While management protocols for a discrete palpable breast lump are standardized in most centres, the approach to an area of palpable asymmetrical thickening in the breast has seldom been addressed. A diagnostic algorithm for palpable asymmetrical thickening of the breast was prospectively evaluated in 116 Oriental women, followed by a retrospective review of their mammograms and histology specimens. Most women (86%) were pre-menopausal and 82% complained of a lump. The thickening eventually resolved spontaneously in 93 (80%) women. None of these 93 women developed cancer at a median follow-up of 41 months. A total of 9 (7.8%) cancers were found in the series of 116 women, including two with a lobular component. The occurrence of cancer was more likely when the woman was older than 43 years or when the thickening was marked (p<0.04). Mammographic review showed correlation of the palpable thickening with localized increase in breast tissue density and/or microcalcifications in 18% of cases. Histology review suggested fibrosis as an explanation for the clinical presentation. Although most cases of thickening tend to resolve with time, a significant number of cancers present in this way. A diagnostic approach with early and liberal imaging and biopsy for high risk women is required.