Cytology Eval II - Ex 6 Flashcards
3 Common Benign Epithelial Neoplasms
- Papilloma 2. Adenoma 3. Basal Cell tumors
Papilloma
Keratinized epithelial cells
Adenoma
Tight clusters of vacuolated cells
Basal cell tumors
Tight sheets of cells with high N:C ratio
Sebaceous hyperplasia & sebaceous adenomas
Have the same cytologic appearance: - arranged in thick clumps - round cells with abundant, highly vacuolated, basophilic cytoplasm - small, round nucleus with dense chromatin **Sebaceous carcinomas are rare
Sebaceous Adenoma
**red lines mark the cell junctions
Sebaceous Adenoma
Follicular Tumors
**Contain basal epithelial cells
- arranged in sheets (very distinct cell junctions; cobblestone appearance)
- scant, lightly basophilic cytoplasm
- small, round nucleus with dense chromatin
**Common on the head and neck
Benign Follicular tumors
- in cats & horses: basal cell tumors
- in dogs: trichoblastomas
- specific classification requires histopathologic examination
Malignant Follicular basal cell tumors
- relatively common in CATS
- rare in dogs
- based upon the degree of malignant transformation observed
- should be confirmed histologically
Common Malignant Epithelial Neoplasms (4)
- Adenocarcinoma
- 68-75% of nasal tumors in dogs - Squamous cell carcinoma
- Transitional cell carcinoma
- Anal sac adenocarcinoma
- neuroendorcrine appearance
- few characteristics of malignancy
Adenocarcinoma
- sheets of cells often with acinar structures
- cells with “signet ring” appearance
- marked anisocytosis and anisokaryosis
- severely anaplastic nasal tumors can have lymphoid appearance
Adenocarcinoma
Anal Gland Tumors
- Common in dogs –> BAD!
- rare in cats
- have malignant behavior
- may induce hypercalcemia
- check sublumbar lymph nodes for metastasis
Anal Gland Tumors - Cytologic Appearance
- Neuroendocrine with several free round nuclei assoc’d with a background of basophilic cytoplasm
- Distinct epithelial cell borders are rare
- Characteristics of malignancy are rare, but tumors typically are malignant
Apocrine Gland Anal Sac Adenocarcinoma (AGASACA)
Poor prognosis
Other common epithelial Neoplasms (3)
- Mammary tumors
- Perianal gland tumors
- Thyroid tumors
- neuroendocrine appearance
Perianal Gland Tumors
* Common in dogs
* most are benign
* located on the caudal half of the animal
* often large and lobulated
* responsive to androgens
* submit histopathology to determine if they are adenomas or carcinomas
Benign Mesenchymal Tumors
* Lack characteristics of malignancy
- lipomas
- fibromas
- neurofibromas
- myxomas
- nerve-sheath tumors
- perivascular wall tumors
- sarcoids (horses)
* May become locally invasive and cause severe disease
* rarely metastasize
Lipomas
Acellular samples common
Adipocytes with large cytoplasmic vacuoles and very small nuclei
Fibromas and Neurofibromas
- same cytologic appearance
- low numbers of small spindle-shaped cells
- thin, centrally-located, oval nuclei
- very uniform
Benign Mesenchymal Tumors
They lack characteristics of malignancy
- Fibromas
- Neurofibromas
- Myxomas
- Nerve-sheath tumors
- Perivascular wall tumors
- Sarcoids (horses)
* May become locally invasive & cause severe dz
* rarely metastasize
Sarcomas
Malignant mesenchymal tumors
- fibrosarcoma
- neurofibrosarcoma
- myxosarcoma
- hemangiosarcoma
- histiocytic sarcoma
* Extensive local tissue invasion
* metastasize, except histiocytic sarcoma
Fibrosarcoma
* soft-tissue sarcoma
* spindle-shaped cells
* marked nuclear variability
* prominent nucleoli
Fibrosarcoma
6 types of round cell tumors
- MCT
- Plasma cell tumor
- Histiocytoma
- Transmissible Venereal tumor (TVT)
- Lymphoma
- Melanoma
MCT - cytolgic appearance
- individualized round cells
- round, centrally located nucleus
- filled wiht metachromatic cytoplasmic granules
- +/- eosinophils &/or reactive fibroblasts
- occasionally, granules will not stain with Diff-Quik stain
Mast Cell Tumors
Plasma Cell Tumor (Plasmacytoma)
- individualized riound cells
- abundent, basophilic cytoplasm
- round, eccentrically placed nucleus
- perinuclear clearing in the area of the Golgi zone
- binucleation is common finding
*usually benign
Plasma Cell Tumor
HIstiocytoma
- common in dogs
- spontaneously regree w/in a few months of dx
- appearance:
individualized round cells
lightly basophilic cytoplasm that becomes paler toward the edges of the cell
ovoid, eccentrically placed nucleus
mitotic figures
often with a basophilic proteinaceous background
infiltrate of small lymphocytes is seen as these tumors regress
Histiocytoma
Transmissible Venereal Tumor
- common in dogs from tropical areas
- typically ocur around genitals & muzzle –> can spread
- appearance:
individualized round cells
abundant, lightly basophilic cytoplasm
round, centrally located nucleus
round, clear, distinct cytoplasmic vacuoles
TVT
Cutaneous Lymphoma
- multiple skin lesions may be seen
- plaque-like lesions common
- appearance:
monomorphic pop of lymphocytes
lymphocytes may be small, intermed, or large
*most cutaneous lymphomas are T cells
Melanoma
Appearance:
- individualized or aggregated
- spindle-shaped or round
- round to variably-shaped nucleus
- large number of BROWN-BLACK melanin granules
