The diagnostic challenge of ovarian carcinoma in normal-sized ovaries: a report of two cases

Normal-sized ovarian carcinoma syndrome (NOCS) is a rare condition characterised by malignancy identified in ovaries of normal size with abdominal metastasis. We report two cases of advanced ovarian carcinoma with ovaries of normal size. The first case was a 13-year-old adolescent with malignant ascites and bilateral normal sized multicystic ovaries detected on ultrasound. Serum cancer antigen 125 (CA 125) and lactate dehydrogenase were markedly raised. A computed tomography (CT) scan showed the presence of thick omental cake but no ovarian tumour. An ultrasound-guided biopsy of the omental cake was undertaken. A histopathological examination and immunohistochemical studies of omentum caking confirmed a diagnosis of high-grade serous carcinoma of ovarian in origin. Despite neoadjuvant chemotherapy, she deteriorated rapidly with acute renal failure and respiratory distress. She succumbed to her disease 10 weeks after diagnosis. The second case, a 69-year-old postmenopausal female presented with malignant ascites and ultrasound evaluation showed hydrometra and bilateral atrophic ovaries. CA 125 was significantly raised. A laparoscopic biopsy of the left ovary and endometrial sampling were performed. A diagnosis of synchronous primary high grade papillary serous ovarian cystadenocarcinoma and endometrial adenocarcinoma were revealed. Relapse occurred despite ongoing adjuvant chemotherapy. We concluded that a preoperative definitive diagnosis of NOCS is difficult. Strong clinical suspicion is needed when all the important causes of malignant ascites are excluded. Radiological-guided biopsy and laparoscopic biopsy are useful to achieve the diagnosis of NOCS.