Pilomatricoma: Histopathologic Evaluation of 100 Cases and Introduction of New Features Publisher



Ghandan A¹ ; Kamyab K² ; Nili A³ ; Mahmoudi H³ ; Azhari V⁴ ; Borzouei A⁴ ; Jamshidi ST⁵ Show Affiliations
Source: Iranian Journal of Dermatology Published:2023

Abstract

Background: Pilomatricoma is a benign skin adnexal neoplasm. Various histological features are observed on microscopic examination. We aimed to evaluate this tumor’s demographic and histological features in detail. Methods: One hundred cases with a diagnosis of pilomatricoma were selected, and demographic and clinical data were entered into a checklist. The pathology slides were reviewed to confirm the diagnosis. The demographic profile of all patients, including age and gender, primary clinical impression, multiplicity of the tumor, microscopic features, and location of tumoral involvement, were extracted. Qualitative data were summarized using frequencies and percentages. Regarding descriptive analysis, the frequency of each histopathologic feature was calculated. Results: Two groups of patients were identified regarding age. This tumor was more common in males among adult patients, while a female preponderance was seen in those under 18. Most lesions were located on the face (40%), followed by upper (32%) and lower (10%) limbs. In addition to well-known histological features, we observed intraepidermal pilomatricoma in two cases presenting unique histopathologic features. Both showed foci of suprabasal cleft formation, while one showed the Borst-Jadassohn phenomenon. These features, in addition to sebaceous differentiation and acantholysis of ghost cells, were not addressed in previous literature. Conclusion: Understanding the diverse and new histological features of pilomatricoma is necessary for differentiating it from other adnexal and soft tissue tumors. © Iranian Journal of Dermatology.