An 8-year-old girl had a painless circumscribed nodule in the right parotid
gland for 4 weeks. A tumour (1.3 cm diameter) within the salivary gland pa
renchyma showed small cystic spaces with horn-like material macroscopically
. The tumour tissue contained solid squamous cell formations and cystic spa
ces limited by multilayered squamous epithelium and covered by layers of or
tho- and parakeratotic cells. The cystic spaces contained keratotic lamella
e. In some areas pin-like epithelial proliferations were seen, All epitheli
al cells were characterized by uniform nuclei, and no atypical mitoses were
seen. Keratinizated masses with partial calcification were occasionally lo
cated in the interstitial tissue and replaced by multinucleated giant cells
. The tumour was classified as a choristoma and resembled a trichoadenoma.
The ectodermally derived oral and salivary gland epithelium may be the sour
ce of skin-like or adnexal rumours.