Primary lung tumors in dogs and cats Flashcards
Primary vs metastatic neoplasia
a primary lung tumor (right image) originates in the lung, usually a solitary tumors (or like 2 nodules)
metastatic lung cancer (left image) is more common.
Describe Primary lung tumors
Low incidence in small animals
- Mostly older animals
- Dogs mean 10-11 years
- Boxer, Doberman Pinscher, Australian
Shepherd, Irish Setter, Bernese Mountain Dog predisposed - Cats mean 12-13 year
- Persian cats predisposed
origin of most lung tumors
Mostly carcinomas of bronchoalveolar origin
Most common type of lung cancer in dogs (3)
- 85% bronchoalveolar carcinomas
- 10-15% other carcinomas
- Histiocytic sarcomas in predisposed breeds
Very rarely are small animal lung tumors benign.
Most common type of lung cancer in cats (3)
- 60-70% adenocarcinomas
- 30-40% other carcinomas
- malignant fibrous histiocytomas, sarcomas, adenomas
Very rarely are small animal lung tumors benign.
medical term for black lung disease
Pneumoconiosis
Clinical signs of primary lung tumor. (6-7)
- Cough
- Dyspnea, tachypnea
- Lethargy
- Anorexia, weight loss
- Hemoptysis
- Lameness
Primary lung tumors are Incidental findings in 30% of cases.
What is Hypertrophic osteopathy
- Rare paraneoplastic syndrome
- Periosteal new bone formation
- Associated with primary and
metastatic lung tumors - Also with non-malignant lesions
- Lameness
- Can resolve
Exact etiopathogenesis is not known.
Metastases in primary lung tumors
Actually have a High rate of metastases!
- Lymph node metastases
- Pulmonary metastases
- Pleural metastases and pleural carcinomatosis
- Distal metastases
- Dogs ~ 50% have metastasis at time of diagnosis
- Cats ~ 75% have metastasis at time of diagnosis
Describe Feline lung – digit
syndrome
- Tumor emboli travel to distant
extra-pulmonary sites - Also “MODAL syndrome”
= Muscle Ocular Digit Aorta Lung - Most commonly digits, Painful lesions in digits
- Diagnosis with FNA and X-rays/CT
= METASTATIC DISEASE, POOR PROGNOSIS!
Diagnosis of primary lung tumor.
Imaging
* X-rays
* CT
* Ultrasound
- FNA
- Biopsy / lung lobectomy
Describe CT Imaging and lung tumors.
- Detects smaller nodules in lung parenchyma than X-rays (1-2mm vs 5-7mm). Thus, helps in detecting pulmonary metastases!
- Lymph node size can be evaluated; helps in evaluating lymph node metastases!
- Helps in surgical planning; location of tumor, distance from hilus.
- Whole body CT To detect other comorbidities.
histopathology of lung tumors taken via
Ultrasound or CT guided (former more common)
Lung lobectomy
vs ultrasound guided tru-cut biopsy
vs thoracoscopic biopsy
Main Tx for primary lung tumor
Surgery!
* Lung lobectomy (either partially or fully)
* Diagnostic! (removed lobe is sent to pathology)
Do not operate if
* Metastases
* Lymphoma
Drug therapeutic Tx for primary lung tumor
Chemotherapy options:
* Vinorelbine, carboplatin (IV)
* Metronomic chemotherapy (means daily PO medication which has diff mechanism of action to IV)
TKI inhibitors (tyrosine kinase inhib.)
* Toceranib
NSAIDs
Drug therapy does not have evidence of true efficacy in dogs or cats. The aim is not curative, its to prolong quality of life.