Case Study

RAD – Severe nodular interstitial pattern with alveolar infiltrate, likely histocytic sarcoma supported by cytology, in a 6 year old MN Husky dog

This 6 year old Husky presented with a history of coughing for 10 days

Physical exam: noisy breathing, temp 102

This 6 year old Husky presented with a history of coughing for 10 days

Physical exam: noisy breathing, temp 102

DX

Severe generalized nodular interstitial pattern with regional alveolar infiltrate; tracheobronchial lymphadenomegaly; scant pleural effusion; hypovolemia; cytology indicates histolytic sarcoma most likely

Image Interpretation

Rads of the thorax – The axial skeleton presents with expected age related changes such as mild osteoarthritis oft he facet joints emphasizing the mid thoracic spine and emerging spondylosis at T8/9.
The lungs are expanded and present multifocal well-delineated interstitial nodules of varying size throughout. Moreover a marked & ill-defined regional alveolar infiltrate is seen obscuring the caudal lung field. There is a steep ventral dip of the carina with an increased soft tissue opacity dorsal tot he main bronchial birfurcation which is consistent with tracheobronchial lymph node enlargement.
Scant pleural effusion is noted.
There is hypovolemia with microcardia and underperfusion of the lung.The abdominal structures included in the views are within normal limits.

Outcome

The radiographic findings are suggestive for fungal or mycobacterial pneumonia such as blastomycosis or other.
Interstitial pulmonary metastatic spread of another primary tumor is a potential too.
A primary or secondary neoplasia of the lung is unlikely.

Consider testing for fungal pneumonia as well as ultrasound guided fine needle aspiration of the lung for further work up. Screen for possible primary neoplasia with abdominal ultrasound.
In case this is inconclusive bronchoscopy with BAL and CT with CT guided biopsy may be considered but for now measures that do not require sedation/GA should be preferred.

Sampling

FNA/telecytology of chest nodule – large aggregates of histolytic cells suggesting histolytic sarcoma or possibly multilobulated lymphohistiocytic infiltration in the lung; Blastomyces infection less likely.