Secondary Extramedullary Myeloma of the Gallbladder: A Case Report.

Extramedullary myeloma (EMM) is an infrequent but well-established manifestation of multiple myeloma (MM), defined as a soft tissue plasma cell neoplasm without bone marrow involvement. Gallbladder involvement in EMM, however, is a very rare occurrence, with only 8 cases found in the English medical literature. Here, we present a case of an older adult male with a gallbladder mass in the presence of increasing serum kappa light chains after a normal bone marrow biopsy confirmed the complete remission of a previous MM diagnosis.

N-terminal sequences in matrin 3 mediate phase separation into droplet-like structures that recruit TDP43 variants lacking RNA binding elements.

RNA binding proteins associated with amyotrophic lateral sclerosis (ALS) and muscle myopathy possess sequence elements that are low in complexity, or bear resemblance to yeast prion domains. These sequence elements appear to mediate phase separation into liquid-like membraneless organelles. Using fusion proteins of matrin 3 (MATR3) to yellow fluorescent protein (YFP), we recently observed that deletion of the second RNA recognition motif (RRM2) caused the protein to phase separate and form intranuclear liquid-like droplets.