2026, Number 2
Inverted follicular keratosis, the dermoscopic chameleon: a report of 6 cases
García SKM, Roldán MR, Arroyo CS, Salazar RE, Toussaint CS, Vega MME
Full text
Language: Spanish
References: 5
Page: 183-188
PDF size: 415.23 Kb.
ABSTRACT
BACKGROUND: Inverted follicular keratosis (IFK) is an uncommon benign neoplasm of follicular origin. Histologically, it is characterized by an exo-endophytic proliferation of squamous cells forming “squamous eddies” without cytologic atypia. Clinically, IFK frequently mimics malignant lesions such as basal cell carcinoma, keratoacanthoma, or squamous cell carcinoma. While dermoscopy is a valuable tool for diagnostic orientation, histopathology remains the diagnostic gold standard.OBJECTIVE: To describe the dermoscopic characteristics and clinicopathological correlation of IFK cases diagnosed at a dermato-oncology clinic.
MATERIALS AND METHODS: A retrospective case series was conducted over a seven-year period (2017–2024), including six patients with a confirmed diagnosis of IFK. Clinical and digital dermoscopic evaluations were performed for all cases, and excisional biopsy was carried out as the definitive diagnostic management.
RESULTS: The study included six patients with an equal sex distribution and a mean age of 40 years (range: 6–60 years). Facial involvement was the most frequent location (50%), and Fitzpatrick skin phototypes III and IV predominated. The initial clinical diagnosis was frequently discordant, with lesions misinterpreted as either benign dermatoses or malignant neoplasms, including basal cell carcinoma, keratoacanthoma, squamous cell carcinoma, basosquamous carcinoma, and melanoma. Dermoscopic evaluation revealed four main patterns: a central yellowish keratinous mass (50%), white-pink structureless areas (50%), blue-gray pigmentation (50%), and radial hairpin vessels (33.3%).
CONCLUSIONS: Inverted follicular keratosis represents a diagnostic challenge due to its clinical and dermoscopic variability. Although pathognomonic dermoscopic features have not yet been established, identifying suggestive patterns may guide the diagnosis; however, histopathological confirmation remains essential.
REFERENCES