Study of Histomorphological Spectrum of Granulomatous Lesions of Skin

Introduction: The granulomatous reaction is defined as a distinctive inflammatory pattern characterised by the granuloma. The term Granuloma was first coined by Virchow in 1864. The granuloma is characterised by collection of activated histiocytes, epithelioid cells and multinucleate giant cells that may or may not be rimed by lymphocytes and/or show central necrosis. The pattern of skin disease varies from one country to another and across different parts within same country. The granulomatous lesions of skin are a common and intriguing problem in developing countries. Aim: To study the histomorphological spectrum of granulomatous lesions of skin. Materials and Methods: This cross-sectional study was conducted in Department of Pathology, Sarojini Naidu Medical College, Agra, Uttar Pradesh, India, over a period of two years (from September 2018 to September 2020). All skin biopsies coming to the Department of Pathology were fixed in 10% neutral buffered formalin for duration of 12 to 24 hours. Paraffin wax blocks were made and 3-4 micrometer section were taken and stained with Haematoxylin and Eosin (H&E), showing granulomas on histology were included in the study. On H&E, stained slide, granulomas were studied for type, morphology and site. Special stains were used for further evaluations and analysis. Results: Out of total 124 cases studied, the maximum patients 34 (27.41%) were of 11-20 years age group. The epithelioid granuloma was the most common type in 76 (61.29%) cases followed by histiocytic granuloma in 24 (19.35%). The infectious granulomatous dermatoses were the most common histological type in which tuberculosis was most common followed by leprosy. Most commonly the lesions were found to involve the whole dermis in 74 (59.68%) cases, followed by upper and mid dermis in 35 (28.22%) cases. Out of 40 cases of leprosy, 17 (42.50%) cases were found Wade-Fite Stain positive. Out of total 57 cases of tuberculosis, 31 (54.38%) cases were found Acid-Fast Bacillus (AFB) positive. Conclusion: Authors concluded that major cause of granulomatous dermatoses in developing countries is still infectious, tuberculosis and leprosy being the leading causes. Histopathology is gold standard for diagnosis and categorisation of granulomatous dermatoses. Special stains are useful in cases of any dilemm