How to improve histopathological results in the biopsy diagnosis of gut dysganglionosis

Abstract

In a methodological survey, the technical prerequisites for optimal histopathological diagnosis of gut dysganglionosis are presented. To make a proper diagnosis, the pediatric surgeon or gastroenterologist and the pathologist must consider certain preconditions. The most important steps for the optimal biopsy diagnosis of an aganglionosis, an ultrashort Hirschsprung segment, a intestinal neuronal dysganglionosis (IND), a ganglioneuromatosis, a hypogenesis, or immaturity of the vegetative gut innervation are: (1) taking 3–4 biopsies the size of a peppercorn (3–5 mm³) with submucosa; (2) the best instruments for taking rectal mucosal biopsies are forceps and scissors or a conventional large biopsy forceps; and (3) biopsies may be taken 1 cm, 3–4 cm, 6–9 cm, and 9–12 cm (or from a preternatural anus) above the pectinate line. A biopsy containing mucosa, muscularis mucosae, and submucosa guarantees a satisfying histopathological diagnosis. The native biopsies can be transported on water-ice if the distance to the pathologist takes no longer than 4–6 h. For long distances, biopsies have to be frozen on dry ice (CO₂ –80 °C) and transported in a sufficient amount of dry ice (adapted to the time of transportation). For biopsy processing, the following points are important: a total of 122 to 160 15-μm-thick native cryostat serial sections have to be cut per biopsy and distributed on four microscope slides. Forty sections are used for lactic dehydrogenase reactions, 32 for succinic dehydrogenase reactions, and the rest for an acetylcholinesterase (AChE) reaction. An AChE reaction alone is sufficient for the diagnosis of Hirschsprung's disease (HD), but never for IND or other developmental malformations of the submucous and myenteric plexuses. Enzymehistotopochemical reactions allow the assessment of functional parameters. These reactions, in contrast to immunohistochemical staining, offer information about the functional activity of special gut structures, e. g., increased AChE activity in nerve fibers of the rectal wall in HD or a lack of dehydrogenase activity in immature ganglia.