Gonadoblastoma : Treatment & Prognosis
Genetics of Gonadoblastoma: Gonadoblastoma develops in patients with gonadal dysgenesis which is a disorder of sex development. It is caused by mutations or deletions in one or more genes required for the development of physiological male phenotype. The gonadal tissue must contain Y chromosome (or portion of Y chromosome containing TSPY locus). The involved genes include WT1, SOX9, SF1, and SRY among others. Treatment and Prognosis: Gonadoblastoma is considered to be a premalignant lesion which can give rise to germ cell tumors, usually seminomas, but any non-seminomatous germ cell tumor can develop. The risk of malignancy can be estimated by observing the degree of external masculinization. The risk is highest in individuals with ambiguous phenotype; intermediate in boys with mild undervirilization; and lowest among girls with Turner syndrome phenotype. Gonadectomy before the development of a germ cell tumor is curative. The gonadal excision is done bilaterally because of association of gonadoblastoma with gonadal dysgenesis and high frequency of bilaterality of this tumor (almost 40% of cases). The image shows germ cell neoplasia-in-situ like cells and sex cord-stromal cells (small dark hyperchromatic cells) arranged around basement membrane material (Call-Exner pattern).