Borderline serous tumor of the ovary discovered during pregnancy: A case report

INTRODUCTION: OFTs are tumors with low malignant potential. They represent 10 to 15% of all epithelial tumors of the ovary. Their mean age of occurrence is less than 10 years than that of carcinomas. CASE REPORT: a 29-year-old female patient, second gesture, with no particular pathological history, consulted for pelvic pain occurring during a pregnancy of 8 SA + 5 days. The examination showed an abdominal-pelvic mass lateralized to the left with an enlarged uterus. Abdomino-pelvic ultrasound showed an evolving mono-fetal pregnancy of 10 weeks of amenorrhea, with two right and left latero-cystic solid formations measuring successively 4 × 4.3 cm and 8.99 × 8.25 cm. Pelvic MRI showed a left latero-uterine solid-cystic mass measuring 8.1 × 6.1 × 7 cm. An exploratory laparotomy was performed after the 16th week of amenorrhea revealed a left solid cystic ovarian mass of 10 cm. A left adnexectomy was performed with a right ovarian biopsy, peritoneal biopsy, epiploic biopsy and peritoneal cytology. The pathology report confirmed a borderline serous tumor of the left ovary on the left annexectomy specimen. The right ovary, epiploic and peritoneal biopsy is without tumor proliferation and the peritoneal fluid is acellular. DISCUSSION: OFT are characterized by their occurrence in women of childbearing age, with an increasingly advanced maternal age for the first pregnancy. Most adnexal masses are diagnosed during the first or second trimester and endovaginal ultrasound in the first trimester is the first-line examination for optimal characterization. Magnetic resonance imaging (MRI) is the recommended second-line examination from 12 weeks of age, in the presence of complex or indeterminate lesions that may be sufficient to distinguish OFMT. Surgical exploration of radiologically highly suspicious adnexal masses during pregnancy is indicated after 15 weeks of amenorrhea, to reduce the risk of miscarriage by alteration of the luteal function of the cyst in the first trimester. CONCLUSION: The occurrence of OFT remains rare during pregnancy, which justifies the exploration of any adnexal mass discovered in the peripartum period, for which imaging plays an indispensable role in orienting the diagnosis.