Tumors of the Thoracic Cavity Flashcards
List the presenting complaint and signalment for chest wall tumors
- Middle age (4-6 yrs) large breed dogs
- Hx of owner noticing a firm and fixed thoracic mass
- Non specific CS of discomfort, lameness, resp signs if growing inwardly
(Chest wall tumors v rare in cats)
Ddx for chest wall tumors in dogs?
1. OSA (MOST COMMON rib tumor in dogs)
2. Chrondrosarcoma
3. Fibrosarcoma
4. Hemangiosarcoma
4. Mast cell tumor
What is the most common rib tumor in dogs?
Osteosarcoma
(Chondrosarcoma 2nd most common)
How to work up and stage a chest wall tumor in a dog?
- Open/Wedge Biopsy for definitive diagnosis of OSA vs CSA
- FNA can ID sarcoma but can’t differentiate between OSA or CSA
- Do CT scan prior to surgery
Treatment plan for a dog with a chest wall tumor (OSA vs CSA)?
- En bloc excision with chest wall reconstruction and Diaphragmatic advancement (if caudally located)
- Prosthetic mesh implant to fill defect
- Thoracostomy tube placed at wound closure
- If rib OSA → must do surgery + chemo
- If rib CSA → surgical excision usually curable, don’t need chemo
How does the treatment plan affect prognosis in dogs with chest wall tumors? (What is the MST)
- Surgical excision + chemo has MST of 1 yr vs surgery alone (6months) for OSA
- CSA can be curable with surgery alone!!! (Must do wedge biopsy to differentiate OSA vs CSA bc of this!)
Are lung tumors common in dogs and cats?
Rare in dogs AND cats, usually found incidentally
DDx for a lung tumor in dogs vs cats?
Dogs:
1. Bronchoalveolar adenocarcinoma
2. Histiocytic sarcoma
Cats:
1. Bronchial adenocarcinoma
What are the presenting complaints and signalment for lung tumors in dogs and cats?
- Usually discovered incidentally
- Possible resp signs
- V/D in cats
- LAMENESS IN CATS!! (Lung digit syndrome)
What cancer can metastasize to the digits in cats, resulting in clinical signs of lameness?
Lung tumors!!
(Bronchial adenocarcinoma)
How to work up and stage a lung tumor in dogs and cats?
- Rads taken on inspiration
How can radiographs help with your DDx list for a lung tumor in a dog?
- Adenocarcinoma rads show well demarcated spherical, solitary mass +/- cavitation
- Histiocytic sarcoma is large, ill defined, irregular, with multiple nodules
What are the negative prognostic indicators associated with lung tumors in dogs?
- Small, < 5cm
- Centrally located near hilus (hard to excise)
- If patient is presenting with CS
- If CT staging shows TB LN or pulmonary metastasis
- Histologic score of tumor
What are the positive prognostic indicators associated with lung tumors in dogs?
- Small, < 5cm
- Peripherally located (easier to excise) vs @ the hilus/central - No evidence of TBLN or pulmonary metastasis
What are the prognostic variables associated with lung tumors in cats?
- Histological grade is most important
- Poorly differentiated = 2 months MST
- Well differentiated = 2 years
- Poor px if metastasis to TBLN, pulmonary, or digits
- Poor px if pleural effusion
Most likely Ddx for a caudal lung tumor in a cat?
Adenocarcinoma
A bernese mountain has multiple tumor like nodules seen on thoracic radiographs. Most likely cause?
Histiocytic sarcoma
What breeds are predisposed to histiocytic sarcoma?
- Bernese Mountain Dogs
- Flat coated retrievers
Treatment plan for a dog with histiocytic sarcoma localized peripherally on the lung?
Surgical removal + adjunctive CCNU
(only if localized which is uncommon bc metastasis is common)
Most common cranial mediastinal tumors in dogs and cats?
- LSA
- Thymoma
What diagnostic tests would you perform to work up and stage for a cranial mediastinal tumor?
- CBC/Chem (Thymoma can cause anemia, hypercalcemia)
- Rads
- U/S guided FNA/cytology (small lymphocytes + mast cells = consistent with Thymoma)
- Flow Cytometry to differentiate Lymphoma vs Thymoma
Sending out a Flow Cytometry is indicated for work up and staging of what tumor?
Cranial mediastinal tumors (to differentiate Lymphoma vs Thymoma)
You receive an FNA/cytology sample from a patient with a cranial mediastinal mass. What are you looking for?
- Small lymphocytes + mast cells is consistent with Thymoma (rather than Lymphoma)
How to treat a cranial mediastinal tumor?
- Surgical excision via median sternotomy if possible
- Radiation therapy (if no sx or as adjunct tx)
- Pyridostigmine for MG if thymoma
