ACHE and Huntington disease: Paraffin embedded H&E stained section along with AChE histochemistry (done on part of the rectal biopsy which is kept frozen) as a double check, seems to be a perfect combination for making a conclusive diagnosis of HD, pre-operatively in the following scenario 1) Rectal biopsy taken from the correct site ie 2–3 cms above the pectinate line.