Suction biopsy of rectal mucosa in the diagnosis of infantile and juvenile types of neuronal ceroid lipofuscinoses.

Rectal mucosa obtained by suction biopsy from 17 patients with infantile-type neuronal ceroid lipofuscinosis (NCL) and from 31 patients with juvenile-type NCL was studied histologically and electron microscopically. In specimens from both types of NCL the lamina propria of the mucosa contained abundant large macrophages, demonstrating positive histochemical reactions for ceroid and lipofuscin. On electron microscopy the macrophages were shown to be filled with cytosomes containing the storage material. In infantile NCL the storage material was amorphous and granular, with only occasional short membranous structures. In juvenile NCL the storage material formed approximately equal amounts of curvilinear profiles and fingerprint profiles. Typical inclusions were found in the capillary endothelial cells, Schwann cells, and smooth cells as well as in macrophages in both types of NCL. In two patients juvenile NCL was diagnosed from the biopsy before the appearance of any neurologic symptoms. It is concluded that morphologic investigation of the easily obtained rectal suction biopsy specimen is a reliable diagnostic method in these types of NCL. It is also useful in screening non-symptomatic patients at risk for NCL and in follow-up studies, when necessary.