Clinician to Clinician: Ovarian mass: Was it benign or malignant?

Struma ovarii, a benign cystic teratoma containing mostly mature thyroid elements, typically presents as a pelvic mass. Rarely do you see pseudo-Meigs' syndrome (a triad of ascites, pleural effusion, and benign ovarian tumor), particularly with an elevated CA-125. Not surprisingly, there are few reports in the literature.

Emergency room case:

A 57-year-old postmenopausal woman presented to our emergency department with a 6-month history of moderately severe and gradually worsening shortness of breath and pleuritic right-sided chest pain. Six months earlier, she had been seen at another hospital for dyspnea on exertion. The woman was diagnosed with a right-sided pleural effusion, and subsequent pelvic ultrasound revealed a large ovarian mass that made us suspect a malignancy.

Physical examination revealed a female of average build in no acute distress. Initially, her vital signs included a pulse rate of 94 with regular rate and rhythm, blood pressure of 159/93 mm Hg, respiratory rate of 20 breaths per minute, non-labored. Her temperature was 96.6°F, and pulse oximetry was 99% on room air. Her breath sounds were diminished on the right side, with dullness over the lower rib cage to percussion, consistent with pleural effusion. Her abdomen was soft and non-tender without any palpable mass. Bowel sounds were audible and normal. Rectal examination was normal with guaiac-negative stool. Finally, her extremities were not edematous.

Laboratory analysis. A comprehensive metabolic panel showed only a slightly decreased serum albumin. Her CBC showed a slightly elevated white blood cell count, and her CA-125 was 944 U/mL (normal <35 U/mL).

Organs removed after gyn consult. Following a consultation with gynecology, 1,500 mL of fluid were removed during thoracentesis and then evaluated. Although the exudative fluid was suspicious for malignancy, cytology was negative. In an exploratory laparotomy (during which intraoperative frozen biopsy revealed no malignancy), the woman's ovarian mass, uterus, and contralateral ovary were removed and omental biopsies were done. There was no evidence of peritoneal metastases, omental thickening, or pelvic lymphadenopathy. Exploration of the upper abdomen was unremarkable. Pathology confirmed the presence of a right ovarian dermoid with thyroid elements within, consistent with struma ovarii.