Primary Mediastinal Nodal and Extranodal Non-Hodgkin Lymphomas: Current Concepts, Historical Evolution, and Useful Diagnostic Approach: Part 1

Aggressive Mediastinal Lymphomas

The mediastinum contains essentially all major intrathoracic organs except for the lungs. A variety of both benign and malignant tumors can involve the mediastinum, of which lymphoma is the most common malignancy. Compared to secondary mediastinal involvement by systemic lymphomas, primary mediastinal lymphomas are less common with several specific entities that are mainly confined to mediastinal lymph nodes, and/or thymus. This review will summarize the clinical, histologic, immunophenotypic and molecular genetic features of the most common and most aggressive primary mediastinal lymphomas as well as provide suggested immunohistochemistry panels and differential diagnoses.

Fatal anterior mediastinal mass in a pregnant lady

We report a fatal case of a 26-year-old nulliparous woman who presented with an anterior mediastinal mass in her late pregnancy. She had complained of a progressively increasing neck swelling and occasional dry cough in the early second trimester, which was associated with worsening dyspnoea, reduced effort tolerance and orthopnoea. Ultrasound of the neck showed an enlarged lymph node, and chest X-ray revealed mediastinal widening. At 35 weeks' gestation, the patient was referred to a tertiary centre for a computed tomography (CT) scan of the neck and thorax under elective intubation via awake fibreoptic nasal intubation as she was unable to lie flat. However, she developed sudden bradycardia, hypotension and desaturation soon after being positioned supine, which required resuscitation. She succumbed after 3 days in the intensive care unit. An autopsy revealed a large anterior mediastinal mass extending to the right supraclavicular region, displacing the heart and lungs, encircling the superior vena cava and right internal jugular vein with tumour thrombus extending into the right atrium. Histopathology examination of the mediastinal mass confirmed the diagnosis of a primary mediastinal large B-cell lymphoma. This report emphasizes the severe and fatal outcome resulting from the delay and misinterpretation of symptoms related to a mediastinal mass.

Anaplastic Lymphoma Kinase (ALK)-Negative Anaplastic Large Cell Non-Hodgkin Lymphoma as a Rare Differential Diagnosis of Lung Cancer: A Case Report

Anaplastic large cell lymphomas (ALCL) are a group of sporadic malignancies that generally have an aggressive clinical course, especially the subtype of anaplastic lymphoma kinase (ALK)-negative ALCL. The appropriate diagnostic study modalities must be chosen to make an accurate diagnosis and promptly initiate specific treatment. We present the clinical case of a 72-year-old male patient with dyspnea on small efforts accompanied by diaphoresis and a weight loss of 10 kg in two months. Physical examination revealed adenopathy in the cervical region and bilateral pleural effusion. The pleural and lung biopsies revealed poorly differentiated metastatic adenocarcinomas. A multidisciplinary analysis was carried out; the typical clinical-radiographic presentation of adenocarcinoma was ruled out with immunohistochemistry, thus determining a diagnosis of ALK-negative anaplastic large cell non-Hodgkin's lymphoma. This case represented a diagnostic and therapeutic challenge since it is a rare entity with a poor prognosis, and there are only a few studies about the choice of appropriate chemotherapy in these patients.

Determination and mechanism of Xiao-Ai Jie-Du decoction against diffuse large B-cell lymphoma: In silico and In vitro studies

ETHNOPHARMACOLOGICAL RELEVANCE

Xiao-Ai Jie-Du decoction (XAJDD) has been used in clinical practice to treat diffuse large B-cell lymphoma (DLBCL); its prescriptions vary based on the pathogenesis of patients.

AIM OF THE STUDY

We aimed to determine the core formula of XAJDD and investigate its mechanism of action against DLBCL.

MATERIALS AND METHODS

Apriori data mining of 187 clinical cases (including 421 Traditional Chinese Medicines, TCMs) was conducted to retrieve the core formula of XAJDD. Comprehensive in silico modeling was used to identify potential active components and corresponding targets. The potential targets of 16 compounds were identified based on network pharmacology using in silico modeling. Thereafter, experimental determination of the active compounds and their mechanism of action in treating DLBCL was performed using different assays (including CCK-8, Annexin V-FITC/PI double-staining, Western blot, and flow cytometry assays).

