large b cell lymphoma | B-cell lymphoma large cell primitive of the mediastinum in women: about five cases

B-cell lymphoma large cell primitive of the mediastinum in women: about five cases



Summary
Primitive mediastinal Lymphoma large cell B (LBPM) is a lymphoma occurring in the anterior mediastinum from the spinal area B-cells thymic. It is a rare entity that has its own peculiarities in terms on epidemiological, clinical and evolutionary histopathology and immuno-operational plan. We report a series of 5 patients hospitalized at the service of Pneumology hospital Ibn Sina between January 2012 and may 2016, and that the diagnosis of LBPM was retained. The average age was 34 years old, the average consultation time was 2 months. The reported symptoms were dyspnea, chest pain, dry cough; two patients had a higher cellar syndrome. LDH was high in 4 patients. Thoracic Imaging showed an anterior mediastinal tissue process in 5 patients. The histological diagnosis was laid on puncture biopsy transparietale scanno-guided in 5 patients, and Immunohistochemistry was decisive in all cases. Patients were addressed to the national Institute of Oncology for treatment. The prognosis of the LBPM is booked, it occurs readily in young women, making it all the more necessary to aggressive therapy to improve the survival rate.

Keywords: Lymphoma primitive B of the mediastinum, mediastinal Lymphoma, non-Hodgkin Lymphoma, mediastinum, woman

Introduction
The B-cell lymphoma large cell primitive of the mediastinum (LBPM) is a lymphoma occurring in the anterior mediastinum, more particularly from the thymic Medullary area B cells. It is a rare entity, represent less than 3% of all lymphomas no hodgkiniens [1], and about 5% of the aggressive lymphomas in adults [2]. It was recognized as a clinico-pathological entity of the other sub-groups of the B-cell lymphoma diffuse large cell in classification who 2008 of tumours of the hematopoietic and lymphoid tissue, with characteristics both in terms epidemiological, clinical and evolutionary, histopathology and immuno-operational level.

Methods
We report a series of 5 patients hospitalized at the service of Pneumology hospital Ibn Sina between January 2012 and may 2016, and that one held the diagnosis of lymphoma B large primitive cell of the mediastinum on pathology results , immunohistochemical, and phenotypic.

Results

The average age of our patients was 34; the average time of consultation at the beginning of the clinical symptomatology was 2 months. The reported symptoms were shortness in 3 cases (60%), chest pain in 4 cases (80%), and cough dry in 3 cases (60%). Two patients had a higher cellar syndrome (40%). All our patients, clinical examination was not peripheral adenopathy and hepatosplenomegaly. LDH was high in 4 patients (80%), with an average of 530 IU/L. Thoracic Imaging showed 4 patients a tissue mediastinal previous process (100%), whose size was greater than 10 cm in 3 cases (60%), associated with huge Mediastinal in 1 patient (20%) Lymphadenopathy, pulmonary nodules in 1 patient (20%), and pleural effusion in 3 patients (60%) (Figure 1, Figure 2). The bronchial fibroscopy showed no abnormality endobronchial in all cases. Histological diagnosis was made on transparietale biopsy guided scanno in 5 patients (100%). The anatomopathological analysis of samples has objectified a proliferation of lymphoid cells of medium to large size, clear and abundant cytoplasm with large nuclei, nucleoli (Figure 2), in tissue fibrosis; the contribution of Immunohistochemistry and phenotyping (CD20 +, CD23 +, CD30 +, CD15-) (Figure 3), was decisive in all cases to make a difference with Hodgkin Lymphoma in his scleronodulaire form. In one patient, the MTR extension revealed locations thyroid, breast and liver; in 4 patients the MTR extension did not disclose other locations. The primitive character of the Mediastinal tumor location was then held. Patients were sent to the national Institute of Oncology for treatment

Discussion

Mediastinal lymphoma are very aggressive lymphomas affecting young people. Three summarize nearly all of this pathology: T Lymphoblastic Lymphoma, mediastinal large cell B lymphoma and Hodgkin Lymphoma classic scleronodulaire [3]. The B Lymphoma large cell primitive of the mediastinum (LBPM) were long considered to be a variant of the classic forms of B lymphomas diffuse large cell. In practice, all against clinical plans, histopathologic, genetic and evolutionary, so although the lymphomas of the 2008 who classification distinguishes them now as an entity apart [4, 5]. The LBPM probably develop from B cells thymic, this hypothesis is supported by observation, in genetic terms, of a characteristic the myelin protein lymphocyte (BADLY) and gene overexpression in 70% cases of LBPM, protein also expressed in B of the Medullary thymic cells 

