Diagnosis of hirschsprung disease using the rectal biopsy: multi-institutional survey

Hirschsprung disease

Hirschsprung disease (HSCR) is a rare congenital intestinal disease that occurs in 1 in 5,000 live births. HSCR is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the intestine. Most patients present during the neonatal period with the first meconium passage delayed beyond 24 h, abdominal distension and vomiting. Syndromes associated with HSCR include trisomy 21, Mowat-Wilson syndrome, congenital central hypoventilation syndrome, Shah-Waardenburg syndrome and cartilage-hair hypoplasia. Multiple putative genes are involved in familial and isolated HSCR, of which the most common are the RET proto-oncogene and EDNRB. Diagnosis consists of visualization of a transition zone on contrast enema and confirmation via rectal biopsy. HSCR is typically managed by surgical removal of the aganglionic bowel and reconstruction of the intestinal tract by connecting the normally innervated bowel down to the anus while preserving normal sphincter function. Several procedures, namely Swenson, Soave and Duhamel procedures, can be undertaken and may include a laparoscopically assisted approach. Short-term and long-term comorbidities include persistent obstructive symptoms, enterocolitis and soiling. Continued research and innovation to better understand disease mechanisms holds promise for developing novel techniques for diagnosis and therapy, and improving outcomes in patients.

A new systematization of histological analysis for the diagnosis of Hirschsprung's disease

BACKGROUND

Hirschsprung's Disease (HD) is characterized by intestinal sub-occlusion and the absence of enteric ganglion cells. A rectal biopsy examination is performed to confirm the diagnosis. In a recent study, we demonstrated that the analysis of 60 sections of rectal mucosa and submucosa stained by H&E may ensure a 90% diagnostic accuracy. Although the need to analyze so many sections makes the process of reading the slides more time-consuming, this encouraged us to study their distribution in the healthy rectal submucosa, to simplify the diagnosis.

OBJECTIVES

To develop a method that facilitates HD diagnosis by studying the distribution of ganglion cells in the submucosal plexus.

METHODS

Using the calretinin technique, we studied the distribution of plexuses in 60 fragments of rectal submucosa from 19 cadavers. After the study, the reading method created was used for diagnosis in 47 cases of suspected HD, using H&E staining. The accuracy was verified by comparing the results obtained with H&E to those obtained with the acetylcholinesterase technique, the golden standard in our laboratory.

RESULTS

The study of submucosal plexus distribution showed that just by examining the submucosal region every 20 µm, approximately, it is possible to locate a ganglionic plexus, and we have already been able to diagnose HD with 93% accuracy.

CONCLUSION

The study of ganglion cell distribution enabled the creation of a simplified method for reading the slides. The method applied achieved good accuracy and it can be used as an alternative method in HD diagnosis.

Hirschsprung Disease for the Practicing Surgical Pathologist

OBJECTIVES

Hirschsprung disease (HD) is a congenital condition defined by the absence of ganglion cells in the distal-most portion of the gastrointestinal tract. Biopsies and resections for HD can be adrenaline inducing for the general surgical pathologist because specimens are infrequent; HD is 1 of only a few neuroanatomic diseases that general surgical pathologists diagnose; numerous preanalytic factors (eg, biopsy adequacy, surgeon sampling protocol, processing artifacts) can affect histologic interpretation; and most importantly, the diagnosis has high stakes.

METHODS

We provide a comprehensive overview of the background, relevant clinical procedures, and pathologic assessment of HD. Grossing and frozen section protocols, an algorithmic approach to diagnosis, and histologic pearls and pitfalls are also discussed.

RESULTS

Evaluation and recognition of the features of HD have evolved significantly in the past 2 decades with the discovery of the value of calretinin immunohistochemistry in the late 2000s and the recent development of straightforward and reproducible histologic criteria for identification of the HD transition zone.

CONCLUSIONS

These advancements have substantially improved the pathologist's ability to reliably evaluate for HD. Nonetheless, as with any high-stakes surgical pathology specimen, clear communication with the clinical team is essential.

