Multifocal kaposiform hemangioendothelioma of soft tissue with bilateral pulmonary involvement in an adolescent Type adiposetissue

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor ofintermediate malignancy with resemblance to Kaposi s sarcoma. It occurs predominantly inpediatric age group as a cutaneous lesion with focal infiltration into the adjacent soft tissueand bone. Although visceral involvement is very uncommon, several cases with bone,retroperitoneal, or mediastinal involvement have been described. There are also occasionalreports of KHE occurring in unusual sites such as thymus, tonsils, larynx, para nasal sinuses,deltoid muscle, spleen, uterine cervix, thoracic spine and even breast tissue. Multifocal KHEis an extremely rare entity with only occasional reports available in the literature; pulmonaryinvolvement has not been previously described. Herein, we report a unique case of multifocalKHE in a 13-year-old boy presenting with a huge soft tissue mass of upper extremitycomplicated by bilateral pulmonary nodules evolving into large necrotic tumoral masses.