The palate of an HIV +ve patient shows the following lesion, the probable diagnosis is:

Kaposi’s sarcoma has four major clinical presentations: classic (chronic), endemic (lymph-adenopathic; African), immunosuppression-associated (transplant), and AIDS-related. The early lesion (patch stage) is characterized by proliferation of small veins and capillaries around one or more preexisting dilated vessel. More advanced lesions (plaque stage) are nodular and show increased numbers of small capillaries or dilated vascular channels interspersed with proliferating sheets of sarcomatous or atypical spindle cells, often with large numbers of extravasated erythrocytes and abundant hemosiderin deposition. Infiltration by chronic inflammatory cells is also variable. In the nodular stage, all the histologic features are more prominent than plaque stage.