Lesions that may be difficult to separate from KS:
(1) angiosarcoma
(2) kaposiform hemangioendothelioma
(3) spindle cell hemangioma
(4) reactive angioendotheliomatosis
(5) bacillary angiomatosis
(6) acroangiomatous dermatitis
(7) pyogenic granuloma
(8) microvenular hemangioma
(9) hobnail hemangioma
(10) dermatofibroma
(11) arteriovenous hemangioma
(12) verrucous hemangioma
(13) reactive vascular proliferation
The immunostain for HHV-8 LNA-1 stains nuclei in Kaposi sarcoma.
Performance of the immunostain is affected by technical factors such as:
(1) antibody
(2) use of an antigen retrieval procedure (pressure cooking in an alkaline buffer)
