Role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in evaluating breast mucosa-associated lymphoid tissue lymphoma: A case series.

Mucosa-associated lymphatic tissue (MALT) lymphoma of the breast is an extremely rare disease; its pathogenesis is not clear because of the rarity of disease, and the best diagnostic method has yet to be established. The metabolic behavior of this lymphoma is not still clear because only a few case reports are present in literature describing the possible role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in this field. This report presents 4 cases of women with histologically proven breast MALT lymphoma who underwent 7 18F-FDG PET/CT throughout the course of disease. All patients underwent staging PET/CT showing in all cases an FDG avid lesion corresponding to breast lymphoma; 3 patients underwent 18F-FDG PET/CT also after chemotherapy. Our results suggest that breast MALT lymphomas are 18F-FDG-avid lymphomas. Positron emission tomography/computed tomography showed heterogeneous but high FDG uptake (mean maximum standardized uptake value 7.9), suggesting that it could be part of diagnostic workup and restaging process.