[Postmortem diagnosis of intravascular large B-cell lymphoma after atraumatic splenic rupture due to splenic infiltration].

Atraumatic splenic rupture (ASR) is a rare but fatal complication of malignant lymphoma. However, only one case of intravascular large B-cell lymphoma (IVLBCL)-related ASR (IVLBCL-ASR) has previously been reported, and the mechanism of IVLBCL-ASR is unknown. We present the case of a 78-year-old man who died unexpectedly and was diagnosed with IVLBCL-ASR pathologically by autopsy. A massive intraperitoneal hemorrhage and four lacerations on the splenic surface were discovered during the autopsy. CD20-positive lymphoma cells that infiltrated into small vessels were highly concentrated in the center of the spleen and were only slightly distributed in the lacerations on the splenic surface. Therefore, increased intrasplenic pressure due to lymphoma cell proliferation was identified as the cause of ASR. The patient had undergone