Renal vein lymphoma embolism in non-Hodgkin lymphoma

Abstract

This report is, to the best of our knowledge, the first description of a case of non-Hodgkin lymphoma (NHL) which was accompanied by a renal vein lymphoma embolism. A 49-year-old female was admitted to our hospital complaining of a right axillary tumor 10 cm in diameter. Biopsy disclosed that the tumor was diffusely infiltrated by abnormal immunoblastic lymphocytes, which were positive for LCA, L26, CD10 and CD79a, but negative for UCHL-1, CD3, CD5, and Ki-1. Serum levels of lactate dehydrogenase 823 IU/L (normal range 110–220) and soluble interleukin-2 receptor 6,600 U/mL (220–530) were elevated. Coagulation tests, such as prothrombin time, activated partial thromboplastin time or plasma level of fibrin degradation products, showed normal results. Systemic examination identified splenomegaly and lymph node (LN) swelling at the hepatic hilum. Bone marrow study findings were normal. According to the WHO classification and Ann Arbor criteria, the patient was diagnosed with NHL, diffuse large B cell-type (DLBCL), stage IIIAXs. Two months after the initiation of combination chemotherapy, enhanced computed tomography (CT) identified an embolus in her left renal vein as a low density lesion (Fig. 1a). We diagnosed the embolus as a thrombus, and initiated anticoagulation therapy. For 8 months, the disease was refractory to multiple courses of combination chemotherapies, including a regimen of rituximab plus CHOP therapy, after which the patient died of systemic disease dissemination. Autopsy was performed in accordance with the guidelines of Matsushita Memorial Hospital and with the informed consent of the patient’s family. Macroscopically, multiple nodular lesions were identified in the right infra-axillary lesion, para-aortic lesion, stomach, uterus, right ovary, skin, pleura and mesenterium. Microscopic examination showed that nodules were uniformly infiltrated by lymphoma cells which were positive for LCA, L26, CD10, CD79a and Bcl-2. Approximately 30% of the lymphoma cells were also positive for MIB-1. Of particular interest was that the large embolus in the left renal vein was found to be a whitish tumor partially covered by a thrombus (Fig. 1b). The tumor was microscopically confirmed as lymphoma involvement (Fig. 1c–e). Microscopic examination also showed lymphoma cell infiltration in the left renal cortex and fat tissue around the left renal vein (Fig. 1f). Lymphoma embolus was not identified in other veins. Venous tumor embolism is occasionally complicated with solid cancers, such as hepatocellular carcinoma invading the portal vein or renal cell carcinoma invading renal veins, and these cancers tend to occur in the more advanced, later clinical phase. They have an unfavorable effect on treatment outcome due to further tumor cell dissemination, organ damage by inadequate blood flow, or venous rupture. DLBCL has a well-established variant entity termed intravascular lymphoma, which is characterized by exclusive or predominant intravascular tumor growth in the lumen of small to intermediate-sized blood vessels. However, tumor embolism in large veins is extremely rare, and, according to our search results, only five NHL cases have been reported with venous tumor embolism, three in the portal vein [1–3], one in the superior vena cava [4], and one in the internal saphenous vein [5], but no reports have been published on M. Yamamoto T. Kobayashi N. Uoshima Department of Hematology, Matsushita Memorial Hospital, 5-55, Sotojima-cho, Moriguchi 570-8540, Japan