Children with Hirschsprung disease in a developing country: A cohort study of the predictors of a positive rectal biopsy result

Chronic constipation, which may be habitually or pathologically caused, is one of the most common complaints in children. One of the important pathological causes is Hirschsprung's disease (HD), which is diagnosed via multiple modalities, mainly rectal biopsy. Our aim was to compare the presentation and different predictive factors for positive rectal biopsy results in a developing country in the Middle East, such as Jordan. This cohort study was conducted at the Jordan University Hospital (JUH). All consecutive children aged <14 years who presented with refractory constipation and underwent rectal biopsies between January 2014 and December 2019 were retrospectively enrolled in the study. In the entire cohort study, 79 patients were enrolled: 45 (57%) were males and 34 (43%) were females. Regarding the biopsy results, 51 (64.6%) cases of refractory constipation without HD and 28 (35.4%) patients with refractory constipation with HD were diagnosed with open rectal biopsies. The male-to-female ratio of HD patients was 3:1. Moreover, 3 (10.7%) children who passed the meconium within the first 24 to 48 hours showed features of HD, while 17 (60.7%) children with delayed passage of the meconium showed features of HD. Abdominal distension was found to be a positive predictor of positive biopsy results (odds ratio [OR] = 4.09, P = .011), and soiling was found to be a negative predictor of positive biopsy results (OR = 0.07, P = .024). In developing countries, children presenting with HD seem to have similar symptoms and signs to those observed with traditional sampling and staining techniques.

Increasing Trend of Calretinin-Positive Mucosal Innervation from Aganglionic Zone toward Transition Zone in Hirschsprung's Disease

INTRODUCTION

 Diagnosis of very short-segment Hirschsprung's disease (vsHD) by rectal suction biopsy is challenging as its aganglionic zone (AZ) overlaps with physiologic hypoganglionic zone and calretinin-positive mucosal nerves may extend from the transition zone (TZ) into AZ. We studied whether an increasing trend/gradient of calretinin-positive mucosal nerves along the distance from AZ toward TZ aids in diagnosis of HD.

MATERIALS AND METHODS

 In this study, 46 rectal suction biopsies from non-HD and HD, and 15 pull-through specimens from short-segment HD were evaluated by mucosal calretinin immunostain (CI) and image processing and analysis (IPA) to measure pixel count (PC, the percentage of calretinin stained pixels in the mucosa). Consecutive longitudinal sections of proximal AZ toward distal TZ in HD pull-through specimens were utilized as a vsHD surrogate model. First, we studied variability of mucosal CI in non-HD biopsies along the distance from dentate line. Second, we determined a cutoff point of mucosal CI by IPA that separated non-HD versus HD and applied this cutoff to longitudinal sections from proximal AZ to distal TZ segments in HD pull-through specimens. Third, we studied whether an increasing trend of mucosal CI was universally observed in HD pull-through.

RESULTS

 Our findings included a significant variability in PC along the biopsy distance in non-HD cases. Positive mucosal CI was found in proximal AZ in 6 (43%) of 14 HD pull-through, among which 1 case lacked submucosal nerve hypertrophy in the proximal AZ. All 14 HD pull-through cases showed an increasing trend/gradient of PC from AZ toward TZ.

CONCLUSION

 Based on our findings, the presence or absence of mucosal CI positivity and submucosal nerve hypertrophy may not reliably diagnose vsHD in rectal suction biopsy. While we acknowledge that the density of mucosal innervation in variable contexts and anatomical locations is unknown and yet to be explored, our study suggests that an increasing trend of positive mucosal CI from AZ toward TZ by IPA might prove to be a useful tool for the diagnosis of vsHD in the future.

Initial experience with per-rectal endoscopic myotomy for Hirschsprung's disease: medium and long term outcomes of the first case series of a novel third-space endoscopy procedure

INTRODUCTION

Hirschsprung's disease (HSCR) is congenital aganglionosis affecting the hindgut and presents with constipation. Surgical pull-through is the current standard treatment but causes morbidity. Per-rectal endoscopic myotomy is a novel third-space endoscopy technique for treating short-segment (SS)-HSCR.

METHODS

Retrospective study of SS-HSCR patients diagnosed on history, contrast enema, rectal biopsies, and anorectal manometry, and treated by PREM. The aganglionic segment was mapped before PREM was performed using third-space endoscopy principles. Stool frequency and laxative usage before and after PREM were compared.

