+ General Considerations
- Trichoepithelioma accounts for 80% of hair follicle tumors (and up to 2%-3% of all feline skin tumors)
- Benign tumor derived from primitive hair matrix cells that show differentiation to either mature or incompletely developed hair follicles
- 17.5% have histologic features of malignancy
- However, biologic behaviour is usually benign with local tumor recurrence and metastasis rare
- Site: dorsal lumbar and lateral thoracic region
- Gross appearance is similar to basal cell carcinoma but some are cystic and contain keratin
- Intradermal mass with overlying epidermis atrophic, hairless and often ulcerated secondary to trauma
- Treatment: surgery
- Prognosis: excellent
+ Feline Trichoepithelioma
- Breed predisposition: Siamese
- In cats, trichoepithelioma is well-circumscribed, > 5 cm in diameter and usually occur over dorsal lumbar area although others report small, slow-growing tumors with a predilection for the head and back
+ Canine Trichoepithelioma
- Mean age 9.3 years
- Breed predisposition: Golden Retriever, German Shepherd Dog, and Bassett Hound
- Histologically unique form with mucinous degeneration reported in the Golden Retrieve