78/79. Benign & malignant epithelial tumors

Question 1

Viral papilloma

Answer 1

 very frequent, papillomaviral origin
 exophytic growth, markedly thickened epidermis
 often: cattle, horse
 mostly on abrasion regions of body (gate of entry for the virus)
 usually multicentric
 spontaneous regression (min. 6 weeks)

Question 2

Inverted papilloma

Answer 2

 endophytic growth
 epidermal proliferation
 only in dogs (rare)

Question 3

Pigmented viral plaques

Answer 3

 brown-to-black colour
 epidermal thickening
 many melanin containing macrophages

Question 4

Multicentric squamous cell carcinoma in situ

Answer 4

 pre-neoplastic lesion, epidermis hyperplasia
 papillomaviral background

Question 5

Squamous papilloma

Answer 5

 non-viral origin
 usually solitary, in older animals
benign

Question 6

Squamous cell carcinoma (SCC)

Answer 6

predisposition
▪ extended UV-light exposition
▪ lack of pigmentation
▪ furless areas; alopecia
 frequent: horse, cattle, dog, cat

Question 7

Basosquamous carcinoma

Answer 7

 predominantly basal cell proliferation
 gives metastasis
 often more agressive than SCC

Question 8

Trichoblastoma

Answer 8

Follicular tumors
originates from the developing follicular epithelium

Question 9

Trichoepithelioma

Answer 9

all 3 layers of follicle are affected
Follicular tumors

Question 10

Adenocarcinoma

Answer 10

Malignant glandular epithelial tumors