Diffuse ground‐glass lung metastasis of tonsillar squamous cell carcinoma in a dog

ABSTRACT

A 12‐year‐old male neutered Chihuahua was referred for investigation of retching evolving over 1 month, with progressively worsening inspiratory dyspnoea over the last 10 days. Physical examination revealed a hyperaemic mass on the left tonsil. A computed tomography scan of the head and thorax identified a tonsillar mass with ipsilateral medial retropharyngeal lymphadenopathy and a diffuse ground‐glass opacity affecting the entire lung parenchyma. Fine‐needle aspirates of the tonsil and draining lymph node, bronchoalveolar lavage and postmortem lung biopsies confirmed a tonsillar squamous cell carcinoma metastasised to the locoregional lymph node and diffused to the lungs. This report illustrates a previously unreported presentation of pulmonary metastases from a tonsillar squamous cell carcinoma, which was confirmed histologically, and demonstrates that bronchoalveolar lavage can help detect these metastases.