Clinical and pathological differential diagnosis of localised granulomatous skin lesions

Granulomas are focal infiltrates consisting mainly of macrophages or macrophage-derived cells (epithelioid, giant cells), chiefly in the case impossibility slow degradation specific antigens. The variability manifestations complicates clinical and pathological diagnosis granulomatous skin diseases due to individual patient reactivity specifics often unidentified triggering factors. mini-review analyses possible approaches differentiating most likely localised lesions (granuloma annulare, sarcoidosis, tuberculides, leprosy, lupus miliaris disseminates faciei) by providing recommendations on key histopathological characteristics. review is illustrated a localized lesion with features that atypical but for some discussed, granuloma annulare (clinical course, localization, vertical infiltrates, destruction elastic fibers, accumulation mucin, solitary eosinophils). Pathologists need consider different diagnostic types histological diagnoses, which may require opposite therapies. Therefore, possibility infection foreign material all inflammation should be considered PAS staining polarized light microscopy recommended as basic steps examination. Special techniques such Ziehl-Nielsen Grocott methenamine silver also applied identify pathogen if necessary. It essential have enough tissue examination, including immunohistochemical polymerase chain reaction. not hesitate ask larger sample early disease Keywords: tuberculoid granuloma, palisade ring-shaped granulomatosis skin, histochemistry, biopsy.