Randall-Type Monoclonal Immunoglobulin Deposition Disease in Bone Scintigraphy.

Bone scintigraphy is recognized as a noninvasive alternative to endomyocardial biopsy for the diagnostic of wild-type (wATTR) and hereditary ATTR amyloidosis (hATTR). Light chain amyloidosis (AL), Randall-type monoclonal immunoglobulin deposition disease , sarcoidosis, hemochromatosis, Fabry disease, and mucopolysaccharidoses are differential diagnosis of ATTR amyloidosis. Bone scintigraphy allows visualization of extracardiac involvements of AL amyloidosis: pleural, retroperitoneal, liver, spleen, and soft tissue. We report the case of a patient who underwent bone scintigraphy for suspected ATTR amyloidosis. Bone scan showed cardiac (Perugini score 2), hepatic, and renal hyperfixation. A cardiac biopsy demonstrated a Randall-type deposit, without amyloid deposit.