Cytology Eval II - Ex 6

Question 1

3 Common Benign Epithelial Neoplasms

Answer 1

1. Papilloma 2. Adenoma 3. Basal Cell tumors

Question 2

Papilloma

Answer 2

Keratinized epithelial cells

Question 3

Adenoma

Answer 3

Tight clusters of vacuolated cells

Question 4

Basal cell tumors

Answer 4

Tight sheets of cells with high N:C ratio

Question 5

Sebaceous hyperplasia & sebaceous adenomas

Answer 5

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

Question 6

Answer 6

Sebaceous Adenoma

**red lines mark the cell junctions

Question 7

Answer 7

Sebaceous Adenoma

Question 9

Follicular Tumors

Answer 9

**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

Question 10

Benign Follicular tumors

Answer 10

• in cats & horses: basal cell tumors
• in dogs: trichoblastomas
• specific classification requires histopathologic examination

Question 11

Malignant Follicular basal cell tumors

Answer 11

• relatively common in CATS
• rare in dogs
• based upon the degree of malignant transformation observed
• should be confirmed histologically

Question 12

Common Malignant Epithelial Neoplasms (4)

Answer 12

1. Adenocarcinoma
   - 68-75% of nasal tumors in dogs
2. Squamous cell carcinoma
3. Transitional cell carcinoma
4. Anal sac adenocarcinoma
   - neuroendorcrine appearance
   - few characteristics of malignancy

Question 13

Adenocarcinoma

Answer 13

• sheets of cells often with acinar structures
• cells with “signet ring” appearance
• marked anisocytosis and anisokaryosis
• severely anaplastic nasal tumors can have lymphoid appearance

Question 14

Answer 14

Adenocarcinoma

Question 15

Anal Gland Tumors

Answer 15

• Common in dogs –> BAD!
• rare in cats
• have malignant behavior
• may induce hypercalcemia
• check sublumbar lymph nodes for metastasis

Question 16

Anal Gland Tumors - Cytologic Appearance

Answer 16

• 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

Question 17

Answer 17

Apocrine Gland Anal Sac Adenocarcinoma (AGASACA)

Poor prognosis

Question 18

Other common epithelial Neoplasms (3)

Answer 18

1. Mammary tumors
2. Perianal gland tumors
3. Thyroid tumors
   - neuroendocrine appearance

Question 19

Perianal Gland Tumors

Answer 19

* 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

Question 20

Benign Mesenchymal Tumors

Answer 20

* 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

Question 21

Lipomas

Answer 21

Acellular samples common

Adipocytes with large cytoplasmic vacuoles and very small nuclei

Question 22

Fibromas and Neurofibromas

Answer 22

• same cytologic appearance
• low numbers of small spindle-shaped cells
• thin, centrally-located, oval nuclei
• very uniform

Question 23

Benign Mesenchymal Tumors

Answer 23

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

Question 24

Sarcomas

Answer 24

Malignant mesenchymal tumors

• fibrosarcoma
• neurofibrosarcoma
• myxosarcoma
• hemangiosarcoma
• histiocytic sarcoma

* Extensive local tissue invasion

* metastasize, except histiocytic sarcoma

Question 25

Fibrosarcoma

Answer 25

\* soft-tissue sarcoma \* spindle-shaped cells \* marked nuclear variability \* prominent nucleoli

Question 26

Answer 26

Fibrosarcoma

Question 27

6 types of round cell tumors

Answer 27

1. MCT 2. Plasma cell tumor 3. Histiocytoma 4. Transmissible Venereal tumor (TVT) 5. Lymphoma 6. Melanoma

Question 28

MCT - cytolgic appearance

Answer 28

- 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

Question 29

Answer 29

Mast Cell Tumors

Question 30

Plasma Cell Tumor (Plasmacytoma)

Answer 30

- 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

Question 31

Answer 31

Plasma Cell Tumor

Question 32

HIstiocytoma

Answer 32

- 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

Question 33

Answer 33

Histiocytoma

Question 34

Transmissible Venereal Tumor

Answer 34

- 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

Question 35

Answer 35

TVT

Question 36

Cutaneous Lymphoma

Answer 36

- 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

Question 37

Melanoma

Answer 37

Appearance: - individualized or aggregated - spindle-shaped or round - round to variably-shaped nucleus - large number of BROWN-BLACK melanin granules