4 Lumps and Bumps

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How common, relative to other types of tumors, are skin/SC masses in dogs? cats?
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Terms in this set (36)
How common, relative to other types of tumors, are skin/SC masses in dogs? cats?
dogs: most common tumor seen
cats: 2nd most common tumor seen
In dogs, __-__% of skin/SC masses are malignant. In cats, __-__% are malignant.
dogs: 20-40%
cats: 50-60%
What is the most common cutaneous neoplasm in dogs?
old paper: mast cell tumor
new paper: lipoma
What are the 5 most common cutaneous neoplasm in cats?
basal cell tumor
mast cell tumor
fibrosarcoma
squamous cell carcinoma
sebaceous adenoma/hyperplasia
when doing an FNA, you may decide to use the 'pincushion' technique, where you redirect the needle but don't apply negative pressure with a syringe.

What is an advantage to this technique? What kinds of tumors is it best for?
less distortion of cell morphology

round cell neoplasms
epithelial neoplasms
when doing an FNA, you may decide to do an aspirate where you apply negative pressure with a syringe.

what kinds of tumors is it best for?
(use this if pincushion technique doesn't work)

dense tumors
You are observing your cytology sample and you believe you have found a malignant epithelial neoplasm. What are it's characteristics?
-cell shape
-cellularity
-cell association
-cell shape: round to polygonal
-cellularity: high
-cell association: clusters
You are observing your cytology sample and you believe you have found a malignant mesenchymal neoplasm. What are it's characteristics?
-cell shape
-cellularity
-cell association
-cell shape: spindle
-cellularity: low (don't exfoliate well)
-cell association: single
You are observing your cytology sample and you believe you have found a malignant round cell neoplasm. What are it's characteristics?
-cell shape
-cellularity
-cell association
-cell shape: round
-cellularity: high
-cell association: no clusters
List 4 criteria of malignancy
-high N:C ratio
-prominent, multiple, or variable size nucleoli
-anisokaryosis, anisocytosis
-atypical mitoses, multinucleation
Is melanoma a round cell tumor?noWhat are the round cell tumors?"LYMPH" Lymphoma TVT Mast cell tumor Plasmacytoma Hisiocytic tumorYou perform a biopsy to obtain a ____ and/or attain a ____definitive diagnosis histologic gradeWhat is the "1, 2, 3 Rule" in cats?post vaccination, you should biopsy if: -lump still growing after 1 month -lump >2 cm -lump still present after 3 mosGive three examples when you may decide to not do a biopsy-diagnosis is certain -complications likely to occur -emergency situation -risk too high/complex locations -results won't change treatmentYou don't want to biopsy an area of a mass that may be necrotic. Necrosis occurs where the tumor has run out of blood supply. What part do you *avoid* in a soft tissue mass? in a bony tumor?soft tissue mass: avoid center; pick a firm area bone tumor: avoid periphery*Canine Papillomas* -young dog - cause: -older dog - cause: -prognosis:-young dog - cause: papillomavirus; typical self-resolves -older dog - cause: uncertain, immune compromise possible; treat with cryosurgery -prognosis: excellent*Canine cutaneous SCC* -common locations -cause -treatment -note: staging is important-locations: nasal planum, ventrum, nail bed -cause: UV light exposure -treatment: if bony lysis in digit, digital amputation*Feline cutaneous SCC* -biologic behavior -cause-locally aggressive if cutaneous, nasal planum -from UV exposure, especially in white/poorly haired cats*Basal Cell Tumor* -most common skin tumor in (dog/cat) -treatment -ddx-most common skin tumor in *cat* -treatment: excise with narrow margins -ddx: basal cell carcinomaGive a few differentials for hyperplasia or "warts" seen on the skin. What is typical surgery?Sebaceous hyperplasia Sebaceous epithelioma Sebaceous adenoma (rare) Sebaceous adenocarcinoma (rare) conservative surgery (note: carcinoma/adenocarcinoma would be ulcerative, inflamed, invasive, more aggressive overall)Hair follicle tumors such as __ and __ are typically benign. They can be cured by conservative surgery and malignancy/metastasis is (common/rare)trichoepithelioma pilomatricoma malignancy/metastasis rareSkin melanomas are usually <2cm and 85% are benign. Digital or subungual melamoas, however, have __% being malignant, with metastasis to __ and__ being common.30% recur after digital amputation, and there (is/isn't) a proven adjuvant therapy. Staging is important!digital/subungual melanomas: -50% malignant -mets to LNs, lungs -no proven adjuvant to surgeryWhen would you remove a lipoma?If it's... -growing rapidly -changing texture -restricting function -bothering the dog -bothering the ownerList three possible ear canal tumors that could occur in older cats and dogs. For the malignant types, what is the biologic behavior? What surgery would you perform?benign: polyps, cysts, papillomas, adenomas malignant: ceruminous ACA, SCC BB: locally aggressive, <15% met MST >2 yrs in dog, 1 yr in cat sx: TECABOPerineal adenomas are ______-induced and can regress after ____.hormone-induced regress after castration (rare in females)*Anal Sac ACA* -biologic behavior -PE/labwork findings -treatment-BB: highly metastatic to lumbar LNs (do full staging!) -PE: mass/swelling felt on rectal palpation; tenesmus -labwork: hypercalcemia (because of PTHrp) -surgery, even if mets to LNHistiocytes are phagocytic cells that come from bone marrow stem cells. There are two major subsets of histiocytes, ___(Ag-presenting cells in the skin) and ___(Ag-processing cells throughout the body).dendritic cells - Ag-presenting cells in the skin phagocytic cells / marcrophages - Ag-processing cells throughout the bodyHistiocytes from the myeloid line are CD34 (+ or -) and histiocytes from the monoblast cell line are CD34 (+ or -)myeloid: CD34+ monoblast: CD34-It can be difficult to distinguis neoplastic histiocytic diseases from granulomatous or inflammatory diseases. ___ and ___ are important diagnostics to diagnose a histiocytic neoplasmBiopsy Immunohistochemistry*Histiocytoma* -age -appearance/biologic behavior -treatment-young, <3 yrs -solitary, button like cutaneous tumors; look like round cells; typically regress within 6 wks -local conservative therapy, or wait for it to regress*Histiocytic Sarcoma* At first, HS is a solitary disease, but may progress to __ __. The Bermese mountain dog is predisposed, and dogs are often middle age to older.Malignant histiocytosis (may also be multicentric origin, not always progression of Histiocytic Sarcoma?)What are the primary sites for histiocytic sarcoma of *interstitial dendritic cell origin*?spleen lung LNs Dermis, SC peri-articular tissues bone marrow CNS (meninges)What are the primary sites for histiocytic sarcoma of *macrophage origin*?spleen bone marrowT/F Histiocytic sarcomas can metastasize anywhere, have a high metastatic rate, and are typically CD18 negative (negative for round cell tumor marker)FALSE -they can met anywhere -they are highly metastatic -usually *CD18+*How do histiocytic sarcomas spread?hematogenous AND lymphatic