Mesenteric Dermoid Cyst Presenting with Left Loin Pain: A Rare Case Report

Abstract

Mesenteric cysts are uncommon intra-abdominal lesions, and the dermoid variety is rarer still. They have no characteristic clinical or radiological signature, so a correct diagnosis before surgery is seldom made. We report a 50-year-old woman who came with continuous, throbbing pain in the left loin, together with ten days of epigastric pain and a history of constipation. Ultrasonography showed a 5.3×4.8×4.3 cm lesion in the left lumbar quadrant, and a complex cyst or a neoplasm was suspected. Contrast-enhanced computed tomography (CECT) showed a well-defined, round lesion in the left anterior pararenal space with areas of fat density; a dermoid cyst (teratoma) and an extra-adrenal myolipoma were the main considerations. At diagnostic laparoscopy, a 4×4 cm cyst was found adherent to the surrounding mesentery and was excised in toto. Opening the cyst released thick, gelatinous, mucinous material. Histopathology showed a fibrocollagenous cyst wall with cystic macrophages, histiocytes, Langerhans cells and a foreign body reaction. Complete excision without unroofing or marsupialisation is the accepted treatment, since incompletely treated cysts tend to recur. This case is reported because of its rarity and to remind clinicians that a mesenteric dermoid cyst can be the answer when a cystic-looking intra-abdominal lump is found at an unusual site.