Thoracic Cavity Tumors

Question 1

clinical signs associated with chest wall tumors?

Answer 1

Discomfort, weight loss, lethargy, and lameness (if cranial rib affected)

Respiratory signs (tachypnea/dyspnea)

Question 2

DDX for chest wall tumors?

Answer 2

Osteosarcoma (OSA) - 73% of all rib tumors

Chondrosarcoma

Question 3

Work up and staging of chest wall tumors?

Answer 3

Thoracic rads - underestimate local dz but good for met check

Cytology - can tell you its a sarcoma but must know subtype

Open wedge biopsy —> from center of field

CT for surgical planning

Question 4

Treatment for chest wall tumors?

Answer 4

En block excision with chest wall reconstruction (max rib excision =6)

Caudal lung lobectomy may be required to permit adequate closure with substantial diaphragmatic advancement

Adjunctive chemo for dogs with OSA

Question 5

How are chest walls reconstructed after tumor resection?

Answer 5

Cranial to mid-thorax locations —> latissimus dorsi muscle flap and external abdominal oblique muscle flap

Caudal thoracic —> diaphragmatic advancement

Prosthetic mesh augmentation depending on size and location of defect

Question 6

What is the prognosis for chest wall tumors ?

Answer 6

OSA

• resection ALONE: MST 120days
• resection + chemo: MST 240days

CSA
-300-1000days

Question 7

What are poor prognostic factors for chest wall tumors??

Answer 7

Tumor type and complete resection

• poor prognosis: OSA > CSA
• local tumor recurrence and met is 5.6x more likely with incomplete resection

Question 8

What clinical sign is associated with lung tumors in cats?

Answer 8

LAMENESS = lung-digit syndrome

Mets to toes —> weight bearing digits and 3rd phalanx

Question 9

Common presenting complaints in dogs with lung tumors?

Answer 9

Non productive cough
Exercise intolerance

Dyspnea and tachypnea - if pleural effusion develops

Question 10

DDX for cat with lung tumor?

Answer 10

Carcinomas ( subclassified by location)

Bronchial ACA&raquo_space; bronchoalveolar ACA

Question 11

DDX for dog with lung tumors?

Answer 11

Carcinoma - bronchoalveolar ACA

Histocytic sarcoma (often multiple masses)

Question 12

There is a lung mass in your canine patient.. what work up will you do?

Answer 12

Radiographs —> well demarcated and spherical solitary mass
— caudal lung lobe commonly affected
—multiple mass think LSA or histiocytic dz

Transthoracic FNA/cytology

Pretreatment biopsy usually not indicated

CT staging —> lung tumors met to tracheobronchial LN and lungs

Question 13

What are the 3main radiographic presentations of lung tumors in cats?

Answer 13

Mixed bronchoalveolar pattern (33%)

Ill-defined alveolar mass (22%)

Pulmonary mass with cavitation (56%)

Question 14

What is strongly correlated with a negative prognosis for lung tumors?

Answer 14

Tracheobronchial LN mets

Question 15

What is the best method for accessing TB lymph node mets>

Answer 15

CT

Rads only 57% accurate for TBLN enlargement

Question 16

Treatment for lung tumors?

Answer 16

Lateral thoracotomy (4th-6th intercostal) for small tumors with hilar LN biopsy 
-median sternotomy for large tumors and inspection of other lung lobes

Complete or partial lobectomy

Question 17

What are the prognostic factors for lung tumors in dogs?

Answer 17

Tumor size= small (<5cm^3)
Location =peripheral is better
Presence of clinical signs —> larger tumor, worse prognosis

Clinical stage —> TBLN or pulmonary mets =worse prognosis

Histologic score of tumor —> vascular/lymphatic or higher grade = worse prognosis

Question 18

What are the prognostic variables for lung tumors in cats?

Answer 18

Histologic grade is most important
-poorly differentiated (MST=2.5m) vs differentiated (MST=23m)

Without LN involvement - 412days
With LN involvement - 7days
Mets to toes - 67days

Pleural effusion is negative prognostic factor

Question 19

What dog breeds are predisposed to histiocytic sarcoma?

Answer 19

Bernese mtn dog/ flat coated retriever

Question 20

Histiocytic sarcomas are of what cell origin?

Answer 20

Malignant tumors of antigen-presenting dendritic cell origin

Question 21

Histiocytic sarcomas commonly metastatize where?

Answer 21

LN
Kidney
Liver
CNS

Question 22

What is the MST time for histiocytic sarcomas with surgical removed and adjunctive CCNU?

Answer 22

568 days

Question 23

Clinical signs associated with cranial mediastinal tumors?

Answer 23

Related to mass effect —> lethargy, coughing, tachypnea, and dyspnea

Caval syndrome —> edema build up in head, neck, and forelimbs

PNS

Question 24

Top DDX for cranial mediastinal tumors

Answer 24

LSA

Thymoma

Question 25

What would you see on a work up of a thymoma?

Answer 25

Chem/CBC - unremarkable (anemia and hypercalcemia)

Rads - mass effect in cranial mediastinum +/- pleural effusion, megaesophagus

Transthoracic u/s with guided FNA/cytology -> neoplasic epithelial cell with large numbers of small MATURE lymphocytes and intermittent mast cells

Flow cytometry —> thymic lymphocytes differentiated from peripheral by expression of CD4 and CD8

Question 26

T/F: thymoma in dogs tend to me more invasive than in cats

Answer 26

True

Question 27

What is the gold standard treatment fo thymoma?

Answer 27

Exploratory thoracotomy to differentiate invasive vs non-invasive

Median sternotomy usually required due to size of tumor
—intercostal thoracotomy in cat

Non-invasive —> blunt-sharp dissection

Question 28

If a thymoma is not amenable to surgery what can you do to treat?

Answer 28

Radiation therapy

Chemo - usually ineffective but can be attempted with steroids for invasive thymoma

Manage myasthenia gravis is present —> immunosuppressive therapy and anticholinesterase treatment

Question 29

Prognosis for thymoma

Answer 29

Dog - good

Cat - excellent

Question 30

What are poor prognostic factors for thymoma

Answer 30

Age: younger = worse
Megaesophagus = worse
Histologic subtype: lymphocyte rich = worse

Question 31

Why do you have myasthenia gravis with thymoma?

Answer 31

Tumor induced antibody production which destroy ACh receptors —> muscle weakness