I was able to find your question written for the first time in Feb. 2012 on another question board and on the same board in 2010 you posted that you had been having some trouble with your memory for the past couple of years.
You mention that you're a research student. I'm assuming that you've since finished being a "student" and perhaps now are a researcher?
There is no such anatomic entity in the brain called a "mammillary poly".
MRI's frequently show the presence of nasal polyps or MAXILLARY RETENTION POLYPS. Therefore, my guess is that the transcription of what should've been MAXILLARY turned into MAMMILLARY.
That is what you're looking at. As far as memory problems are concerned, obviously you've got a long history of feeling a memory problem.
If it has been stable for 11 years according to your posts then, I would not worry too much about thiamine deficiency
unless of course, you feel that ETOH use is excessive or there are other symptoms such as hallucinations
But I would say for the present you don't need to worry about thiamine deficiency based on the MRI report.
Hope I have answered your query. Let me know if I can assist you further.
Dr Dariush Saghafi, Neurologist