Diagnostic challenges of hypoganglionosis based on immunohistochemical method

Background: Hypoganglionosis resembles Hirschsprung’s disease as in both diseases, patients may present with severe constipation or pseudo-obstruction. To date, diagnosis of hypoganglionosis is still difficult to be established due to lack of international consensus regarding diagnostic criteria. This study aims to evaluate the use of immunohistochemistry to provide objective support for our initial subjective impression of hypoganglionosis as well as to describe the morphological features of this study. Methods: This is a cross-sectional study. Three resected intestinal samples from patients with hypoganglionosis at Kyushu University Hospital, Fukuoka, Japan were included in this study. One healthy intestinal sample was used as control. All specimens were immunohistochemically stained with anti-S-100 protein, anti-α-smooth muscle actin (α-SMA), and anti-c-kit protein antibodies. Results: (I) S-100 immunostaining: hypoplasia of the myenteric ganglia and marked reduction of intramuscular nerve fibers were observed in several segments of the intestine. (II) α-SMA immunostaining: the pattern of the muscular layers was almost normal in all segments; however, some areas showed hypotrophy of the circular muscle (CM) layers and hypertrophy of the longitudinal muscle (LM) layers. (III) C-kit immunostaining: a decreased in the number of interstitial cells of Cajal (ICCs) was observed in almost all segments of the resected intestine, even around the myenteric plexus. Conclusions: Each segment of intestine in hypoganglionosis had different numbers of ICCs, sizes, and distributions of ganglions, as well as patterns of musculature, which may range from severely abnormal to nearly normal. Further investigations regarding the definition, etiology, diagnosis, and treatment of this disease should be performed to improve the prognosis of this disease.