DISCUSSION:
One of the frequent and serious manifestations of advanced malignancies is pericardial involvement, which includes various degrees such as pericarditis, pericardial effusion, pericardial tamponade, and constrictive pericarditis(4). Symptomatic effusion mostly presents with tachycardia, dyspnea (our patient’s chief complaint), and echocardiographic characteristics of right heart failure, but it can also occur asymptomatically (5,6).
Pericardial effusion rises mainly from blockage of the lymphatic and venous drainage of the pericardium which is caused by adjacent compression, direct tumoral infiltration, or via hematogenous spread. Pericardial effusions in cancer patients can also be triggered by chemotherapy and radiotherapy. Other complications like infections and autoimmune diseases, can also cause pericardial effusion in these patients(4,7). The typical findings on electrocardiogram are sinus tachycardia and low voltage defined as maximum QRS amplitude <0.5 mV in the limb leads. New-onset atrial fibrillation can be present. Electrical alternans, characterized by beat-to-beat alternation in the QRS complex, represent the swinging of the heart in the pericardial fluid(3). Echocardiography is considered to be the primary imaging modality for pericardial effusion, and it is recommended to be done before, during and after treatment to monitor the patient(1,2).
Lymphoma is a haematological malignancy that emerges from the clonal proliferation of lymphocytes at different maturation stages. It presents with fatigue, night sweats, enlarged painless lymph nodes, and weight loss. Lymphoma is classified into 2 major subgroups: Hodgkin (10%) and non-Hodgkin lymphoma (90%) (2). Lymphomas involving the mediastinum have a wide age range, and occur in both pediatric and adult populations(11).
Chen et al compared pediatric and adult lymphomas involving the mediastinum, and reported that pediatric patients had a higher incidence of T-LBL/T-ALL, prevalence of dyspnea, stage IV tumors frequency, and relative tumor diameter, compared to adults. They were also more likely to be male(12).
Cardiac and pericardial involvement of lymphoma is extremely rare. It accounts for 0.5% of cardiac involvement and 1% of all extranodal non hodgkin lymphomas. It is more common in high-grade lymphomas, particularly double-hit/triple-hit subtypes, and shows a poor prognosis, as in other malignancies(6). Bertog et al. studied 163 patients diagnosed with constrictive pericarditis, and lymphoma was the aetiology in only 2 of the patients (9). In another study, out of 8 patients undergoing pericardiectomy for malignant constrictive pericarditis, only one was diagnosed with lymphoma(10). This unlikeliness has sometimes led to incorrect approaches and treating patients with multiple pericardiocenteses or management according to other diagnoses like tuberculosis(13).
On the other hand, malignancy involving the pericardium is usually a late secondary feature(8). In a case study-based systematic review on lymphoma-associated cardiac tamponade, Shareef et al evaluated 52 cases aged 9 to 95 (median 52), out of which 49 patients had non-Hodgkin lymphoma, and observed that most of these patients were diagnosed with lymphoma prior to hospital presentation (80.8%) (4). They also reported that the median overall survival of patients with lymphoma and cardiac tamponade is 4 months, and there is no significant difference between lymphoma diagnosis before or after this complication.
A chest x-ray identifies an anterior mediastinal mass mostly when it is very large (bulky disease) and produces mediastinal widening. It demonstrates tumour bulk and pleural effusion. Chest computed tomography (CT) scans are examined for precise tumour location, presence of necrosis, pulmonary parenchymal involvement, chest wall invasion, and more assessment of pleuropericardial effusion(14,15). Definitive diagnosis is achieved via biopsy and histopathological examination, and treatment begins after complete staging according to Ann Arbor classification.