Diagnostic Dilemma

An Unusual Thrombocytopenia

Presentation

An 86-year-old woman accompanied by her daughter presented to our hospital with epistaxis and melena for the past month but denied hemoptysis or hematemesis. The daughter reported that the patient has had multiple new bruises and petechiae on both of her arms during that time. The patient denied fevers, chills, night sweats, weight loss, and appetite changes.

Her past medial history included hypertension. She was otherwise healthy, lived alone, and cared for herself. She did not have regular

Assessment

The patient was well appearing with temperature of 37.2°C, pulse of 107 beats/min, respiratory rate of 21 breaths/min, and blood pressure of 166/69 mm Hg. Physical examination revealed mild increased work of breathing and diffuse ecchymosis on bilateral arms. Initial labs revealed a hemoglobin level of 5.2 g/dL with mean corpuscular volume of 81 f. and platelets of 2.0 K/mcL. Additional studies showed a fibrinogen level of 176 mg/dL, haptoglobin of 73 mg/dL, negative Direct Coombs antibody

Diagnosis

Waldenstrom macroglobulinemia is predominantly diagnosed in patients > 50 years of age with an incidence of approximately 1400 cases per year in the United States.¹ Classified as a non-Hodgkin lymphoma, Waldenstrom macroglobulinemia leads to abnormal proliferation of B lymphocytes producing paraprotein (IgM) that infiltrates the bone marrow, leading to cytopenias.² IgM paraprotein has been shown to have antiplatelet activity by interfering with fibrin monomer polymerization.³ This leads to

Management

The patient underwent two sessions of plasma exchange followed by initiation of definitive therapy with dexamethasone, rituximab, and cyclophosphamide. She had a rapid rise in her hemoglobin and platelet count by day 4 of treatment initiation. Her headaches resolved, and her other presenting symptoms subsided throughout the course of her hospitalization. She was discharged home with close oncologic follow up.

Acknowledgments

We thank Jeremiah Pasion, MD, for preparation of the bone marrow biopsy image shown in Figure 1.