With M-protein positive, could transthyretin amyrodosis be easily excluded? Not necessarily! Wild-type transthyretin amyrodosis with Waldenström's macroglobulinaemia: a case report.

Background: Generally, it is said that amyloid light-chain (AL) develops not only in multiple myeloma but also in Waldenström's macroglobulinemia. We experienced a case of M-protein positive and diagnosed as wild-type transthyretin amyrodosis (ATTRwt) accompanied with Waldenström's macroglobulinemia. Case summary: The patient was 72-year-old male, and the main complaint was dyspnoea in April 2020 and visited a nearby doctor. He was introduced to the Department of Haematology at our hospital for high levels of serum immunoglobulin M, M-protein positivity, and cardiac hypertrophy with a suspect of AL amyloidosis. Duodenal mucosal biopsy and abdominal skin biopsy showed no amyloid deposits, and left iliac bone marrow biopsy diagnosed Waldenström's macroglobulinemia and with no amyloid, and Kumamoto criteria score 1. Last of all, ATTRwt was diagnosed for endocardial biopsy. Discussion: This is a very rare case of ATTRwt with Waldenström's macroglobulinaemia.

A case in which SGLT2 inhibitor is a contributing factor to takotsubo cardiomyopathy and heart failure.

SGLT2 inhibitors are reported to have advantages in protecting against heart failure events. However, there are also reports of concerns when given to older persons or persons with geriatric syndrome. Our case is an example of a patient with a history of chronic thyroiditis where the SGLT2 inhibitor triggered a thyroid crisis, and blood catecholamine overload caused takotsubo cardiomyopathy and heart failure. .