RESULTS

Nine patients (age 7.5 [± 5.2] years; 7 male) underwent PREM during a 4-year period. Mean aganglionic segment length was 6.3 cm, mean procedure time 96.1 minutes, and mean length of hospital stay 2.5 days. Median follow-up was 17 months (range 9-58 months). Stool frequency was 1/4.4 days before vs. 1/1.2 days after PREM (P = 0.0004). Mean laxative usage was 5.4 units of laxative (UL) before vs. 0.4 UL after PREM (P = 0.0002). No laxatives were used by 6/9 patients after PREM. The single adverse effect seen (anal stenosis) was treated with dilatation.

CONCLUSIONS

PREM is a safe and effective minimally invasive procedure to treat SS-HSCR and results in long-term response.

Rectal Biopsy Technique for the Diagnosis of Hirschsprung Disease in Children: A Systematic Review and Meta-Analysis

ABSTRACT

The diagnosis of Hirschsprung disease (HD) depends on the histopathological analysis of rectal biopsies. This review aims to define the best rectal biopsy technique. A systematic literature review and proportional meta-analysis of the available case series studies of rectal biopsies were performed in this study. All case series with more than five rectal biopsies in children younger than 18 years of age suspected of HD that described at least one type of rectal biopsy were included. The studies that did not specify the rate of conclusive results and the rate of complications of the biopsy procedures were excluded. According to the literature review, there were four different techniques of rectal biopsy: open, suction, punch, and endoscopic. In the title and abstract screening process, we assessed 496 articles, 159 fulfilled the eligibility criteria, and 71 studies reported our outcomes of interest and were included in the meta-analysis. The pooled proportion of conclusive results was 94% in open biopsies (95% CI 0.89-0.98), 95% in punch (95% CI 0.90-0.98), and 88% in suction group (95% CI 0.85-0.92). The pooled proportion of complication rates was 2% in open biopsies (95% CI 0.00031-0.04), 0.039% in suction (95% CI 0.00023-0.0006), and 2% in punch biopsies (95% CI 0.00075-0.04). Suction, punch, and open techniques presented comparable rates of conclusive results. In the suction group, the association between different methods of histopathological analysis increased conclusive results rates; however, the punch biopsy was associated with significantly higher complication rates than the suction technique.

Diagnostic Algorithm in Hirschsprung's Disease: Focus on Immunohistochemistry Markers

BACKGROUND/AIM

Hirschsprung disease (HD) is caused by the congenital absence of ganglion cells in the distal bowel (aganglionosis). Rectal biopsy is considered important for its diagnosis. The aim of this study was to apply immunohistochemical staining using a minimal set of antibodies and develop an algorithm that will assist in the diagnosis of HD.

PATIENTS AND METHODS

Rectal or colonic biopsies were performed in patients with HD (n=26) or patients treated for other bowel diseases (n=34). Immunohistochemical staining was performed for MAP1b, peripherin, S-100, calretinin, NSE, bcl-2 and CD56 proteins.

RESULTS

Staining for CD56, S-100, peripherin and calretinin facilitated the identification of ganglion cells. The use of CD56 and S-100 antibodies together resulted in the highest rate of ganglion cell staining intensity (94%).

CONCLUSION

We propose a practical diagnostic algorithm with the application of CD56 and S-100 antibodies that can be used in clinical practice in children suspected of Hirschsprung's disease.

PHOX2B Immunostaining: A Simple and Helpful Tool for the Recognition of Ganglionic Cells and Diagnosis of Hirschsprung Disease

Hirschsprung disease (HD) is a congenital disorder of the enteric nervous system that occurs in ∼1 in 5000 live births. It is characterized by the absence of ganglionic cells (GCs) in the distal intestine. The diagnosis relies on the thorough analysis of a rectal suction biopsy (RSB), which must show a complete absence of GCs after careful examination of at least 100 serial sections. Such a negative characteristic explains the difficulty of this diagnosis. Moreover, GCs may be immature in very young or preterm born children, making them hard to recognize. Therefore, ancillary techniques have been developed as diagnostic help, such as acetylcholinesterase histochemistry and calretinin immunostaining. These techniques reveal only indirect clues, focusing mainly on the changes in nerve fibers, but not on GCs themselves. As PHOX2B has been shown to be a very specific transcription factor in GCs and in progenitor enteric nerve cells, we have assessed (i) PHOX2B immunostaining in immature enteric ganglia and (ii) the use of PHOX2B immunostaining for the recognition of GCs on RSBs for suspicion of HD. We have observed PHOX2B expression in all GCs, both mature and immature, and its complete absence in Hirschsprung cases. We suggest that the use of PHOX2B immunostaining is of great help (i) in the recognition of GCs on RSBs regardless of their differentiation and therefore (ii) in the diagnosis of HD.

