Serous surface papillary borderline tumor of ovary – An underdiagnosed entity

A young female presented with complaints of dysmenorrhea for 8 months. Ultrasound of the pelvis showed an echogenic mass in the left adnexa with papillary projections and internal vascularity and encasing the left ovary. Subsequent magnetic resonance imaging (MRI) showed an intensely enhancing, lobulated solid mass with a frond-like appearance, and papillary projections surrounding the left ovary reminiscent of a “sea-anemone.” The right ovary showed a cystic lesion without enhancing papillary projections or mural nodules. There was mild pelvic ascites and few peritoneal nodules in the pelvis. The presumptive radiologic diagnosis was serous surface papillary borderline tumor (SSPBT) of the left ovary and a benign cyst in the right ovary. The patient was treated with the left salpingo-oophorectomy, right ovarian cystectomy, peritoneal, and omental biopsies. Histopathology confirmed the diagnosis of SSPBT of the left ovary with microinvasion (<5 mm) of the ovarian surface. The right ovarian cyst was a follicular cyst. The peritoneal biopsies were positive for implants from SSPBT. This report highlights the diagnostic utility of “sea-anemone” sign and reviews the clinical and radiopathologic features of SSPBT.