Palisading-like arrangement of immature ganglion cell in myenteric ganglia is a unique pathological feature of immaturity of ganglia.

• The presence of a normal number of immature ganglion cells indicates immaturity of ganglia. • A palisading arrangement of ganglion cells is a new pathological feature of immaturity of ganglia, which disappears once ganglion cells mature. Immaturity of ganglia (IG), an allied disorder of Hirschsprung disease (AD-HSCR), develops as neonatal ileus, but the dysmotility spontaneously resolves after several months. The diagnosis of IG using HE staining is often difficult. We herein report a new pathological finding of IG called the 'palisading-like pattern', which may be helpful for improving the diagnostic accuracy. Cases of IG that were managed over the past 28 years were retrospectively reviewed. We investigated the clinical course and pathological findings for Hematoxylin-Eosin (HE) staining. The conventional diagnostic criteria for IG were (1) a normal or slightly increased number of ganglion cells and (2) ganglion cells with small nuclei. Among the 155 cases, 28 were diagnosed with IG, and 10 were retrospectively confirmed by HE staining. A palisading-like pattern was confirmed at the time of the initial ileostomy (median age, 2.5 days), and the palisading-like pattern had completely disappeared by the time of stoma closure (median age, 215 days) in all 10 cases. A palisading-like pattern is not present in other diseases. Even if immunostaining data are not available for a further analysis, the detection of a palisading-like pattern on HE staining makes an accurate diagnosis possible. LEVEL IV. [ABSTRACT FROM AUTHOR]