Histologic evaluation of fresh human ovarian tissue before cryopreservation.

Transplantation of cryopreserved tissue from patients with cancer may carry the risk of reactivation or redissemination of micrometastases. This prospective study was conducted to evaluate the potential involvement of micrometastases in ovarian tissue in cancer patients. Ovarian biopsies were collected from patients who underwent ovarian tissue cryopreservation, in our IVF unit before chemotherapy between 2000 and 2008. Indications for cryopreservation included breast cancer (n=13), osteosarcoma (n=13), hematologic malignancies (n=13), uterine cervix carcinoma (n=2), endometrial carcinoma (n=1), colon cancer (n=1), and brain medulloblastoma (n=1). The samples were stained with hematoxylin and eosin, and examined histologically. Immunoperoxidase broad-spectrum cytokeratin staining was also performed on specimens from breast cancer patients. There were 44 patients (age range 5-40 yr) who yielded 40 specimens. No gross pathologic involvement was observed, and the histologic examination revealed normal histology with no evidence of metastases. Our findings showed that for the purpose of considering ovarian tissue cryopreservation in cancer patients, the likelihood of microscopic metastases within ovaries of normal appearance is apparently very low. Clarification of the actual risk of ovarian involvement and any subsequent risk of micrometastases and tumor reimplantation requires further investigation.