Fine needle biopsy of solitary pulmonary metastasis.

When a nodule which is increasing in size is detected on a chest radiograph the question arises whether it is a primary or metastatic tumour. Experience has shown that the removal of a singular metastasis of an extrapulmonary tumour has a 5-year survival of about 25-30%, if the primary tumour is removed as well. The cytologic results of fine needle biopsy may give clues for the possible localization of the primary tumour. A selective search is then justified and may be rewarding. In 30 cases of 48 pulmonary lesions the cytological and histological results of the operative specimen were compatible with solitary lung metastasis of an extrapulmonary primary tumour. In 18 of 48 cases there was strong evidence for a second primary lung tumour. Fine needle biopsy helps clarify the nature of the lesion and may also give information regarding the site of the extrapulmonary primary tumour. This is important for patient management, therapy and prognosis.