Immunohistochemical studies of pediatric intestinal pseudo-obstruction: bcl2, a valuable biomarker to detect immature enteric ganglion cells.

To identify the diagnostic pitfalls as well as the value of immunohistochemical studies in making a pathologic evaluation of a pediatric intestinal pseudo-obstruction (IPO), this study reassessed the pathology of 87 surgically resected intestines from 80 patients under the impression of IPO and 10 normal controls using immunohistochemical studies. The main diagnostic pitfall was the interpretation of the enteric nervous plexuses in the transitional zone and the detection of the indistinct or immature neurons indistinguishable from enteric glial cells or satellite cells. Immunohistochemical study was a very helpful diagnostic adjunct to delineating the immature neurons (bcl2), the size of the enteric ganglia and neuromuscular innervation (S-100 protein, synaptophysin, and CD56), and the interstitial cell of Cajal (c-Kit) and myopathy (SMA). With help of immunohistochemistry, our series of IPO could classify as neuropathy (92.5%), myopathy (2.5%), and the idiopathic forms (3.8%) more clearly. In terms of the types of neuropathy, Hirschsprung's disease (HD), pure hypoganglionosis, and intestinal neuronal dysplasia (IND-B) were diagnosed in 71.3%, 6.3%, and 48.8% of patients, respectively. IND-B was associated with other neuropathies, HD in 77.0% and hypoganglionosis in 7.7%, rather than being present in a pure form. Immature ganglion cells were found in 48.8%. Because a reduced number of interstitial cells of Cajal was commonly associated with HD in 84.2%, hypoganglionosis in 40%, and IND-B in 76.9% of cases, it might be a preceding or aggravating factor related to an IPO. In terms of detecting immature ganglion cells, we found bcl2 most helpful.