Inflammatory pseudotumour of the lung.

Inflammatory pseudotumours of the lung are extremely rare. Their pathogenesis is controversial, their diagnosis is often difficult and their clinical behaviour may be unpredictable - ranging from benign to locally invasive, to metastatic in spite of an apparently 'benign' histology. A patient who presented with multiple recurrent lesions in the contralateral lung almost two years after the resection of a large primary tumour of the left upper lobe is reported.