Quantitation of cellular components of the enteric nervous system in the normal human gastrointestinal tract - report on behalf of the Gastro 2009 International Working Group

Background Patients with gastrointestinal neuromuscular diseases may undergo operative procedures that yield tissue appropriate to diagnosis of underlying neuromuscular pathology. Critical to accurate diagnosis is the determination of limits of normality based on the study of control human tissues. Although robust diagnostic criteria exist for many qualitative alterations in the neuromuscular apparatus, these do not include quantitative values due to lack of adequate control data. Purpose The aim of this report was to summarize all relevant available published quantitative data for elements of the human enteric nervous system (neuronal cell bodies, glial cells, and nerve fibers) from the perspective of the practicing pathologist. Forty studies meeting inclusion criteria were systematically reviewed with data tabulated in detail and discussed in the context of methodological variations and limitations. The results reveal a lack of concordance between observations of different investigators resulting in data insufficient to produce robust normal ranges. This diversity highlights the need to standardize the way pathologists collect, process, and quantitate neuronal and glial elements in enteric neuropathologic samples, as suggested by recent international guidelines on gastrointestinal neuromuscular pathology.