[A case of primary malignant lymphoma of the spleen which was difficult to be diagnosed].

A 55-year-old woman who had a chief complaint of left abdominal and back pain. She was diagnosed with pancreatic cancer associated with splenic metastasis (Stage IVb) by CT and MRI study and was treated with chemotherapy of gemcitabine (GEM). Chemotherapy was discontinued due to adverse event (grade 3). CT study at this point reveals the effectiveness of GEM. The tumor was localized, and an operation was performed. The tumor was diagnosed as primary malignant lymphoma (diffuse large B-cell lymphoma) of the spleen. The splentic tumor is extremely rare, so a surgical treatment was indicated for making a correct diagnosis. This was an interesting case of malignant lymphoma that GEM revealed a cytoreductive result.