Not Your Everyday Duodenal Ulcer: Massive Gastrointestinal Bleed Secondary to Extramedullary Plasma Cell Myeloma.

The differential for gastrointestinal (GI) bleeding is broad, ranging from peptic ulcers and infection to variceal hemorrhage and neoplasms. The rarer causes of GI bleeds are frequently overlooked and as such can ultimately be more dangerous. Extramedullary multiple myeloma, an atypical plasma cell dyscrasia arising outside of the bone marrow, involves the GI tract in <5% of cases and often presents with nonspecific symptoms.

Loss of Mismatch-repair Protein Expression and Microsatellite Instability in Upper Tract Urothelial Carcinoma and Clinicopathologic Implications.

Background: Upper tract urothelial carcinoma (UTUC) may arise in the setting of hereditary non-polyposis colorectal cancer (Lynch syndrome [LS]) or sporadically. Variable frequencies of microsatellite instability (MSI) were found in UTUC. For advanced solid MSI tumors, targeted therapy with programmed death-ligand 1 inhibitors is available.