Vascular Neoplasms and Reactive Proliferations

See Chapter 85 .

Bright red, 1- to 6-mm papule, commonly on the trunk or upper extremities ( Fig. 94.1 ); appears during adulthood; early, tiny lesions can be macular.

Dermoscopy: red to red-blue lacunas (well-demarcated round to oval, red to red-blue structures).

Solitary, painful papule or nodule on the extremities, or in the nail bed (beneath the nail plate) in young adults ( Fig. 94.2 ).

A glomus cell is a perivascular contractile cell that influences vessel diameter as a means of controlling temperature.

Pink to dark red patches and plaques with superimposed papules ( Fig. 94.3 ) that slowly enlarge and occasionally regress.

Commonly found on the neck and trunk.

Congenital or acquired during childhood or young adulthood.

On a spectrum with kaposiform hemangioendothelioma.

Early-onset lesions can be associated with Kasabach–Merritt phenomenon (consumptive coagulopathy with decreased platelets) – see below.

Ill-defined, pink to violaceous plaques or nodules ( Fig. 94.4 ); sometimes deeply seated; any site.

May be congenital and generally appears by 2 years of age.

Locally aggressive, persistent.

Associated with Kasabach–Merritt phenomenon (KMP).

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  Life-threatening thrombocytopenic coagulopathy associated with a vascular tumor, usually a kaposiform hemangioendothelioma or tufted angioma in an infant ( not an infantile hemangioma)

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  Presents with a rapidly enlarging, indurated, ecchymotic mass associated with marked thrombocytopenia and a consumptive coagulopathy (see Fig. 94.4 )

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  Rx: difficult; sirolimus (rapamycin) or vincristine plus prednisone