First, etiology
The etiology of ovarian fibroma disease is not yet clear.
Second, pathogenesis
1, Gross morphology
About 6/7 are unilateral, the ovary can be partially or completely involved, the involved ovary is enlarged, with a diameter of 6-12 cm, an average of 8 cm, with a white, smooth or nodular surface, lobulated, with a solid section, hard texture, most are white, a few are gray or yellow, about 1/3 can see small cysts, with the largest cyst diameter up to 2.5 cm.
2, Tissue morphology
Sarcomatous fibroblasts proliferate at the lesion site and produce varying degrees of collagen fibers, surrounding the normal ovarian structure, including all stages of follicles and corpus luteum. The small cysts seen with the naked eye are residual cystic follicles within the lesion. Flavonized stromal cells are occasionally seen in the proliferating fibroblasts or normal ovarian stroma. In a few cases, granulosa cell nests or hollow tubular structures similar to supportive cells appear in the fibrous hyperplasia foci, and half of the cases are accompanied by focal stromal edema.