LAUSR

A58-year-old Caucasianmanwas referred to ourDepartment for a splenic mass incidentally detected with abdominal ultrasonography. History included evening fever, weight loss, and fatigue for 3months.At admission, physical examinationwas unremarkable, except for a palpable splenomegaly. Laboratory studies showed increased white cells count (11.01 × 10/μL), platelets count (418 × 10/μL), lactated dehydrogenase level (LDH) (350 U/L), C-reactive protein (10 mg/dl), erythrocyte sedimentation rate (113), and decreased hemoglobin level (8.7 g/dl), whereas procalcitonine level was normal and tumor markers as well as HBV and HCV tests were negative. Computed tomography (CT) scan showed an 11 cm solid mass in the spleen with lowdensity center suggesting necrosis and moderate heterogeneous contrast enhancement (Fig. 1b). Positron emission/computed tomography (PET/CT) revealed themass to be intensely hypermetabolic (SUVmax 34.0), but no abnormal uptake was detected elsewhere (Fig. 1a). Posterior iliac crest bone marrow biopsy and esophagogastroduodenoscopy were negative. A presumed diagnosis of PSL was made, and splenectomy was scheduled with both diagnostic and therapeutic intentions. Prior to surgery, the patient received immunization against Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b, as recommended by current guidelines. At laparotomy, splenomegaly was evident, and the mass extended beyond the splenic capsule and invaded the diaphragm. Splenectomy with en bloc partial diaphragmatic resection was performed, requiring chest tubes insertion. On macroscopic examination, the spleen was 17×15×23.5 cm and contained a 12 cm well demarcated tender whitish mass. Histology revealed monotonous proliferation of large lymphoid cells, in a background of granulocytes. The individual cells showed irregular borders and atypical nuclei, including marked nucleoli, foci of necrosis, and numerous mitosis (Fig. 2a and b). The K-67 labelling index was > 90%. No white or red pulp involvement was detected, and splenic hilar lymph nodes were negative. Immunohistochemistry was strongly positive for CD20 (Fig. 2c), CD30 (Fig. 2d), CD45 (Fig. 2e), and MUM1 (Fig. 2f), whereas CD3, CD 10, CD34, CD68, BCL2, BCL6, and MYC were unexpressed. No translocation of BCL2, BCL6, and CMYC was also found by FISH. The final diagnosis was consistent with primary splenic diffuse large B cell lymphoma (PSDLBCL), stage IE according to the revised staging system based on the Lugano Classification and classified as non-germinal center B cell-like (non-GCB). Postoperative course was characterized by the onset of portal vein thrombosis, and the patient was discharged 12 days after surgery with anticoagulation therapy. Aftermultidisciplinary team counseling, hewas given 4 cycles of adjuvant rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).