Bilateral massive osseous metaplasia of ovaries: "ovarian stones"

We report a case of bilateral ovarian ossifications with images that mimic stone formations. A 65-year-old woman presented with a 2-year history of pelvic pain. Computed tomographic scan and pelvic ultrasound identified an enlarged uterus with two calcified lesions interpreted as leiomyomas. Surgical exploration revealed two ovaries with a cystic appearance and stony hard areas. The cyst contents consisted of chocolate-colored material. The pathologic findings were compatible with benign bilateral ovarian endometriotic cysts with extensive ossification. The pelvic pain resolved completely after the surgery. Though the cause of this rare case remains unknown, recognition of cysts with a content of chocolate-colored material and pigment-laden histiocytes allowed us to make the diagnosis of bilateral ovarian endometriotic cysts with extensive ossification. Complete excision was the treatment of choice.