Primary rectal mucosa-associated lymphoid tissue lymphoma in a patient with previously identified primary biliary cirrhosis and secondary Sjögren's syndrome.

An 83-year-old female began treatment with prednisolone and ursodeoxycholic acid at 62 years of age, following a diagnosis of primary biliary cirrhosis (PBC) and secondary Sjögren's syndrome (SjS). With persisting bloody stools, the patient underwent colonoscopy at 83 years of age. Histopathological evaluation revealed mucosa-associated lymphoid tissue (MALT) lymphoma. The elevated rectal lesion resolved with rituximab treatment. We report this case because although patients with SjS are at increased risk of malignant lymphoma, primary rectal MALT lymphoma is very uncommon in association with PBC and secondary SjS.