Localised calcified amyloidosis a mimic of malignancy

Background and purpose: Amyloidosis is a rare disease caused by the deposition of insoluble fibrils in extracellular spaces in different organs. Amyloidosis of the breast is rare, which can present with localised involvement, secondary amyloidosis or systemic or multiple myeloma-associated amyloidosis. Amyloidosis has several imaging findings which include mammographic calcifications, mass and axillary lymphadenopathy. These images often warrant histological analysis which confirms amyloidosis. The latter more often results in non-surgical management. Methods and results: Our case is that of a 72-year-old female who presented for a routine mammogram and breast ultrasound due to a family history of breast cancer. On imaging, there are clusters of pleomorphic calcifications seen in the right breast lower inner quadrant. The calcifications are located at the site of the previous reduction surgical scar associated with architectural distortion. These calcifications appear to have increased in size when compared with the previous imaging from 2012 and 2019. The histology showed extensive calcifications, an abundance of amorphous eosinophilic material and foreign body-type giant cells. The amorphous material showed staining with Congo red. A referral to the haematology unit with a thorough investigation including Serum or urine protein electrophoresis, Serum-free light-chain assay, PET and CT scan, Echocardiogram and Holter showed no evidence of systemic or multiple myeloma-associated amyloidosis. Conclusion: Amyloidosis of the breast is an easily overlooked entity and forms part of the differential diagnosis of all mammographic calcifications of the breast. The histological confirmation prevents unnecessary surgical interventions from discordant suspicious radiological findings and benign breast histology. Instead, allowing for essential amyloidosis work-up including the exclusion of haematological malignancy. The establishment of localised amyloidosis follows a benign course and conservative management. References: (1) Charlot, M, Seldin, D, O'hara C, Skinner M & Sanchorawala, V (2011): Localised amyloidosis of the breast: a case series, Amyloid, 18:2, 72-75, (2) Lytle, A, Darvishian, F, Ozerdem, U (2019) Localized amyloidosis: A diagnostic pitfall in breast pathology, Pathology - Research and Practice, Volume 215, Issue 12,2019,152699,View Large Image Figure ViewerDownload Hi-res image Download (PPT)