--show up on PET--the PET scans measure oxygen usage rates that would not necessarily be elevated/reduced in amyloid-containing tissues--but, possibly, some effects of amyloid in tissues might be interpretable by a savvy PET investigator. (I suspect that a lot of these potential effects could be explained by conditions that are far more common, though.)

It might be hard at this point to use the old lip biopsy samples to test for amyloid--generally a fat biopsy (stained with Congo Red, to reveal the monoclonal light protein chains) is considered a more sure way to go (although almost any body tissue can be examined). The reason fat biopsy is often preferred is that amyloid tends to congregate in extracelllular spaces and that is relatively easy to see when aspirating fat cells.

Amyloid--both the acquired and familial types--is very rare. One would think that there might have been some indication of it previously if it were there (though it is true that doctors don't think to test for it often). It can be associated with sicca syndrome, but there are a lot of other conditions--especially seronegative Sjogren's, which can also mimic the neuropathy of amyloid--that seem more likely at first thought.

Have you ever had an immunofixation electrophoresis of both serum and urine to check for M-proteins or Bence Jones protein fragments? Almost always people with acquried amyloid have some degree of monoclonal (M-protein) presence:

http://www.neuro.wustl.edu/neuromusc...er/amyloid.htm

As you may know, Kmeb is our resident expert on amyloid testing/biopsies (though to my knowledge she hasn't has a lip/salivary gland one done that looked for that specifically).

PM us, if you want, with other info you think is relevant.