Magnetic resonance imaging of primary breast lymphoma

PURPOSE: Primary lymphomas of the breast (PBNHL) are uncommon. Magnetic resonance imaging (MRI) features of these malignancies can be relevant in establishing the extent of disease and planning the appropriate therapeutic strategy, usually represented by chemo- and radiotherapy, rather than surgery. The purpose of this study was to assess MRI features of PBNHL. MATERIALS AND METHODS: MRI examinations performed on seven patients with known PBNHL were retrospectively evaluated. Lesions were analysed for both morphology and kinetics and classified according to the Breast Imaging Reporting and Data System (BI-RADS) categories. RESULTS: The mean MRI maximum diameter was 44 mm (range 12-69). Six lesions showed a mass-like enhancement; one lesion showed a non-mass-like enhancement. For mass-like lesions, kinetic curve assessment of initial rise showed slow enhancement in one lesion, rapid enhancement in four lesions and medium enhancement in one lesion. Assessment of delayed enhancement showed plateau in five lesions and washout in one lesion. MRI BI-RADS categories were distributed as follows: one BI-RADS II, one BI-RADS III, three BI-RADS IV and two BI-RADS V. CONCLUSIONS: MRI features of primary breast lymphomas in this study cohort suggest that the occurrence of a PBNHL should be considered in the presence of large enhancing lesions of the breast, especially if associated with skin thickening. MRI may also have an important role in the assessment of response to therapy and diagnosis of recurrence.