Displaced granulosa cells in the fallopian tube mistaken for metastatic granulosa cell tumor.

A 44-yr-old woman underwent a total hysterectomy and bilateral salpingectomy secondary to uterine leiomyomas. Gross examination of the fallopian tubes revealed no masses or lesions; however, 2 small foci of granulosa cells were identified microscopically within one of the fallopian tubes. These foci were suspicious for granulosa cell tumor metastases. The patient subsequently underwent a bilateral oophorectomy, which revealed no primary granulosa cell tumor. Immunohistochemical studies were used to help support the benign nature of the granulosa cells within the fallopian tube. A review of the literature revealed only 1 similar case report of displaced benign granulosa cells within the fallopian tubes. The ovaries in both this case and the previous case report were found to contain multiple cystic follicles, suggesting ovulation as the likely mechanism of displacement. Knowledge of this rare occurrence and the use of immunohistochemical staining are paramount to making a correct diagnosis, thus preventing a misdiagnosis of malignancy and possible unnecessary treatment.