[B] 1.79 Benign epithelial tumors

Question 1

Tumours of the epidermis

Answer 1

Papilloma

• Benign epithelial proliferation
• Exophytic growth
• Fibrovascular stroma
• Can be viral/non-viral
• Cattle/horse

Question 2

Congenital papilloma is seen in which species

Answer 2

• Foal
• Calf
• Piglet

Question 3

Oncogenic papillomavirus

Answer 3

• Mostly on irritated skin areas
• Usually multicentric
• Usually labial in horses
• On the head of dogs
• p53 inhibition due to oncoproteins

Question 4

Oncogenic papillomaviruses: In cattle

Answer 4

• 6 types, 2 subgroups
• Different localisation for each

Question 5

Oncogenic papillomaviruses: Histopathology

Answer 5

• Orthokeratototic & parakeratotic hyperkeratosis
• Epidermal hyperplasia
• Nuclear inclusion bodies
• Koilocytes: In the upper cell layers of str. spinosum

Question 6

Inverted papilloma

Answer 6

• Benign, endophytic growth
• Epidermal proliferation
• Dogs only
• 1-2 cm diameter in the dermis → Expands to subcutis
• Little pore on the surface of the lesion

Question 7

Adenoma

Answer 7

• Benign tumour of glandular epithelium
• Many histologic variations (tubular, lobular)

Question 8

List the benign epithelial tumours

Answer 8

• Papilloma
• Inverted papilloma
• Adenoma