The patient went on to have a resection.

Histology

MICROSCOPIC DESCRIPTION:

Sections show acellular keratinous debris with foci of dystrophic calcification and multinucleated giant cell reaction. There are several small foci of intact squamoid epithelium present, consistent with an epidermoid cyst. No skin adnexal structures are seen. There is no evidence of malignancy.

FINAL DIAGNOSIS: Epidermoid cyst.