or even before. The occurrence of ITGCN in Down's syndrome has not been reported previously but is likely to occur, as there is evidence that these patients have increased risk of developing germ cell tumors.