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Laryngeal Masses 573

Laryngeal Masses Client Education
Sheet
VetBooks.ir Diseases and Disorders

○ Malignant: squamous cell carcinoma
BASIC INFORMATION
the mass is nonresectable (e.g., recover
and lymphoma (most common in cats); ○ Discuss a contingency with the owner if
Definition also chondrosarcoma, mast cell tumor, with tracheostomy vs. euthanize).
Benign or malignant proliferation of laryngeal fibrosarcoma, rhabdomyosarcoma, osteo- • Functional laryngeal exam (sedation) to
tissues sarcoma, melanoma, mixed cell tumor, rule out laryngeal paralysis (pp. 574 and
adenocarcinoma, undifferentiated sarcoma 1125) should precede laryngoscopy (general
Epidemiology • Metastatic: lymphoma, plasma cell tumor, anesthesia) to directly visualize the mass.
SPECIES, AGE, SEX thyroid neoplasia • Cells should be obtained for diagnosis
• Rare in dogs and cats; occurs most often in by FNA and/or endoscopic or surgical
middle-aged or older animals DIAGNOSIS biopsy.
○ Benign lesions may be more common in ○ Cytologic analysis adequate for some
younger animals. Diagnostic Overview tumor types (e.g., lymphoma, mast cell
• Higher incidence of laryngeal tumors in male Diagnosis often hinges on direct observation of tumors)
dogs and cats the larynx in an anesthetized or heavily sedated ○ A misleading cytologic or histologic
patient. Fine-needle aspiration (FNA) or biopsy diagnosis of lymphoid hyperplasia may
ASSOCIATED DISORDERS is needed to identify type of mass. be initially obtained by needle cytology
• Signs associated with acute or chronic upper or pinch biopsies in patients with primary
airway obstruction (p. 1004) Differential Diagnosis laryngeal neoplasia.
○ Stridor, dysphonia, collapse, cyanosis, • Laryngeal paralysis (dogs > cats) • CT or MRI (p. 1132) can better show the
dyspnea (increased inspiratory effort) • Laryngeal collapse extent of the mass and possible involvement
• Dysphagia (p. 277) • Elongated soft palate (dogs, especially of other regional structures.
• Aspiration pneumonia (p. 1269) brachycephalic)
• Extra-esophageal reflux • Nasopharyngeal polyp (cats > dogs) TREATMENT
• Pharyngeal or laryngeal foreign body
Clinical Presentation • Granulomatous masses Treatment Overview
DISEASE FORMS/SUBTYPES • Laryngeal osseous metaplasia Immediate goal is to remove/reduce laryngeal
Benign or malignant masses • Retropharyngeal lymphadenopathy luminal obstruction. Additional treatment
• Cuterebra depends on extent of lesion and type of
HISTORY, CHIEF COMPLAINT mass.
Any of the following are possible: Initial Database
• Acute or progressive history of inspiratory • CBC, biochemistry panel, and urinalysis are Acute General Treatment
stridor usually unremarkable. Patient stabilization as necessary:
• Dysphonia • Cervical radiographs may show a soft-tissue • Oxygen by face mask, oxygen cage, or nasal
• Exercise intolerance opacity in the area of the larynx, leading to cannula if needed (p. 1146)
• Dysphagia/gagging laryngeal distortion or decreased laryngeal • Sedation (e.g., acepromazine 0.005-0.01 mg/
• Dyspnea luminal space. The normal larynx of dogs, kg IV, with or without butorphanol 0.2 mg/
• Cyanosis, collapse especially if mineralized, should not be kg IV)
• Cough confused with an abnormality (e.g., foreign • Endotracheal intubation
• Ptyalism body). • Tracheostomy if in severe distress (p. 1166)
• Mass in the neck • Ultrasonography may allow identification of
laryngeal masses because of the distortion of Chronic Treatment
PHYSICAL EXAM FINDINGS normal structural/anatomic relationships. It • Small, benign lesions may be surgically
• May be normal; mass can be an incidental may also facilitate FNA of mass. excised by submucosal resection or partial
finding at time of endotracheal intubation • Thoracic radiographs can demonstrate laryngectomy.
• Inspiratory dyspnea, with gasping if severe metastasis or aspiration pneumonia. • Laryngeal lymphoma is amenable to treat-
○ Dyspnea does not improve with open- • Fluoroscopy can demonstrate soft-tissue ment with chemotherapy.
mouth breathing. opacity in the laryngeal area or dynamic • Large, invasive lesions or malignant
• Stridor obstruction. Free-standing protocols require tumors are best removed surgically by total
• ± Palpable mass in the ventral laryngeal area minimal restraint. laryngectomy combined with a permanent
• Coughing and/or gagging due to laryngeal tracheostomy.
compression Advanced or Confirmatory Testing ○ Glucocorticoid administration (dexa-
• Weakness • Patients with laryngeal masses may be at the methasone 0.05-0.1 mg/kg IV) at the
• Ptyalism cusp of respiratory collapse despite showing time of surgery may help reduce laryngeal
• Halitosis only moderate (inspiratory) dyspnea and edema.
may be unable to recover from anesthesia ○ Permanent tracheostomy can palliate signs
Etiology and Pathophysiology without respiratory distress/suffocation. of respiratory distress in nonresectable cases
• Laryngeal tumors cause obstruction by exter- Therefore, before sedation/anesthesia for or cases managed conservatively. Rarely
nal compression or intraluminal obstruction. upper airway evaluation have the following successful in cats or small dogs because
• Primary ready: tracheal lumen becomes obstructed with
○ Benign: oncocytoma (do not metastasize ○ An appropriate-sized endotracheal tube secretions
but very locally aggressive), laryngeal cyst, ○ A tracheostomy kit (p. 1166) • Certain tumors may be best treated with
laryngeal polyp, rhabdomyoma, granular ○ Clip hair from the ventral neck (prepara- radiation therapy. Consultation with an
cell tumor, lipoma tion for tracheostomy if needed) oncologist is recommended.

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