Incidental finding of transthyretin myocardial amyloidosis in a patient with neurological symptoms and unexplained skeletal pain on bone scintigraphy using ^99mTc-DPD: A case report.

Hereditary transthyretin amyloidosis (hATTR) is considered a rare disease. This is precisely why there are cases of undiagnosed transthyretin amyloidosis, in patients present with restrictive cardiomyopathy, with or without neurological or other symptoms. There are cases of incidental detection of hATTR in patients with cardiac or neurological symptoms using whole-body scintigraphy with diphosphonates. In this paper, we present the accidental detection of hATTR in a 65-year-old patient with neurological and cardiac symptoms, who was referred for skeletal scintigraphy with skeletally avid radiopharmaceuticals due to skeletal pain of unknown origin. Significantly increased uptake of radiopharmaceuticals in the myocardium was observed, corresponding to a Perugini score of 3, with semi-quantification of the heart/contralateral lung fixation ratio (H/CL) of 2.6 in the second hour after radiopharmaceutical application. Ultrasound of the heart was in favor of concentric cardiomyopathy. Due to the high suspicion of hATTR, a genetic test was performed, which showed a pathological mutation of the gene for transthyretin. Hereditary hTTR is probably a more common disease than reported in the literature. Using hATTR detection algorithms and raising awareness of the possible existence of this disease, timely diagnosis using scintigraphy with bone avid radiopharmaceuticals and appropriate therapy can help patients and their close relatives.