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Inciteful Med

Testing and Diagnosis: Understanding the Results

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The definitive way to diagnose Hirschsprung disease is through a rectal suction biopsy. Pathologists evaluate this tissue sample to confirm aganglionosis, which is a complete lack of nerve cells in the bowel. Specialized stains like Calretinin ensure an accurate diagnosis.

Key Takeaways

  • • A rectal suction biopsy is the gold standard test to definitively diagnose Hirschsprung disease.
  • • Contrast enemas and anorectal manometry are often used first to map out the affected bowel and check for normal reflexes.
  • • A positive diagnosis requires the pathology report to confirm aganglionosis, which means there are no nerve cells in the tissue sample.
  • • In the absence of normal nerve cells, the remaining nerve fibers often become abnormally thickened or hypertrophic.
  • • Specialized tissue stains like Calretinin and AChE provide the most accurate pathology results and prevent misdiagnosis.

Diagnosing Hirschsprung disease is a step-by-step process that moves from observing symptoms to confirming the exact biological makeup of the intestine. Because several conditions can cause severe constipation, doctors use a combination of imaging, pressure tests, and microscopic analysis to get a clear answer [1][2].

The Diagnostic “Roadmap”

Most children will undergo a series of tests to help the surgical team map out the affected area before any treatment begins.

1. Contrast Enema (Imaging)

A contrast enema is often the first step [1]. A special liquid that shows up on X-rays is gently placed into the rectum. Doctors look for a transition zone (TZ)—the point where the narrow, unrelaxed (aganglionic) part of the bowel meets the stretched-out, healthy part [3][4].

  • Note on Total Colonic Aganglionosis (TCA): In some newborns or children with TCA, the transition zone may not be visible on an X-ray [3][5]. Because the entire colon lacks nerve cells, it remains uniformly narrow and fails to show the classic “ballooning” or megacolon shape. This is why a “normal” looking X-ray does not completely rule out the disease.

2. Anorectal Manometry (Pressure Test)

This test measures how the muscles and nerves in the rectum respond to pressure [6]. A small balloon is inflated in the rectum to see if the internal anal sphincter relaxes.

  • Absent RAIR: In a healthy child, the reflex (called the Rectoanal Inhibitory Reflex or RAIR) causes the muscle to relax. In Hirschsprung disease, this reflex is absent—the muscle stays tight [6][7].
  • Accuracy: A normal RAIR result is almost 100% effective at ruling out Hirschsprung disease [6].

3. Rectal Suction Biopsy (The Gold Standard)

The only way to definitively diagnose Hirschsprung disease is with a rectal suction biopsy [8][2]. A small tool is used to take tiny samples of the inner lining of the rectum.

Understanding the Pathology Report

When the biopsy sample goes to a lab, a pathologist looks at it under a microscope. Here are the key terms you might see:

  • Aganglionosis: This is the hallmark of the disease. It means there are no ganglion cells (nerve cells) found in the sample [9][10].
  • Nerve Fiber Hypertrophy: In the absence of nerve cells, the remaining nerve fibers often become abnormally large or thick (greater than 40 micrometers) as they try to compensate [11][12].
  • Meissner and Auerbach Plexuses: These are the two layers of the “gut brain.” The biopsy must be deep enough to include the submucosal (Meissner) plexus to be considered accurate [1][13].
  • Hypoganglionosis: A related condition where nerve cells are present but in very low numbers [9].

The Importance of Advanced Staining

Standard “H&E” (Hematoxylin and Eosin) staining can sometimes make it hard to see tiny nerve cells. Specialized stains are much more accurate:

  • Calretinin (IHC): This is often preferred because it is very easy to read. If calretinin is present (positive), it means nerve cells are there and the child likely does not have Hirschsprung [14][15].
  • Acetylcholinesterase (AChE): This stain looks for overactive nerve fibers. A “positive” AChE stain (showing dark, thick fibers) supports a diagnosis [16][15].

Pathology Report “Completeness Checklist”

To ensure the most accurate diagnosis, ask if the report confirmed:

  1. Tissue Adequacy: Was enough submucosa collected to find nerve cells? [17]
  2. Staining Method: Was Calretinin or AChE used? [14][8]
  3. Presence/Absence of Ganglion Cells: Does the report state no ganglion cells were seen? [18]
  4. Nerve Size: Were the nerve fibers described as hypertrophic (thickened)? [12]

Once diagnosed, determining the length of the segment is the next step. See Subtypes, Genetics, and Family Risks.

