A 53-year-old man, who was normally well and had a known diagnosis of vitiligo, presented in the surgery, saying he had felt low for the past six months. He described early morning waking, decreased appetite, feelings of hopelessness, poor concentration, and lethargy and anhedonia. The onset of symptoms corresponded to a reduction in working hours and with a holiday looming he was increasingly anxious. The routine blood tests were undertaken to exclude thyroid disease. Results revealed an Hb of 4.7g/dl, with MCV 137fl while other initial tests were normal.

Subsequent vitamin B12 measurement was 30ng/l. What could be the most probable diagnosis for this condition? * This image based case is from Docplexus editorial team for educative purpose only. Source: Haymarket