Primary Mediastinal Large B-Cell Lymphoma in a Child Presenting With Superior Mediastinal Syndrome and Chylous Pleural and Pericardial Effusion

Chylotamponade in Pediatric Primary Mediastinal Large B-Cell Lymphoma

Chylotamponade involves rapid accumulation of chyle in the pericardium elevating the pericardial pressures above normal right heart filling pressures, and is extremely rare. A 12-y-old boy presented to the emergency with complaints of facial puffiness for 1 mo and breathing difficulty for 1 wk. The neck veins were distended, and the heart sounds were muffled. A chest CT demonstrated a large anterior mediastinal mass with pleural and pericardial effusions. Echocardiography confirmed cardiac tamponade. Pericardiocentesis revealed chylopericardium. He was placed on a chyle leak diet, and the drain was removed after 48 h. Biopsy of the mediastinal mass revealed a primary mediastinal B-cell lymphoma. He was successfully managed with chemotherapy. The index case demonstrates how prompt identification and management of chylotamponade and treatment of the underlying cause can lead to good clinical outcomes.

Primary Mediastinal B-Cell Lymphoma: Novel Precision Therapies and Future Directions

Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct clinicopathologic disease from other types of diffuse large B-cell lymphoma (DLBCL) with unique prognostic features and limited availability of clinical data. The current standard treatment for newly diagnosed PMBCL has long been dependent on a dose-intensive, dose-adjusted multi-agent chemotherapy regimen of rituximab plus etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH). Recent randomized trials have provided evidence that R-CHOP followed by consolidation radiotherapy (RT) is a valuable alternative option to first-line treatment. For recurrent/refractory PMBCL (rrPMBCL), new drugs such as pembrolizumab and CAR-T cell therapy have proven to be effective in a few studies. Positron emission tomography-computed tomography (PET-CT) is the preferred imaging modality of choice for the initial phase of lymphoma treatment and to assess response to treatment. In the future, baseline quantitative PET-CT can be used to predict prognosis in PMBCL. This review focuses on the pathology of PMBCL, underlying molecular basis, treatment options, radiotherapy, targeted therapies, and the potential role of PET-CT to guide treatment choices in this disease.