Purpose or Case Report: The aim of this report is to document the clinical presentation, multimodality imaging features, and management of patients with diffuse intra-abdominal Infantile Hemangioma (IH) and Kaposiform Hemangioendothelioma (KHE).
Methods & Materials: Retrospective review of our Vascular Anomalies Center database yielded two cases of diffuse intra-abdominal IH and one case of KHE. Further reviews of the clinical charts were performed to document the clinical presentation, multimodality imaging features, and the management outcomes.
Results: Patient 1 was a 7-month-old female who was transferred with high output heart failure. Her clinical history was significant for small bowel resections at an outside institution for bowel perforation at 2 weeks of age. Ultrasound, CT, and MRI studies demonstrated a diffuse intra-abdominal mass. Mesenteric arteriogram demonstrated significant tumor blush of the mesentery and porta hepatis. Percutaneous biopsy revealed an IH. Propranolol was initiated and resulted in improved symptoms and regression. MRI study after 3 years showed involution of the IH.

Patient 2 was a 12-month-old with a history of sickle cell trait who presented with abdominal distention, ascites, and platelet consumption. CT and MRI studies showed a diffuse intra-abdominal mass involving the mesentery, small bowel, retroperitoneum and the pancreas. An open biopsy revealed a KHE. He was initiated on vincristine regimen for 1 year. Follow up CT study at 4 years demonstrated no evidence of residual tumor and resolution of the Kasabach-Merritt syndrome.

Patient 3 was a 40-day-old female with a known facial hemangioma who presented with bloody stools. Initial MRI study showed subtle findings concerning for a proliferating intra-abdominal IH. Patient was initiated on propranolol for facial hemangioma and presumed intra-abdominal IH. Repeat MRI study at 5 months demonstrated proliferation of a well-defined soft tissue mass encasing the branches of superior mesenteric artery and vein. MRI study at 21 months demonstrated involution of the IH.
Conclusions: Although diffuse intra-abdominal IH and KHE are very rare, they should be included in the differential diagnosis in infants who present with a diffuse intraabdominal tumor, gastrointestinal bleeding, bowel perforation, and platelet consumption as seen with KHE. Specific imaging features can prevent delay in diagnosis and appropriate medical and surgical management. In cases where uncertainty persists, histopathologic diagnosis is suggested.