Home > D. Systemic pathology > Genetic and developmental
anomalies > attenuated familial adenomatous polyposis
attenuated familial adenomatous polyposis  Saturday 1 December
2012  "attenuated FAP" (attenuated familial adenomatous
polyposis); AFAP phenotype  The concept that AFAP is invariably
characterized by less than 100 adenomas has been disputed
following the use of dye-spray during colonoscopy.  Four
subjects had a family history consistent with FAP but had less
than 20 adenomas on standard colonoscopy.  In each of the
subjects, the use of dye-spray highlighted over 1000 adenomas.
These were sufficiently large to be recognized and counted
within the subsequent colectomy specimen. In a more recent
series of genetically proven cases of AFAP, 12 of 24 subjects
with a formal polyp count had >100 adenomas, and 7 of these had
>500 adenomas.  While true AFAP does exist, these findings raise
the possibility that many cases of AFAP are in fact classical
FAP in which the majority of adenomas remain relatively sma