Cutaneous cytology Flashcards
What are the 5 major types of cutaneous round cell tumors?
- lymphoma
- mct
- histiocytoma
- plasmacytoma
- transmissible venereal tumor (TVT)
When might you find high numbers of lymphocytes on a cutaneous cytology prep?
- lymphoma
- hyperplasia of local lymphoid tissue (SALT or LN)
- lymphocytic inflammatory infiltrate
How can you tell lymphoma vs lymphocytic infiltrate/reactive lymphoid tissue?
Lymphoma = monomorphic cell population (usu medium or large cells)
Inflammatory or hyperplastic lymphocyte populations = usu mixed cells (mostly small lymphocytes), often accompanied by plasma cells
What are these cutaneous aspirates indicative of?
Keratin-filled cysts
What kind of material is this? What kind of cutaneous lesion was it drawn from?
Sebum – sebaceous cyst
What kind of lesion is suggested by this aspirate?
Lymphoma – monomorphic population of lymphocytes (medium/large) w/ prominent nucleoli
What kind of lesion is this aspirate likely from?
A reactive lymphoid population – note mixed populatio of small and medium lymphocytes + plasma cells
If this erythematous lesion were found in a young dog and later regressed, what kind of neoplasm is it most likely to be?
Cutaneous histiocytoma –> neoplasm of Langerhans cells
can be erythematous, ulcerated; can develop infiltrate of inflammatory cells as the tumor regresses (in late stages, an aspirate may contain more neuts, lymphs, +/- plasma cells vs histiocytes)
How would you describe the cells in this aspirate of a cutaneous histiocytoma?
‘generic’ round cells
pale basophilic, ‘grainy’ cytoplasm
round to oval nuclei
What is the top ddx for this aspirate of a red, ulcerated neoplasm from a young dog?
Histiocytoma
‘generic’ round cell; basophilic ‘grainy’ cytoplasm, round to oval nuclei
If you get this aspirate from a cutaneous mass, what is the differential? How would you describe the cells? What other cells sometimes accompany the cells?
Mast cell tumor:
- round cells w/ numerous purple-staining cytoplasmic granules
- nucl may be obscured by granules
- often accompanied by eosinophilic infiltrate; reactive mesenchymal cells (fibroblasts) and collagen are sometimes present
Diagnosis?
Well differentiated MCT
Diagnosis?
Poorly differentiated MCT:
- generally corresponds to high grade tumors
- has multiple criteria of malignancy (hypogranulation, binucleation, mitotic fiures, anisocytosis, anisokaryosis)
Dx of this tumor on a cat?
Feline ‘histiocytic’ mast cell tumor –> Are hypogranular MCTs
Dx?
Feline visceral MCT - these tumors sometimes exhibit non-staining granules, given them a ‘vacuolated’ or degranulated appearance
Can see these types of MCTs in GIT, spleen, abdl LNs
Dx? How would you describe the cells?
Plasmacytoma
- cells have round, eccentrically located nuclei w/ clumped chromatin
- cytoplasm is deep blue, may have a perinuclear golgi zone
- binucleated and/or multinucleated cells are often seen
Dx?
Plasmacytoma
What kind of vaginal tumor is this? What are characteristics of cells of this tumor type?
Transmissible venereal tumor (TVT)
- Round cells with high mitotic rate and prominent nucleoli
- Anisocytosis
- Anisokaryosis
- ‘punctate’ cytoplasmic vacuolation often present
What kind of cells are these that were aspirated from a cutaneous mass?
Basal/basilar cells
- have high N:C ratios, form ribbons and/or ‘grape-like’ clusters, and can have melanin if from pigmented areas
- These can come from a variety of different tumor types: most are classified as trichoblastomas in the dog
- Can be found in other lesions: epidermal cysts, follicular neoplasms, etc
What kind of lesion does this aspirate come from?
Sebaceous cell tumor –> aspirates often contain large ‘3D’ clumps of cells that have small nuclei and cytoplasm filled w/ numerous small sebum vacuoles
What kind of cell is this? What are characteristics of this cell type?
Mature keratinized squamous cell
- normal mature squamous cells are usu v. large, flat, polygonal cells
- mature cells have small, condensed nuclei or can be anucleate
- If keratinized = turquoise blue cytoplasm; stain purple; or have purple or magenta staining ‘keratohyaline’ granules
- If nonkeratinized = clear cytoplasm
What kind of cells are these?
Anucleate, keratinized sq cells
Contain melanin
(this one is from a keratin filled cyst)
What kind of tumor is this? What are characteristics of this kind of tumor?
Squamous cell carcinoma
- well differentiated cells resembling normal sq cells
- poorly cohesive and few clumps
- lower N:C ratio than most carcinomas
- sometimes have less differentiated areas that look like basal cells
- often accompanied by suppurative inflammation
What kind of tumor is this?
SCC w/ suppurative inflammation
What kind of tumor is this?
Melanoma
What kind of tumor is this?
Poorly-differentiated melanoma
What kind of tumor is this?
Soft tissue sarcoma
(histo dx = fibrosarcoma)
What kind of tumor is this?
Soft tissue sarcoma
(histo dx: hemangiopericytoma)
What kind of tumor is this?
Lipoma
What kind of neoplasm is this?
Liposarcoma – malignant adipocyte neoplasm
- the cells may appear somewhat similar to those from lipomas but w/ much larger nuclei and criteria of malignancy
- more commonly, these cells have a spindle-cell appearance, similar to other sarcomas, sometimes w/ cytoplasmic lipid vacuoles
