Practical methods to differentiate thymic malignancies by positron-emission tomography and tumor markers.

PURPOSE: An accurate diagnosis of thymic malignancies is important, but challenging due to the broad range of differential diagnoses. This study aims to evaluate the efficacy of PET/CT and tumor markers for diagnosing thymic malignancies. METHODS: Patients admitted to our department between January 2012 and December 2021 with primary anterior mediastinal tumors were retrospectively evaluated. We evaluated the relationship between the maximum standardized uptake value (SUVmax), tumor markers, and pathological diagnosis in four groups: thymic carcinoma, thymoma, lymphoma, and others. RESULTS: In total, 139 patients were included in this study. The SUVmax was significantly higher in lymphoma, thymic carcinoma, and thymoma, in that order. The cytokeratin 19 fragment (CYFRA 21-1) was significantly higher in thymic carcinoma than in the other groups. An ROC curve analysis indicated that the optimal cut-off values of SUVmax for thymic carcinoma plus lymphoma and CYFRA 21-1 for thymic carcinoma were 7.97 (AUC = 0.934) and 2.95 (AUC = 0.768), respectively. Using a combination of cut-off values (SUVmax = 8, CYFRA 21-1 = 3), the accuracy rate for diagnosing thymic carcinoma was 91.4%. CONCLUSIONS: The SUVmax and CYFRA 21-1 levels are significant indicators for the diagnosis of thymic carcinoma. Combining these indicators resulted in a more accurate diagnosis of thymic malignancies, which could facilitate the decision-making process for determining the optimal treatment strategies.

Efficacy of Residual Site Radiation Therapy (ISRT) in Patients with Primary Mediastinal Lymphoma with Deauville Score 4 Following R-CHT: Results of a Retrospective Mono Institutional Study.

BACKGROUND: In order to evaluate the efficacy of residual site radiation therapy (RSRT) in terms of progression-free survival (PFS) and overall survival (OS) in patients with primary mediastinal lymphoma (PMBCL) with Deauville Score 4 (DS 4) following rituximab and chemotherapy treatment (R-ICHT). METHODS: Thirty-one patients with PMBCL were recruited. After completion of R-ICHT, patients were staged with 18F-fluorodeoxyglucose positron-emission tomography, showing DS 4, and were treated with adjuvant RSRT. The chosen techniques for RT delivery were intensity-modulated radiation therapy (IMRT) or three-dimensional conformal RT (3D-CRT). Most patients underwent the first one using cone-beam computed tomography (CBCT). All patients were evaluated every 3 months for the first 2 years and every 6 months afterwards for a period of at least 5 years, with clinical and radiological procedures as required. RESULTS: All patients received RSRT with a dose of 30 Gy in 15 fractions. The median follow-up time of 52.7 months (IQR: 26-64.1 months). The 5-year OS rate was 100%. The 2-year and 5-year PFS rates were 96.7% and 92.5%, respectively. Patients with relapsed disease had been treated with high-dose chemotherapy (HDC) and autologous stem cell transplantation (auto-SCT). CONCLUSION: RSRT in patients with PMBCL treated with ICHT and DS 4 did not impact unfavorably on patient survival.

Concomitant occurrence of genetically distinct Hodgkin lymphoma and primary mediastinal lymphoma.

Synchronous Hodgkin Lymphoma and Primary Mediastinal B-cell Lymphoma is possible, with molecular analyses proving the absence of clonal filiation between both entities. This suggests a common etiology but the existence of two divergent clones.

Survival among patients with composite and sequential lymphoma between primary mediastinal lymphoma/diffuse large B-cell lymphoma and classical Hodgkin lymphoma: A population-based study.

BACKGROUND: Data on composite and sequential lymphoma between primary mediastinal lymphoma/diffuse large B-cell lymphoma (LBCL) and classical Hodgkin lymphoma (cHL) are rare. METHODS: We identified 25 cases with composite lymphoma (CL), 116 cases developing LBCL as a second primary cancer after cHL (cHL-LBCL), and 74 cases developing cHL as a second primary cancer after LBCL (LBCL-cHL) from the Surveillance, Epidemiology, and End Results (SEER) 18 database. Comparisons of overall survival (OS) and lymphoma cause-specific survival (CSS) between patients with cHL-LBCL or cHL-LBCL and their de novo counterparts were performed. RESULTS: The 5-year OS of patients with CL was 74.8 %. No significant difference in unadjusted OS and lymphoma CSS were observed between patients with de novo LBCL (LBCL-1 group) and patients with cHL-LBCL. However, the age- and stage-adjusted cHL-LBCL group had inferior OS and lymphoma CSS compared with that in the LBCL-1 group. The unadjusted and adjusted OS and lymphoma CSS in the LBCL-cHL group were significantly worse than patients with de novo cHL. CONCLUSIONS: CL between LBCL and cHL may have good outcomes. cHL survivors had poorer outcomes after a LBCL diagnosis versus patients with LBCL-1. Significantly poor outcomes were observed in patients with LBCL-cHL compared with patients with de novo cHL.

