Histomorphological Spectrum of Granulomatous Dermatoses in a Tertiary care Hospital in Bihar

Background: Granulomatous skin lesions represent a broad category of dermatopathology, characterized by chronic inflammation with granuloma formation. These lesions arise from diverse infectious, inflammatory, and idiopathic causes and often pose diagnostic challenges. Histopathological examination plays a pivotal role in identifying the granuloma type and underlying etiology. Given regional variation in infectious disease prevalence and diagnostic access, it is important to evaluate the local pattern of granulomatous dermatoses to aid timely diagnosis and treatment. In the Indian context, particularly in regions like Bihar where tuberculosis and fungal infections are common, such an evaluation is clinically relevant. Objectives: • To study the histopathological patterns of granulomatous skin lesions in patients presenting to a tertiary care hospital in Bihar. • To classify the types of granulomas and correlate them with the underlying etiology. • To identify the most frequent causes and age-wise distribution of granulomatous dermatoses in the studied population. Materials and Methods: This retrospective study was conducted in the Department of Pathology at Netaji Subhas Medical College and Hospital, Patna, Bihar ,India for one year. Skin biopsy specimens from 106 clinically suspected granulomatous lesions were reviewed. Tissue sections were stained with hematoxylin and eosin, and special stains such as Ziehl-Neelsen (ZN) and periodic acid-Schiff (PAS) were used when necessary. Granulomas were classified as tuberculoid, sarcoid-like, foreign body, suppurative, or necrobiotic. Clinical data including age, sex, site of lesion, and provisional diagnosis were retrieved and correlated with histopathological findings. Results: The most common type of granulomatous lesion was tuberculoid granuloma, followed by foreign body and suppurative granulomas. The age group most affected was 21–40 years, and extremities were the most frequent site of involvement. Tuberculosis accounted for the highest number of cases, followed by fungal infections and leprosy. Special stains confirmed mycobacterial and fungal etiologies in a subset of cases. A clinico-histopathological correlation was achieved in 84% of cases, reinforcing the diagnostic value of skin biopsy. Conclusion: Histopathological examination remains essential in diagnosing granulomatous skin lesions, particularly in endemic regions. The predominance of tuberculoid granulomas in this study reflects the high burden of cutaneous tuberculosis in Bihar. Early tissue diagnosis using biopsy and relevant special stains can guide appropriate antimicrobial therapy and prevent misdiagnosis. A structured approach to classifying granulomas significantly improves diagnostic yield and supports better patient outcomes.