RESULTS

The core formula of XAJDD included six herbs: Astragalus mongholicus Bunge (Huangqi, family: Fabaceae), Scutellaria barbata D. Don (Banzhilian, family: Lamiaceae), Prunella vulgaris L. (Xiakucao, family: Lamiaceae), Smilax glabra Roxb. (Tufuling, family Smilacaceae) and Fritillaria thunbergii Miq. (Dabei, family: Liliaceae), and Curcuma zanthorrhiza Roxb. (Ezhu, family: Zingiberaceae); Databases including 62 druggable compounds and 38 DLBCL-related structural targets were constructed; ∼0.3 million data points produced by computational modeling based on potential compounds and targets six components from XAJDD, including astibin, folic acid, baicalin, kaempferol, quercetin, and luteolin, significantly inhibited DLBCL cell proliferation, induced apoptosis, and suppressed the expression of key oncogenes.

CONCLUSION

This study provides an integrated strategy for determining the core formula of XAJDD and reveals the molecular mechanisms underlying the treatment of DLBCL, which were consistent with the principle of "monarch (Jun), minister (Chen), adjunctive (Zuo), and guide (Shi)", confirming that XAJDD may serve as a promising natural therapeutic agent against DLBCL.

Diagnostic Approach to Pulmonary B-Cell Lymphomas in Small Biopsies, with Practical Recommendations to Avoid Misinterpretation

Pulmonary lymphomas are rare. With the current less invasive approaches used to obtain material for diagnosis, the diagnosis of pulmonary lymphoma is now frequently established in a small biopsy rather than in a resection. Therefore, the diagnosis has become more challenging and requires correlation with the clinico-radiologic presentation and with ancillary studies (immunohistochemistry, flow cytometry, cytogenetics, and/or molecular analysis). Due to the rarity of pulmonary lymphomas, clinical suspicion of a lymphomatous process is low at initial presentation, and material may be only submitted for histopathology. For this reason, herein, we provide recommendations to arrive at the correct diagnosis of the most common lung B-cell lymphomas (marginal zone lymphoma of mucosa-associated lymphoid tissue, diffuse large B-cell lymphoma, intravascular large B-cell lymphoma, lymphomatoid granulomatosis) in the setting of small biopsies, utilizing only immunohistochemistry. The differential diagnosis varies according to the lymphoma subtype and includes reactive conditions, solid tumors, and other hematolymphoid malignancies. Although morphology and immunohistochemistry may be sufficient to establish a diagnosis, in some cases, the best recommendation is to obtain additional tissue via a VATS biopsy/wedge resection with material submitted for flow cytometry, cytogenetics, and/or molecular studies to be able to properly classify a pulmonary lymphoid process.

Approach to Imaging of Mediastinal Masses

Mediastinal masses present a diagnostic challenge due to their diverse etiologies. Accurate localization and internal characteristics of the mass are the two most important factors to narrow the differential diagnosis or provide a specific diagnosis. The International Thymic Malignancy Interest Group (ITMIG) classification is the standard classification system used to localize mediastinal masses. Computed tomography (CT) and magnetic resonance imaging (MRI) are the two most commonly used imaging modalities for characterization of the mediastinal masses.

A case of suspected primary mediastinal large B-cell lymphoma: An uncommon cause of sudden death

Primary mediastinal large B-cell lymphoma (PMLBCL) is an aggressive tumor originating from thymic B-cells. Clinically, it presents with general signs such as cough, chest pain and dyspnea. Although these symptoms are not specific, they are severe enough to reveal the disease. We report an autopsy case of a 25-year-old man, with a recent past history of cough and dyspnea, for which he consulted twice the emergency department and no diagnosis was made. He presented to the Emergency Unit, with a sudden onset of a dyspnea followed by a loss of consciousness. He was shortly declared dead after, a medico-legal autopsy was requested. On external examination, no traumatic lesions on the body were found, an important cyanosis of the face and ears, was, however, found. On autopsy, a mediastinal mass was found, measuring 19 cm × 25 cm and weighing 600 g, extending to the infra-hyoid region and to the thoracic cage and infiltrating the pericardium. Trachea had a necrotic mucosa with a partially obstructive lymph node mass. The diagnosis of a primary mediastinal large B-cell lymphoma was suspected based on pathological and immunohistochemical findings. The cause of death was finally attributed to respiratory failure due to this tumor.

