Gonadoblastoma in a patient with del(9)(p22) and sex reversal: report of a case and review of the literature.

Studies of distinct clinical prototypes have significantly contributed to our understanding of evolutionary abnormalities and their association with neoplasia. We describe a phenotypic female, aged 20 years at report, who was examined as an infant for developmental retardation. The clinical characteristics of the 9p- syndrome were present and the external genitalia were those of a normal female. The karyotype was 46XY,del(9)(p22). The parental karyotypes were normal. No SRY deletion or mutation was detected. Sonography showed the presence of a uterus. Basal luteinizing hormone values were normal; follicle stimulating hormone values were high (40 IU/L). Stimulation with human chorionic gonadotropin did not produce any rise in testosterone. The gonads were removed and histologic analysis disclosed dysgenetic gonads with gonadoblastoma in situ. This case constitutes the fourth case of gonadoblastoma developing in an individual with 9p- syndrome and sex reversal. This and analogous prototypes point to a locus (or loci) on the short arm of chromosome 9, which either constitutes a nonspecific suppressor gene or a gonadoblastoma suppressor gene. An alternative hypothesis would be that a gonad not normally differentiated is more prone to gonadoblastoma development without any specific gene involvement.