Borderline tuberculoid Hansen’s disease over a port wine stain: A rare clinical presentation with review of literature

We report a rare case of borderline tuberculoid (BT) Hansen’s disease (HD) occurring over a pre-existing port wine stain (PWS) in a middle-aged male. The patient presented with a well-defined, ichthyotic, hypoesthetic patch localized entirely within the PWS over the right lower leg. Slit-skin smear was negative for acid–fast bacilli, and histopathology revealed well-formed epithelioid granulomas, confirming BT HD. The unique co-localization of HD within a vascular malformation raises intriguing questions regarding local cutaneous immunity, altered neural architecture, and microcirculatory factors that may predispose such areas to infection. The patient was treated with standard multidrug therapy with clinical improvement. This case highlights an unusual coexistence of infectious granulomatous and vascular disorders, emphasizing the need for careful evaluation of new lesions arising within congenital birthmarks.