Rectal biopsy in type 4 glycogenosis. An ultrastructural cytochemical study.

Rectal biopsy material from a patient with type 4 glycogenosis was studied by ultrastructural cytochemical methods. The diagnosis of the disease was made on the basis of the patient's clinical history, the autopsy findings, and the histopathological features. Numerous large macrophages were observed in the rectal mucosa. They contained large vacuoles filled with filamentous material and small granules. This amylopectin was stained by the Thiery method (periodic acid-thiocarbohydrazide-silver proteinate) after 18 hours of exposure to thiocarbohydrazide; only 30 minutes was sufficient to demonstrate seemingly normal beta-glycogen particles in epithelial cells.