Clinical and epidemiological characteristics of pilomatricomas in a Mexican pediatric population

Background: Pilomatricoma is a common benign adnexal neoplasm in children. There are few epidemiological studies on this subject, with most relying solely on descriptive statistics. Methods: A cross-sectional study conducted in two tertiary hospitals in Mexico City from January 2017 to December 2023. Clinical and electronic records of patients with histopathological diagnosis of pilomatricoma, both sexes, under 18 years old, with any type of present comorbidity were selected. Records of patients with diagnosis not confirmed by histopathology or incomplete records were not included in the study. Results: Fifty-two cases with pilomatrixoma were included in the study, showing a total of 74 lesions. About 23.1% of the cases had multiple pilomatrixomas. 40.4% of the cases experienced pain; this symptom was associated with lesions > 15 mm in diameter and with multiple pilomatrixomas. Risk factors for lesions > 15 mm included age under 8 years, positive tent sign, tumor evolution longer than a year, and a non-classical clinical variety. The head and neck were the most commonly affected areas. The left upper extremity presented larger pilomatrixomas (median 18.5 mm) and occurred more frequently in adolescent patients (mean age 12.1 years) compared to other body areas. Conclusions: Pilomatrixoma in children shows clinical diversity, with specific findings based on size, number, and anatomical location.