Background: Normal-sized ovarian carcinoma syndrome (NOCS) is characterised by malignancy identified in ovaries being of normal size with metastasis in peritoneal cavity. Without ovarian mass(es) of significant size, it is challenging to reach to a diagnosis of ovarian carcinoma when all the other causes of malignant ascites have been ruled out.

Case: We reported two cases of advanced ovarian carcinoma in extreme age groups with ovaries being of normal size. First case was a 13 years old adolescent with malignant ascites and bilateral normal sized multicystic ovaries detected on ultrasound. CA 125 and LDH were markedly raised. Computed tomography scan showed presence of thick omental cake with no evidence of ovarian tumour. Ultrasound-guided biopsy of omentum was undertaken. Histopathological examination (HPE) and immunohistochemical studies of omentum caking confirmed a diagnosis of high-grade serous carcinoma of ovarian in origin. Despite neoadjuvant chemotherapy (carboplatin and paclitaxel), she deteriorated rapidly with acute renal failure and respiratory distress. She succumbed to her disease 10 weeks after diagnosis. For the second case, a 69 years old postmenopausal female with malignant ascites and radiological evaluation only showed hydrometra. Bilateral ovaries were atrophic. CA 125 was significantly raised. Diagnostic laparoscopy revealed small bilateral ovaries with superficial seedling and peritoneal deposits. Left salpingo-oophorectomy for HPE and endometrial sampling were performed. A diagnosis of synchronous primary high grade papillary serous ovarian cystadenocarcinoma and endometrial adenocarcinoma was revealed. She was planned for neo-adjuvant chemotherapy followed by interval debulking surgery.

Conclusion: Preoperative definitive diagnosis of NOCS is difficult. Strong clinical suspicion is needed when all the important causes of malignant ascites are excluded.