Objective:

To describe a case of B12 deficiency with an unclear initial workup.  

Background:

B12 deficiency is a commonly seen disorder which may present with a myriad of symptoms and neuro-imaging findings. These findings overlap with several other demyelinating and vitamin deficiency disorders making a thorough workup essential. This workup requires testing of several serum markers as well as neuro-imaging to rule out other etiologies of a patient’s symptoms. One such etiology of B12 deficiency is carcinoid syndrome related malabsorption of B12. Adding to the complexity this diagnosis can be a normal/elevated B12 level with an absence of any other clear diagnosis. 

Design/Methods:

Case Report

Results:

A fourty-two-year-old patient with carcinoid tumor presented to the hospital with progressive numbness over the previous two years. Workup demonstrated unimpressive CSF studies and serum workup, including an elevated B12 level. Neuro-imaging demonstrated no significant demyelinating findings but with abnormal edema signal with patchy enhancement predominantly in the dorsal columns of the ventral cervical spinal cord. Due to the lack of evidence supporting an alternative diagnosis along with classic MRI findings and a history of recent B12 supplemental injection, the patient was diagnosed with B12 deficiency and discharged home on B12 supplementation with close follow up. After follow up, the patient reported improvement of her symptoms with appropriate B12 supplementation.

Conclusions:

This case highlights the challenge that diagnosing progressive numbness attributable to B12 deficiency can present, along with the myriad of etiologies which may contribute to the diagnosis. It reinforces the importance of detailed history taking with regards to a patient’s medical history, such as carcinoid syndrome, and recent medications taken at home, like B12 injections, which may help delineate a diagnosis or have acutely normalized and hidden a chronic B12 deficiency.