Round Cell Neoplasms Flashcards
What are the characteristics of round cells?
Readily exfoliate
monolayers, individual cells
round or oval cells
distinct cytoplasmic borders
What are the 6 round cell tumors?
Lymphoma
plasma cell
Histiocytoma
TVT
mast cell
Melanocytic neoplasms*
With which round cell types is histopathology recommended?
mast cell tumor
lymphoma
melanoma
With what round cell neoplasm can hypercalcemia of malignancy be seen?
T-cell lymphoma
What is the relationship to size of a lymphoblastic cell compared to a RBC?
2x the size of a RBC
Tumor type?
Benign or malignant?
Round cell, lymphoma
malignant
What type of lymphoma do felines typically get?
small cell GI lymphoma
A patient with B cell lymphoma typically has a better prognosis than T-cell lymphoma. T/F
Substage a animals do better than b. T/F
Both True
Where does leukemia originate vs. lymphoma?
leukemia= starts in BM, centrifugal spread
Lymphoma= starts in L.N., centripetal spread
What are the characteristics of a plasma cell tumor?
Dark blue cytoplasm***
perinuclear area of clearing***
Round, eccentric nucleus ***
May see binucleation/multi
marked anisokaryosis
Plasma cell neoplasm of bone marrow
multiple myeloma
Plasma cell tumors are more common in cats than dogs. T/F
FALSE***
What are the common extramedullary sites for plasma cell tumors?
digits, GI, ears, oral
liver, spleen
What are the criteria needed to dx multiple myeloma?
light chains Ig in urine
osteolysis
monoclonal gammopathy (heavy chains Ig)
> 20% plasma cells in BM
Tumor type?
Plasma cell tumor
Tumor type?
Benign or malignant?
Plasma cell tumor
malignant
A 1 year old canine presented with an alopecic mass on the base of its neck. Has an ulcerated, umbilicated center. What is the likely tumor?
histiocytoma
Tumor type?
Like DDX?
Round cell tumor
Histiocytoma (based on picture)
could also be plasma cell tumor, mast cell
What are the two types of histiocytosis in dogs?
cutaneous
systemic
Do felines get histiocytomas?
What are the two possible related conditions that can appear similar?
NO
Feline progressive dendritic cell histiocytosis
Pulmonary langerhans cell histiocytosis
What are the predisposed breeds to histiocytic sarcoma?
Bernese Mountain Dogs, Rottweilers, Flat Coated
Retrievers, Golden Retrievers and sporadically in many other breeds
An aggressive histiocytic neoplasm that arises at
multiple sites simultaneously
Malignant histiocytosis
In what breed is malignant histiocytosis common?
Bernese mountain dogs
Tumor type?
Round cell
histiocytosis, malignant
like disseminated histiocytic sarcoma
On collecton of a MDB, a dog has concurrent anemia, thrombocytopenia, hypoalbuminemia, hypocholesterolemia with generalized splenomegally & mottling on U/S. A round cell neoplasm is identified. What type likely? What’s the prognosis?
Histiocytic sarcoma - hemophagocytic form
Very poor prognosis
What are the characteristics of TVT?
pale basophilic cytoplasm
Clear vacoules****
central to eccentric nculeus
coarse chromatin
one or more prominant nucleoli****
mod/high N:C
mature tumors may contain mature lymphocytes present
High mitotic rate***
Tumor type?
Round cell, TVT (vacuoles, mitotic figures)
From what cells are TVT derived from?
histiocytic (dendritic/macrophages)
What is the treatment of choice for TVT?
vincristine
Is metastasis to regional L.N. common for TVT?
No, 5-17%
what do the granules of mast cells contain?
Histamine, heparin, TNF, proteases, lipid mediators, proteases, and other cytokines
Tumor type?
What is the difference in staining shown?
Mast cell tumor
L- WG, R-Diff quick
What common concurrent findings do we see with mast cell tumors on cytology?
eosinophils
reactive fibroblasts
collagen lysis
What is the paraneoplastic syndrome associated with mast cell tumors?
GI ulceration
Tumor type?
Describe the common findings seen with these tumors on cytology?
Mast cell tumor
reactive fibroblast (upper right)
collagen lysis (lower left)
In which list of breeds below are mast cell tumors typically more aggressive?
Boxers, Boston terriers, Bulldogs, Pugs
Labs, Goldens, Shar Peis, Terriers, Weimers, RR
Labs, Goldens, Shar Peis , Terriers, Weimers , RR
Are mast cells typically more aggressive in dogs or cats or horses?
DOGS
what locations for mast cell tumors have a poorer prognosis?
nailbed, mucocutaneous jxn, scrotal
Is the visceral form of mast cell tumors found in the GI, spleen, liver more common in dogs or cats?
cats
A dog with a mast cell tumor has a normal sized draining LN. Does this exclude the possibility of metastasis?
NO
A dog that is diagnosed with melanoma of the digit or in the mouth is more/less aggressive than the trunk?
more
Tumor type?
melanoma
Tumor type?
melanoma
List the 5 categories of tissue lesions?
hemorrhagic
cystic
inflammatory
neoplastic
mixed cell population
A small soft mass was palpated on a canines shoulder. What is the likely diagnosis?
Keratin-filled cyst
(epidermal inclusion cyst or follicular cyst)
What do keratin cyst typically contain?
keratinized cells
amorphous material
cholesterol crystals (picture)
A mass on the neck of a dog that produces a brown fluid upon aspiration that is acellular and proteinaceous background. Likely dx?
apocrine cyst
A small mass on the head of a dog that deflates and produces an oily brown tinged fluid when aspirated. What is the likely dx?
sebaceous cyst
How do you determine that a sample is hemorrhagic on not just blood contamination?
Macrophages containing RBC or RBC breakdown products (hemosiderin, hematoidin)
If iatrogenic hemorrhage= PLT will be present
What are the two RBC breakdown products shown?
Hemosiderin- black pigment
Hematoidin- orange crystal
What percentage of cells should be neutrophils for a lesion to be considered neutrophilic inflammation?
>85%
What are the nuclear changes in NT that indicated degenerative changes?
How do you differentiate from degenerative changes and toxic changes?
What nuclear change can be seen in these degenerative neutrophils?
Karyolysis
what characterizes pyogranulomatous inflammation?
neutrophils & >15% macrophages
Type of lesion?
Inflammatory
Panniculus
What characterizes eosinophilic inflammation?
Possible DDX?
>10%
Allergy, fungal/parasitic, eosinophilic granuloma complex, neoplasia (lymphoma, mast cell)
What characterizes lymphoplasmacytic inflammation?
Possible DDX?
mixed lymphoid population
Ag/Immune stimulation, early viral infection, chronic inflammation, regressing histiocytoma
Type of lesion? Be specific
Inflammatory
lymphoplasmacytic
Cyptococcus
Type of Lesion?
inflammatory
Lymphoplasmocytic
To which cells does multinucleation not could as a criterion of malignancy?
macrophages
osteoclasts
What are the 8 characteristics of malignancy?
anisokaryosis
pleomorphism
High N:C ratio
mitotic figures
prominent nucleoli
coarse/clumped chromatin
nuclear molding
mutlinucleation
With what category of neoplastic cells can N:C not be used as a criterion for malignancy?
Round cells
In general, how many characteristics of malignancy are needed for a tumor to be considered malignant?
3+
What characterizes a mixed cell population?
Both inflammatory cells and non-inflammatory cells
Why do we need to be cautious when we interpret mixed cell populations?
inflammatory cells (NT) can causes other cells to appear malignant
