A case report of non-traumatic renal artery pseudoaneurysm due to chemotherapy for diffuse large B-cell lymphoma

Abstract

Dear Editor, Renal artery pseudoaneurysm (RAP) is a major cause of delayed hemorrhage after renal trauma [1]. RAP has been reported almost exclusively in mechanical renal injury, especially in iatrogenic renal injury, such as percutaneous renal surgery, renal biopsy, open renal surgery, and endoscopic renal surgery [2]. RAP as a complication of chemotherapy for renal malignancy seems very rare and has not been reported in the literature. We report here a case of non-traumatic RAP due to chemotherapy for diffuse large B-cell lymphoma (DLBCL). A-75-year-old male presented with complaint of left flank pain and weight loss. The computed tomography (CT) scan revealed poorly enhanced renal mass occupying the whole left kidney and abdominal lymph node swelling with infiltrative progression into stomach (Fig. 1a). The Fluorodeoxy-glucose positron emission tomography (FDG-PET) scan showed abnormal increased uptake of the whole left kidney, upper pole of the right kidney, and mesenteric lymph nodes. He underwent CT-guided needle biopsy of left kidney (Fig. 1b). Biopsy of the left kidney mass revealed scattered small foci consisting of mediumto large-sized atypical lymphocytes with irregularly shaped nuclei, in the background of diffuse infiltration of smaller atypical lymphocytes. A diagnosis of DLBCL, not otherwise specified, was made and R-CHOP (rituximab and CHOP) chemotherapy was started. During the course of chemotherapy, he experienced intermittent left flank pain with gradual decrease in hemoglobin. Although the overall size of the tumor and the abnormal uptake on FDG-PET scan decreased after three cycles of R-CHOP chemotherapy, enhanced CT scan showed advent of intratumoral hemorrhage and saccular pseudoaneurysm in left renal artery. After the fifth cycle, the tumor started to enlarge and he became transfusion dependent for severe anemia. Enhanced CT scan revealed expansion of RAP and intratumoral hemorrhage (Fig. 1c), though the tumor showed no viability on FDG-PET scan. For the treatment of RAP and intratumoral hemorrhage, he underwent coil embolization of RAP with Nester and Tornado coils (Cook Medical, Bloomington, IN, USA). Pseudoaneurysm in a branch of the left renal artery was occluded successfully (Fig. 1d and e). Thereafter, the tumor shrank gradually and he became transfusion independent. In this case, we experienced RAP as a rare complication of chemotherapy for DLBCL. Pseudoaneurysms are thought to consist of the surrounding tissue wall after an artery is completely or partially injured. Although CTguided needle biopsy of the tumor was performed in the present case, we conjectured that the procedure was irrelevant to pseudoaneurysm formation because the site of biopsy was distant from both the pseudoaneurysm and the renal artery (Fig. 1b and c). It is supposed that lymphoma invasion injured the artery wall and caused RAP. This case illustrates a possible contribution of RAP to Y. Masamoto :Y. Imai : S. Seo :M. Kurokawa (*) Department of Hematology & Oncology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan e-mail: kurokawa-tky@umin.ac.jp