Treatment of a giant pulmonary emphysematous cyst with primary bronchoalveolar papillary carcinoma in a Shih Tzu dog.

OBJECTIVE: To report the surgical treatment of a pulmonary emphysematous cyst concurrent with primary pulmonary bronchoalveolar papillary carcinoma in a dog. STUDY DESIGN: Clinical case report. ANIMALS: 12-year-old 6.4 kg spayed female Shih Tzu dog. METHODS: The dog presented for surgical treatment of pulmonary emphysema. Radiography revealed that more than half of the left caudal lung lobe was enlarged and hyperlucent and computed tomography (CT) confirmed the presence of an emphysematous space. Thoracoscopic lung lobectomy was attempted but was converted to an intercostal thoracotomy due to poor visualization and pleural adhesions. A left caudal total lung lobectomy was performed using a self-cutting endoscopic stapler. RESULTS: The dog recovered uneventfully and a postoperative histopathologic diagnosis of pulmonary cystic bronchoalveolar papillary carcinoma was made. Re-evaluation using a CT scan with contrast study on postoperative days 27 and 177 revealed no evidence of residual, metastatic, or recurrent lesions. The dog has been doing well since surgery during the 11 month follow-up period. CONCLUSION: This case report suggests a potential relationship between pulmonary emphysematous diseases and primary lung tumors in dogs.

Metastatic pancreatic carcinoma and bronchioloalveolar adenomas in an Egyptian fruit bat (Rousettus aegyptiacus).

An adult female, intact Egyptian fruit bat (Rousettus aegyptiacus) was presented for lethargy, anorexia, and markedly reduced flying activity. Physical and ultrasound examinations were suggestive of an abdominal mass with free fluid within the abdomen. Based on the poor and deteriorating clinical condition of the animal, euthanasia was elected. Gross necropsy revealed an irregular thickening at the root of the mesentery and a diffusely, dark-red liver with rounded hepatic margins. Histologic examination revealed extensive neoplastic effacement of the pancreas with invasion into the surrounding mesentery and mesenteric lymph nodes and metastatic spread to the liver. Based on the morphology of the neoplastic cells, the involvement of the pancreas, and immunohistochemistry, a diagnosis of metastatic pancreatic carcinoma was made. Additionally, two small neoplasms were identified in the lungs. These masses were distinct from the carcinoma, and their morphology was consistent with bronchioloalveolar adenomas. This is the first known report of either benign pulmonary lesions or pancreatic carcinomas in the order Chiroptera.

Bronchial carcinoma in a red-shouldered hawk (Buteo lineatus).

Respiratory neoplasms are rare in birds. This report describes carcinoma of the bronchial epithelium in a red-shouldered hawk (Buteo lineatus) that presented with weakness and lethargy lasting 4 days that progressed to seizures. Grossly, the caudal air sac and coelomic cavity contained approximately 15 ml of dark brown cloudy fluid that displaced the intestines cranially. Nodular plaques were present on the viscera and air sacs. Microscopic examination of tissues revealed a mass that expanded the bronchial lumen and was composed of papillary proliferations of rows of small cuboidal epithelial cells that were small and uniform in size with a low mitotic index. Metastases were present on the surfaces of caudal air sac, kidney, and multifocal peritoneal surfaces of the coelomic cavity. Clinical signs were most likely the result of West Nile virus infection, which was confirmed by immunohistochemistry of brain tissue.

Tracheobronchial neuroendocrine carcinoma in a cat.

A tracheobronchial neuroendocrine carcinoma in a 10-year-old cat with a history of coughing, dyspnoea and anorexia is described. Endoscopic examination revealed a yellowish mass protruding into the trachea and partly obstructing the right bronchial lumen. Histological examination of biopsy samples revealed a hypercellular tumour consisting of sheets or ribbons of small hyperchromatic cells, with oval to spindle-shaped nuclei and minimal cytoplasm; nucleoli and mitotic activity were absent. The findings were confirmed on post-mortem examination. The small neoplastic cells were immunolabelled to varying degrees by antibodies against neuron-specific enolase, S-100 protein, synaptophysin and vimentin. Ultrastructural studies revealed scattered neurosecretory granules and scanty cellular junctional complexes, including desmosomes and tonofilaments, in neoplastic cells.

Metastatic malignant mesothelioma in a dog.

A case of malignant mesothelioma in a 5 1/2-year-old St Bernard dog is described. The distribution of the neoplasm was to the pericardium and peritoneum and not the pleura. Distant metastases were found in the bronchial lymph node and bone marrow.

Endobronchial metastasis in a dog with sarcoma.

