Pancytopenia caused by unsuspected pernicious anemia complicating sickle cell beta-thalassemia.

We have described a a 23-year-old black woman with sickle cell beta-thalassemia who had a urinary tract infection and who was incidentally found to be pancytopenic. Although her anemia was categorized as "normocytic, normochromic" by an electronic particle counter, evaluation of the pancytopenia confirmed unsuspected pernicious anemia. Greater vigilance and a higher index of suspicion are crucial for early diagnosis of pernicious anemia in patients with other known hemoglobinopathies.