[6]. compared with diffuse large cell B, the LBPM Lymphoma occurs in younger subjects, 30 to 40 years [2], with a predominantly female, high LDH, and an intra-thoracique extension frequent neighborhood as the pleura bodies, him pericardium and lung parenchyma [7]. As the tumor is often large, greater than 10 cm, the subjects present with a superior cellar syndrome or symptoms in connection with a mediastinal syndrome (cough, Dyspnea) [8]. The data in our series join in this perfectly those of literature, with an average age of 34 years, symptoms of cough, dyspnea, chest pain and upper cellar syndrome, and LDH high in 80% of cases. The extension to the organs of neighborhood is also found in our series, with a parenchymatous lung damage in 20% cases, and a pleural extension in 60% of cases. On the anatomopathological plan, the typical appearance is that of diffuse beaches marked by the proliferation of large round cells with clear cytoplasm, associated with fibrosis, either thick, hyaline, or penicillee, Compartmenting the population tumor [1]. The Immunohistochemistry study has a major interest for the diagnosis and remove the other lymphoid tumours and/or fibrosantes. This is B-cells expressing CD19, CD20, CD22 and CD79a, CD23 and for 69% of them, CD30 but not CD15 [9, 10]. A Pakistani study demonstrated that ACL (leukocyte Cell Antigen) is the only marker to definitively differentiate a LBPM of a cHL (classic of Hodgkin's Lymphoma), when the characteristics of these two entities overlap also. This marking is unfortunately not available in routine in our percentage-pathology laboratory [11]. Since its publication in 1993, the international prognostic index (IPI) is the tool used for the treatment of patients with B Lymphoma large cell [12]. However, the IPI is probably not discriminative in patients with LBPM. Indeed, the disease concerns young patients with a tumor often limited to the mediastinum. Thus, despite the gravity of the pathology, the IPI score is low for more than half of patients and does not reflect the reality of the situation [13]. A Canadian study showed that the more than 40 years old, the rate of LDH greater than twice normal and Performans Status greater than or equal to two were associated with an unfavorable evolution [14]. The LBPM is both rare and newly recognized entity, there are so very few prospective data and a lack of treatment protocols-randomised studies, and controversies abound around the optimal therapeutic approach. In these young patients, it is crucial to take into account in the choice of treatment side effects long term. It is important to choose an optimal first-line treatment as treatment at the time of relapse give poor results [14, 15]. Therapeutic progress give encouraging results with the contribution of monoclonal antibodies (Rituximab), and the use of consolidation by high-dose chemotherapy in the more serious patients. The Protocol DA-R-EPOCH (Rituximab, Etoposide, Prednisone, Vincristine, Cyclophosphamide, Doxorubicin dose-adjusted) used in a retrospective study in phase II has shown satisfactory results, with a 94% complete response rate, and survival without event of 93% at 3 years. [16]. the place of radiation therapy is far from clearly defined, some studies suggest that she would especially have an interest in the case of partial remission, which may become full after radiotherapy. Pet - FDG Imaging is an assessment tool that can identify refractory diseases at an early stage, allowing you to ask the indication of consolidation radiotherapy [17]. In our work, we could not evaluate the therapeutic response, or long term follow-up, since our patients have been sent to the national Institute of Oncology for the treatment.

Conclusion

If the prognosis of the LBPM was reserved, phenotyping gains allow now to define specific molecular profiles, a therapeutic approach that is more targeted, in keeping with the era of medicine custom. It remains, however, that this disease occurs happy with young women, makes it all the more necessary to the prospective randomized studies to implement protocols to improve survival, while minimizing the effects secondary long-term.

State of current knowledge on the subject

Primitive mediatisnaux B lymphomas probably develop from B cells thymic;

Primitive Mediastinal B lymphomas are aggressive lymphomas affecting young people;

Primitive Mediastinal B lymphomas present peculiarities in terms on epidemiological, clinical and evolutionary histopathology and immuno-operational plan.

Contribution of our study to the knowledge

Epidemiological peculiarities (female);

Special pathology and immuno-Histochemical;

Therapeutic approach with discussion of the contribution of each therapeutic modality, taking into account the risk-benefit balance.

Conflicts of interest

The authors state no conflict of interest.

Contributions of the authors

All the authors contributed to the conduct of this work. The authors also declare having read and approved the final version of the manuscript.