The Co-Existence of Micronodular Thymoma and Lymphoma: A Clinicopathological and Immunohistochemical Study of Two Cases

Two cases with the co-existence of micronodular thymoma and lymphoma are presented. The patients are two female patients 54 and 60 years of age who presented with symptoms of chest pain, general malaise, cough, and dyspnea. Diagnostic imaging demonstrated the presence of an anterior mediastinal mass. Initial biopsy was interpreted as an epithelial neoplasm compatible with thymoma. Surgical resection took place demonstrating the presence of micronodular thymoma in both cases. In addition, in both cases the lymphoid proliferation infiltrated surrounding adipose tissue. However, in one case the lymphoid proliferation was composed of atypical lymphocytes with irregular nuclei and increase mitotic activity positive for CD3 and TDT, while in the second case, the lymphoid proliferation was composed of more mature lymphocytes with a monocytoid appearance and positive for CD20. Both of these cases represent an unusual association and one that must be kept in the differential diagnosis especially in cases of micronodular thymoma.

Patients and Families' Participation in Multidisciplinary Tumor Conferences Improves Patient and Family-Focused Cancer Care: Lessons Learned From a Debate on the Role of Radiation Therapy in Primary Mediastinal Non-Hodgkin Lymphoma

Incorporation of patients' preferences often leads to improved outcomes when included in the multidisciplinary tumor conference/board (MTC). However, patients' wishes are not included or considered in the MTC decision-making. We need better strategies and approaches for patient-inclusive, shared decision-making. When finding ourselves at a crossroads regarding the next step in a patient's treatment, we saw a unique opportunity for an MTC with the patient and her husband in attendance. The results of a full literature review regarding the role of consolidative radiation therapy (RT) in a patient with primary (thymic) B-cell lymphoma after completion of chemotherapy and fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) scan with a Deauville score of 4 were presented in a creative, engaging debate-style forum with visual aids. The patient and her husband were able to follow the discussion and, in the end, a consensus recommendation, heavily focused on the patient's preferences, was offered and adopted, which ultimately resulted in the avoidance of excess treatment and likely improved her long-term quality of life outcome. These collaborative and innovative interactions benefit not only our patients but enrich our lives too as healthcare providers and strengthen us as a cancer care team in terms of understanding diversity in decision-making processes.

Diagnostic difficulties of antero-superior mediastinal masses with cardiac infiltration. Endovascular bioptic alternative approach

The diagnosis of mediastinal masses is challenging due to the variety of possiblepathologies , and its definitive diagnosis is mainly confirmed by histological evaluation. Sometimes some lesions may have a greater intravascular rather than mediastinal development and the collection of a biopsy sample becomes even more complex. In these cases endovascular catheter biopsy is helpful in the collection of the necessary biological material, having to adapt to the type of surface and consistency of the mass to be analyzed. Endovascular catheter biopsy was performed with a biliary forceps to sample a mediastinal mass with greater endovascular and cardiac development, with a hard and difficult to sample surface. The histological result was diagnosed with non-hodgkins lymphoma.

Approach to Mediastinal Fine Needle Aspiration Cytology

Mediastinal fine needle aspirations are routinely encountered in cytopathology practice. Mediastinal lesions may pose diagnostic challenges owing to their rarity and locations associated with the complexity of the mediastinal anatomic structures in the thoracic cavity. Diagnosing mediastinal lesions and guiding patient management usually require correlating with clinical and radiologic findings, being familiar with cytomorphologic features and appropriately triaging the diagnostic material for ancillary testing. This review proposes a practical approach to interpret mediastinal fine needle aspirations and emphasizes potential diagnostic pitfalls for mediastinal lesions including benign cysts, thymic neoplasms, lymphoproliferative disorders, germ cell tumors, mesenchymal tumors, and metastatic tumors.

Incidence, mortality, and survival analyses of patients with thymic lymphoma

Objectives

To explore the clinical and prognostic characteristics of thymic lymphoma and the effects of current treatments on the prognosis.

