Keratoacanthoma is a benign epithelial tumor which develops rapidly over a period of 4 to 8 weeks. The appearance is that of a papule or nodule with rounded edges and a central keratin-filled crater. A fully developed lesion is usually 1 to 2 cm. in diameter. After an initial period of rapid growth, spontaneous regression begins and it is usually complete within 4 to 6 months, leaving only a slightly depressed residual scar. Keratoacanthomas are usually solitary, but multiple lesions have been reported.1-3
Histopathologic criteria for the diagnosis of keratoacanthoma are characteristic. There is a keratin-filled crater with overhanging edges of epidermis. The crater is surrounded by acanthotic epithelium with cohesive rounded epithelial masses which have an intact basal-cell layer. Varying degrees of dyskeratosis occur in the acanthotic prickle-cell layer, but definite invasion of the dermis is usually lacking. These distinctive histopathological features when supported by the typical clinical
FREEMAN RG, CLOUD TM, KNOX JM. Keratoacanthoma of the Conjunctiva: A Case Report. Arch Ophthalmol. 1961;65(6):817–819. doi:10.1001/archopht.1961.01840020819014
Monkeypox Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.