Frequently Asked Questions

What is the transition zone on a contrast enema?
The transition zone is the point where the narrow, affected part of the bowel meets the healthy, stretched-out part. Identifying this zone on an X-ray helps doctors map out the area that lacks nerve cells.
What does an absent RAIR mean on an anorectal manometry test?
An absent Rectoanal Inhibitory Reflex (RAIR) means the rectal muscle stays tight instead of relaxing when pressure is applied. This lack of a normal reflex is a strong indicator of Hirschsprung disease.
What does aganglionosis mean on a pathology report?
Aganglionosis means there are completely no ganglion or nerve cells found in the biopsy sample. This complete absence of nerve cells is the hallmark feature required to officially diagnose Hirschsprung disease.
Why is a rectal suction biopsy required for diagnosis?
While imaging and pressure tests provide clues, a rectal suction biopsy is the only way to definitively diagnose the condition. It allows pathologists to look directly at the tissue under a microscope to confirm if nerve cells are missing.
Why are Calretinin or AChE stains used on the biopsy?
Standard tissue staining can make it difficult to see tiny nerve cells. Specialized stains like Calretinin and Acetylcholinesterase (AChE) make the nerve cells and fibers much easier to identify, leading to a highly accurate diagnosis.

Questions for Your Doctor

  • • Does the pathology report confirm 'aganglionosis,' and was the tissue sample deep enough to see the submucosal (Meissner) plexus?
  • • Was Calretinin or Acetylcholinesterase (AChE) staining used on the biopsy? If not, can these stains be added for a more accurate result?
  • • Did the biopsy show 'hypertrophic nerves'? How does the thickness of these nerves relate to the length of the affected bowel?
  • • On the contrast enema, where exactly is the 'transition zone' located? Does this match what you saw during the physical exam?
  • • If the anorectal manometry showed an absent RAIR, does that automatically mean it is Hirschsprung, or could it be an 'allied disorder' like hypoganglionosis?

Questions for You

  • • Has my child's doctor explained exactly where the nerve cells are missing in their colon?
  • • Do I have a copy of the pathology report to keep in my child's permanent medical records?
  • • Did the medical team mention if the biopsy results were 'definitive' or if they need to repeat the test due to an inadequate sample?
  • • Am I clear on the difference between the 'aganglionic' segment and the 'transition zone'?

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References

  1. 1

    Hirschsprung disease.

    Montalva L, Cheng LS, Kapur R, et al.

    Nature reviews. Disease primers 2023; (9(1)):54 doi:10.1038/s41572-023-00465-y.

    PMID: 37828049
  2. 2

    State of the Art Bowel Management for Pediatric Colorectal Problems: Functional Constipation.

    Bokova E, Svetanoff WJ, Rosen JM, et al.

    Children (Basel, Switzerland) 2023; (10(6)) doi:10.3390/children10061078.

    PMID: 37371309
  3. 3

    Atypical onset of total colonic Hirschsprung disease in a small female infant: A case report.

    Mărginean CO, Meliţ LE, Gozar H, et al.

    Medicine 2018; (97(38)):e12315 doi:10.1097/MD.0000000000012315.

    PMID: 30235683
  4. 4

    Development of Clinical Referral Score Model for Early Diagnosis of Hirschsprung's Disease in Suspected Pediatric Patients.

    Khorana J, Phiromkanchanasak P, Kumsattra J, et al.

    Healthcare (Basel, Switzerland) 2021; (9(6)) doi:10.3390/healthcare9060678.

    PMID: 34200020
  5. 5

    Barium enema findings in total colonic aganglionosis: a single-center, retrospective study.

    Yan J, Sun J, Wu R, et al.

    BMC pediatrics 2020; (20(1)):499 doi:10.1186/s12887-020-02403-3.

    PMID: 33126876
  6. 6

    Anorectal Manometry May Reduce the Number of Rectal Suction Biopsy Procedures Needed to Diagnose Hirschsprung Disease.

