Page 741 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

716 CHAPTER 3

VetBooks.ir 3.179 3.180

Figs. 3.179, 3.180 Lung tumours. Note the
multifocal white, roughened patches (3.179), which
correspond to variably-sized tumours within the lung
parenchyma, seen in section (3.180).

3.181 3.182

Pleural
effusion

Fig. 3.181 Thoracic radiographs of a horse with a
granular cell tumour. A discrete oval opacity is present Fig. 3.182 Ultrasound image of a horse with
in the dorsal lung field. thoracic metastatic neoplasia. Hypoechoic pleural
fluid surrounds the poorly aerated tip of a lung lobe.
A mixed echogenicity circular mass is confluent with
mature horses (>7 years of age). Similarly, metastatic
pulmonary neoplasias are uncommon in horses, the pleural surface of the lung (arrow).
but occur more frequently than primary lung
tumours. These include haemangiosarcoma, SCC, Diagnosis
adenocarcinoma, fibrosarcoma, hepatoblastoma, Diagnostic screening tests that may help to identify
chondrosarcoma and undifferentiated sarcomas or neoplasia include cytological examination of tra-
carcinomas among others. Lung metastatic tumours cheobronchial aspirates, BAL fluid or pleural fluid.
have been reported in animals as young as 3 months Thoracic radiographs usually identify the presence
of age. of one or multiple soft-tissue opacities and may sug-
gest the presence of pleural effusion (Fig. 3.181).
Clinical presentation Ultrasonography will confirm the presence of pleural
Clinical signs are non-specific, but may include fluid and may also reveal an irregular lung surface or
depression, exercise intolerance, weight loss and architecture for masses located at the lung surface
fever, which can be intermittent. Other signs such (Fig. 3.182). Ultrasound-guided biopsy of thoracic
as cough, epistaxis or dyspnoea may occur. Pleural or pulmonary masses may allow ante-mortem diag-
effusion is common, especially in some metastatic nosis of lung tumours by histology, histochemistry
tumours. and/or immunohistochemistry.