Kaposiform Hemangioendothelioma in a Newborn with KasabachMerritt Syndrome

A 1-month-old infant was admitted to the infectious department due to a firm mass on his right thigh with a probable diagnosis of abscess. The parents claimed that it had appeared one week following injection of hepatitis vaccine at birth. physical examination was unremarkable but a tumoral mass with blue discoloration and mild erythema which was palpated almost on whole thigh of the infant. He was afebrile. Laboratory tests showed a moderate thrombocytopenia (ranging from 40,000- 80,000/mm3). Sepsis work-up study was negative and coagulation profile was within normal range. Considering the most common causes of neonatal thrombocytopenia, “neonatal alloimmune thrombocytopenia” and “idiopathic thrombocytopenic purpura” (ITP) were ruled out. Maternal platelets were normal and history of ITP was negative. Imaging studies were suggested for the infant to rule out the possibility of hemangioma, as a probable cause of thrombocytopenia, causing “kasabach-merritt” syndrome. Thigh-x-ray showed soft tissue edema without evidence of any abnormal collection. Ultrasound study showed a heterogeneous tumor with increased echogenicity of subcutaneous tissues along with swelling in quadriceps muscles of right thigh. Spectral arterial Doppler was biphasic on right lower extremity which could be due to an inflammatory process in quadriceps muscles.