Antiphospholipid antibodies in malignancy: are these pathogenic or epiphenomena?

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by arterial and venous thrombotic events associated with antiphospholipid antibodies. Antiphospholipid syndrome is commonly seen with collagen vascular diseases; however, other entities that can cause APS include chronic viral infections, certain medications, and malignancies. We present an interesting patient with an atypical presentation and course of presumed APS, which lead us to perform an exhaustive search for a secondary cause. The patient was ultimately found to have splenic marginal zone lymphoma. Analysis of the current data in the literature is presented for APS, antiphospholipid antibodies, and malignancy. Based on the literature findings and our experience, we recommend a thorough and repeated evaluation for an underlying malignancy in patients who have an atypical presentation and features of APS.