Microscopic gonadoblastoma in dysgenetic gonad of an infant: an ultrastructural study

Gonadoblastoma: evidence for a stepwise progression to dysgerminoma in a dysgenetic ovary

Gonadoblastomas are neoplasms of dysgenetic gonads which may undergo regression or become overgrown by malignant germ cell tumors (mGCTs). Since little is known about their relationship to normal gonadal development and mGCTs, we studied the phenotype and antigenic profile of gonadoblastomas in comparison with adjacent dysgerminomas and fetal gonads. Three cases of gonadoblastomas and fetal gonads of both sexes were analyzed using oncofetal markers to M2A-antigen (M2A), germ cell alkaline phosphatase (PLAP/GCAP), receptor tyrosine kinase c-kit (c-kit), and somatic angiotensin converting enzyme (sACE) as well as the proliferation marker MIB-1. Morphologically, microfollicular pattern of gonadoblastomas showed a fetal germ cell organization reminiscent of oocytic clusters of fetal ovaries. They contained both cell types, similar to oocytes (M2A-, GCAP-, c-kit+/-, sACE-) and oogonia (M2A+, GCAP+, c-kit+, sACE+). The percentage of germ cells immunoreactive for oncofetal markers and the proliferation index increased from microfollicular over coronary patterns to adjacent dysgerminomas. Supportive cells of gonadoblastomas showed a uniform phenotype (CK18+, vimentin+, sACE+, alpha-inhibin+, M2A-) but in contrast to fetal germ cells lacked a clear equivalence to fetal tissues. Our results show that gonadoblastomas mimic female fetal ovary and exhibit a stepwise progression from follicular pattern to coronary pattern and finally to dysgerminomas.

3-Year-old phenotypic female with campomelic dysplasia and bilateral gonadoblastoma

The authors report the case of bilateral gonadoblastomas in a phenotypic female, with a 46,XY karyotype, with campomelic dysplasia. Although campomelic dysplasia with gonadal dysgenesis should be expected to contribute to an increased risk of gonadoblastoma, this is the first documented case report of campomelic dysplasia and gonadoblastoma. Phenotypic females with campomelic dysplasia should be karyotyped once the skeletal dysplasia is recognized. phenotypic females with campomelic dysplasia should undergo gonadectomy if their karyotype includes a Y chromosome or fragment.

Carcinoma in situ, gonadoblastoma, and early invasive neoplasia in a nine-year-old girl with 46,XY gonadal dysgenesis

Carcinoma in situ (CIS), gonadoblastoma, and early invasive neoplasia were detected in the dysgenetic gonad of a nine-year-old girl with 46,XY gonadal dysgenesis. A close relationship between the three neoplastic components was supported by morphological and immunohistochemical studies. Our findings support the hypothesis that all germ cell tumours, including gonadoblastomas, originate from CIS germ cells formed during early embryonic life.

Abnormal sexual differentiation and neoplasia

The prevalence of neoplasia is increased in individuals with certain disorders of sexual differentiation. Etiology and frequency of neoplasia vary with the particular disorder. In uncomplicated cryptorchidism, the testis is at least 10 times more likely to undergo neoplastic transformation than a normal scrotal testis. Neoplasia probably is a function of both testicular location (intraabdominal) and underlying dysgenetic structure. If cryptorchidism is unilateral, and if orchiopexy has not been performed prior to age 6-10 years, orchiectomy should be encouraged. In those forms of gonadal dysgenesis not associated with a Y chromosome (e.g., 45,X; 45,X/46,XX; 46,XX) there is no definite increase in neoplasia, suggesting that elevated gonadotropin levels per se are not carcinogenic. Gonadal tumors are found in at least 30% of individuals with XY gonadal dysgenesis and are particularly frequent (55%) in H-Y antigen-positive patients. These tumors are almost always gonadoblastomas or dysgerminomas. Similar tumors are found in 15%-20% of 45,X/46,XY individuals. In either situation the neoplastic transformation could be a) secondary to the existence of XY gonadal tissue in an inhospitable environment, or b) integrally related to that process--genetic or cytogenetic--producing the dysgenetic gonads. The risk of neoplasia is sufficiently high that most of these patients should be offered early gonadal extirpation. The prevalence of gonadal tumors is not increased in Klinefelter's syndrome, further indicating that gonadotropins are not carcinogenic per se. However, Klinefelter patients are 20 times more likely to develop a carcinoma of the breast than are 46,XY males. Extragonadal germ cell tumors also are more common. In female pseudohermaphrodites there is probably no increased risk of neoplasia, whereas, in true hermaphrodites neoplasia is unusual but does occur. Neoplasia occurs in patients with complete testicular feminization (complete androgen insensitivity) but rarely in those with incomplete testicular feminization/Reifenstein's syndrome, 5 alpha-reductase deficiency, anorchia, agonadia, or testosterone biosynthetic defects. In complete testicular feminization the risk of malignant tumors is small prior to age 25. After age 25, it is about 2%-5%. Orchiectomy is recommended after pubertal feminization.

Gonadoblastoma: unusual presentation in a patient lacking persistent müllerian ducts

We report a patient with a disorder of sexual differentiation who presented with a 46,XY karyotype, absent internal Müllerian ducts, a vaginal pouch, hypospadias, and bilateral cryptorchidism with a gonadoblastoma in one testis. A human chorionic gonadotropin stimulation test and tissue 5-alpha-reductase and androgen receptor assays were normal. Except for the absence of internal Müllerian ducts, this patient most closely resembles the disorder of dysgenetic male pseudohermaphroditism (DMP). On this basis, we hypothesize that the internal Müllerian ducts in DMP may manifest anywhere along a spectrum that extends from normal to complete absence of structures depending on the degree of gonadal dysgenesis. This case also illustrates the importance of testicular biopsy in patients with dysgenetic testes because of the high likelihood of germ cell neoplasms in these gonads.

Gonadal and extragonadal germ cell neoplasia of childhood

Germ cell tumors in children are characterized by diverse clinical, pathologic, and prognostic features. For this reason, it is difficult to generalize about the behavior of these tumors; cases must be evaluated individually, with consideration for the age of the patient at diagnosis, the anatomic site of the tumor, and its histologic appearance. Experimental models and cytogenetic studies of teratomatous development have contributed to our basic understanding of the biology of differentiation and tumorigenesis.