The Hematological Differential Diagnosis of Mediastinal Masses.

Mediastinal masses commonly present in children and may pose diagnostic challenges, particularly with limited sampling. This article aids the pathologist by reviewing the hematologic differential diagnosis of a pediatric mediastinal mass, along with ancillary testing useful for rendering the correct diagnosis. A review of the more common lymphomas is presented, including classic Hodgkin lymphoma, T-lymphoblastic leukemia/lymphoma, and primary mediastinal (thymic) large B-cell lymphoma, along with brief mentions of less common entities such as gray zone lymphoma and thymoma as well as non-neoplastic conditions such as benign cysts and infections.

Pembrolizumab for refractory primary mediastinal B-cell lymphoma with central nervous system involvement.

Primary mediastinal large B-cell lymphoma (PMBCL) is a rare aggressive B-cell lymphoma characterized by the frequent presence of amplification and translocation events at 9p24.1, resulting in the expression of the programmed cell death-1 (PD-1) ligands PD-L1 and PD-L2. Pembrolizumab, a humanized anti-PD-1 monoclonal antibody, binds PD-1 and blocks this interaction, enhancing the activity of the immune system against tumor cells, and has shown activity in PMBCL and in some cases of primary and secondary central nervous system (CNS) lymphoma. We report the case of a 40-year-old woman diagnosed with relapsed PMBCL and secondary CNS involvement who responded to pembrolizumab monotherapy, allowing for a later allogeneic stem cell transplant.

The utility of CD83, fascin and CD23 in the differential diagnosis of primary mediastinal large B-cell lymphoma versus classic Hodgkin lymphoma.

Primary mediastinal large B-cell lymphoma (PMBL) and classic Hodgkin lymphoma (CHL) are the most common large cell lymphomas arising in the mediastinum and are thought to be closely related histogenetically. Although the distinction between PMBL and CHL is usually straightforward, in some cases it is challenging and rarely these neoplasms have intermediate features and qualify for the diagnosis of mediastinal gray zone lymphoma (GZL). CD83 and fascin are markers of CHL and CD23 is a marker of PMBL. In this study we assess the utility of this combination of these immunohistochemical markers to distinguish CHL from PMBL. We retrospectively collected cases of PMBL, CHL and GZL from three centers. Tissue sections were stained with CD83, fascin and CD23. CD83 was expressed in the neoplastic cells of 100% of CHL (22/22), 93% of GZL (16/18) and 41% of PMBL (9/22). Similarly, fascin was positive in the neoplastic cells of 100% of CHL (22/22), 86% of GZL (18/21) and 32% of PMBL (7/22). CD23 was positive in 95% of PMBL (21/22), 67% of GZL (12/18) and 9% of CHL (2/22). CD83 and fascin are sensitive markers for CHL but not specific whereas CD23 is sensitive for PMBL and uncommon in CHL. The GZL cases in this study had an intermediate immunophenotype, but the results were closer to CHL than PMBL. A large panel of immunohistochemical studies is recommended to distinguish CHL from PMBL entities and we suggest that CD83, fascin and CD23 add value to panels designed for this differential diagnosis.

[œsotracheal fistula complicating primary mediastinal large B cell non-Hodgkin's lymphoma: a case study]. / Fistule œsotrachéale compliquant un lymphome non hodgkinien B médiastinal primitif: à propos d'un cas.

Primary mediastinal non-Hodgkin's lymphoma(PMNHL) is a rare cancer. Exceptionally, it can be complicated by tracheœsophageal fistulas, directly connecting the esophagus and the trachea and secondary to esophageal tumor or chemotherapy (hence the interest of our case). We report the case of a 24-year old Moroccan female patient, treated for primary mediastinal large B cell NHL revealed by dyspnœa associated with dysphagia and alteration of general condition. The patient underwent chemotherapy but her health condition worsened after a second treatment due to the occurrence of recurrent pulmonary infections associated with cough during meals making swallowing impossible. Esogastroduodenal fibroscopy was performed which confirmed the diagnosis of tracheœsophageal fistula. Outcome was marked by patient's death despite endoscopic stent placement and a good response to chemotherapy. Early discovery of tracheœsophageal fistula in patients with PMNHL is essential because it enables the implementation of an appropriate treatment.

The treatment of primary mediastinal large B-cell lymphoma: a two decades monocentric experience with 98 patients.

