The tumour border on contrast-enhanced spectral mammography and its relation to histological characteristics of invasive breast cancer.

Abstract

Contrast-enhanced spectral mammography (CESM) is one of the new diagnostic modalities implemented in clinical practice. In the case of these techniques, there are two major issues to be addressed: (1) their diagnostic usefulness, and (2) the relation between parameters assessed using these techniques and well-known diagnostic/prognostic/predictive markers (histological, clinical, and molecular). Therefore, we studied the relationship between the tumour margin assessed on CESM and (1) tumour borders defined on the basis of macroscopic and microscopic examination, (2) pT, (3) pN, and (4) tumour grade in a group of 82 breast cancer patients. Based on CESM, the tumour border was defined as sharp, indistinct or spiculated, whereas in the case of lesions showing weak or medium enhancement on CESM the borders were classified as unspecified. We found a statistically significant relationship between tumour margin on CESM and (1) macroscopic border (a spiculated margin on CESM was found only in carcinomas with an invasive border on histological examination; p = 0.004), (2) pT (p = 0.016), and (3) pN (nodal involvement was observed most frequently in carcinomas with a spiculated or indistinct margin on CESM; p = 0.045). Moreover, in cases with an undefined margin on CESM (cases showing weak or medium enhancement on CESM), both invasive and pushing borders were found on histological examination. The results of our preliminary study suggest that it is possible to assess macroscopic borders of examined lesions on the basis of CESM imaging. This might be useful in planning the extent of surgical excision. On the other hand, the assessment of the tumour margin on CESM might not be precise in cases showing weak enhancement.