Case Presentation: Patient is an 85-year-old woman with a history of CAD, AS s/p TAVR, HFrEF, HTN, HLD, hypothyroidism, LV thrombus, and COPD who presented with worsening dyspnea on minimal exertion for 1 week. Previously independent, her SOB had made it impossible to complete her ADLs. She was never a smoker and had no recent changes to her medications. She had no orthopnea, increased lower extremity swelling, chest pain, fever, cough, sick contacts, or recent travel. Labs were notable for a leukocytosis to 16 which was lymphocyte predominant, thrombocytopenia to the 70s-80s (baseline 90s-110s). Labs also notable for new mild transaminitis and elevated Pro-BnP. Chest X-ray revealed clear lungs. She was given IV furosemide, IV steroids and nebulized albuterol/ipratropium for presumed COPD exacerbation in setting of acute decompensated heart failure exacerbation. Given her initial CBC findings, a viral trigger to the COPD exacerbation was considered more likely.
She was maintained on therapy for COPD and heart failure for several days without significant improvement. CT chest was unremarkable except for old pulmonary nodules, unchanged in size. As part of her work up for the transaminitis, she underwent an abdominal US which demonstrated splenomegaly to 20.8cm (average normal size is 11cm). Viral studies including respiratory viral panel, HIV, hepatitis, and EBV were all negative. Given new splenomegaly, in combination with CBC findings and now smudge cells seen on peripheral smear, Hematology was consulted, and flow cytometry was sent. Flow returned positive for a B-cell lymphoma, later confirmed to be splenic marginal zone lymphoma on FISH and bone marrow biopsy.
Discussion: Splenic marginal zone lymphoma is a rare type of non-Hodgkin’s B-cell lymphoma. It is so rare, that it comprises <1% of all non-Hodgkin’s lymphomas. It occurs at a median age of 65-70, most common in Caucasians and without gender preference. Patients tend to present with massive splenomegaly with little or no lymphadenopathy as was seen in this patient. One-quarter of patients are asymptomatic, and the presence of B-symptoms is rare. Lymphocytosis is common, however, and cytopenias are seen in around 25% of patients which are usually the result of hypersplenism, as was the suspected cause of thrombocytopenia in this case. Most patients have an indolent course with median survival of around 10 years, however approximately 30% develop a more aggressive form with median survival of around 4 years. Given the indolent course, treatment is reserved for patients who are symptomatic from the splenomegaly and/or who have significant cytopenias. Treatment can be with rituximab or splenectomy.
Conclusions: Internists should readily consider alternative etiologies to dyspnea beyond pulmonary and cardiac. This patient’s progressive dyspnea was likely related to her worsening splenomegaly despite treatment for both heart failure and COPD, which led to her ultimate diagnosis of splenic marginal zone lymphoma.