Clinicopathological Characteristics of Skin Adnexal Tumors: Insights from a Two-Center Retrospective Study

Background/Objectives: Skin adnexal tumors (SATs) are rare neoplasms originating from sebaceous glands, hair follicles, and sweat glands, often presenting diagnostic challenges due to their histopathological diversity and clinical resemblance to other lesions. This epidemiological and clinicopathological study aimed to evaluate SATs diagnosed between January 2018 and October 2024 across two medical centers in Turkey. Methods: A total of 652 cases were analyzed based on demographic features, tumor size, anatomical localization, and histological subtypes per the 2018 WHO classification. The study also explored the predictors of malignancy, including tumor size and multifocality. Results: Among the cases, 98% were benign and 2% malignant. Sebaceous tumors were the most common (34.5%), followed by eccrine/apocrine (34.2%) and follicular tumors (31.3%). Benign tumors showed a slight female predominance (56.6%), while malignant tumors were more frequent in males (61.5%). The majority of tumors were located in the head and neck region (84.6%), and a tumor size >20 mm was significantly associated with malignancy. Conclusions: This study, one of the largest series from Turkey, highlights the importance of clinicopathological correlation in SATs. It contributes to the literature by identifying size-based cut-off values for malignancy prediction and by assessing interobserver agreement, multifocality, and tumor subtype distribution.