Clinicopathological spectrum of granulomatous dermatitis in a tertiary care hospital
Amrita Bhattacharya, RPS Punia, GP Thami, Harsh Mohan
Granulomatous dermatitis frequently presents a diagnostic challenge to dermatopathologists as an identical histologic picture is produced by several causes. This study aims at classifying granulomatous dermatitis based on etiology and morphology of granulomas, and to highlight significance of clinical correlation in making a specific diagnosis. A prospective analysis of 100 skin biopsies for granulomatous dermatitis was done. The salient clinicopathological parameters were assessed to bring out statistical significance. 84% of cases were diagnosed as infectious granulomatous dermatitis and 16% cases were of non – infectious granulomatous dermatitis, according to the etiological classification. The predominant cause of infectious granulomatous dermatitis was leprosy in 70.2% of cases followed by cutaneous tuberculosis in 23.8% of cases. All cases of cutaneous tuberculosis were composed of well-formed epithelioid cell granulomas with high sensitivity but low specificity. Presence of caseation necrosis and Langhans and foreign body giant cells were seen in 68.4% and 78.9% of cases respectively. The other less common causes were fungal infections in 4.7% of cases and cutaneous leishmaniasis in 1.2% of cases. Majority of cases of non- infectious granulomatous dermatitis were a result of sarcoidosis (37.5%) followed by erythema nodosum (18.7%). The other less common causes were foreign body granulomas, granulomatous cheilitis (12.5%) and necrobiosis lipoidica, granulomatous rosacea and granuloma annulare (6.25%). According to the morphological classification majority of cases were of epithelioid cell granulomas (81%), followed by histiocytic granulomas (11%). Other salient morphological pointers, such as perineural destruction and periadnexal location were also assessed. Special stains were also used to support the diagnosis. 90% of cases achieved clinicopathological correlation with combination of clinical impression and morphology being useful for making definite diagnosis in most of the cases.