Exam 1 - Principles of Surgical Oncology: Specific Skin/SQ Tumor Types Flashcards
before pursuing surgery, what should you always do in the case of suspected cancer?
STAGING!!!!!!! PLAN!!!!!! ALWAYS DO AN FNA EVEN IF IT FEELS LIKE A LIPOMA!!!
if 1 represents a marginal excision & 2 represents a wide excision, what is the importance of this picture?
if you only did a marginal excision, you wouldn’t get the whole tumor
if you did a wide, you would get clean margins
what is an example of a radical excision?
amputation of a limb
what kind of excision should be done in the case of a benign skin tumor?
marginal excision
what are some examples of a benign skin tumor?
epidermal/follicular cyst, & sebaceous gland adenoma
what is the general type of tumor? how would you remove it?
benign skin tumor - marginal excision
when removing a lipoma, what’s different about the incision made?
incise over the center
how is a lipoma removed?
shell the lipoma out making sure to keep the capsule intact
why are you more concerned about hemostasis in large lipomas?
they may have neovascularization
if there is excess skin after a lipoma is removed, what can you do?
excise the skin
what is this
giant lipoma
what is different when removing an intramuscular lipoma?
may require an en bloc removal of a muscle belly
what is this?
intramuscular lipoma
what would you expect to see on a CT scan of a patient with an infiltrative lipoma?
linear striations throughout the mass
how do you treat an infiltrative lipoma?
treat like a malignant skin mass - remove with margins & follow with radiation
what is scary about infiltrative lipomas?
high rate of recurrence even with aggressive surgery
what is this?
ct of a infiltrative lipoma - linear striations throughout the mass
T/F: a liposarcoma is easy to diagnose pre-op
FALSE
T/F: CT characteristics may be helpful in diagnosing a liposarcoma
true!
what are some CT characteristics that may be helpful if you think your patient has a liposarcoma?
heterogenous, soft tissue opacity, nodular in appearance, mineralization, & regional lymphadenomegaly
how do you treat a liposarcoma?
like other soft tissue sarcomas - wide surgical excision
when removing a mast cell tumor, surgical dose depends on what?
grade of tumor!
what do you do if you don’t have a biopsy of a mast cell tumor before surgical excision?
assume a higher grade
if appropriate margins can’t be obtained in a mast cell tumor removal, what should be considered?
neoadjuvant therapies!
what are examples of neoadjuvant therapies for mast cell tumors?
prednisone 1mg/kg - up to 80% reduction in tumor volume in 70% of cases
radiation
chemo
when removing grades I-II mast cell tumors, what is appropriate for surgical excision?
2cm laterally & 1 fascial plane deep - adequate for most lower grade tumors
what does proportional margins entail in mast cell tumor removal?
margin is equal to the widest diameter of the tumor - can be applied to smaller, low grade MCT
what is an example of a proportional margin taken in a mast cell tumor removal?
1cm tumor = maximum lateral diameter is 1 cm
what margins does this represent?
proportional
this surgical excision type is appropriate for what types of mast cell tumors?
grades I-II
2 cm laterally & 1 fascial plane deep
name the tumor
mast cell tumor
when removing a grade III mast cell tumor, what are the appropriate margins?
3cm laterally & 1 fascial plane deep
when you have a mast cell tumor, you may have a higher incidence of high grade if the tumor is located in what anatomical locations?
preputial, scrotal, subungal, oral, & perivulvar
how do feline cutaneous mast cell tumors tend to behave like?
benign manner
why are wide margins typically unnecessary in removing a feline cutaneous mast cell tumor?
typically behave in a benign manner & often not possible because they are frequently on the face
T/F: subcutaneous mast cell tumors involve the cutaneous layer/skin
false!!!
what is the prognosis for subcutaneous mast cell tumors?
good prognosis - behave like low grade cutaneous mast cell tumors
what is this?
subcutaneous mast cell tumor - histopath
these are examples of what?
feline cutaneous mast cell tumors
how would you remove a feline cutaneous mast cell tumor?
proportional margins
where are the most common locations for soft tissue sarcomas?
limbs & trunk
how do soft tissue sarcomas feel?
firm & fixed on palpation
what is prognosis of soft tissue sarcomas dependent on?
ability to achieve complete margins & the grade of the tumor
what is the origin of soft tissue sarcomas?
mesenchymal - multiple subtypes
what is this?
soft tissue sarcoma
why not biopsy a soft tissue sarcoma?
only correct 60% of the time
why is grading of soft tissue sarcomas very important?
prognosis, possible neoadjuvant/post-op treatment, & margins needed during surgical excision
what are the guidelines for surgical removal of soft tissue sarcomas?
2-3cm laterally & 1 fascial plane deep recommended when achievable
why is surgical removal of soft tissue sarcomas more difficult on limbs?
hard to get the necessary margins - need to consider neoadjuvant vs. post-op radiation & potentially radical excision (amputation)
recommended margins for surgical removal?
2-3cm laterally & 1 fascial plane deep - soft tissue sarcoma
how may you go about removing this soft tissue sarcoma?
radical excision - amputation of the limb
what is this an example of?
soft tissue sarcoma that came back due to incomplete margins in 1st surgical removal
why must you refer feline injection site sarcomas?
they are very locally aggressive & advanced imaging is necessary as the first surgery may be the only chance
what are the recommended margins for surgical removal of a feline injection site sarcoma?
5cm laterally & 2 fascial planes deep
what are the necessary margins needed for surgical excision?
5cm laterally & 2 fascial planes deep
if a dog presents with a mammary tumor, what are the chances it is benign or malignant?
50/50
if a cat presents with a mammary tumor, what are the chances it is malignant?
85%
if a dog’s mammary tumor is larger (2+cm) & ulcerated, it is more likely to be what?
malignant
during removal of a mammary tumor, what is also recommended?
spay - impact on survival may be controversial
when removing mammary tumors, when should you take the underlying fascia?
never - except for when the mass is adhered
what is a lumpectomy?
removal of the mammary mass with ~1cm margin
what is a single mastectomy?
removal of a single gland, with 1-2 cm margin around the tumor
what is a regional mastectomy?
removal of glands 1-3, or glands 3-5 en bloc
what is a unilateral mastectomy?
removal of an entire mammary chain
what is a bilateral mastectomy?
removal of both mammary chains
when removing a mammary tumor in the dog, surgical dose depends on what?
tumor behavior, tumor size, & number of tumors
in cats, what is the current recommended treatment for mammary tumors?
bilateral chain mastectomy in all cases - may need to be staged
what are the recommended margins for mammary tumors in cats for surgical excision?
1-2cm margins around tumor/tumors - otherwise smaller margins
what is the goal of removing a mammary tumor in cats?
remove mammary tissue & lymphatics
for digit tumors in dogs, are benign or malignant tumors more common?
malignant
what are the most common malignant digit tumors in dogs?
SCC (50%)»_space; melanoma»_space; STS»_space; MCT»_space; osteosarcoma
T/F: staging isn’t important in digit tumors
false - it is very important
how do you treat digit tumors?
digit amputation is indicated but you still need to consider margins
how would you treat this?
digit amputation
