Diagnosis: Seborrheic Keratosis
Sharply circumscribed, pigmented plaque with an uneven surface.
Sharply circumscribed, pigmented plaque with an uneven surface.
Submitted by Alaa Saad. Originally posted October 18, 2010.
See case discussion.
• Melanoma • Pigmented basal cell carcinoma • Verruca vulgaris • Solar lentigo • Actinic keratosis • Dermatosis papulosa nigra
• Most common benign epithelial tumor — "stuck-on" waxy appearance • Dermoscopy: comedo-like openings, milia-like cysts, fissures/ridges, "brain-like" pattern • Sign of Leser-Trélat: sudden appearance of multiple eruptive SKs — associated with internal malignancy (controversial) • Dermatosis papulosa nigra: small SKs on face in individuals of African descent • Stucco keratoses: white, stuck-on SKs on lower extremities • No malignant potential — but pigmented SK can mimic melanoma clinically • Histology: acanthosis with horn cysts and pseudohorn cysts, squamous and basaloid cells
Tags: seborrheic, keratosis, alaa saad