[Clinical characteristics of intravascular large B cell lymphoma: a single-center retrospective study]

[Clinicopathological and genetic analysis of interstitial disease-like pulmonary intravascular large B cell lymphoma]

Objective: To investigate the clinicopathological features and genetic mutation status of pulmonary intravascular large B cell lymphoma. Methods: The clinicopathological data of eight patients diagnosed with pulmonary intravascular large B cell lymphoma, from April 2018 to May 2023, were retrospectively analyzed. The genetic profile of six patients was detected via next-generation sequencing (NGS) and followed up. Results: All patients included one male and seven females, with a median age of 64 years (ranging from 45 to 66 years). Respiratory symptoms were the most common (7 cases), B symptoms in two cases, hemophagocytic syndrome in two cases. Multiple diffuse ground-glass opacities in both lungs were observed based on the high-resolution chest CT scan. Six cases of mild to moderate ventilation or diffusion dysfunction were observed based on the pulmonary function tests. Moreover, two cases of hypoxemia and two cases with type Ⅰ respiratory failure were recorded. The serum lactate dehydrogenase level increased (7/8), β2-MG level increased (2/8), neuron-specific enolase level increased (7/8), total number of peripheral blood lymphocytes decreased (7/8), and clinical stages were all stage Ⅳ. The neoplastic lymphoid cells were lodged in the lumina of venules and capillaries of the alveolar septum; the tumor cells were large, with prominent nucleoli and frequent mitotic figures. The malignant cells were detected in the extravascular surrounding lung tissue in all cases. The tumor cells expressed mature B cell-associated antigens CD20 and CD79a, and the vascular endothelial markers CD31 and CD34 showed that the tumor cells were filled in the blood vessels, infiltrated blood vessel walls, and perivascular areas. One case was germinal center-type, seven cases were non-germinal center-type, two cases were double-expressing lymphoma, and all cases were EBER-negative. Furthermore, the top five genes with mutation frequencies detected by NGS were MYD88 (5/6), PIM1 (5/6), CD79B (4/6), TCF3 (4/6), and TP53 (3/6). Of the eight cases, seven patients received R-CHOP-based chemotherapy, six cases had complete remission after chemotherapy, one case died, and one case was lost to follow-up. Conclusions: Pulmonary vascular large B cell lymphoma is rare, which shares similar patterns with interstitial lung disease on imaging. Transbronchial lung biopsy is an effective method to confirm the diagnosis. Immunochemotherapy with BTK inhibitors can provide a survival advantage for patients in the future based on molecular typing.

Prospective therapeutic studies of disseminated extranodal large B-cell lymphoma including intravascular large B-cell lymphoma

This study aimed to establish a standard treatment for disseminated extranodal large B-cell lymphoma, including intravascular large B-cell lymphoma (DEN-LBCL/IVL), and to validate the clinical diagnostic criteria we proposed. Between 2006 and 2016, 22 patients were enrolled in a clinical trial conducted by the Hokuriku Hematology Oncology Study Group. The first cycle of chemotherapy consisted of dose-reduced cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with delayed administration of rituximab. From the second to the sixth cycle, patients received conventional rituximab and CHOP therapy. The primary endpoint was overall survival (OS), while the secondary endpoints included the complete response (CR) rate and time to treatment failure (TTF). The results showed a CR rate of 73%, a median OS of 65 months, and a median TTF of 45 months. These findings indicate that patients with DEN-LBCL/IVL were effectively treated with our new chemoimmunotherapy regimen. Our clinical diagnostic criteria are useful for identifying patients who require early intervention.

Hemophagocytic syndrome and neurological involvement in a case of intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of non-Hodgkin's lymphoma, and is divided into Western and Asian variants. The latter is rarely found to have neurological system involvement. In China, there have only been a few diagnosed cases of IVLBCL. Here, we present a Chinese case of Asian-variant IVLBCL with neurological symptoms. A 32-year-old Chinese man presented with bilateral lower limb numbness and persistent fever. He also complained of difficulties in urination and defecation. In addition, splenomegaly and pancytopenia were observed. We identified 3% dysplastic lymphocytes in his peripheral blood film, and his bone marrow biopsy led to a diagnosis of Asian-variant IVLBCL. Lumbar spine magnetic resonance imaging, which revealed an edematous spinal cord, further confirmed neurological involvement. The patient refused treatment from the time of diagnosis, and died 2 months after being discharged. IVLBCL is a highly aggressive but nonspecific clinical manifestation that is difficult to diagnose; therefore, a greater understanding of the disease is needed. The current first-line therapy involves R-CHOP combination therapy (cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab); however, the overall prognosis of IVLBCL remains poor.