Image 9 of 74



Image Description

Microscopic Features: This image of an ovarian fibroma shows a proliferation of bland, fibroblast-type spindle cells arranged in intersecting fascicles. The stroma has dense hyaline plaques.

The cells have scant eosinophilic cytoplasm and oval or elongated wavy nuclei with minimal or no cytologic atypia. Some cases have bizarre nuclei with degenerative-type atypia. Nuclear palisading may create Verocay body-like areas.

Mitotic activity is low and averages no more than 1-2 mitoses/10HPF. Mitotically-active fibromas show increased mitotic activity (range 4 to 19 mitoses/10HPF; mean 6.7 mitoses/10HPF) in the absence of cytologic atypia. Increased mitotic activity, by itself, is not indicative of malignancy.

Image 9 of 74