Adnexal masses in the third trimester of pregnancy in Mahdieh Hospital, Tehran, between 2002 and 2006

Background: The prevalence of adnexal tumour has been reported to vary between one in eight thousands to 2.3% of pregnancies according to investigational techniques administered. Broader use of ultrasonography in pregnancy and the increasing rate of caesarean section (c-section) could be expected to lead to the diagnosis of more adnexal tumours compared to previous studies.

Aim and objectives: To identify the histological types, clinical manifestations, prevalence of malignant forms, and to assess the risk of two selected treatment approaches i.e. surgical (invasive) vs. conservative.

Method: This retrospective descriptive study was conducted on patients admitted to Mahdieh Hospital, Tehran, between 2002-2006 with confirmed adnexal tumours in the third trimester of pregnancy. Patients’ medical records were reviewed for age, gestational age, parity, the reason for admission, diagnostic approach for adnexal tumour, ultrasound characteristics (where available), surgical and histopathological findings.

Results: In all, 45 patients were recognised. Mean age was 27.8 (±4.8) and mean gravity was 2.1 (±1.2). Incidence rate for surgically confirmed adnexal malignancy in the third trimester was one in 570 live births and one in every 184 caesarean section. In forty three patients, diagnosis and tumour resection occurred during caesarean section of whom the reason for c-section was the adnexal mass in five cases, 33 were accidentally found during c-section due to obstetrics indications and the remainder (5 cases) was due to both causes. One case underwent tumour resection after post-partum tuboligation and one after vaginal delivery followed by laparatomy. No complication due to malignancy was found. Diagnostic procedure was ultrasonography only in 10 patients (23%). of whom, half were in the third trimester and half were detected in the first trimester with the adnexal mass being 5-10 cm in diameter. All were benign in line with histological features. In 35 patients, no mass was reported despite ultrasonography. All had benign features in histopathology and the most frequent diagnosis was paratubal cyst followed by serous-cyst adenoma.

Conclusion: Adnexal tumour complications in the third trimester are not frequent and the risk of malignancy is low. Therefore, if diagnosed, it is not a definite indication for an urgent surgical intervention provided that ultrasonographic feature of the mass is benign.