Virilizing ovarian fibrothecoma with minor sex cord elements in a 13 year old girl: a rare case

Fibrothecoma accounts for 3-4% of all ovarian neoplasms; it is usually hormonally inactive, but can be estrogenic or sometimes androgenic (11%); it is rare under 30 years. In a very few cases, minor sex cord elements (less than 10% of the tumor area) are present; therefore, it is considered as a separate subgroup of stromal tumors. The importance of immunohistochemistry in recognizing this kind of tumor has been fully documented, with variable results on inhibin staining, but specific positivity for calretenin in such cases. We report here the rare case of a 13-year-old child with ovarian fibrothecoma and minor sex cord stromal elements, who showed negativity for inhibin and positivity for calretenin.