Is mammography of value in women with disseminated cancer of unknown origin?

Mammography is often requested to try to identify occult primary breast car cinoma in women with metastatic cancer of unknown primary site. This study aimed to investigate whether mammography is of use in these patients in ide ntifying the breast as the origin of the metastatic disease. Thirty-one wom en with a working diagnosis of metastatic cancer underwent mammography in a n attempt to determine the primary site. None of these women had a palpable breast mass. The site of presentation, pathological type of tumour, site o f origin, and benefit of mammography and mammography-provoked biopsy were c larified far each patient. The patients were also followed up to determine survival. The commonest sites of presentation were lung (45%), lymph nodes (19%) and abdomen (16%). The primary sites of these cancers were identified with confidence in 27 patients (87%). The commonest known primary tumour s ites were lung (45%), breast (16%) and ovary (16%). Abnormal mammograms wer e detected in four patients (13%), but three of these did not have breast c ancer. In one, the site of origin remained indeterminate, as either breast or lung. Five (16%) had a confident diagnosis of breast carcinoma; all of t hese women had normal mammograms. We conclude that mammography in women pre senting with metastatic disease from an unknown primary site is unhelpful a nd is not recommended. Furthermore, we could not demonstrate its value in w omen presenting with axillary lymphadenopathy.