Clinicohistopathological Concordance of Cutaneous Granulomatous Disorders at a Tertiary Care Hospital in Northern India: A Cross-sectional Study

Abstract

Introduction: Granulomatous inflammatory pattern is a chronic inflammation with a limited number of possible conditions that cause it. Therefore, for treatment purposes, its diagnosis is mandatory. The overlapping clinical and histological features of granulomatous dermatitis demand a proper system of classification. The aetiology, histopathological granuloma patterns, and the morphology of various skin lesions can be informative and supportive towards their diagnosis. Aim: To determine the distribution of various cutaneous granulomatous disorders in the demographical region and their causative agents. Materials and Methods: This cross-sectional study was conducted in the Histopathology section of the Department of Pathology, Government Medical College, Jammu and Kashmir, India over a period of five years (1st November 2014-31st October 2019) involving a prospective and retrospective analysis of 1,150 skin biopsies. A clinical diagnosis of Infectious Cutaneous Granulomatous Disorders (IGDS) was made in 560 cases included in the study. Out of 560 cases, the histopathological diagnosis of IGDS was confirmed in 361 cases. The aetiology and granuloma histology were studied. A clinicopathological agreement was established with the kappa test. Results: Leprosy was the most common histopathological diagnosis, with 343 out of 361 cases (95.01%), followed by tuberculosis with 9 out of 361 cases (2.49%). Leprosy subtypes included Lepromatous Leprosy (LL) in 75 cases (21.87%), followed by Borderline Tuberculoid (BT) in 71 cases (20.70%). Among the nine cases of cutaneous tuberculosis, Lupus Vulgaris (LV) was found in five cases (55.56%), followed by Scrofuloderma (SD) in three cases (33.33%), and Tuberculosis Cutis Orificialis (TCO) in one case (11.11%). The cases of leprosy showed maximum clinicopathological concordance in 343 cases (68.33%), with the BT type being the most concordant with the clinical diagnosis at 30 out of 64 cases (46.88%). A statistical analysis of kappa was applied to the subtypes of leprosy, and the observed kappa value was 0.3439, indicating agreement between histology and clinical diagnosis. Conclusion: Histopathological examination is the gold standard for diagnosing, categorising, and determining clinicopathological concordance of cutaneous granulomatous lesions. The wide spectrum of clinical differentials can be narrowed down. Although the importance of clinical examination and ancillary techniques for confirming the diagnosis cannot be denied, considering all aspects together can lead to a final conclusive diagnosis.