The patient went on to have a resection. 

Histology

The sections show mature squamous epithelium with attached fibrous stroma, small blood vessels, small nerves and lobules of mature fat. The squamous epithelium is associated with loose abundant laminated keratin, features a granular layer, and is thin without dysplasia.  There are no adnexal skin structures.  There are no immature elements. There is no evidence for malignancy.

FINAL DIAGNOSIS: mature teratoma of the conus