Respiratory Tumors Flashcards
Feline nasal tumors most commonly affect where
nasal planum
*nasosinal much less common than the dog- mean age 10 years
What are the predispositions for dogs to get canine nasal tumors
1) Medium to large breeds
2) 10 years of age
3) Dlichocephalic breeds
4) Environmental exposures - pollution, smoke
How do nasal planum tumors present
crusting, erythema, superficial erosions, ulcers
progress to deep erosions and ulcers
How do nasosinal tumors present
-epistaxis, mucopurulent discharge (unilateral to bilateral)
-facial deformity
-dyspnea, sneezing
-chronic duration (2-3 months)
How should you diagnostically work up nasal tumors
-PE: BMBT (buccal mucosal bleeding time), BP
-Bloodwork: CBC w platelets, PT/PTT
-3v TXR
-Ct skull
-Rhinoscopy
-Bx
-Regional LN FNA, esp if enlarged- 10% positive
How do you assess for nasal passage patency
glass slide- should see two spots of condensation
stethoscope
cotton ball
occlude one nostril but can be very stressful
What is the normal buccal bleeding time
2-4 minutes clot will be formed
What is the most useful radiograph view for assessing for nasal tumors
dorsoventral (DV) view
*very limited clinical role
What is the superior imaging value for nasal tumors
CT scan
findings
-destruction of ethmoid bones
-destruction of bones surrounding the nasal cavity
-abnormal soft tissue in the retrobulbar space and air passages
-Hyperostosis of the lateral maxilla
How do you collect samples from the nasal cavity
-Rhinoscopy- small samples
-Curette
-Laryngeal cup forceps/ uterine biospy forceps
-Core
-Hydropulsion (60ml or bulb syringe with saline, may yield larger pirces, pending CT imaging)
-Rhinotomy- bloody, last resort option
How do you measure where the cribriform plate is
measure to the medial canthus is because the cribriform plate is caudal to it so you dont get nerve tissue on your biopsy
some species have it cranial to this
Nasal tumors in dogs are what kinds of tumors
Carcinoma (roughly 2/3)
-Adenocarcinoma
-Squamous cell carcinoma
-Solid carcinoma
Sarcoma
-Chondrosarcoma
-Fibrosarcoma
-Osteosarcoma
Misc: Hemangiosarcoma, Mast Cell tumors
Nasal tumors in cats what typically what types
carcinomas
-can also be lymphoma (usually FeLV negative)
What is the biologic behavior of sinonasal tumors
very locally aggressive
slow to metastasize - low incidence at time of presentation, up to 50% at time of necropsy, lymph nodes, lungs, metastasis rarely the cause of death
How do you treat sinonasal tumor
palliative
surgery- lacks clean margins
chemotherapy not curative when used alone
radiation is the treatment of choice for these tumors **
What is the treatment of choice for sinonasal tumors
Radiation - can treat the entire tumor
disadvantages: cost, availability, side effects (acute and late) - mucositis, skin changes, dry eye, cataracts
What are the side effects of treating sinonasal tumors with radiation
Mucositis
Skin changes
Dry eye
cataracts
acute effects attack rapidly dividing cells- oral mucositis, rhinitis, moist desquamation, keratoconjunctivitis, blepharitis
late effects- slowly dividing cells: chronic rhinitis (recurrent nasal discharge, epistaxis, congestion), cataracts, corneal changes, bone necrosis, oral nasal fistulas, skin fibrosis
improving with newer planning and treatment technologies
What is the efficacy of radiation for sinonasal tumors
most will experience significant improvement in clinical signs
palliative RT improves clinical signs in approx 90% , median survival time is 7-8 months
How do you supportively treat the effects of treating sinonasal tumors with radiation
acute effects usually occur towards the end of therapy
-nutritional support if severe mucositis; feeding tubes if needed, very rare
-analgesics
-antibiotics
-ocular support (artificial tears, cyclosporine)
-prevent self-trauma (ecollar)
What newer modalities develop to maintain or increase dose to tumor but spare normal tissues better
IMRT: better normal tissue sparing, acute side effects are less, specialized equipment
SRT: Increased dose per fraction, 1-5 fractions, probable efficacy as IMRT
How do you treat feline nasal tumors
radiation
chemotherapy if LSA
What is the prognosis of nasal tumors in dogs
No treatment / palliative care = 2 to 4 months
Radiation = 18 months
