pathology
Last reviewed 01/2018
Keratoacanthoma is characterized by:
- keratin filled crypt
- surrounding rapidly-dividing squamous cells
- cellular changes:
- atypial mitoses
- loss of polarity
Lesions may exhibit pseudocarcinomatous features with nests of epithelial cells breaking away from the main body of the tumour. These may be difficult to differentiate from squamous cell carcinoma. Features suggesting keratoacanthoma include:
- well-differentiated squamous cells:
- little anaplasia or pleomorphism
- excessive keratin productioin
- a well-delineated border to the front of pseudocarcinomatous extensions
- stromal fibrosis in the latter stages
Nevertheless, examination of a small area of biopsy may lead a histopathologist to an incorrect diagnosis of malignancy; it is prudent to relay the clinical suspicion of a keratocanthoma.