Clinical Laboratory Hematology 3rd Edition by Shirlyn McKenzie, Lynne Williams

Exercise 40

Kathy, a 36-year-old female, experienced a recent 35-lb weight loss. Her tongue was red and fissured. She also complained of chronic fatigue and shortness of breath upon exertion. Physical examination suggested signs of jaundice and increased numbness and a tingling sensation of fingers and toes. She was hospitalized with the general diagnosis of moderate anemia, jaundice, and neurological symptoms. Her admitting CBC demonstrated the following laboratory results:
The following abnormal erythrocyte morphology was reported:
Consider the reflex tests that might be important in identifying the etiology of this anemia.
Based on the initial CBC results, further testing was ordered with the following results:
Examination of a bone marrow aspirate revealed an erythroblastic hyperplasia with megaloblastic erythroblasts.
What further testing can be done to obtain a definitive diagnosis?