Lecture 19 4/3/25 Flashcards
What are the characteristics of skin tumors?
-very common primary complaint
-FNA is often diagnostic, especially for lipomas and mast cell tumors
-FNA is recommended for all skin masses
What are the characteristics of squamous cell carcinoma?
-tumor of squamous epithelium
-strong evidence for UV induction
-white cats more likely to develop than other colors of cats
-low metastatic rate; goes to LNs and lungs
-surgery is treatment of choice
-good MST with surgery but recurrence is common
-other treatments are less effective but are options for non-surgical tumors
What are the characteristics of squamous cell carcinoma in situ/Bowen’s disease?
-mainly seen in cats
-must biopsy to diagnose
-not yet cancerous, but about to become cancerous
-strongly associated with papillomavirus infection, which cannot be cured
-surgical excision is treatment of choice in patients that are uncomfortable and/or have affected mobility
-can also do radiation or imiquimod cream
What are the characteristics of basal cell carcinoma?
-similar to SCC but in a deeper layer of the skin
-very rare cancer
-metastasis is very very rare in dogs and uncommon in cats
-surgery with 5 to 10 mm margins is typically curative
What are the characteristics of subcutaneous lipomas?
-very common
-benign tumors of fat
-do NOT transform into liposarcomas
-surgery is curative; only recommended if animal is bothered by lipoma
-injectable triamcinolone may resolve/improve tumors
What are the characteristics of intramuscular lipomas?
-rare
-intramuscular lipomas have a tendency to appear between semimembranosus and semitendinosus muscles
What are the characteristics of infiltrative lipomas?
-rare
-benign, but will invade adjacent tissues like muscle and bone
-often recur after excision; must remove all invaded tissue
radiation has been effective at stopping growth when surgery is not possible/desired
What are the characteristics of hair base tumors?
-multiple types that all act similar
-benign with rare exceptions
-cytology may call it a basilar neoplasm; requires histopath. to distinguish and determine aggressiveness
What are the characteristics of cutaneous/dermal melanomas?
-tumor of melanocytes
-biologically less aggressive than oral or digital melanomas
-lower metastatic rate; goes to LNs and lungs
-surgery is treatment of choice
-good MST
What are the characteristics of perianal adenomas?
-benign tumors in perianal region
-can impair defecation and urination if they grow too large
-often testosterone driven
-treatment is neutering +/- mass resection
-should consider Cushing’s in neutered animals and females
-called “hepatoid” tumors due to cell appears on cytology/histopath.
-respond to androgen and estrogen blockers
What are the characteristics of perianal epitheliomas and adenocarcinomas?
-rare
-require biopsies to differentiate
-higher chance of regrowth after treatment
-lower metastatic rate
-surgery is treatment of choice
-respond to androgen and estrogen blockers
What are the characteristics of digit tumors?
-often present with lameness +/- swelling
-radiographs often show lysis,, especially if subungual
What are the differentials for digit tumors?
-digital melanoma
-SCC
-pyogranulomatous inflammation
-benign tumors
-fracture
What are the characteristics of digital squamous cell carcinoma?
-most common digital tumor of dogs and cats
-possible to have multiple digital involvement, but rare
-schnauzers, poodles, and labs are predisposed
-digit amputation +/- partial foot amputation is treatment of choice
-lower metastatic rate; goes to LN and lungs
-good MST; tumor is rarely cause of death
What are the characteristics of digital melanoma?
-second most common digital tumor in dogs
-rare in cats
-high metastatic rate; goes to LNs and lungs
-surgery +/- vaccine is treatment of choice
-good MST
-vaccine used, benefit unclear
What are the characteristics of pinna tumors in cats?
-common site of UV induced changes in cats
-typically SCC; can see hemangiosarcoma and basal cell carcinoma
-pinnectomy is treatment of choice
-good MST with surgery
What are the characteristics of pinna tumors in dogs?
-most commonly histiocytomas
-histiocytomas are benign and can be neglected unless bothersome
-mast cell tumors are treated with pinnectomy +/- chemo dependent on grade
What are the characteristics of ear canal tumors?
-rare
-cause recurrent ear infections, pain, and bleeding
-may be seen with otoscope; may need video otoscopy
-biopsy is diagnostic of choice to determine neoplastic vs inflammatory
-laser removal can be done if small
What are the characteristics of ceruminous gland adenocarcinoma?
-tumor of ceruminous glands
-rarely metastatic; can go to LNs and lungs
-treatment of choice is total ear canal ablation and bulla osteotomy (TECA-BO) in dogs and cats
-radiation has been reported as helpful for control in non-surgical cases
-excellent MST with surgery
What are the characteristics of cystadenomatosis?
-benign proliferation of multiple cysts in feline ears
-blue/black cystic ear nodules
-may be pre-neoplastic
-can predispose to infections
-most effective treatment is unknown
