Pleomorphic carcinoma of lung

Pleomorphic carcinomas of the lung are a rare type of non-small cell lung carcinomas (NSCLC) classified under sarcomatoid carcinomas of the lungs.

Epidemiology

These tumours are thought to account for 0.1-0.4% of all lung malignancies.

Associations

There is a recognised association with smoking.

Pathology

Histologically, a pleomorphic carcinoma is defined as either: 

• a non–small cell lung carcinoma combined with neoplastic spindle and/or giant cells
  or 
• a carcinoma that consists of only spindle and giant cells: due to this some publications may synonymously use the term with spindle cell carcinoma of the lung or giant cell carcinoma of the lung

At least 10% of the carcinoma should comprise spindle and/or giant cells for it to be classified as a pleomorphic carcinoma.

Radiographic features

There no published specific imaging features for this histological subtype. Most CT features are thought to be dependent on the epithelial component of the tumour ⁵.

The tumours can be either endobronchial (central) or peripheral (the latter location is considered commoner ^1,7). They can frequently involve the pleural and/or chest wall. Larger tumours may show central low attenuation. Some publications suggest an upper lobe predilection ⁵. While many can be well-defined, some can be lobulated, ill-defined or even spiculated ⁵.

Treatment and prognosis

A spindle cell histology is generally associated with a more aggressive clinical course ^3,4. The presence of pleural invasion is associated with a much worse prognosis ⁷.