Comparison of inconclusive rates between suction rectal biopsy and open strip rectal biopsy in children of different age groups: a single-center retrospective study

Background

Rectal biopsy for the diagnosis for Hirschsprung's disease (HD) can be performed in several ways. Suction rectal biopsy (SRB) is the most widely used method for neonates and younger infants while open strip biopsy (OSB) is reserved for older children. Current notions suggest that SRB should not be used in older infants due to perceived thicker fibrous tissue in their rectal walls leading to higher rates of inconclusive results. This study aims to compare the inconclusive rates of both methods in children of different age groups.

Methods

A retrospective study were carried out with patients aged 13 years who underwent SRB or OSB during a 4-year period in a single center. Rectal biopsies were performed on patients with HD with previous endorectal pull-through surgeries excluded. Primary outcomes were rates of inconclusive results for SRB and OSB overall and when divided into different age groups.

Results

79 biopsies (57 SRB and 22 OSB) were included in the study. 12 biopsies (9 SRB and 3 OSB) were deemed inconclusive. There was no significant difference in the rate of inconclusive results between patients underwent SRB and OSB overall (15.8% vs 13.6%, p=1.000). The same results were obtained when patients were divided into under one year and over one year groups or other different age groups (30.0% vs 33.3%, p=1.000).

Conclusions

Despite low biopsy numbers, our study suggests that SRB provides comparable rates of inconclusive results with OSB in children of all age groups.

Are We Underdiagnosing Hirschsprung Disease?

Hirschsprung disease (HSCR) is conventionally defined as aganglionosis of the distal rectum and a variable length of proximal contiguous bowel with a transition zone of ganglionic, but neuroanatomically abnormal, bowel located immediately upstream. Recent improvement in our understanding of the pathology and genetics of HSCR and relevant animal models indicates highly variable expressivity. The spectrum of intestinal neuropathology includes patients with very short-segment aganglionosis, limited to the distal 1 to 2 cm of the rectum, and possibly patients with no true aganglionic segment, but nonphysiological transition zone pathology in their distal rectums. The presence or absence of submucosal ganglion cells in a rectal biopsy is not sufficient to exclude these patients, in whom submucosal nerve hypertrophy and/or abnormal cholinergic mucosal innervation may be the only diagnostic clues. In addition, diagnosis or exclusion of HSCR by rectal biopsy now relies in part on mucosal patterns of calretinin immunohistochemistry, with less emphasis on submucosal tissue adequacy and assessment of cholinergic innervation. These recent trends in the surgical pathology approach to rectal biopsies may miss patients at the phenotypically milder end of the malformation spectrum, with profound implications for subsequent management, prognosis, and genetic counseling.

Diagnosis of Hirschsprung Disease

Diagnosis or exclusion of Hirschsprung disease (HSCR) is a frequent exercise in any pediatric hospital. Although HSCR may present at different ages and with varied clinical findings, the most common presentation is a neonate with severe constipation or signs of intestinal obstruction. A variety of diagnostic tests including contrast enema and anorectal manometry may be used as diagnostic screens, but diagnosis ultimately rests upon histopathological evaluation of a rectal biopsy. For the experienced pathologist, conventional hematoxylin-and-eosin-stained sections often suffice to exclude HSCR or establish the diagnosis. However, ancillary diagnostic tests such as acetylcholinesterase histochemistry or calretinin immunohistochemistry are complementary and extremely helpful in some cases. In this Perspectives article, we review the clinical and pathological features of HSCR, highlight those that are found in most patients, and discuss how to address particularly challenging aspects of the diagnostic workup.

