Abstract: Background: Sarcoidosis is a multi-system disease with unknown etiology characterized by the formation of granulomas in various organs. It affects people of all ethnic backgrounds and occurs at any time of life. This disease can affect any organ with a frequency varying according to ethnicity, sex and age most of the time affecting the pulmonary system with symmetrical bilateral hilar adenopathy. Extrapulmonary manifestations in skin, eyes, liver or lymphatic system can take a great morbimortality in patients. Objectives: To a) indicate the phenotypes with similar characteristics with a cluster analysis and b) describe the principal features of those phenotypes. Methods: A model-based clustering was performed in a cohort of 342 sarcoidosis patients, diagnosed and follow-up from 1999 to 2019 at northern Spain hospital. Four homogeneous phenotypes were proposed in our study (C1: parenchymal lung involvement with dyspnea; C2: erythema nodosum and artic ular involvement with asthenia; C3: isolated hilar adenopathy; C4: miscellaneous extrapulmonary sarcoidosis). Chi-square test and ANOVA were used to compare, respectively, categorical, and continuous variables among groups. Two-sample t-tests and the partition of Pearson?s chi-square statistic for were used in pairwise comparisons. Results: Cluster analysis identified four groups: C1 (n=128; 37.4%), C2 (n=75; 21.9%), C3 (n=82; 24.0%), and C4 (n=57; 16.7%) (Table 1). Lung involvement was predominant in all clusters, ranged from 93.3% (C2) to 100% (C3). Extrapulmonary involvement was significantly higher in C2 (97.3%) and C4 (98.2%). Systemic steroids were significantly more used in cluster 1 (75.8%) compared to the rest (C2: 57.3%; C3: 48.8%; C4: 47.4%) (Figure 1). Conclusion: Sarcoidosis has a heterogenous disease, and a cluster analysis can be a useful tool to identify the clinical patterns and can be useful for the management.

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