Methods

Patients diagnosed as primary thymic lymphoma between 1975 and 2018 from the nine states of the US were identified, including Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle–Puget Sound, and Utah. Incidence and mortality rates were analyzed using SEER*Stat 8.3.9 software. Univariate and multivariate Cox regressions were performed to identify prognostic factors. The Kaplan–Meier curve and log-rank test were used to compare overall survival (OS) among different treatments.

Results

A total of 233 patients diagnosed as thymic lymphoma were identified, and eight of them were lost to follow-up or died upon diagnosis. The incidence of thymic lymphoma was 2.032 per ten million (95% CI: 1.777–2.312), and the mortality rate was 0.649 per ten million (95% CI: 0.508–0.817). Among the 225 patients with definite follow-up, 98 were males and 127 were females, with a median age of 33 years. The Cox regression results showed that age and pathological type were independent risk prognostic factors. The 5-, 10-, and 20-year OS were 80.0%, 77.5%, and 70.9%, respectively. For Ann Arbor stage I and II patients, there was no significant difference between the surgical group (N = 78) and the non-operative group (N = 65; P = 0.270). The radiotherapy group (N = 79) had better OS than the non-radiotherapy group (N = 64) in the first 25 years, and the prognosis in the later years was not significantly different (P = 0.051). The chemotherapy group (N = 37) had a significantly better prognosis than the non-chemotherapy group (N = 37; P = 0.020). Patients who received postoperative radiotherapy (N = 45) or who only received radiotherapy (N = 34) seemed to have better OS than that of patients who only received surgery (N = 33), although the difference was not significant (P = 0.063).

Conclusions

Age and pathological type were independent prognostic factors for thymic lymphoma. Surgical treatment had limited effects on OS, while both radiotherapy and chemotherapy could significantly improve the survival outcome.

Multiparameter diagnostic model based on 18F-FDG PET and clinical characteristics can differentiate thymic epithelial tumors from thymic lymphomas

OBJECTIVE

To evaluate the diagnostic performance of combined multiparametric ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG PET) with clinical characteristics in differentiating thymic epithelial tumors (TETs) from thymic lymphomas.

PATIENTS AND METHODS

A total of 173 patients with 80 TETs and 93 thymic lymphomas who underwent ¹⁸F-FDG PET/CT before treatment were enrolled in this retrospective study. All patients were confirmed by pathology, and baseline characteristics and clinical data were also collected. The semi-parameters of ¹⁸F-FDG PET/CT, including lesion size, SUVmax (maximum standard uptake value), SUVmean (mean standard uptake value), TLG (total lesion glycolysis), MTV (metabolic tumor volume) and SUVR (tumor-to-normal liver standard uptake value ratio) were evaluated. The differential diagnostic efficacy was evaluated using the receiver operating characteristic (ROC) curve. Integrated discriminatory improvement (IDI) and net reclassification improvement (NRI), and Delong test were used to evaluate the improvement in diagnostic efficacy. The clinical efficacy was evaluated by decision curve analysis (DCA).

RESULTS

Age, clinical symptoms, and metabolic parameters differed significantly between patients with TETs and thymic lymphomas. The ROC curve analysis of SUVR showed the highest differentiating diagnostic value (sensitivity = 0.763; specificity = 0.888; area under the curve [AUC] = 0.881). The combined diagnostics model of age, clinical symptoms and SUVR resulted in the highest AUC of 0.964 (sensitivity = 0.882, specificity = 0.963). Compared with SUVR, the diagnostic efficiency of the model was improved significantly. The DCA also confirmed the clinical efficacy of the model.

CONCLUSIONS

The multiparameter diagnosis model based on ¹⁸F-FDG PET and clinical characteristics had excellent value in the differential diagnosis of TETs and thymic lymphomas.

