Page 109 - Problem-Based Feline Medicine

7 – THE COUGHING CAT 101

Diagnosis Differential diagnosis

Radiographs. Inhaled and penetrating foreign bodies, benign or para-
● Cervical radiographs may show soft tissue masses sitic granulomas of the airways, and lung lobe torsions,
of the throat and trachea. abscesses and pulmonary infiltrates with eosinophils
● Thoracic radiographs showing solid tissue masses (PIE) may mimic neoplastic masses. Biopsy is often
or nodular interstitial pattern are highly supportive required to differentiate.
of neoplasia. Multiple orthogonal views (left and
right lateral projections, as well as both dorsoven- Treatment
tral and ventrodorsal views) are important to assess
Tracheal (adenocarcinoma) and some bronchial tumors
potential mass lesions. Hilar lymphadenopathy may
(bronchogenic carcinoma) may be surgically resectible.
be present.
Surgical resection is the treatment of choice for solitary
Other imaging modalities, such as CT or MRI may be
pulmonary neoplasms. Cure or long-term remission is
employed.
possible with wide surgical margins, generally meaning
Histological examination of the mass(es) is required for complete lung lobectomy. If non-resectible, excision of
definitive diagnosis, as well as for distinguishing the ori- nodules may palliate clinical signs.
gin of the tumor. Biopsy options include percutaneous
Chemotherapy and radiation have been disappointing in
fine-needle (20–22 gauge) aspiration, percutaneous core generalized pulmonary neoplasms. Metastases from dis-
®
biopsy with 14–18 gauge TruCut -style needle, bron-
tant tumors carry a grave prognosis, although pulmonary
choscopy for cytology via BAL or bronchial brushings, or
lymphoma may attain remission with chemotherapy.
transbronchial lung biopsy.
● Ultrasound is a poor tool to guide percutaneous General supportive care and nutrition are important.
biopsy needles, unless the entire lung lobe has
become consolidated, as the sonic beam is reflected Prognosis
by any aerated lung tissue. Triangulating the land-
marks based on two right-angled radiographic views Prognosis is fair to excellent with surgically resectible
is extremely effective. However, pulmonary tumors primary pulmonary neoplasms that have not metasta-
in cats often have a thin rim of neoplastic tissue sur- sized at the time of surgery.
rounding a large necrotic mass, which makes it very
Prognosis is grave with metastatic disease or malignant
difficult to get diagnositic tissue using needle biospy
pleural effusions.
techniques.
● Transbronchial cytology (TTW or BAL) is often
disappointing, because of the interstitial nature of the Prevention
lesion, as neoplastic diseases rarely cross into the air-
None known.
way lumen. Transbronchial lung biopsy is a promis-
ing technique.
● Surgical biopsy during open thoracotomy is an LARYNGITIS
option, generally during lobectomy. Local lymph
nodes should be biopsied for staging of the tumor. Classical signs
There is evidence that any mass in the lung large
● Dysphonia (voice changes) and stridor.
enough to biopsy requires thoracotomy and surgi-
● Harsh gagging cough.
cal excision, because even benign inflammatory
● Inspiratory dyspnea.
diseases (i.e., eosinophilic granulomatosus)
respond poorly to medical management, and that
eventually, thoracotomy is required. Pathogenesis
Thoracocentesis and cytology of pleural fluid may be Laryngeal edema may occur secondary to laryngeal
diagnostic. trauma (bite wounds, endotracheal intubation, near-