Abstract: Objective: To summarize the clinical features, histopathological characteristics, and misdiagnosis situations of granuloma annulare, providing references for clinical diagnosis. Methods: A retrospective analysis was conducted on the clinical data and histopathological manifestations of 279 patients diagnosed with granuloma annulare by pathology in our hospital from December 2018 to July 2024. The age, gender, lesion location, clinical subtypes, histopathological types, and misdiagnosis rate of the patients were analyzed. Results: A total of 279 patients were included, with a male-to-female ratio of 3∶4 and an average age of 48.8 years. The majority of patients (78.85%) were middle-aged or elderly (≥40 years old). In terms of clinical subtypes, there were 231 cases of localized type, 43 cases of generalized type, 3 cases of perforating type, and 2 cases of subcutaneous type. Histopathological changes were predominantly palisaded granuloma annulare in 216 cases, interstitial type in 30 cases, subcutaneous type in 27 cases, and perforating type in 6 cases. Among 279 patients, 99 (35%) were misdiagnosed. The most common misdiagnosis was eczema/atopic dermatitis (18 cases). Conclusion: The clinical misdiagnosis rate of granuloma annulare is high. It occurs frequently in middle-aged and elderly individuals. The localized type is more common clinically, and the histopathology is predominantly characterized by palisaded granuloma.

Key words: granuloma annulare, clinical features, histopathology, differential diagnosis