Human Oncoviruses and Thoracic Tumors: Understanding the Imaging Findings

Approximately 1.4 million virus-induced cancers occur annually, representing roughly 10% of the cancer burden worldwide. Seven oncogenic DNA and RNA viruses (ie, oncoviruses) are implicated in approximately 12%-25% of all human cancers owing to a variety of mechanisms as uncommon consequences of the normal viral life cycle. These seven well-recognized human oncoviruses are Epstein-Barr virus (EBV), human T-lymphotropic virus 1, hepatitis B virus, hepatitis C virus, HIV, human papilloma virus (HPV), and human herpesvirus 8 (HHV-8). Several viruses-namely, EBV, HPV, and Kaposi sarcoma herpesvirus or HHV-8-are increasingly being recognized as being related to HIV and/or AIDS, the growing number of transplant cases, and the use of immunosuppressive therapies. Infectious and inflammatory processes, and the accompanying lymphadenopathy, are great mimickers of human oncovirus-related tumors. Although it is often difficult to differentiate these entities, the associated clinical setting and radiologic findings may provide clues for an accurate diagnosis and appropriate management. Malignant lymphoid lesions are best evaluated with multidetector chest CT. The radiologic findings of these lesions are often nonspecific and are best interpreted in correlation with clinical data and histopathologic findings. ^©RSNA, 2022.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Massive pericardial effusion as the first manifestation of childhood non-Hodgkin's lymphoma: A case report

Although one of the serious manifestations of advanced malignancies is pericardial involvement, pericardial involvement of lymphoma is extremely rare. We present a case of a 6-year-old girl arriving at the hospital with dyspnea and pleuritic chest pain, which is eventually diagnosed with massive pericardial effusion due to mediastinal non-Hodgkin lymphoma.

Mediastinal Lymphoproliferative Disorders

Lymphoproliferative disorders comprise 50% to 60% of all mediastinal malignancies in both children and adults. Primary mediastinal involvement is rare (∼5%), whereas secondary mediastinal involvement by systemic disease is more common (10% to 25%). Primary mediastinal disease is defined as involvement by a lymphoproliferative disorder of mediastinal lymph nodes, the thymus, and/or extranodal mediastinal organs without evidence of systemic disease at presentation. In this review, the clinical, radiologic, histopathologic, immunohistochemical, and genetic features of some of the most characteristic mediastinal lymphoproliferative disorders are presented. The entities discussed here include: classic Hodgkin lymphoma with emphasis on nodular sclerosis and mixed cellularity types, and non-Hodgkin lymphomas, including primary mediastinal (thymic) large B-cell lymphoma, mediastinal gray zone lymphoma, mediastinal diffuse large B-cell lymphoma, thymic marginal zone lymphoma, mediastinal plasmacytoma, T-lymphoblastic lymphoma, and anaplastic large cell lymphoma. Although not a malignant process, hyaline vascular Castleman disease is also discussed here as this disorder commonly involves the mediastinum. Despite multiple advances in hematopathology in recent decades, the day-to-day diagnosis of these lesions still requires a morphologic approach and a proper selection of immunohistochemical markers. For this reason, it is crucial for general pathologists to be familiar with these entities and their particular clinicoradiologic presentation.

Diagnostic Challenges in Fine-Needle Aspiration Cytology of Mediastinal Tumors and Lesions

CONTEXT.—

Mediastinal tumors/lesions are frequently encountered in daily cytopathology practice. These lesions are accessible through endoscopic/endobronchial ultrasound-guided or computed tomography-guided fine-needle aspiration cytology and represent a wide range of primary and metastatic tumors. This often poses diagnostic challenges because of the complexity of the mediastinal anatomic structures. Tumors metastatic to mediastinal lymph nodes represent the most common mediastinal lesions and must be differentiated from primary lesions.

OBJECTIVE.—

To provide an updated review on the fine-needle aspiration cytology of mediastinal tumors/lesions, with an emphasis on diagnostic challenges. This review encompasses thymic epithelial neoplasms, mediastinal lymphoproliferative disorders, germ cell tumors, neuroendocrine tumors, soft tissue tumors, and metastatic tumors. Differential diagnoses; useful ancillary studies, including targeted immunohistochemical panels; and diagnostic pitfalls are discussed.

DATA SOURCES.—

Data were gathered from a PubMed search of peer-reviewed literature on mediastinal tumors. Data were also collected from the authors' own practices.

CONCLUSIONS.—

Fine-needle aspiration cytology plays a vital role in evaluation of mediastinal lesions. Being familiar with the clinical and cytomorphologic features of these lesions, appropriately triaging the diagnostic material for ancillary testing, and correlating with radiologic findings are important in arriving at correct diagnoses and guiding management.

