Retroperitoneal kaposiform hemangioendothelioma with tufted angioma‐like features in an infant with Kasabach–Merritt syndrome

Abstract

Kasabach-Merritt syndrome denotes profound thrombocytopenia and coagulopathy in an infant with a vascular tumor. A retroperitoneal vascular tumor with an unusual combination of histopathological features is reported, and compared with vascular lesions described in the reported cases of Kasabach-Merritt syndrome in the literature. A large retroperitoneal tumor that had expanded through the sigmoid mesocolon into the sigmoid colon wall was resected from an 8-month-old infant with fully developed Kasabach-Merritt syndrome. Histological examination revealed a combination of venous (cavernous) malformation, kaposiform hemangioendothelioma and tufted angioma-like areas. Cellular tumor components (especially tufted angioma-like parts) infiltrated the wall of the sigmoid colon to the submucosal level. Immunohistochemical staining with antibodies to the Ki-67 antigen and proliferating cell nuclear antigen showed a low proliferative activity, whereas the antiapoptotic bcl-2 protein was expressed diffusely in tumor cells. This is the first reported case of a vascular tumor with tufted angioma-like elements found in the retroperitoneum, and the first reported in combination with kaposiform hemangioendothelioma and venous malformation in the same lesion. Considering the immunohistochemical results and overlapping histological features, it may be considered that tufted angioma and kaposiform hemangioendothelioma represent different growth patterns or stages in the development of a single type of hemangioma.

Kaposiform hemangioendothelioma: Case report and literature review

“…The absence of HHV-8 LNA-1 in KHE underscores a different pathogenesis from Kaposi sarcoma [21] . But the concurrence of features of tufted angioma (TA) and KHE in the same specimen of some patients raises the question as to whether these tumors exist on a continuum [12,22] . There are also reports about a dynamic transformation between both tumors within a single patient, which suggests they are two variants of the same vascular tumor [23] .…”

Treatment of retroperitoneal kaposiform hemangioendothelioma: 2 case reports

“…Physicians administered repeated platelet transfusions, leading to temporal elevation of platelet and subsequent severe platelet reduction. 2) The differential diagnosis of retroperitoneal KHE [2,4] includes retroperitoneal solid tumors such as neuroblastoma, primitive neuroectodermal tumors (PNET) and other hematologic tumors, such as lymphoma, idiopathic thrombocytopenic purpura (ITP). Among the 2 children mentioned above, one was misdiagnosed as neuroblastoma and received antineuroblastoma chemotherapy briefly.…”

Kaposiform hemangioendothelioma: a rare cause of spontaneous hemothorax in infancy. Review of the literature

“…Investigators have hypothesized that KH and tufted angioma may represent different growth patterns or stages in the development of a single entity [5,[11][12][13][14].…”