Abdominal wall endometrioma: ultrasonographic features and correlation with clinical findings

The diagnosis of abdominal wall endometrioma (AWE) is often confused with other surgical conditions. Certain factors relating to knowledge of the clinical history of the disease make correct diagnosis and treatment difficult.

To present the clinical findings and ultrasonographic (US) features of AWE with special emphasis on size-related features.

This study reviewed abdominal wall endometriomas during a 2-year period in the Radiology Department of Sifa University Hospital, Izmir.

Eleven women (mean age 32.6 years) with 12 scar endometriomas (mean diameter 29.2 mm) were consecutively evaluated by US and Colour Doppler examination (CDUS) prior to surgery. Lesions were grouped into large (≥3 cm) and small nodules. Vascularisation was classified as location (central, peripheral and mixed) and severity (absent, moderately vascular and hypervascular). In each patient, the nature of pain (absent, cyclic: associated with menstruation and continuous), historical and clinical data were documented. Four patients underwent Magnetic Resonance Imaging and their findings were presented. Fisher's exact test, χ(2) test for categorical data and the unpaired T-test for continuous variables were used for statistical analysis.

In all the women, US of the AWE showed the presence of a solid hypoechoic mass (less echogenic than the surrounding hyperechoic fat) within the abdominal wall. There was a significant correlation between AWE sizes with repeated caesareans and the mean time between the last operation and admission to hospital (p<0.05). Large endometriomas showed increased central vascularity (p<0.05). Cyclic pain was more frequent in small lesions, whereas continuous pain was more commonly found in patients with larger lesions (p<0.05).

AWE is often misdiagnosed clinically because endometriosis may occur years after the caesarean section, the pain is often non-cyclic in nature, and there is not always a palpable tender mass. The sonographic and Doppler findings, along with proper correlation with clinical data, may substantially contribute to the correct diagnosis of endometrioma.