A Novel Objective Pathologic Criterion for Isolated Hypoganglionosis

Isolated hypoganglionosis (IHG) is histologically characterized by small numbers of myenteric ganglion cells and small myenteric ganglia; however, no numerical diagnostic criteria for IHG have been established. Therefore, this study aimed to develop quantitative pathologic criteria for IHG. We evaluated 160 resected intestinal tissue specimens from 29 pediatric autopsies and 10 IHG cases. These specimens were obtained from the jejunum, ileum, ascending colon, transverse colon, and rectum. Morphologic features of the myenteric ganglion cells and myenteric ganglia were quantified and analyzed in digitized HuC/HuD-immunostained and CD56-immunostained sections, respectively. Quantitative criteria were developed with a scoring system that used parameters with the area under the receiver operating characteristic curve (AUC) values > 0.7 and sensitivity and specificity exceeding 70%. The selected parameters were the number of myenteric ganglion cells per cm and the number of myenteric ganglia with an area > 2500 µm²per cm. The score for each parameter ranged from −1 to 2, and the total score of the scoring system ranged from −2 to 4. With a cutoff value of ≥ 2 (AUC, 0.98; 95% CI: 0.96-1.00), the scoring system had a sensitivity of 96% (95% CI: 0.82-1.00) and a specificity of 99% (95% CI: 0.95-1.00). We devised a novel pathologic criterion based on the quantification of the number of myenteric ganglion cells and ganglia. Furthermore, this criterion showed high diagnostic accuracy and could lead to a definitive diagnosis of IHG in clinical practice.