Error traps and culture of safety in Hirschsprung disease

Hirschsprung disease affects many children every year around the world. Currently, there is an extensive menu of diagnostic methods, and surgical treatments. This situation compels the physicians to follow the rationale of these interventions. The comprehensive diagnosis and treatment of Hirschsprung disease need singular procedures. The clear understanding of how to perform each of these techniques, as well as to read the results is mandatory. Otherwise, the medical team may perform unconscious errors and fall into traps. Many errors still happen in patients with Hirschsprung, resulting in a spectrum of problems; from delayed diagnosis to unnecessary colectomies. In other patients, the damage to the anal canal results in fecal incontinence. When this is established, it is an unreversed and devastating social problem. This article describes why these errors occur and how to prevent them.

Digital pathology imaging and computer-aided diagnostics as a novel tool for standardization of evaluation of aganglionic megacolon (Hirschsprung disease) histopathology

Based on a recently introduced immunohistochemical panel (Bachmann et al. 2015) for aganglionic megacolon (AM), also known as Hirschsprung disease, histopathological diagnosis, we evaluated whether the use of digital pathology and 'machine learning' could help to obtain a reliable diagnosis. Slides were obtained from 31 specimens of 27 patients immunohistochemically stained for MAP2, calretinin, S100β and GLUT1. Slides were digitized by whole slide scanning. We used a Definiens Developer Tissue Studios as software for analysis. We configured necessary parameters in combination with 'machine learning' to identify pathological aberrations. A significant difference between AM- and non-AM-affected tissues was found for calretinin (AM 0.55% vs. non-AM 1.44%) and MAP2 (AM 0.004% vs. non-AM 0.07%) staining measurements and software-based evaluations. In contrast, S100β and GLUT1 staining measurements and software-based evaluations showed no significant differences between AM- and non-AM-affected tissues. However, no difference was found in comparison of suction biopsies with resections. Applying machine learning via an ensemble voting classifier, we achieved an accuracy of 87.5% on the test set. Automated diagnosis of AM by applying digital pathology on immunohistochemical panels was successful for calretinin and MAP2, whereas S100β and GLUT1 were not effective in diagnosis. Our method suggests that software-based approaches are capable of diagnosing AM. Our future challenge will be the improvement of efficiency by reduction of the time-consuming need for large pre-labelled training data. With increasing technical improvement, especially in unsupervised training procedures, this method could be helpful in the future.

Diagnostic Accuracy of Combined Acetylcholinesterase Histochemistry and Calretinin Immunohistochemistry of Rectal Biopsy Specimens in Hirschsprung's Disease

BACKGROUND

Acetylcholinesterase (AchE) histochemistry has been established as an accurate diagnostic tool for Hirschsprung's disease (HD). In addition, calretinin immunohistochemistry is also reported as a reliable and adjunctive method to diagnose HD. We investigated the diagnostic value of combined AchE histochemistry and calretinin immunohistochemistry in rectal suction biopsies from HD and non-HD patients.

METHODS

We retrospectively reviewed 99 rectal suction biopsy specimens including 4 repeat biopsies from 95 patients (34 HD and 61 non-HD). Each specimen was evaluated with hematoxylin-eosin, AchE histochemistry, and calretinin immunohistochemistry.

RESULTS

Of 95 patients, only 21 (22.1%) showed some ganglion cells. All 61 non-HD cases revealed no abnormal AchE-positive fibers. Of 34 HD patients, 32 exhibited abnormal AchE fibers, but 2 showed no stained fibers. None of the tissues from the HD patients exhibited calretinin immunoreactivity. Test sensitivity and specificity of AchE histochemistry alone were 93.5% and 100.0%, respectively, while calretinin immunohistochemistry were 100.0% and 85.2%, respectively.

CONCLUSIONS

AchE histochemistry is a good diagnostic method for HD, if feasible, and a combination of AchE histochemistry and calretinin immunohistochemistry will help increase the accuracy of the diagnosis of HD.

