[A Case of Splenogenic Malignant Lymphoma with Difficult Preoperative Diagnosis].

A 75-year-old man was serendipitously found to have a splenic mass during a routine abdominal ultrasound screening for chronic kidney disease. He was subsequently referred to the gastroenterology department for further evaluation. Contrast- enhanced CT scans revealed multiple splenic lesions with heterogeneous enhancement, while MRI demonstrated low T1 and high T2 signal intensities. The initial diagnostic impression favored either hemangiosarcoma or malignant lymphoma; however, the patient opted for conservative management with regular follow-up. After a 6-month period, the largest splenic mass had increased in size from 77 mm to 110 mm, prompting a referral to the surgical department. With a preoperative diagnosis of hemangiosarcoma, the patient underwent laparoscopic splenectomy along with combined diaphragmatic resection and reconstruction. Postoperative histopathological examination revealed diffuse large B-cell lymphoma. Splenic malignancy is a rare disease, and a definitive diagnosis cannot often be established through imaging alone. When a splenic malignant tumor is suspected, surgical resection should be considered, as it serves both diagnostic and therapeutic purposes.