Keratoacanthoma

Abstract

Dermatopathology is the practice of assessing cutaneous diseases at the cellular level by performing microscopic examination of skin biopsy tissue samples. Histologic examination is a valuable diagnostic tool, frequently affecting treatment decisions. Understanding the correlations of a disease's pathophysiology and its microscopic morphology is essential in enhancing clinicians' diagnostic acuity. Therefore, this column is designed to present clinicalYpathologic correlations on common, clinically relevant diagnoses. This is a case of keratoacanthoma. BRIEF CLINICAL HISTORYA 66-year-old man presents to a dermatology clinic asking for treatment of a volcano-shaped lesion on his right forearm. He first noticed this about 2 months ago as a small pink ''pimple,'' but it has since grown steadily to a large size. He has been applying over-the-counter topical antibiotics daily, with no apparent effect. The lesion can be tender and bleeds with accidental trauma.