A 3-year-old neutered male Australian Shepherd mix dog presented with metastatic soft tissue sarcoma arising from a primary tumor in the left lumbar fascia. Two separate metastases to the lungs were characterized by neoplasia within bronchiolar walls, which caused obstruction of the bronchiolar lumina and atelectasis of adjacent alveoli, a characteristic feature of endobronchial metastasis. Neoplastic cells of the primary lumbar neoplasm, metastatic pulmonary lesions, and additional widespread metastatic masses identified postmortem were similarly immunoreactive for vimentin, but non-immunoreactive for cytokeratin, cluster of differentiation 18, synaptophysin, chromogranin, and desmin. The present report describes a naturally occurring case of endobronchial metastasis in a dog.

Computed tomography characteristics of canine tracheobronchial lymph node metastasis.

Tracheobronchial lymph node evaluation is critical for accurate staging of canine thoracic neoplasia and is more accurately achieved with computed tomography (CT) than radiography. Thoracic CT scans of 18 canine patients with known tracheobronchial lymph node histopathology and 10 clinically normal dogs were compared to establish if enlargement or contrast enhancement pattern correlated with metastatic status. Absolute lymph node size and three anatomically normalized lymph node ratios were significantly correlated with metastasis or severe granulomatous lymphadenitis (P < 0.0003). Transverse maximum lymph node diameter of 12 mm or lymph node to thoracic body ratio of 1.05 are proposed cutoffs, above which metastatic involvement is very likely; however, only minimal accuracy was gained with normalized ratios. Lymph node contrast enhancement pattern was also significantly correlated to disease. A heterogenous and/or ring pattern was related to metastatic disease (P = 0.03). Recommended protocol for CT examination of the tracheobronchial lymph nodes is 1-1.5 mm slices and intervals, intravenous contrast, and control of respiratory motion.

Cutaneous metastases of a bronchial adenocarcinoma in a cat.

This case report describes a cat with metastasis of a bronchial adenocarcinoma to the abdominal skin. The cat had been treated with antibiotics and corticosteroids for several episodes of coughing when it acutely developed erythema, pustules and plaques on the abdominal skin. Diagnosis was based on cytological examination of fine-needle aspirates of cutaneous pustules, X-ray examination of the thorax and histological examination of skin biopsy samples. As the prognosis was poor, the cat was euthanased. Necropsy findings confirmed the diagnosis. Cutaneous metastases of lung carcinoma are rare in cats but have been reported in the digits with underlying bone involvement. To the authors' knowledge, this is the first report of metastasis of a feline bronchial carcinoma to the ventral skin.

Myxoma of the equine respiratory tract.

Bronchial myxoma occurred in an aged Arab mare with longstanding respiratory disease wrongly attributed to chronic obstructive pulmonary disease. Blood gas and maximum intrathoracic pressure change measurements were not consistent with this latter diagnosis, and this was supported by aerosol antigen provocation tests. Radiography demonstrated a hilar mass in the thorax, and this proved to be a myxoma at necropsy.

Metastatic carcinoma presenting as hind-limb lameness: diagnosis by synovial fluid cytology.

A dog presented for evaluation of left hind-limb lameness and pain associated with manipulation of the tail. Synovial metastasis of a carcinoma was diagnosed by joint fluid examination. A primary bronchiolar-alveolar carcinoma with widespread (including synovial and skeletal) metastases was diagnosed on postmortem examination. Metastasis to synovial surfaces is uncommon, but when it occurs, the metastasis-induced arthritis may be the initial presenting complaint for which medical attention is sought. Although rarely reported, cytological examination of synovial fluid may be diagnostic. This paper presents an interesting clinical case and reviews the literature concerning metastatic disease of the synovium.

Tumours of the lung.

Lung tumours are not common in domestic animals; there has not been the increase in epidermoid carcinomas and anaplastic small-cell carcinomas that has occurred in man this century. Adenocarcinoma is the most common type in animals. The biological behaviour of each type of tumour in animals seems to be much the same as in man. The tumours are described histologically, the main categories being: epidermoid carcinoma, anaplastic carcinoma, adenocarcinoma, combined epidermoid and adenocarcinoma, carcinoid tumours, bronchial gland tumours, benign tumours, and sarcomas.

Classification of lung carcinomas in the dog and cat.

A total of 218 lung carcinomas from dogs and cats were examined histologically. The tumors were classified into adenocarcinoma, squamous-cell carcinoma, bronchial gland carcinoma, and alveolar-cell carcinoma. We believe that adenocarcinoma should be subdivided into differentiated and undifferentiated types because the two are distinct histologically and vary in frequency in the cat and dog. It is also important to recognize bronchial gland carcinoma, a distinct histological type, and to subdivide alveolar-cell carcinoma into three separate types: anaplastic small-cell and large-cell types, and adenomatosis type.