Abstract
Macrocytosis is relatively common and can be due to various etiologies. More common causes include vitamin B12/folate deficiency, liver disease, alcohol use, hypothyroidism, and myelodysplastic syndrome. A work-up often yields the etiology, but in some patients, it remains elusive. We present a case of a 75-year-old female with persistent and unexplained macrocytosis. A work-up for the common causes was unremarkable. However, she had a markedly elevated triglyceride level. This report implies a possible association between hypertriglyceridemia and macrocytosis. Further study is warranted to explore this relationship and red blood cell uptake of triglycerides.