Successful treatment of tracheal lymphoma in a Siamese cat

Retrospective study of feline tracheal mass lesions

OBJECTIVES

This multicentre, retrospective observational study aimed to describe the clinical presentation, diagnostic methods, treatment and outcomes of cats with tracheal masses.

METHODS

Eighteen cats from five academic or secondary/tertiary animal hospitals were included.

RESULTS

The median age at diagnosis was 10.7 years (mean 9.5; range 1-17). There were nine castrated males, seven spayed females, one intact male and one intact female. Fourteen (78%) were domestic shorthairs, one (6%) was an Abyssinian, one (6%) was an American Shorthair, one (6%) was a Bengal and one (6%) was a Scottish Fold. The most common presenting complaints included chronic respiratory distress or dyspnoea (n = 14), followed by wheezing/gagging (n = 12), coughing (n = 5) and voice changes (n = 5). There was cervical tracheal involvement in 16/18, and two showed involvement of the intrathoracic trachea. The following methods were used for diagnosis: ultrasound-guided fine-needle biopsy (UG-FNB) and cytology (n = 8), bronchoscopic forceps biopsy and histopathology (n = 5), surgical resection and histopathology (n = 3), forceps biopsy via an endotracheal tube (n = 1) and histology of tissue sputtered from a cough (n = 1). Lymphoma was most often diagnosed (n = 15), followed by adenocarcinoma (n = 2) and squamous cell carcinoma (n = 1). Most lymphoma cases received chemotherapy with or without radiation according to various protocols, and partial (n = 5) or complete responses (n = 8) were noted. Kaplan-Meier survival data for cats with lymphoma revealed a median survival time of 214 days (95% confidence interval >149 days), which was significantly longer than that of other types of tumours (21 days).

CONCLUSIONS AND RELEVANCE

Lymphoma was the most prevalent diagnosis, and showed a good response to chemotherapy with or without radiation therapy. Various diagnostic procedures were performed, and UG-FNB and cytology are good diagnostic procedures for cervical tracheal lesions. Owing to the variety of treatment protocols at different centres, it was impossible to compare outcomes.

CT measurements of tracheal diameter and length in normocephalic cats

OBJECTIVES

The aim of this study was to measure the tracheal dimensions of normocephalic cats using CT.

METHODS

CT images of 15 client-owned normocephalic cats were retrospectively evaluated to measure the length of the feline trachea. Transverse and vertical inner diameters were measured in five different tracheal regions, and the cross-sectional area of the tracheal lumen was calculated for each point of measurement. Descriptive statistics were applied using a two-tailed t-test.

RESULTS

The mean ± SD length of the trachea was 125.13 ± 14.41 mm. Male cats had significantly larger tracheas than female cats. The transverse diameter first increased by 0.94 mm between the most cranial point of measurement and the middle of the trachea. It then decreased by 1.38 mm between the middle of the trachea and the most caudal point of measurement. The vertical diameter decreased by 1.16 mm between the first point of measurement and the penultimate point, and then increased by 0.06 mm between the penultimate point of measurement and the end of the trachea. The two different diameters resulted in an elliptical trachea shape.

CONCLUSIONS AND RELEVANCE

The feline trachea was circular only at its cranial and caudal ends, and elliptical with a dorsoventral flattening along the rest of its length. Vertical and transverse diameters varied along the entire length. Tracheal shape differences should be considered when performing permanent tracheostomy, tracheal anastomosis or stenting in cats.

Tracheal Squamous Cell Carcinoma Treated with Tracheal Resection and Anastomosis in a Cat

A 10-year-old male castrated domestic shorthair cat presented for a suspected tracheal mass. Radiographs confirmed an intraluminal tracheal mass. Tracheal resection and anastomosis of 5 tracheal rings was performed with minimal, mild intraoperative complications and no postoperative complications. Histopathology of the tracheal mass revealed a diagnosis of squamous cell carcinoma (SCC) with incomplete margins both cranially and caudally. Further treatment, including surgical revision, radiation therapy, or chemotherapy, was recommended. At the time of publication, no further treatment has been initiated, and a scheduled consultation with the oncologist has been canceled. The cat is doing well at home with no reported signs of recurrence 120 days postoperatively. This is the first report of a cat with a tracheal SCC to be treated with a tracheal resection and anastomosis and only the third feline tracheal SCC to be treated in the veterinary literature.