L3: Epithelial And Neuroendocrine Flashcards
Chars. Of epithelial neoplasms
- readily exfoliate
- cohesive clusters and sheets
- have distinct cytoplasmic borders w/ membranes adherent to each other displaying tight cell junctions (desmosomes)
- round, oval, or polygonal cells
- acinar (glandular) formation
- usually met via LYMPHATICS if malignant
Criteria of malignancy for epithelial neoplasms
- nuclear features can be a reliable indicator usually
- histopath may be required for dx in mammary and hepatocellular tumors
Hepatocellular carcinoma
- a type of epithelial tumor
- required histopath for accurate dx
- cells look normal on cyto, but malignant on histopath
- most commonly in left lateral liver lobe
Epithelial neoplasia nomenclature
Benign: oma, adendoma (glandular); ie. Sebaceous epithelioma
Malignant: carcinoma or adenocarcinoma (glandular); ie. Squamous cell carcinoma
Most common tumor in the dog
Adnexal tumors (arise from the hair follicles)
-most common single type of tumor = mast cell tumor
Cutaneous adnexal neoplasms chars.
- type of epithelial neoplasm
- used to be called basal cell tumor
- most common cutaneous tumor of the dog and cat**
- Site predilection: head and neck
- most are benign
- tightly adherent clumps of deeply basophilic epithelium
- high N:C ratio
- melanin pigment may be present (black, rod-shaped granules)
- occasional nucleoli may be seen
- can have sebaceous or follicular differentiation
Chars. Of Apocrine gland tumors
- type of epithelial tumor
- arise from sweat glands
- cuboidal to polygonal cells
- cells may contain pigment
- mostly benign (70%)
- exfoliate in sheets and clumps
Types of apocrine gland tumors
Apocrine adenoma Apocrine carcinoma Ceruminous gland adenoma -common in cocker spaniels and shih tzu Ceruminous gland carcinoma -common in cocker spaniels and cats -almost always malignant in cats -50/50 malignant in dogs
Chars. Of sebaceous gland tumors
- type of epithelial tumor
- arise from sebaceous glands
- polygonal cells with finely vacuolated cytoplasm
- typically have low N:C ratio
- grossly looks warty and pedunculated
- types: sebaceous adenoma, sebaceous epithelioma, sebaceous carcinoma
Two types of perianal neoplasms
1) circumanal gland (hepatoid)
- epithelial
2) Anal sac apocrine gland
- neuroendocrine
Chars. Of circumanal gland neoplasms
-aka “perianal gland adenoma” or “hepatoid tumor”
-looks similar to hepatocytes
cytologically
-arise from modified sebaceous glands in dogs (ie. Perianal, thigh, tail, dorsum)
-most are benign
-most common in older intact male dogs
-surgical excision typically curative
-recurrence possible (androgen driven), so should neuter!
Cytological appearance of circumanal gland neoplasms
- clusters of large, polyhedral hepatoid appearing cells w/ pink hued abundant basophilic cytoplasm
- round to oval nucleus with clumped chromatin and 1 or 2 prominent nucleoli
- smaller “reserve cells” may also be present with higher N:C ratio along the periphery
Distinction b/w circumanal gland adenoma and adenocarcinoma
- may require histopath
- most tumors in intact males benign
- some tumors in females and neutered males may be malignant and can met to regional LN
Chars. Of anal sac apocrine gland adenocarcinoma
- malignant apocrine gland (epithelial) tumor
- common in older dogs
- mets to sublumbar LN
- can cause hypercalcemia
- tumors may be very small but can met at any size
- clumps or sheets of epithelium with indistinct cell borders
- cells appear lysed or “neuroendocrine”
- high N:C ratio with fairly uniform nuclei
- indistinct nucleoli
Test for hypercalcemia of malignancy
Increased parathyroid hormone related protein (should normally be 0)
