Bronchioalveolar carcinoma

Bronchioalveolar carcinoma accounts for 1-2% of all primary pulmonary tumours. It arises in the pulmonary parenchyma in the terminal bronchioalveolar regions, often in areas of scarring. It is generally considered to be a variant of bronchial adenocarcinoma but with distinctive features.

It is most common in patients above the age of 50 years. It is not related to smoking and affects both sexes equally.

Clinical presentation is similar to other lung tumours but:

• bronchial obstruction, haemoptysis and distal infection are uncommon as the tumour is endobronchial
• some cases present with bronchorrhoea - large volumes of clear, watery sputum

Diagnosis:

• chest X-ray - typical features may include:
  • a single, irregular peripheral shadow - may resemble pneumonic consolidation with an air bronchogram within the tumour opacity
  • multiple tumour opacities - tend to develop within one lung and then become bilateral
• bronchoscopy and bronchial biopsy - usually negative
• fine needle aspiration biopsy } usually necessary
• surgical biopsy at thoracotomy } for diagnosis

Surgical resection is the treatment of choice as:

• the tumour is slow growing
• metastases are uncommon
• it is insensitive to radiotherapy or chemotherapy

Prognosis:

• 50% 5 year survival for localised disease