BACKGROUND: The purpose of this study is to investigate the most suitable first-line approach and the best combination treatment for primary mediastinal large B-cell lymphoma (PMLBCL) as they have been matter of debate for at least two decades. METHODS: Our single centre experience in the treatment of 98 de novo PMLBCL patients over the last 20 years is reviewed. All patients received MACOP-B chemotherapy. Thirty-seven received both rituximab and mediastinal radiotherapy; 30 were irradiated after chemotherapy, although not receiving rituximab and 20 received rituximab without radiotherapy consolidation. Eleven patients received chemotherapy only. RESULTS: Sixty-one (62.2%) patients achieved a complete response after MACOP-B (with or without rituximab); among the 27 (27.6%) partial responders, 21 obtained a complete response after radiotherapy. At the end of their scheduled treatment, 82 patients (83.7%) had a complete and 6 a partial response (6.1%). Eleven patients relapsed within the first 2 years of follow-up. The 17-year overall survival is 72.0% (15 patients died); progression-free and disease-free survival are 67.6% and 88.4%, respectively. A statistically significant difference in overall and progression-free survival was noted among treatment groups, although no disease-free survival difference was documented. CONCLUSIONS: Our data indicate that a third-generation regimen like MACOP-B could be considered a suitable first-line treatment. Mediastinal consolidation radiotherapy impacts on survival and complete response rates and remains a good strategy to convert partial into complete responses. Data suggest that radiotherapy may be avoided in patients obtaining a complete response after (immuno)chemotherapy, but this requires confirmation with further ad hoc studies.

[Hodgkin and non-Hodgkin lymphoma of adolescents and young adults]. / Lymphomes hodgkiniens et non hodgkiniens des adolescents et des jeunes adultes.

Lymphoma is one of the most frequent cancers in adolescent and young adults. Hodgkin Lymphoma is curable in more than 90% of cases. Recent pediatric and adults protocols aimed to decrease long term toxicities (mostly gonadic and cardiovascular) and secondary malignancies, reducing the use of alkylating agents and limiting radiation fields. Risk-adapted strategies, using positron emission tomography staging, are about to become a standard, both in adult and pediatric protocols. These approaches allow obtaining excellent results in adolescents with Hodgkin lymphoma. On the other hand, treatment of adolescents with diffuse large B-cell lymphoma raises some questions. Even through children have good outcomes when treated with risk-adapted strategies, adolescents who are between 15 and 18 years old seem to experience poorer survivals, whereas patients older than 18 years old have globally the same outcome than older adults. This category of patient needs a particular care, based on a tight coordination between adults and pediatric oncologists. Primary mediastinal lymphomas, a subtype of BLDCL frequent in young adult population, exhibits poorer outcomes in children or young adolescent population than in older ones. Taking together, B-cell lymphoma benefited from recent advances in immunotherapy (in particular with the extended utilization of rituximab) and metabolic response-adapted strategies. In conclusion, adolescent and young adult's lymphomas are very curable diseases but require a personalized management in onco-hematological units.

Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome.

Positron emission tomography-computed tomography (PET/CT) is a routine investigation for the staging of lymphomas. Contrast-enhanced computed tomography is mandatory whenever parenchymal lesions, especially in the liver and spleen are suspected. We report a rare case of primary mediastinal T-cell lymphoma evaluated with contrast-enhanced PET/CT that showed features of superior vena cava syndrome.

Primary mediastinal lymphoma: diagnosis and treatment options.

Primary mediastinal large B-cell lymphoma (PMBCL) is a unique B-cell lymphoma variant that arises from a putative thymic medulla B cell. It constitutes 2-4% of non-Hodgkin lymphomas and occurs most frequently in young females. PMBCL is characterized by a diffuse proliferation of medium-to-large B cells associated with sclerosis. Molecular analysis shows that PMBCL is a distinct entity compared to other types of diffuse large B-cell lymphomas. PMBCL is characterized by a locally invasive anterior mediastinal bulky mass. The combination of rituximab with CHOP/CHOP-like regimens followed by mediastinal radiation therapy (RT) is associated with a 5-year progression-free survival of 75-85%. However, the role of consolidation RT still remains uncertain. More intensive regimens, such as DA-EPOCH-R without mediastinal RT, have shown very promising results. The conclusive role of PET-CT scan requires prospective studies and there is hope that this may allow to de-escalate RT and accordingly yield reliable prognostic information.

Utilidad de la mediastinoscopia: resultados de 140 procedimientos / Mediastinoscopy: experience with 140 procedures

Objetivo: determinar la sensibilidad y especificidad de la mediastinoscopia para diagnóstico y estadiaje de enfermedades del tórax. Métodos: se revisó la información general incluida en la base de datos del servicio de Cirugía de Tórax del Hospital Dr. R. A. Calderón Guardia, de 140 pacientes sometidos a mediastinoscopia durante el periodo comprendido entre 1989 y 2013, la cual se complementó con datos específicos obtenidos de los expedientes clínicos...