they often die from local disease
sarcomas do better, smaller is better
feline nasal planum squamous cell carcinoma typically occurs in ______ cats
older cats with unpigmented noses and white faces
How does feline nasal planum squamous cell carcinoma present
prolonged history of crust/ scab on nose
transient response to antibiotics, steroids
How do you work up feline nasal planum squamous cell carcinoma
Cytology
Bx
LN
3c TXR
How do you treat feline nasal planum squamous cell carcinoma
1) Best: Cryotherapy for small, superficial lesions- can be repeated. can only go for 2mm
2) Surgery: for deeply penetrating lesions, removes the nasal planum
3) Radiation
4) Photodynamic therapy
5) Chemotherapy: intralesional, retinoids
What is the penetration depth of cryotherapy when treating feline nasal planum squamous cell carcinoma
2mm
if deeper then surgery is indicated
What are your differentials for mediastinal mass
1) Thymoma (thymic epithelial tumor) *
2) Lymphoma *
3) Ectopic thyroid carcinoma
4) Chemodectoma
5) Histiocytic sarcoma
6) other sarcomas
7) Thymic brachial cyst
8) Lipoma
How do you diagnostically work up a mediastinal mass
1) US guided mediastinal FNA or possibly tru-cut biopsy
2) Cytology- often lymphocyte rich aspirate = tymoma or lymphoma
3) Flow cytometry to differentiate:
T lymphocytes have both CD4 and CD8 receptors unlike peripheral lymphocytes anywhere else in the body
4) Pre-operative thoracic CT scan: if a non lymphoma diagnosis
If a mediastinal mass is a lymphocyte rich aspirate, then what are your two differentials
1) Thymoma
2) Lymphoma
do flow cytometry to differentiate further
Lymphocytes with CD4+ and CD8+ cells indicate a diagnosis of __________ with a mediastinal mass
thymoma
t lymphocytes that react to self antigens are
phagocytized by the thymus
thymus atrophies at the time of
deciduous tooth loss - replaced with fat
How do you treat thymoma
surgery
How do you treat ectopic thyroid
surgery
how do you treat chemodectoma
radiation therapy
How do you treat LSA
chemotherapy
What do mediastinum masses look like on radiographs
-Mass in cranial mediastinum
-Pleural effusion
-Megaesophagus
-Aspiration pneumonia
What is precaval syndrome *
also called cranial vena cava syndrome
-thymic mass causing compression or obstruction of the cranial vena cava
-edema in the face and neck
reversible if thymic mass eliminated
a group of symptoms that may develop when substances released by some cancer cells disrupt the normal function of surrounding cells and tissues
Paraneoplastic syndromes
paraneoplastic syndromes affect ____ of dogs with thymomas
2/3rds of dogs with thymomas
What should you do if you suspect a hypercalcemia paraneoplastic syndrome
-run ionized calcium if serum calcium elevated
-run PTH and PTHrp concentrations (other differentials for hypercalcemia)
What are some common paraneoplastic syndromes
-Hypercalcemia
-Myasthenia gravis +/- megaesophagus
-Polymyositis
-Erythema multiforme
-Arrhythmias
-Other immune disorders
-Exfoliative dermatitis (cats)
What causes acquired myasthenia gravis
decreased quantity of postsynaptic nicotinic acetylcholine
receptors at the NMJ leading to impaired neuromuscular transmission
thymomas produce antibodies to the postsynaptic receptors
How do thymomas cause myasthenia gravis
thymomas produce antibodies to the postsynaptic receptors- impaired neuromuscular transmission
these animals will have serum autoantibodies against muscle acetylcholine receptors
do anti-acetylcholine receptor (AChR) antibody titer
What test can you do for myasthenia gravis when thinking it might be caused by thymoma
1) anti-acetylcholine receptor (AChR) antibody titer
2) Edrophium chloride (short acting anticholinesterase drug) negative response = salivation, retching, vomiting, diarrhea
positive response = improved muscular strength or persistent muscular weakness
3) Pyridostigmine bromide or neostigmine bromide- preoperative anticholinesterase drug
T/F: thymomectomy for thymoma treatment, cures paraneoplastic acquired myasthenia gravis
False- it can develop after thymomectomy-
-likely not resolve in cats
-possibly resolve in dogs
T/F: megaesophagus will resolve following thymomectomy for thymoma treatment
False- likely will not resolve
risk of aspiration pneumonia
gastrostomy tube?
