BASICS
- Tumors of the respiratory system are most commonly located in the thoracic or sinusal/parasinusal structures
- Incidence is very low—thoracic cavity neoplasia was reported in 35 of 5629 necropsies. Primary lung tumors—7.9% of thoracic neoplasia
- The most frequent primary lung tumor is the granular cell tumor (or myoblastoma). They may be accompanied by osteoproliferative abnormalities of carpal, tarsal, and fetlock joints
- Lung is a relative frequent site for secondary metastases from other organs
- 50–68% of nasal passage tumors are malignant with SCC being the most frequent. SCC originates from mucosal or alveolar teeth epithelium and starts invading locally before metastasizing regionally
- Nasal/paranasal tumors—SCC (most frequent); mature adults, more frequent in aged horses. Mean age 8–12.4 years
- Primary pulmonary tumors—>7 years. Pulmonary granular cell tumor (most frequent); mean age 13 years, range 8–22 years
- Lung metastases from distant primary tumors—mean age 8 years, range 3 months to 14 years
- Sex predilection—majority of females for pulmonary granular cell tumors and males for intrathoracic metastatic adenocarcinoma.
- Thoracic respiratory tumors;
- Underweight
- Signs of pleural effusion and ventral edema
- Tachypnea
- Coughing
- Dyspnea
- Hemoptysis
- Abnormal lung auscultation sounds
- Pallor, icterus, and intermittent epistaxis in cases of hemangiosarcoma
- Proliferative osteopathy of carpal, tarsal, fetlock joints rarely seen
- Nasal/parasinusal tumors:
- Nasal discharge (frequent); foul smelling
- Facial deformity for large tumors
DIAGNOSIS
TREATMENT
MEDICATIONS
FOLLOW-UP
MISCELLANEOUS