DP21 A clinicohistopathological review of cases diagnosed histologically as sarcoidal tissue reaction: a retrospective descriptive study
Authors: Chandra Akash Deep , Khandpur Sujay , Ramam M , Bhari Neetu , Gupta Vishal , Agarwal Shipra 
Published: June 2024

Abstract
A sarcoidal tissue reaction pattern can be found in various dermatoses, including sarcoidosis (prototype), granuloma annulare (sarcoidal type), leprosy, cutaneous tuberculosis and orofacial granulomatosis [Weedon D. The granulomatous reaction pattern. In: Skin Pathology (Weedon D, ed), 5th edn. Philadelphia: Churchill Livingstone, 2015; 212–16]. This study aimed to review cases diagnosed histologically as sarcoidal tissue reaction and to assess their clinical and histopathological features. From the year 2014 onwards, 48 slides were retrieved with histopathological diagnosis of sarcoidal tissue reaction on skin biopsy. From these, clinical data of 29 cases could be reviewed, which were then analysed. Among 29 cases of sarcoidal tissue reaction, 25 were diagnosed as cutaneous sarcoidosis on clinical assessment. Among them, cutaneous lesions were most commonly located on the head and neck region. The most common morphology was plaque (20%), while the majority of cases had lesions with at least two morphologies (44%). Most lesions were erythematous in colour (68%). The number of lesions was variable, ranging from single in 8% of cases to more than 10 in 52% of cases. Histologically, grenz zone was seen in 12% of cases. The classic naked granuloma was observed in the majority of cases (72%). The granulomatous infiltrate was most commonly in a pandermal interstitial location, in 56% of cases, followed by perivascular with interstitial distribution (16%) and perivascular, perieccrine and interstitial location (12%). An interesting observation was the presence of granulomas in a ‘leprosy’ pattern, namely superficial and deep, discrete, oval, oblong and curvilinear configuration of granulomas, in 20% of cases (Ramam M, Yadav D. Epithelioid cell granuloma. Indian J Dermatopathol Diagn Dermatol 2018; 5: 7–18). The density of granulomas throughout the dermis was high in 64% of cases. Admixed with granulomas, other cell types were also observed, including eosinophils (28%), plasma cells (12%) and foamy histiocytes (4%). Fibrinoid necrosis within the granulomas and intergranuloma fibrosis were observed in 16% and 8% of cases, respectively. Inclusion bodies within giant cells, for example asteroid bodies and Schaumann bodies, were seen in 28% and 8% of cases, respectively. Four cases diagnosed with sarcoidal tissue reaction showed nonsarcoidosis dermatoses on clinical assessment. Two had cutaneous tuberculosis with pulmonary involvement, confirmed by imaging and Mantoux testing. Granulomatous rosacea was found in another case, presenting with erythematous papules and plaques in photodistributed areas of the face. The final case involved leprosy, characterized by hypoaesthetic plaques, ulnar clawing and multiple nerve thickening. The study confirms typical features of cutaneous sarcoidosis, aligning with established literature. Additionally, it highlights the four cases where the sarcoidal reaction pattern was present in nonsarcoidal dermatoses. This underscores the importance of clinicohistopathological correlation when encountering conditions mimicking sarcoidosis.