Rectal hemangioma mimicking uterosacral endometriosis on transvaginal ultrasound examination

Many authors1-4 have demonstrated the value of transrectal and transvaginal sonography (TVS), in addition to rectal endoscopic sonography in the evaluation of uterosacral ligaments and rectal wall involvement by deep pelvic endometriosis. Rectal cancers, on the other hand, have been assessed mainly by transrectal sonography and rectal endoscopic sonography5. We report an exceptional case of a hemangioma of the rectal wall mimicking an endometriotic deposit of the uterosacral ligament on TVS. This case confirms the ability of the technique to detect subperitoneal lesions, but also demonstrates the difficulty in locating the lesions in some cases, and the possibility of diagnoses other than endometriosis. A 47-year-old woman presented with a history of several months of pelvic pain. Physical examination revealed a painful nodule in the right retrocervical area. TVS using a Logic 500 apparatus (General Electric Medical Systems, Milwaukee, WI, USA) with a 6–9-MHz transvaginal transducer revealed, in the right posterior subperitoneal space, a 21 × 13-mm hypoechoic nodule with an irregular contour, replacing the normal adipose tissue between the uterus and rectum, and which caused pain when compressed by the probe. Additionally, small, apparently cystic hypoechoic areas were seen (Figures 1 and 2). Power Doppler ultrasound examination did not show flow within the mass. A diagnosis of endometriotic deposit arising from the right uterosacral ligament was suggested. Sagittal transvaginal ultrasound images comparing: (a) the right (RT) and (b) the left (LT) posterior subperitoneal space, showing a 21 × 13-mm hypoechoic nodule in the right retrocervical area (arrow). Small, possibly cystic, hypoechoic areas are seen. Transverse transvaginal ultrasound images of: (a) the right (RT) and (b) the left (LT) subperitoneal spaces, demonstrating the hypoechoic nodule on the right (arrow). Laparoscopy demonstrated a subperitoneal 20 × 19-mm mass contiguous with the right lateral rectal wall and the right uterosacral ligament. Resection of the mass with disc resection of the rectal wall was performed. Histological examination showed a hemangioma involving the submucosa, muscularis propria and subserosa of the rectal wall, sparing the mucosa, muscularis mucosae and serosa. Features of endometriotic involvement of the uterosacral ligaments are thickening, asymmetry between the two ligaments, and irregularity or the appearance of nodules. In the study of Bazot et al., the sensitivity and specificity of TVS for the diagnosis of endometriotic involvement of the uterosacral ligaments and intestines were 70.6% and 95.9%, and 87.2% and 96.8%, respectively1. Rectal hemangioma is far less frequent than deep pelvic endometriosis and imaging reports are sparse6-8. The presence of phleboliths on plain abdominal radiography or computed tomography can give an accurate diagnosis and these are present in 26–50% of cases9, 10. On magnetic resonance imaging (MRI), hemangiomas are seen to have heterogeneous high or low signal intensity on T1-weighted and high signal intensity on T2-weighted images6. In our case, power Doppler ultrasound examination did not demonstrate flow inside the mass, probably because of slow flow in the vessels and the small size of the lesion. On the other hand, the presence of small and possibly cystic hypoechoic areas (Figure 1) is quite unusual for uterosacral ligament and rectal endometriosis, and could have raised the possibility of another diagnosis . To summarize, deep pelvic endometriosis is the first diagnosis suggested when there is a painful hypoechoic nodule of the uterosacral ligament or the rectal wall on TVS. However, other differential diagnoses should be considered, including the uncommon diagnosis of rectal hemangioma. R. Hourani*, R. Sarkis , D. Atallah , L. Klein-Tomb?, M. Ghossain*, * Department of Radiology, Hôtel Dieu de France, Saint-Joseph University Hospital, Avenue Alfred Naccache, PO Box 166830, Achrafieh, Beirut, Lebanon, Department of General Surgery, Hôtel Dieu de France, Saint-Joseph University Hospital, Avenue Alfred Naccache, PO Box 166830, Achrafieh, Beirut, Lebanon, Department of Obstetrics and Gynecology, Hôtel Dieu de France, Saint-Joseph University Hospital, Avenue Alfred Naccache, PO Box 166830, Achrafieh, Beirut, Lebanon, ? Department of Pathology, Hôtel Dieu de France, Saint-Joseph University Hospital, Avenue Alfred Naccache, PO Box 166830, Achrafieh, Beirut, Lebanon