Pulmonary Chondrosarcoma In a Newfoundland

Patient Information:

Age: 5 years

Gender: Neutered Male

Species: Canine

Breed: Newfoundland

History:

Patient presented to the emergency clinic for vomiting and diarrhea. Chest radiographs were taken as part of diagnostics and 2 rounded soft tissue nodules were visualized in the caudal portion of the left cranial lung lobe measuring ~2.5 and 1.7cm

Ultrasonographic Findings:

There was a well circumscribed hypoechoic nodule in the left mid lung field measuring 0.8x0.7cm. Around this nodule there was a "shred sign" noted. The rest of the lung field displayed normal A-lines.

Abdominal Ultrasound Interpretation:

Lung nodule- the findings were moderate and indicated either primary or metastatic pulmonary neoplasia (lung abscess, benign lesion, parasitism or fungal infection cannot be ruled out without biopsy).

Additional Diagnostics:

A CT was performed which confirmed an isolated cluster of small nodules in the caudal portion of the left cranial lung lobe. The rest of the lung lobes were normal. An ultrasound guided fine needle aspirate was performed on the peripherally visualized nodule and submitted to Eastern VetPath.

Cytology Findings:

The slides are moderately cellular and consist of a few red blood cells and nucleated cell population predominated by individual round to irregularly shaped cells with very few scattered leukocytes. The round to irregularly shaped cells have a cytoplasm and an eccentric, round to oval nuclei, and have a finely stippled chromatin pattern and 1-3 prominent nucleoli. Anisokaryosis is moderate. The cells are surrounded by a very lkarge amount of think pink matrix.

Diagnosis:

Highly suspect chondrosarcoma.

Treatment:

The patient was referred to a boarded surgeon for lung lobectomy of the caudal aspect of the left cranial lung lobe. At the time of surgery, a firm, pale purple, nodular 3.5cm mass was present on the periphery of the caudal aspect of the left cranial lung lobe. Histopathology confirmed a low grade chondrosarcoma that was completely excised. The patient is doing great following surgery and will follow-up with oncology as appropriate.

Discussion:

While the lungs are a common location for metastatic chondrosarcoma, there were no other primary sources found for this tumor in our patient. There is very little data in the literature in humans or animals on primary chondrosarcoma within the pulmonary tissue; however it has been reported in both humans and dogs. It is currently believed that prognosis is good with lung lobectomy if the mass is discovered early and can be completely resected and is low grade.

This case also illustrated how only peripheral lung lesions can be visualized with ultrasound techniques. This is due to air interference, which effectively "blocks" visualization of lesions present within the deep lung tissue. Only a small portion of this nodular mass was seen on ultrasound. Fortunately, in this case, the area was large enough to obtain a diagnostic cytology sample with ultrasound guidance.