Sclerosing Stromal Tumors, Thecomas, and Fibromas of the Ovary: An Immunohistochemical Profile

The immunohistochemistry of 11 sclerosing stromal tumors (SSTs). 11 fibromas, and 5 thecomas was studied to determine criteria for the assessment of 5 densely sclerotic, calcified ovarian tumors of uncertain diagnosis occurring in young women. The results indicate that the staining pattern for alpha glutathione S-transferase can be used to distinguish SSTs, fibromas, and thecomas. CD34, by highlighting the vascular pattern and density, can be used to distinguish between SSTs and other tumors in the thecoma-fibroma group. Alpha-inhibin and calretinin mirrored the alpha glutathione S-transferase staining. Vimentin, smooth muscle actin, and muscle specific actin were generally positive, but desmin was negative in all but one tumor. These results suggest that at least four of the five tumors of uncertain diagnosis were SSTs that had undergone end-stage sclerosis and calcification.