Metachronous multiple primary cancers involving pulmonary non-Hodgkin lymphoma and bladder cancer: a case report.

Multiple primary cancers (MPC) are characterized by the synchronous or metachronous occurrence of two or more distinct histopathological tumor types. We report a rare clinical case of a 65-year-old woman diagnosed with pulmonary mucosa-associated lymphoid tissue (MALT) marginal zone B-cell lymphoma and subsequent invasive bladder carcinoma. The patient, previously treated with multiple lines of chemotherapy for MALT lymphoma, was admitted to our hospital with lower abdominal and perineal pain accompanied by gross hematuria for one week. Cystoscopic examination and transurethral resection of the bladder lesion confirmed the diagnosis of bladder cancer. She later underwent laparoscopic radical cystectomy, and postoperative histopathological evaluation revealed invasive urothelial carcinoma infiltrating the cervical and vaginal fornix stroma.