Tufted angioma (angioblastoma). A benign progressive angioma, not to be confused with Kaposi's sarcoma or low-grade angiosarcoma.

Twenty patients are described with an unusual form of angiomatous proliferation, which most commonly arose on the neck and upper trunk in young persons. Because of the histologic finding of small circumscribed angiomatous tufts and lobules scattered in the dermis, we suggest the term tufted angioma for this lesion. Over half the angiomas developed within the first 5 years of life, but only three patients reportedly had lesions at birth. The clinical course was variable, but most of the lesions slowly extended, eventually covering a large part of the trunk and neck in some patients. Despite the progressive spread of angiomas, they appear to be benign, and malignant change has not been encountered. The microscopic appearance of the angiomatous tufts shows some similarity to the angiomatous tissue of strawberry angioma, but the angiomatous lobules are much larger and extend deeper in the latter condition. Cell marker studies suggest that the cell lobules of the angiomas consist of closely packed blood capillary endothelial and perithelial cells. Familiarity with distinctive histologic features of tufted angioma should prevent these lesions from being misdiagnosed as either Kaposi's sarcoma or as angiosarcoma.