Infectious Granulomatous Dermatitis at a Tertiary Care Centre in North Maharashtra: A Histopathological Study.

INTRODUCTION: Infectious granulomatous dermatitis is a distinctive entity of chronic inflammation. Recognizing the aetiology of granulomatous lesion is challenging to the dermatopathologist. The definitive diagnosis of the granulomatous lesions of skin with identification of aetiological agent is very essential for specific treatment and an appropriate desirable outcome.

AIM: To study the histomorphology of various granulomatous lesions of skin and classify them, accordingly into different categories.

MATERIALS AND METHODS: A retrospective study of skin biopsies received in the Department of Pathology over a period of five years (June 2009-June 2014) was objectively reviewed. The skin biopsies diagnosed histopathologically as granulomatous dermatitis on H&E stained sections were selected. Complete clinical and relevant history were recorded. Special stains were employed whenever required.

RESULTS: A total of 137 cases exhibited granulomatous reaction pattern. Among the granulomatous lesions of skin, tuberculoid granulomas were seen in 109 cases (79.56%), foreign body type in 12 cases (8.75%), suppurative and necrobiotic granulomas each in 7 cases (5.1%) and histiocytic and mixed inflammatory type each in one case (0.7%). Leprosy was the most common granulomatous lesion in 66.4% of the cases (91/137).

CONCLUSION: Leprosy was the most common granulomatous lesion with Borderline Tuberculoid Leprosy (BTL) as common sub type followed by tuberculoid leprosy. Hence the combination of clinical data and histomorphological findings are essential for establishing an accurate diagnosis of granulomatous lesion of skin.