Structures mimicking sex cord-stromal tumours and gonadoblastomas in the ovaries of normal infants and children

Determination and stability of sex

How is the embryonic bipotential gonad regulated to produce either an ovary or a testis? In males, transient early activation of the Y chromosome Sry gene makes both germ cells and soma male. However, in females, available evidence suggests that the process of ovary sex determination may take place independently in the germline and somatic lineages. In addition, in contrast to testis, in ovary somatic cells, female-to-male gonadal sex reversal can occur at times throughout ovary development and maturation. We suggest that a single gene pathway, likely hinging on the Foxl2 transcription factor, both initiates and maintains sex differentiation in somatic cells of the mammalian ovary.

Foxl2 is required for commitment to ovary differentiation

Genetic control of female sex differentiation from a bipotential gonad in mammals is poorly understood. We find that mouse XX gonads lacking the forkhead transcription factor Foxl2 form meiotic prophase oocytes, but then activate the genetic program for somatic testis determination. Pivotal Foxl2 action thus represses the male gene pathway at several stages of female gonadal differentiation. This suggests the possible continued involvement of sex-determining genes in maintaining ovarian function throughout female reproductive life.

Pathologie des hermaphrodismes

Hermaphroditism is a general term referring to all discrepancies between phenotype and genotype of sex development. It must be preferred to sexual ambiguity which refers mainly to external genitalia anomalies. Hermaphroditism is studied on an historical and pathogenetical perspective. Short embryological summaries are integrated. The defects of sexual differentiation due to hormone deficiency are first studied: androgen insensitivity, steroid 5 alpha-reductase 2 deficiency, defects of testosterone synthesis, persistant mullerian ducts syndrome. Sexual determinism deficiencies are then presented: Turner syndrome, XX males, pure gonadal dysgenesis, true hermaphroditism, mixed gonadal dysgenesis, Drash and Frasier syndrome. Tumors of dysgenetic gonads followed. Mixed tumors developed in dysgenetic gonads are gonadoblastoma and dysgerminoma. Sex cord tumors are androgen insensitivity associated tumors, Leydig cells tumors and adrenal cell inclusion tumors. Sex reversion genes open new perspectives.

Sertoli-Leydig cell tumor of the ovary, a rare cause of precocious puberty in a 12-month-old infant

We report a 12-month-old infant who presented with a 4-month history of isosexual precocious puberty secondary to an estrogenizing Sertoli-Leydig cell tumor of the ovary. Total serum immunoreactive inhibin and subunits A and B were markedly elevated before surgical resection and subsequently decreased 7 wk later into the normal prepubertal range. Twenty weeks following surgical removal, the patient presented again with central precocious puberty; inhibin B levels were raised on this occasion, a luteinizing releasing hormone stimulation test confirmed central precocious puberty. This is the youngest reported occurrence of this rare sex cord stromal neoplasm. The prognosis of this extremely rare tumor presenting at this early juvenile stage is uncertain. This report illustrates the usefulness of serum inhibin as a tumor marker during therapeutic suppression with leuprorelin acetate for central precocious puberty. Analysis of genomic and tumor DNA revealed a normal nucleotide sequence for the LH receptor and the Galpha(s) gene. To understand the molecular pathogenesis of this tumor we analyzed mRNA levels for the inhibin A and B subunits, FSH receptor, LH receptor aromatase, steroidogenic factor-1 and the ER beta genes. Molecular characterization reveals the presence of genes specific for granulosa and Leydig cells; the relative expression of these genes, in addition to its histologic characteristics, suggests that this tumor may result from a dysdifferentiation of a primordial follicle.

Ovarian granulosa cell proliferations of pregnancy: a report of nine cases

Granulosa cell proliferations that simulated small neoplasms were incidental findings in the ovaries of nine pregnant women. The lesions were typically multiple and associated with atretic follicles. In eight cases, the granulosa cells were arranged in solid, insular, microfollicular, and trabecular patterns, but in the ninth case, there was a prominent sertoliform tubular pattern. The granulosa cells typically contained scanty cytoplasm and grooved nuclei, resembling the cells of adult-type granulosa cell tumors. However, in one case large nodules of markedly luteinized cells with variably sized, round, nongrooved nuclei were present; the nodules in this case superficially resembled pregnancy luteomas. In the case with a sertoliform pattern, the cells had abundant vacuolated cytoplasm. The lesions described probably reflect an unusual physiological response to the elevated chorionic gonadotropin level of pregnancy rather than early stages of neoplasia.

Ovarian tumorlike structures, biovular follicles, and binucleated oocytes in children: their frequency and possible pathologic significance

The occurrence of microscopic gonadoblastomalike and sex cord tumor with annular tubuleslike structures, biovular follicles, and binucleated oocytes was analyzed in 288 ovaries from 222 consecutive pediatric autopsies. Tumorlike structures were identified in 29% of the autopsies studied, biovular follicles were observed in 52%, and binucleated oocytes in 19%. These changes were not observed in 22 ovaries from adults. Sixteen cases with gonadoblastomalike structures were stained immunohistochemically for placental alkaline phosphatase and were nonreactive for this marker. These tumorlike structures and multiovular follicles are probably an expression of abnormal folliculogenesis that apparently disappears as the child matures and should not be confused with true neoplasms. Although these morphologic structures resemble the patterns of specific types of gonadal neoplasms, there is little evidence to suggest any potential for future neoplastic transformation.