    Meinds RJ, Trzpis M, Broens PMA

    Journal of pediatric gastroenterology and nutrition 2018; (67(3)):322-327 doi:10.1097/MPG.0000000000002000.

    PMID: 29652729
  7. 7

    Can Propofol Be Used to Assess the Presence of the Rectoanal Inhibitory Reflex During Anorectal Manometry Studies?

    Arbizu RA, Amicangelo M, Rodriguez L, Nurko S

    Journal of pediatric gastroenterology and nutrition 2022; (74(1)):33-37 doi:10.1097/MPG.0000000000003283.

    PMID: 34478251
  8. 8

    Diagnosis of Hirschsprung Disease.

    Ambartsumyan L, Smith C, Kapur RP

    Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society 2020; (23(1)):8-22 doi:10.1177/1093526619892351.

    PMID: 31791203
  9. 9

    Rare Variant Hirschsprung Disease Presenting as Large Bowel Obstruction in Adulthood: Hypoganglionosis in the Anorectal Canal.

    Lee RY, Li H, White RV, et al.

    ACG case reports journal 2021; (8(5)):e00610 doi:10.14309/crj.0000000000000610.

    PMID: 34549071
  10. 10

    Causes and consequences: development and pathophysiology of Hirschsprung disease.

    Burns AJ, Goldstein AM

    World journal of pediatric surgery 2024; (7(4)):e000903 doi:10.1136/wjps-2024-000903.

    PMID: 39600627
  11. 11

    Morphometric profile of large intestinal neuronal plexuses in normal perinatal autopsies and Hirschsprung disease.

    Subramanian H, Badhe BA, Toi PC, Sambandan K

    Neurogastroenterology and motility 2017; (29(3)) doi:10.1111/nmo.12939.

    PMID: 27620161
  12. 12

    Submucosal Nerve Diameter in the Rectum Increases With Age: An Important Consideration for the Diagnosis of Hirschsprung Disease.

    Conces MR, Beach S, Pierson CR, Prasad V

    Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society 2022; (25(3)):263-269 doi:10.1177/10935266211049689.

    PMID: 34791945
  13. 13

    Aganglionosis with the absence of hypertrophied nerve fibres predicts disease proximal to rectosigmoid colon.

    Narayanan SK, Soundappan SS, Kwan E, et al.

    Pediatric surgery international 2016; (32(3)):221-6 doi:10.1007/s00383-015-3835-4.

    PMID: 26527582
  14. 14

    Hirschsprung Disease Diagnosis: Calretinin Marker Role in Determining the Presence or Absence of Ganglion Cells.

    Rakhshani N, Araste M, Imanzade F, et al.

    Iranian journal of pathology 2016; (11(4)):409-415.

    PMID: 28855933
  15. 15

    Clinical Relevance of Pathological Diagnosis of Hirschsprung's Disease with Acetylcholine-Esterase Histochemistry or Calretinin Immunohistochemistry.

    Romero P, Burger A, Wennberg E, et al.

    Children (Basel, Switzerland) 2024; (11(4)) doi:10.3390/children11040428.

    PMID: 38671645
  16. 16

    Reevaluation of concurrent acetylcholinesterase and hematoxylin and eosin staining for Hirschsprung's disease.

    Yoshimaru K, Matsuura T, Yanagi Y, et al.

    Pediatrics international : official journal of the Japan Pediatric Society 2021; (63(9)):1095-1102 doi:10.1111/ped.14596.

    PMID: 33417724
  17. 17

    Are We Underdiagnosing Hirschsprung Disease?

    Kapur RP, Ambartsumyan L, Smith C

    Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society 2020; (23(1)):60-71 doi:10.1177/1093526619889434.

    PMID: 31747832
  18. 18

    Anti-Glypican 3, a Novel Ancillary Maker in the Histological Assessment of Hirschsprung's Disease.

    Ludwig K, Volpe A, Guzzardo V, et al.

    Journal of pediatric gastroenterology and nutrition 2016; (62(5)):692-7 doi:10.1097/MPG.0000000000001020.

    PMID: 26513623

This page explains Hirschsprung disease diagnostic tests and pathology terminology for educational purposes. Always consult your child's pediatric gastroenterologist or surgeon to interpret specific test results.

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