Cytopathology of Mesenchymal Neoplasia Flashcards
Dr. Short
What is the definition of mesenchymal?
loosely organized undifferentiated, mostly mesodermal cells that give rise to such structures as connective tissue, blood, lymphatics, bone, and cartilage
T/F: Like round cells, mesenchymal cells exfoliate well
FALSE - do not exfoliate easily with FNA
What are properties of mesenchymal neoplastic cells?
low to moderate cellularity
typically spindle/stellate shaped
indistinct, cytoplasmic borders
Mesenchymal or round?
mesenchymal
How do you name mesenchymal neoplasia?
What are properties of a hemangiopericytoma?
perivascular wall tumor
wispy cytoplasm
crown cells
What tumor is this from?
hemangiopericytoma
What are peripheral nerve sheath tumors?
commonly schwannomas or neurofibromas
brachial plexus
trigeminal nerve
Type?
peripheral nerve sheath tumor
How can a cat get fibrosarcoma?
1) multicentric form causes by feline sarcoma virus 2) no relation to FSV, solitary 3) injection site sarcoma
Look at myxoswrcomas
What stain do you use for lipomas and why?
methylene blue
once dipped in fixative, lipids dissolve and remove cells. methylene blue is water-soluble
What are characteristics of lipomas?
Soft, movable mass within subcutis, difficulty staining slides! Methylene blue!!!
lipocytes have large, clear cytoplasm - nucleus pushed to one side
Look at liposarcoma
send off if seems like lipoma but under microscope does not look like one
Look at hemangiosarcoma
How do hemangiosarcomas appear on microscope?
Samples are usually bloody (hemodilute) - low cellularity, spindle-shaped, plump cells
Lots of blood!
What do rhabdomyosarcomas look like on cytology?
multinucleate strap cells
What do leiomyosarcomas look like on cytology?
difficult to distinguish, cigar-shaped
What are characteristics of osteosarcomas?
osteoBLASTS
What is this?
multi-lobular osteochondrosarcoma
What is a chondrosarcoma?
tumor of aplastic cartilage cells
2nd most common bone tumor
What are cytologic features of chondrosarcomas?
bright, pink pool of smooth-granular material
What are characteristics of melanocytic tumors?
Where are melanocytic tumors malignant?
muco-cutaneous junction, footpad, digits
Where are melanocytic tumors typically bening?
cutaneous and uveal tumors
Where are melanocytic tumors in a cat? Horse?
Cats: head, pinna, uveal
Equine: ventral aspect of tail or genitalia
Describe the microscopic characteristics of melanocytoma / malignant melanoma
often easily noted by pigmentation - dark black, circular cells, cell detail obscured, may see free melanin granules
can be amelanotic but see COM, need histopath
