Intravascular B-cell lymphoma: case report of a rare cause of pulmonary arterial hypertension

Background: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease characterized by proliferation of malignant lymphoid cells within the small vessels of various organs resulting in diffuse thrombosis. It most commonly affects the central nervous system and the skin, but if it involves the pulmonary arteries it can cause acute severe pulmonary hypertension (PH) and right heart failure. Early diagnosis is essential as the clinical course is extremely aggressive. In this report, we present a case of rapidly progressive PH and subsequent right ventricular (RV) failure secondary to IVLBCL. We review the important differential diagnoses and diagnostic evaluation needed to make a correct and early diagnosis.

Case summary: A 53-year-old, previously healthy man developed 2 months of progressive shortness of breath. After being treated for presumptive pneumonia, he was admitted with hypoxic respiratory failure, altered mental status, and severe PH. He developed RV failure and subsequent liver failure. He was ruled out for pulmonary embolism. Despite aggressive management with inhaled nitric oxide and epoprostenol, inotropes, and continuous renal replacement therapy, the patient passed away. Post-mortem examination revealed the presence of IVLBCL with extensive involvement notable of the brain, heart, lungs, and pulmonary arteries.

Discussion: The acute development of severe PH and RV failure in the absence of pulmonary emboli is uncommon and represents a challenging diagnostic and management clinical scenario. When accompanied by altered mental status, constitutional symptoms and an elevated lactate dehydrogenase, clinicians should have a high index of suspicion for intravascular lymphoma, as early diagnosis is critical to maintain a reasonable chance of survival.