Kaposiform hemangioendothelioma in an adult spleen: An unusual presentation

Abstract

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm typically seen in skin and soft tissue of extremities in infants and children. Although visceral or adult KHE is extremely rare, several cases have been reported. We describe an unusual case of KHE in a 38 year old female who presented with a 2 year history of left upper quadrant pain, splenomegaly and portal venous thrombosis. An extensive workup was not conclusive and revealed only a JAK2 mutation on peripheral blood. This finding coupled with splenomegaly raised suspicion for an early myeloproliferative disorder. Splenectomy was performed for symptomatic relief. No discrete masses or lesions were grossly identified. Microscopically, the spleen was completely replaced by a neoplastic spindle cell proliferation. The diagnosis was KHE replacing the entire spleen. Two reactive lymph nodes were found in the splenic hilum, free of tumor. Follow up 2 years after splenectomy revealed no sign of recurrence or metastasis. To the best of our knowledge, this is the first report of incidental KHE arising in and completely replacing the entire spleen. Despite the long standing disease, no extrasplenic invasion or lymph node metastasis was present, suggesting an overall benign neoplastic process.