A rare case of littoral cell angioma with paroxysmal nocturnal hemoglobinuria

Rationale: We report a rare case of littoral cell angioma (LCA) in a patient with paroxysmal nocturnal hemoglobinuria (PNH). To our knowledge, this is the first report of these 2 rare conditions occurring together, which may help clarify their relationship and its importance in clinical practice. Patient concerns: A 38-year-old man had recurrent anemia and dark brown urine, accompanied by abdominal pain that worsened over time, which required several hospital visits and long-term follow-up. Diagnoses: Follow-up scans showed progressive splenomegaly with multiple nodules. In combination with histopathology and immunohistochemistry results (CD31, CD34, and ERG positive; Ki-67 around 5%), these findings confirmed a final diagnosis of LCA in a patient with previously diagnosed PNH. Interventions: The patient received treatment with oral prednisone, sodium bicarbonate, and vitamin E for PNH. As the splenic lesions enlarged and blood counts worsened, he subsequently underwent laparoscopic splenectomy in February 2025. Outcomes: After surgery, both LCA and anemia concurrently resolved, with normalization of hematologic parameters and resolution of abdominal symptoms. Lessons: This case suggests a potential association between LCA and PNH. Splenectomy provided dual benefits by treating the splenic tumor and improving hemolysis. Given the possible risk of malignant transformation, long-term follow-up is recommended.