Challenges in the diagnosis of intestinal neuronal dysplasia type B: A look beyond the number of ganglion cells

Table 1 Comparison between Hirschsprung’s disease and intestinal neuronal dysplasia type B regarding the main clinical and histopathological aspects

	HD	IND-B
Histopathological findings on rectal biopsies	Absence of ganglion cells in the submucosal and myenteric plexuses	Hyperplasia of the submucosal nerve plexuses
Clinical Picture	Neonatal bowel obstruction or severe constipation	Neonatal bowel obstruction or severe constipation
Treatment	Surgical (colorectal pull-through)	Diet, laxatives, enemas or surgical (if complications)

HD: Hirschsprung’s disease; IND-B: Intestinal neuronal dysplasia type B.

Table 2 Summary of the histopathological criteria for the diagnosis of intestinal neuronal dysplasia type B

Diagnostic criteria	Definition
Frankfurt Consensus[32], 1990	Mandatory criteria	Submucosal plexus hyperplasia
		Increased activity of the AChE enzyme in nerve fibers around submucosal blood vessels
	Complementary criteria	Neuronal heterotopy
		Increased AChE activity in the lamina mucosa
Meier-Ruge et al[33], 2004	Quantitative criteria	At least 20% of giant nerve ganglia1 in the submucosa, in 25 submucosal ganglia
	Age criteria	Patients must be older than 1 yr

¹Giant nerve ganglia: A ganglion with more than eight ganglion cells.

AChE: Acetylcholinesterase.

Table 3 Immunohistochemical markers for the diagnosis of intestinal neuronal dysplasia type B

Immunohistochemical marker	Immunoexpression pattern
Bcl-2[54]	Positive expression in immature and mature ganglion cells
Calretinin[39,54]	Positive expression in mature ganglion cells in submucosal and myenteric plexuses
	Positive expression in intrinsic nerve fibers and ectopic neurons in the mucosa
c-kit[60-62]	Positive expression in Cajal cells in muscle layers and myenteric nerve plexuses
GAP43[63]	Absence of expression in muscularis mucosae and/or in the circular muscular and/or longitudinal muscular
	Positive expression in nerve plexuses
Hu C/D[38]	Positive expression in mature ganglion cells in submucosal and myenteric plexuses
NGF (mast cells)[64]	Expression of mast cells close to ganglia
NCAM (CD56)[60,61,63,65]	Positive expression in neurons of the muscular layers
	Variable expression in nerve fibers in muscle layers and mucosa
NO synthase[66]	Positive expression in ganglion cells
NSE[61]	Positive expression in nerve fibers in the muscle layers and mucosa
Peripherin[66,67]	Positive expression in ganglion cells
PGP9.5[60,68]	Positive expression in enlarged nerve trunks, hyperplastic nerve ganglia, and heterotopic nerve cells
	Positive expression in neurons of the inner intestinal muscle layer
PTEN[69]	Reduced expression in submucosal and myenteric nerve plexuses
RET[54,66]	Positive expression in mature and immature ganglion cells
S100[60,61,66]	Positive expression in ganglion cells
	Positive expression in nerve fibers in the muscular layers and mucosa
Synaptophysin[60,62,63,65,66,70]	Positive expression in synaptic vesicles in plexuses and nerve fibers
SMA (1a4)[61,71]	Positive expression in muscle fibers from muscular layers and muscularis mucosa
Sox10[46]	Positive expression in glial and ganglion cells in nerve plexuses

Bcl-2: B-cell lymphoma 2; c-kit: Transmembrane tyrosine kinase receptor; GAP43: Growth associated protein 43; Hu/CD: RNA binding protein Hu (HuC and HuD) - also referred to as type-1 anti-neuronal nuclear antibodies (ANNA-1); NGF: Nerve growth factor; NCAM: Neural cell adhesion molecule; NO: Nitric oxide; NSE: Neuron-specific enolase; PGP9.5: Protein gene product 9.5; PTEN: Phosphatase and tensin homologue deleted on chromosome 10; RET: Rearranged during transfection - immunohistochemical detection of RET proto-oncogene; SMA: Smooth muscle antibody; Sox10: SRY-box transcription factor 10.