A Clinicopathological and Dermoscopic Correlation of Seborrheic Keratosis

BACKGROUND: Seborrheic keratosis (SK) is the most common benign epidermal tumor of the skin. Even though SK has been well characterized clinically, dermoscopically, and histopathologically, data regarding clinical dermoscopic and histopathological correlation of different types of SK are inadequate. AIM: We carried out this study to establish any correlation between the clinical, dermoscopic, and histopathological appearance of SK and its variants. METHODS: This was a descriptive study. Patients with SK were evaluated with respect to age, sex, family history of similar lesions, site of lesions, and symptoms associated with the lesions. Dermoscopy was performed in all cases. Biopsies were taken from the lesions and assessed for histopathology. RESULTS: The most common age group affected by SK was 31–50 years (42%). A female preponderance of 76% was seen. Majority of our patients had a positive family history (62%), though Sun exposure was not seen to be a major factor. The most common clinical variant was common SK (CSK) (46%). The most common dermoscopic findings seen in CSK were comedo-like (CL) openings, fissures and ridges (FR), and milia-like (ML) cysts. Dermatosis papulosa nigra and pedunculated SK had characteristic FR and CL openings on dermoscopy. Stucco keratoses showed network-like (NL) structures and sharp demarcation. CL opening on dermoscopy corresponded to papillomatosis and pigmentation, ML cysts corresponded to horn cysts, FR corresponded to papillomatosis, and NL structures corresponded to an increase in basal layer pigmentation. CONCLUSIONS: This study emphasizes the use of dermoscopy in improving the diagnostic accuracy of SK. The correlation between the various histological and dermoscopic features is described.