Matched-pair analysis comparing the outcomes of T cell/histiocyte-rich large B cell lymphoma and diffuse large B cell lymphoma in patients treated with rituximab-CHOP

Catch the Calcium: T-Cell Histiocyte-Rich B-Cell Lymphoma Presenting as Hypercalcemia

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is an extremely rare and aggressive subtype of diffuse large B-cell lymphoma (DLBCL) that typically presents in middle-aged patients and carries a poor prognosis. Hypercalcemia presenting as the initial manifestation of the disease is rare, with only one other case reported in the literature. We report a case of a 90-year-old male who presented with progressive lethargy and unintentional weight loss. Initial workup showed elevated serum calcium of 14.6 mg/dL, corrected for albumin, and creatinine of 1.51 mg/dL. He had a suppressed iPTH of 6.3 pg/mL and normal PTHrP (13 pg/mL). Computed tomography (CT) scan of the abdomen and pelvis was performed to rule out underlying malignancy, which showed splenomegaly and enlarged retrocrural and porta hepatis lymph nodes. Bone marrow biopsy was performed to evaluate for hematological malignancy, which revealed findings diagnostic of THRLBCL. While rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is one of the mainstay therapies for DLBCL and has been shown to have comparable outcomes in THRLBCL, there are documented concerns with its toxicity profile limiting the ability of older patients (60 years and older) to complete therapy. Our patient was treated with R-mini-CHOP, which is much better tolerated in this patient demographic. R-mini-CHOP features decreased doses of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) with the conventional dose of rituximab. This case discusses a rare subtype of non-Hodgkin lymphoma presenting with a unique manifestation of hypercalcemia. We highlight the importance of thorough investigation for causes of hypercalcemia as well as the efficacy and tolerability of R-mini-CHOP in this elderly patient demographic.

The identification of TCF1+ progenitor exhausted T cells in THRLBCL may predict a better response to PD-1/PD-L1 blockade

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare and aggressive variant of diffuse large B-cell lymphoma (DLBCL) that usually affects young to middle-aged patients, with disseminated disease at presentation. The tumor microenvironment (TME) plays a key role in THRLBCL due to its peculiar cellular composition (<10% neoplastic B cells interspersed in a cytotoxic T-cell/histiocyte-rich background). A significant percentage of THRLBCL is refractory to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP)-based regimens and to chimeric antigen receptor T-cell therapy; thus, the development of a specific therapeutic approach for these patients represents an unmet clinical need. To better understand the interaction of immune cells in THRLBCL TME and identify more promising therapeutic strategies, we compared the immune gene expression profiles of 12 THRLBCL and 10 DLBCL samples, and further corroborated our findings in an extended in silico set. Gene coexpression network analysis identified the predominant role of the programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis in the modulation of the immune response. Furthermore, the PD-1/PD-L1 activation was flanked by the overexpression of 48 genes related to the functional exhaustion of T cells. Globally, THRLBCL TME was highly interferon-inflamed and severely exhausted. The immune gene profiling findings strongly suggest that THRLBCL may be responsive to anti–PD-1 therapy but also allowed us to take a step forward in understanding THRLBCL TME. Of therapeutic relevance, we validated our results by immunohistochemistry, identifying a subset of TCF1⁺ (T cell–specific transcription factor 1, encoded by the TCF7 gene) progenitor exhausted T cells enriched in patients with THRLBCL. This subset of TCF1⁺ exhausted T cells correlates with good clinical response to immune checkpoint therapy and may improve prediction of anti–PD-1 response in patients with THRLBCL.

Metabolic tumor volume, cancer cell fraction, and prognosis - the case of T-cell/histiocyte-rich large B-cell lymphoma

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare aggressive lymphoma characterized by a paucity of neoplastic B-cells and a majority of reactive T-cells with or without histiocytes. In the 'Positron Emission Tomography-Guided Therapy of Aggressive Non-Hodgkin Lymphomas' trial (clinicaltrials.gov NCT00554164; EudraCT 2006-001641-33), its frequency was less than 3%. While cancer cell content by quantitative histology was 10-times lower, baseline total metabolic tumor volume (TMTV) by 18-fluorodesoxyglucose positron emission tomography was 10-times higher in THRLBCL than in diffuse large B-cell lymphoma (DLBCL). When THRLBCL and DLBCL populations were matched for TMTV, the survival curves were superimposable. However, when the populations were matched for cancer cell volume by multiplying TMTV by cancer cell fraction, outcome in THRLBCL was worse than in DLBCL. Whether genetic differences between cancer cells, tumor-promoting properties of non-neoplastic cells, or both are responsible for inferior cancer cell volume-related outcome in THRLBCL, remains to be elucidated.

