Case Report A case of neoplastic granulosa cells in the fallopian tube, but no evidence of granulosa cell tumor

The discovery of displaced granulosa cells in the fallopian tube is concerning for a granulosa cell neoplasm and can lead to further surgical intervention. Discerning the risk of neoplasm can be challenging, even with immunohistochemical staining of CD56, a highly sensitive marker of granulosa cell neoplasm. A 48-year-old underwent an uncomplicated hysterectomy and bilateral salpingectomy for symptomatic fibroids and was found to have a small focus of granulosa cells staining positive for CD56 in her left fallopian tube. Post-operative imaging demonstrated a left adnexal mass. The patient underwent a left oophorectomy. Final pathology demonstrated a benign mucinous cystadenofibroma without evidence of granulosa cell neoplasm. Displaced granulosa cells require further pathologic and surgical evaluation, but do not always equate to neoplasm and should be managed accordingly.