[8][9] Trauma may result in the production of microshunts, wherein the capillary pressure fills the lesion's lymph spaces with erythrocytes, hence promoting the formation of aneurysmal microstructures.
[13] There is a biphasic pattern in the early stages: in the papillary dermis, the vascular spaces are dilated and slit-like, resembling lymphatic vessels, which are concentrated around sweat glands and frequently form small hemangiomatous nodules, dissecting the collagen bundles.
In the deep dermis, the vascular spaces are angulated and slit-like, resembling lymphatic vessels, with solid intraluminal projections and a hobnail appearance.
[8][14] Clinical differential diagnoses include infantile hemangioma, melanocytic lesions, tufted angioma, insect bite, Kaposi sarcoma, erythema multiforme, and dermatofibroma, depending on the stage of evolution.
The histological differential diagnoses include epithelioid hemangioma, early Kaposi's sarcoma, progressive lymphangioma, and well-differentiated angiosarcoma.