Bowel obstruction due to post-sclerotherapy inflammation and hemorrhage in a mesenteric lymphatic malformation: a case report

Lymphatic malformations (LMs) are rare benign fluid-filled cystic lesions that can cause significant complications when located in the abdomen. A six-year-old boy with a mesenteric macrocystic-dominant mixed-type LM, located in the lower abdomen and measuring 8.2 × 15.7 × 5.4 cm (H × W × D), underwent two sessions of intralesional bleomycin sclerotherapy over the course of approximately 22 months due to recurrent episodes of acute abdominal pain of otherwise unexplained origin. Over the course of three days after the second session, he developed a bowel obstruction. Retrospective review of Magnetic Resonance Imaging (MRI) revealed pre-existing small bowel encasement by the LM at the site of the current obstruction. A laparotomy with an en bloc resection of the involved bowel segment and the associated LM was performed. The bowel segment measured approximately 20 cm in length and was located 40 cm proximal to the ileocecal valve. Intraoperatively, a hematoma was found in one of the macrocysts of the LM. We hypothesize that bleomycin-induced inflammation and the development of the intracystic hematoma led to expansion, which exacerbated the pre-existing encasement and ultimately resulted in a bowel obstruction, and that the patient’s earlier pain episodes may have been due to intermittent intestinal entrapment within the LM. Pathological examination confirmed a hemorrhagic, multicystic LM with perivascular inflammation, supporting the proposed mechanism. Mesenteric, macrocystic-dominant mixed-type abdominal LMs may abruptly expand after sclerotherapy with bleomycin due to hemorrhage and local inflammation, which in turn can result in intestinal entrapment and obstruction.