Bronchial carcinoma

From Dog
Histological appearance of bronchial carcinoma[1]

Primary bronchial carcinoma are a relatively rare pulmonary neoplasia of dogs[2].

Unlike humans, primary pulmonary carcinomas are quite rare in dogs.

Primary bronchial carcinoma often metastasize to the pulmonary parenchyma and surrounding pleural tissues. Secondary pulmonary edema and hypertrophic osteoarthropathy may be observed in advanced cases.

Primary bronchial tumors are mostly carcinomas with a predominance for adenocarcinoma. They are usually classified as bronchial, bronchioalveolar, or alveolar carcinoma. Bronchioalveolar tumors are frequently multicentric but can present as diffuse bronchioalveolar carcinomas.

Types of bronchial carcinoma in dogs include:

  • Papillary adenocarcinoma (non-small cell carcinoma)[3]
  • Bronchioloalveolar carcinoma [4]
  • Adenosquamous carcinoma (small cell carcinoma)
  • Bronchial squamous cell carcinoma (non-small cell carcinoma)[5]
  • Bronchial gland carcinoma
  • Neuroendocrine carcinoma[6]

Affected dogs usually present with coughing, dyspnea, epistaxis, fever, weight loss and anorexia.

Diagnosis is based on imaging with radiography, CT or MRI. Tracheobronchial washes or tracheal endoscopy are frequently employed as well.

Regional mediastinal lymphadenopathy is suggestive of a poorer prognosis.

A differential diagnosis would include heartworm disease, kennel cough, lungworm (e.g. Filaroides osleri) and chronic bronchitis.

Treatment usually requires lobectomy via thoracotomy or endoscopy in cases where the trachea is unaffected by metastases, and is usually curative[7]. Adjunct radiation therapy or chemotherapy may be required.

Systemic chemotherapy, intrapleural chemotherapy or both with combinations of cisplatin, carboplatin and mitoxantrone have been employed for treating malignant pleural effusions.

Immunotoxin therapy has shown some promise in experimental models, although antibodies against immunotherapy eventually renders this method impractical[8].

References

  1. Microscopy U
  2. Hahn FF et al (1996) Primary lung neoplasia in a beagle colony. Vet Pathol 33(6):633-638
  3. Hong KM et al (2007) Inactivation of LLC1 gene in nonsmall cell lung cancer. Int J Cancer 120(11):2353-2358
  4. Kraegel SA et al (1992) K-ras activation in non-small cell lung cancer in the dog. Cancer Res 52(17):4724-4727
  5. Benfield JR & Hammond WG (1992) Bronchial and pulmonary carcinogenesis at focal sites in dogs and hamsters. Cancer Res 52(9):2687s-2693s
  6. Saegusa S et al (1994) Pulmonary neuroendocrine carcinoma in a four-month-old dog. J Comp Pathol 111(4):439-443
  7. Mosing M et al (2008) Endoscopic removal of a bronchial carcinoma in a dog using one-lung ventilation. Vet Surg 37(3):222-225
  8. Henry CJ et al (2005) Clinical evaluation of BR96 sFv-PE40 immunotoxin therapy in canine models of spontaneously occurring invasive carcinoma. Clin Cancer Res 11(2):751-755