Ultrasound-Guided Anterior Mediastinotomy: A Feasible Tool for Critical Lymphoma Patients

A significant part of all neoplasms growing in anterior mediastinum are lymphomas (25%). Achieving a correct diagnosis and a clear definition of a lymphoma’s subtype is crucial for beginning chemotherapy as soon as possible. However, most patients present a large mediastinal mass that compresses vessels and airway, with serious cardiorespiratory repercussions. Therefore, having multiple tools available to biopsy the lesion without worsening morbidity becomes fundamental. Patients enrolled in this study were unfit for a surgical biopsy in general anesthesia and the need to begin chemotherapy as fast as possible prompted us to avoid percutaneous fine needle aspiration to prevent diagnostic failures. Our observational study included 13 consecutive patients with radiological findings of anterior mediastinal mass. Ultrasonography was performed directly in the theatre to mark the lesion and to localize vessels and vascularized neoplastic tissue. Open biopsy was carried out in spontaneous breathing with a laryngeal mask and with short-acting medications for a rapid anesthesia, performing an anterior mediastinotomy. The mean operative time was 33.4 ± 6.2 min and spontaneous respiration was maintained throughout the procedure. No complications were reported. All patients were discharged in the first or second postoperative day after a chest X-ray (1.38 ± 0.5 days). The diagnostic yield of this approach was 100%. With the addition of ultrasonography right before the procedure and with spontaneous breathing, anterior mediastinotomy still represents a useful tool in critical patients that could hardly tolerate a general anesthesia. The diagnostic yield is high, and the low postoperative morbidity allows a rapid onset of chemotherapy.

Superior vena cava syndrome caused by mediastinal lymphoma: A rare clinical case

The superior vena cava syndrome refers to a medical emergency resulting from superior vena cava compression, which develops in 2%-4% of non-Hodgkin lymphomas. Primary mediastinal (thymic) large B-cell lymphoma is an unusual and aggressive non-Hodgkin lymphoma that can present with superior vena cava syndrome.

We report the case of a Caucasian 21-year-old female, who presented with acute superior vena cava syndrome, having started 2 weeks before. Chest computerized tomography disclosed an anterior mediastinal mass (18 × 14 cm). Thoraco-abdominopelvic magnetic resonance imaging was performed in order to differentiate compression versus mass invasion. A gross anterior mediastinal mass (109 × 60 × 105 mm) occupying the totality of the prevascular space was found, extending from the sternal furcula to the pericardium, fully embedding the superior vena cava. A computerized tomography guided biopsy was performed. Histopathological and immunohistochemical analysis was consistent with Primary mediastinal (thymic) large B-cell lymphoma.

Primary mediastinal (thymic) large B-cell lymphoma has unique clinicopathologic aspects and it should be considered in a young patient with Superior vena cava syndrome. Prompt recognition, a timely diagnosis and appropriate treatment are crucial for prognosis.

Primary CD20-positive mediastinal diffuse large B-cell lymphoma

Primary mediastinal B-cell lymphoma (PMBCL) is a rare tumour with different characteristics from other type of lymphomas. Clinical manifestations may vary and cause delay in diagnosis and management. We present a 22-year-old patient with symptoms of shortness of breath, weight loss, and night sweats. Laboratory studies only showed a markedly high lactate dehydrogenase (LDH) level and thoracic computed tomography (CT)scan revealed a large mediastinal mass. Core biopsy-guided CT scan was performed and the pathological and immunohistochemistry established a PMBCL diagnosis. We administered Rituximab Dose-Adjusted Etoposide Prednisolone Vincristine Cyclophosphamide Doxorubicin (R-DA-EPOCH) chemotherapy regimen and the patient responded well to treatment. This is an example of rare case of mediastinal lymphoma with challenges to overcome to achieve diagnostic and therapeutic success. Failure to differentiate PMBCL with other systemic diffuse large B-cell lymphoma (DLBCL) could skew treatment algorithm and prevent optimal response. Administration of proper systemic therapy, especially in young, low-risk patients could yield excellent outcome.