Cytology of Solid Tissues Flashcards
types of cytologic samples
fluids
needle aspirates
solid tissue imprints
advantages of cytology to clinician/practitioner
economical
rapid
profitable to practice
advantages over histopathology
Round cell tumors-easier to detect
Detection, Identification of microorganisms
No shrinkage artifact
disadvantages
Non-diagnostic samples
No tissue architecture
- cant: characterize tissue invasion, see relationship with inflammation, distinguish hyperplasia from neoplasia in some tissues, grade tumors
Small sample size
Basic rules to specimen evaluation
1) Understand what normal looks like for various collection sites
2) Examine the ENTIRE specimen at low magnification
3) Only evaluate intact cells, avoid areas that are thick, understained
4) Recognize artifacts & contaminants
what is the start of a logical standard approach to cytology
inflammatory vs non-inflammatory
FNA slide preparation
Prepare films quickly (can use EDTA)
Too thick or broken cells = non-diagnostic
Air dry
Keep away from formalin!
– Don’t ship slides in same box with biopsy
Stain
– Diff-quik, Wright-Giemsa
non-diagnostic samples: only blood
Needle too large
Lesion is vascular
Lesion is mesenchymal tissue (connective tissue)
non-diagnostic samples: all cells broken
Material clotted prior to making smear
Not gentle enough when making smear
non-diagnostic samples: cells too thick to interpret
Didn’t spread cells out adequately
Made “squirt” preparation
non-diagnostic samples: nothing on slide
Missed lesion
Lipoma (fat dissolved in alcohol dip)
Lesion is connective tissue
Inadequate staining due to formalin fumes
Made preparation next to formalin
Mailed samples in same box with tissues fixed in formalin
Inadequate staining due to age of sample - Should stain within 4 to 5 days of making smear.
T/F ulcerated lesion may not have representative cells on imprint
true
bacteria and neutrophils almost always present
why should you not refrigerate slides
condensation and cell lysis
what will fingerprints on the slide result in
keratin artifacts
cytology of inflammatory lesion
what kind of inflammatory cells present
is inflammation due to infectious agent
organisms other than bacteria to look for
Systemic fungal diseases (Histoplasmosis, Cryptococcosis, Blastomycosis, Coccidiodomycosis)
Other fungal: Sporotrichosis, Aspergillus
Protozoal diseases (Leishmaniasis or Toxoplasmosis)
T/F if have lots of lymphoblasts you have lymphoma
true
how to recognize malignancy
1.Variability/pleomorphism (criteria of malignancy)
- Cells where they don’t belong.
Eg, epithelial cells in lymph nodes or abdomiinal fluid.
T/F malignant neoplasms can have monotonous population of cells, usually have no significant inflammation, cellular piling
true
Nuclear criteria of malignancy
Anisokaryosis (variation in size of nuclei)
Abnormally clumped chromatin
Abnormal nucleoli
Abnormal mitotic figures
Micronuclei (satellite nuclei)
Variable sized nuclei in same cell
Nuclear molding
classification of neoplasms
Round (discrete) cell tumors
Tumors of epithelial origin
Tumors of connective tissue origin
types of round cell tumors
Lymphoma (lymphosarcoma)
Plasma cell tumors
Histiocytomas
Transmissable venereal tumors
Malignant histiocytosis
epithelial tumors
omas, adenomas, adenocarcinomas
Some have distinctive appearance, such as endocrine tumors, basal cell tumors, perianal gland tumors, etc.
mesenchymal tumors
omas, sarcomas
Lipomas
hemangiopericytomas
hemangiosarcomas
osteosarcomas
chrondrosarcomas
round cell tumors
cells usually individual (discrete)
usually plenty of cells present
circular cells with round nuclei, distinct cytoplasmic borders
may be well differentiated (mast cell tumors)
T/F cutaneous and subcutaneous plasma cells tumors are typically benign in behavior
true
plasma cell tumors in bone marrow
multiple myeloma
very malignant, serum glob will be increased
Transmissible venereal tumors
Round cells with discrete vacuoles in the cytoplasm
TVT exfoliate readily, can imprint instead of aspirating
can be anywhere
histocytoma
typically young dogs (4-8 m;
malignant histiocytic tumors
usually in large breed dogs
can be either single tumors or systemic tumors like lymphoma
If they are everywhere they are referred to malignant histocytosis
Will have the round cells but will also have multi nucleated cells
Can be derived from the monocytes line in the bone marrow- will be phagocytic
Mast cell tumors-summary
granules; Diff Quik problem (5%?); eosinophils
Histiocytoma- summary
often young dog (can be any age), benign appearing
TVT summary
location (+/-), cytoplasmic vacuoles, prominent nucleoli
lymphoma summary
small amt of cytoplasm, usually blast cells
plasma cell summary
eccentric nuclei, Golgi, abundant cytoplasm
Malignant histiocytosis, histiocytic sarcoma summary
abundant vacuolated cytoplasm, many multinucleated cells, look like macrophages with criteria of malignancy
epithelial tumors
cells in sheets or clusters
cells often large with abundant cytoplasm
hepatoid tumors
resemble liver cells- lots of cytoplasm and single prominent nucleolus
Common, tend to be benign and responsive to testosterone: usually neuter at time of removal
T/F is a lesion is proliferating and eroding it is usually a tumor or fungal infection
true
mesenchymal tumors
Elongated nuclei and cytoplasmic tails (spindle cells)
Cells usually individual
Active fibroblasts resemble malignant mesenchymal cells
soft tissue sarcomas
Fibrosarcoma
Hemangiopericytoma
Neurofibrosarcoma
Peripheral nerve sheath tumor
Poorly differentiated sarcoma
T/F soft tissue sarcoma grading schemes are based on histopathology
true
examples of epithelial tumors
SCC, Thyroid tumor
non neoplastic, non inflammatory agents
Hematomas, seromas
Cysts
Some infectious agents
Eg, Cryptococcus, Malasezia
what can you see with hematomas
macrophages have phagocytized RBCs and contain hemosiderin
what are hematoid crystals
RBC breakdown product
epidermal inclusion cysts
common in dogs
looks like brown toothpaste
make up of keratin
