Residual ovarian tissue mimicking malignancy in a patient with mucinous carcinoid tumor of the ovary - A case report

BACKGROUND: Mucinous carcinoid tumor of the ovary is an uncommon lesion in reproductive-age women. If a patient status post total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO) for this tumor presents with a pelvic mass, recurrence of the tumor must be considered, as must the presence of residual ovarian tissue producing physiologic cysts with mass effect, termed the ''ovarian remnant syndrome. '' Benign ovarian follicle cysts may have cellular atypia and mimic malignancy. CASE: A female, one year status post TAH-BSO for mucinous carcinoid tumor of the ovary, presented with pelvic mass. Clinical and radiologic evidence supported the diagnosis of recurrent tumor. Aspiration biopsy material was compatible with malignancy, and immunocytochemical stains supported a neuroendocrine origin of the cells. Surgical excision and histologic examination of the mass revealed ovarian tissue with features of corpus luteum and follicular cyst. CONCLUSION: Numerous pitfalls exist when considering an unusual tumor. While the patient's history, clinical impressions and immunocytochemistry may strongly suggest malignancy, move common benign entities may mimic malignancy and should be considered in the differential diagnosis.