Pancreatic T/histiocyte-rich large B-cell lymphoma: A case report and review of literature

Primary pancreatic lymphoma (PPL) is an extremely rare form of extranodal malignant lymphoma. The most common histological subtype of PPL is diffuse large B cell lymphoma (DLBCL). In rare cases, PPL can also present as follicular lymphoma, small lymphocytic lymphoma, and T cell lymphoma either of non-Hodgkin’s lymphoma or of Hodgkin’s lymphoma. T-cell/histiocyte-rich large B-cell lymphoma (T/HRBCL) is an uncommon morphologic variant of DLBCL with aggressive clinical course, it is predominantly a nodal disease, but extranodal sites such as bone marrow, liver, and spleen can be involved. Pancreatic involvement of T/HRBCL was not presented before. Herein, we report a 48-year-old male who was hospitalized with complaints of jaundice, dark brown urine, pale stools, and nausea. The radiological evaluation revealed a pancreatic head mass and, following operative biopsy, the tumor was diagnosed as T/HRBCL. The patient achieved remission after six cycles of CHOP chemotherapy. Therefore, T/HRBCL can be treated similarly to the stage-matched DLBCL and both of them get equivalent outcomes after chemotherapy.

EBV-positive large B-cell lymphomas in young patients: a nodal lymphoma with evidence for a tolerogenic immune environment

Few studies have reported Epstein-Barr virus-positive (EBV(+)) large B-cell lymphomas (LBCLs) in young patients without immunodeficiency. We identified 46 such cases in patients ≤45 years of age and analyzed the clinical and pathological characteristics. EBV(+) LBCLs affected predominantly males (male:female = 3.6:1), with a median age of 23 years (range, 4-45 years). All patients presented with lymphadenopathy and 11% also had extranodal disease. Morphologically, 3 patterns were identified: T-cell/histiocyte-rich large B-cell lymphoma-like (n = 36), gray zone lymphoma (n = 7), and diffuse LBCL-not otherwise specified (n = 3). Tumor cells (EBV(+) in >90% of cells) expressed B-cell antigens, were often CD30 and PD-L1 positive, and showed a nongerminal center immunophenotype. A total of 93% expressed EBV latency type II and 7% latency type III. Indoleamine 2,3-dioxygenase was expressed on background accessory cells. The most common treatment regimen was rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (58%), with local radiation therapy added in 21%. With a median follow-up of 22 months, 82% of patients are in clinical remission and only 8% died of disease. Younger patients achieved a significantly higher overall survival than prior series of EBV(+) LBCLs reported in the elderly (P < .0001). In conclusion, EBV(+) LBCLs are not restricted to the elderly. Young patients present with nodal disease and have a good prognosis.

Matched-Pair Analysis of Open versus Laparoscopic Nephroureterectomy for Upper Urinary Tract Urothelial Cell Carcinoma

Objective: Laparoscopic nephroureterectomy (LNU) offers a superior morbidity profile compared with open nephroureterectomy (ONU) in treating upper urinary tract urothelial cell carcinoma. Evidence of oncological equivalence between LNU and ONU is limited. We compare operative and oncological outcomes for LNU and ONU using matched-pair analysis. Methods: Of 159 patients who underwent a nephroureterectomy at a single institution between April 1992 and April 2010, 13 pairs of ONU and LNU patients were matched for gender, age, tumour location, tumour grade and stage. Operative details, post-operative characteristics and recurrences were collated and survival rates analysed using the Kaplan-Meier method. Results: There was no significant difference in mean operation time between LNU (191 min) and ONU (194 min, p = 0.92). There was no significant difference in the 5-year survival rate between LNU and ONU (overall survival 59.1% vs. 73.5%, p = 0.18; progression-free survival 24.0% vs. 56.0%, p = 0.14; cancer-specific survival 60.9% vs. 73.5%, p = 0.56; bladder cancer recurrence-free survival 8.7% vs. 0.0%, p = 0.09). Conclusion: Amidst limited RCT and comparative studies, this study presents further evidence of oncological equivalence between LNU and ONU. There was a trend towards poorer outcomes following LNU though, which merits further study.