Abstract
BACKGROUND: Splenectomy is a common procedure for cytoreductive surgery in ovarian cancer. Secondary infective endocarditis after splenectomy for malignancy has not been previously reported. CASE PRESENTATION: A 54-year-old female patient who underwent splenectomy for cytoreductive surgery of ovarian cancer had an elevated postoperative white blood cell (WBC) count and subsequent intestinal obstruction. Echocardiography revealed vegetation on the mitral valve leaflet, and next-generation sequencing identified Gemella morbillorum in the blood. Subsequently, she was diagnosed with infective endocarditis and ultimately died from septicemia. CONCLUSION: Postsplenectomy secondary infective endocarditis warrants attention. This requires preoperative proper assessment of tolerance for surgical complications, recognizing the implications of an elevated WBC count after splenectomy, actively managing postoperative intestinal obstruction, and identifying opportunistic infections. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12893-025-03376-9.