What do you need to consider when doing anesthesia for a dog with myasthenia gravis
ventilatory support with anesthesia and recovery
avoid respiratory depression with anesthetic drugs
What gives a poorer prognosis with thymomas
invasive tumors
effusion
metastasis
paraneoplastic syndromes
incomplete resection (consider reexcision for recurrent)
What is the prognosis thymomas treated with ocmplete thymomectomy
around 425 days or 20 months
Are primary lung tumors or pulmonary metastasis more common
pulmonary metastasis
T/F: almost all primary lung tumors are malignant (carcinoma)
True
What are the clinical signs of pulmonary tumors
cough / hemoptysis
dyspnea
lethargy
weight loss
lameness
incidental finidng
digit mass (cats)
What do pulmonary tumors look like on thoracic radiographs
solitary lung mass
often caudodorsal lung fields
evaluate lymph nodes
pleural effusion
You notice a solitary lung mass on thoracic radiograph on the caudodorsal lung field
What are your differential diagnoses for these
-Primary lung tumor (carcinoma)
-Metastasis
-Malignant histiocytosis
-Granuloma
-Fungal (travel history)
-Pulmonary infiltrates with eosinophils (parasitic)
-Pulmonary lymphomatoid granulomatosis
-Esophageal?
-Hiatal Hernia?
What allows for more sensitive evaluation of thorax to evaluate potential pulmonary tumors
CT
can assess lymphadenopathy
other pulmonary lesions (intra-lung metastasis)
For pulmonary tumors, what does CT not do
does not distinguish resectability (this is done intraoperatively)
does not inform invasiveness / adhesions
If you have a solitary lung lesion and see lymphadenopathy then what does this mean
it is 83% sensitive, 100% specific for having lymph node metastasis
very important for prognosis
fine needle aspirate of a lung mass is typically done by
ultrasound, occasionally CT guidance
low risk of complications if lesion is peripherally located
AVOID penetrating normal lung tissue - centrally located masses are unable to be sampled
not wrong to bypass if lesion is solitary and classic in appearance ie surgical explore
What should you avoid when doing an FNA of lung tumor
AVOID penetrating normal lung tissue (get pneumothorax) - centrally located masses are unable to be sampled
What is the treatment of choice for lung tumors
evaluate all lung fields for evidence for metastasis
evaluate and biopsy hilar lymph nodes
intercostal lobectomy and look at tracheobronchial LNs
Thoracoscopic lobectomy (VATs) is limited to
smaller peripheral lesions
<5cm diameter, away from hilus
Thoracoscopic lobectomy (VATs)
smaller peripheral lesions
<5cm diameter, away from hilus
one lung ventilaton / blocker catheter
unable to dissect lymph nodes
endoscopic retrieval bag
less morbid, faster recovery
What is them most common type of primary lung tumor
Adenocarcinoma
less commonly: SCC, anaplastic carcinoma,
malignant histiocytosis, highly malignant
Primary lung tumors are slowly progressive but also malignant how do the metastasis
pattern via lung, lymph nodes, pleural space
you typically follow up lung tumor treatment with adjuvant therapy if lymph node metastasis, high grade tumor, pulmonary metasis, or incomplete excision. What drugs?
Navelbine (vinorelbine)
platinum drugs
Metastasectomy is a surgical procedure to remove metastases, which are cancerous growths that have spread from a primary tumor to other parts of the body.
metastectomy
-long interval from primary tumor control to development of pulmonary metastasis - increase 8 months survival time
-improves survival
microwave ablation
treats lung lesions
