Successful Management of Kaposiform Hemangioendothelioma with Long-Term Sirolimus Treatment: a Case Report and Review of the Literature

Abstract

Background: Kaposiform Hemangioendothelioma (KHE) is a rare vascular tumour of the infancy and the first decade of life. It is locally aggressive and potentially life threatening when associated with consumptive coagulopathy, known as Kasabach-Merritt syndrome (KMS). No consensus or guideline for the therapy has been reached because of the lack of prospective trials, and the different standard care suggestions are based on retrospective case series.

Case report: We report the case of a 9-month-old male with KHE and KMS in which the initial response, obtained with prednisone and vincristine, was subsequently consolidated and strengthened by long-term treatment with sirolimus, a mTOR inhibitor. A summary of the published data is presented as well.

Conclusions: The inhibition of mTOR pathway represents the most important therapeutic innovation introduced in the last few years for KHE. Our case shows the effectiveness and good tolerance of long-term therapy with sirolimus.

Keywords: Kaposiform Hemangioendothelioma; Kasabach-Merrit syndrome; Prednisone; Sirolimus; Vincristine.

Figure 1

Abdominal MRI performed at 1, 9, 16 months. (A) MRI at the diagnosis. Solid tissue hypointense on T2-weighted images with post-contrast enhancement extended in the retroperitoneal area surrounding all upper abdominal vessels, adrenal glands and the left renal hilum (61×12 mm, black arrows). Lesions with the same characteristics also interest the hepatic hilum (36×12mm, white arrow) and the mesenteric adipose tissue. Left kidney enlarged with pyelectasis. Pancreas enlarged with areas showing post-contrast enhancement at the body-tail level. Progressive reduction in mass size after 1 month (B), 9 months (C) and 19 months (D).

Figure 2

Biopsy histological features. Hematoxylin Eosin 400X magnification. Proliferation of neoplastic spindle cells, sparsely forming capillaries with red blood cells inside.