BRAIN METASTASES FROM AN UNKNOWN PRIMARY TUMOR - WHICH DIAGNOSTIC PROCEDURES ARE INDICATED

Seventy two patients presenting with symptomatic brain metastases from undiagnosed primary neoplasms were retrospectively reviewed. Primary malignancies were diagnosed before death in 54 patients and remained u nknown in 18 patients. Lung cancer was the most common primary tumour (72%), followed by breast cancer, colon carcinoma, and melanoma. On ph ysical examination, 51 patients had organ specific symptoms or signs p roviding guidelines to the diagnostic evaluation. In 24 of the 52 pati ents with a primary lung tumour, and in four of the 20 patients withou t, organ specific complaints or findings suggested this tumour type, r esulting in a positive predictive value of 85%. Overall, radiography a nd CT of the chest were very useful in detection of primary lung tumou rs. This could partly be explained by the high prior probability of de tecting such tumours. Other diagnostic procedures should be used on in dication only. The prognosis of patients with confirmed primary tumour position did not differ from those with unidentified primary tumour.