Palpable breast cancer which is mammographically invisible

We have evaluated tumour characteristics, local recurrence rates and progno stic markers in 40 women with symptomatic palpable breast cancer proven by cytology, but in whom routine two-view mammography failed to detect a radio logical abnormality. False negative mammograms were identified by cross-ref erencing all negative mammograms performed at the Royal Victoria Infirmary during the period 1995-1999, with pathological records at the same institut ion. The average age was 48 years. The majority of the tumours were invasiv e ductal carcinomas, 35 with an average size of 24mm. There were 16 Grade I I and 15 Grade III tumours. Lymphovascular invasion was seen in 18 on histo logy and six patients had distant metastases. Of those patients treated by conservation therapy there has been only one local recurrence, with a media n follow-up of 18 months. We conclude that mammographically invisible tumou rs are of common histological type, are frequently high grade and node posi tive and occur mainly in the younger age group. However, BCT remains a viab le option in the treatment of these tumours. (C) 2001 Harcourt Publishers, Ltd.