Utility of Peripherin Versus MAP-2 and Calretinin in the Evaluation of Hirschsprung Disease

Hirschsprung disease (HD) is a congenital malformation resulting from the lack of migration of ganglion cells in the colon. The absence of ganglion cells in rectal suction biopsies aids in diagnosis, but evaluation of these small biopsies can be difficult. In this study, we compare the microtubule-associated protein-2 (MAP-2), calretinin, and peripherin immunohistochemical stains in 237 selected biopsies performed to rule out HD. By H&E stain, a total of 78 biopsies had ganglion cells, whereas 83 biopsies had no ganglion cells, and an additional 76 biopsies were equivocal for ganglion cells. Of the 78 biopsies with ganglion cells, MAP-2 was positive in 73 (94%), calretinin in 76 (97%), and peripherin in 78 (100%). Of the 83 biopsies with no ganglion cells, calretinin and peripherin highlighted nerve fibrils and ganglion cells, respectively, in 3 biopsies, whereas MAP-2 was positive in only 1 biopsy. Of the 76 biopsies equivocal for ganglion cells, 16 cases were positive by all 3 stains, an additional case by both calretinin and peripherin, and 2 cases by peripherin only. All of the newly positive biopsies were from patients without HD. This study demonstrates that peripherin is superior in helping to rule out HD in these small biopsies, highlighting ganglion cells in virtually all cases with ganglion cells, whereas MAP-2 and calretinin are less sensitive for identification of ganglion cells and nerve fibrils, respectively. In patients with HD, a panel using calretinin and peripherin with or without MAP-2 may be most helpful in identifying transition zones.

Rectal Suction Biopsy in Patients With Previous Anorectal Surgery for Hirschsprung Disease

OBJECTIVES

The aim of the study was to determine rates of histologically positive, negative, and inconclusive rectal suction biopsies in post-pull-through patients with Hirschsprung disease evaluated for potential residual aganglionosis at our institution and to determine how patients were managed after a post-pull-through rectal suction biopsy.

METHODS

Thirty-nine post-pull-through suction biopsies from our institution were reviewed. Samples, stained with H&E and often acetylcholinesterase and/or calretinin, were categorized as "histologically" positive, negative, or inconclusive for aganglionosis. Subsequent clinical action was categorized as bowel resection, no further procedure, or rebiopsy. Agreement between histologic diagnosis and clinical action was assessed.

RESULTS

Histologically, all biopsies were inconclusive (46%) or negative (54%) for residual aganglionosis. Postbiopsy clinical action included redo pull-through (5%), no further procedure (59%), or rebiopsy (36%). Rebiopsy was sought in 2 of 21 histologically negative patients and in only 12 of 18 histologically indeterminate patients. Eventual redo pull-through procedures in 6 of 39 patients showed 4 with residual aganglionosis and 2 with abnormalities suggesting residual "transition zone."

CONCLUSIONS

Our findings show that suction biopsy after pull-through was frequently histologically indeterminate and never definitively positive for residual aganglionosis. When biopsy was histologically indeterminate, rebiopsy was pursued less commonly than may be expected. Our findings emphasize that suction biopsy examination is not a "criterion standard" for residual aganglionosis, but instead a component of a diagnosis that ultimately combines clinicopathologic factors, the constellation of which can sometimes spare patients from a more invasive full-thickness biopsy.

Choline Transporter Immunohistochemistry: An Effective Substitute for Acetylcholinesterase Histochemistry to Diagnose Hirschsprung Disease With Formalin-fixed Paraffin-embedded Rectal Biopsies

Acetylcholinesterase enzymatic histochemistry (AChE EHC), which highlights abnormal cholinergic nerves in the mucosa of aganglionic bowel, has been used for decades to evaluate rectal biopsies for Hirschsprung disease (HSCR). While useful diagnostically, AChE EHC is not compatible with conventional formalin-fixed and paraffin-embedded (FFPE) tissues and is not widely available. The choline transporter (ChT) is a putative alternative marker of cholinergic nerves. ChT immunohistochemistry (IHC) was investigated using FFPE biopsies and resections from patients with confirmed HSCR, as well as appropriate non-HSCR controls. ChT immunostaining was effective at identifying cases with HSCR and qualitatively similar to AChE EHC on frozen section. Among 3 pathologists, the diagnostic positive and negative predictive values based on ChT IHC ranged from 0.84-0.94 and 0.85-0.89, respectively, with good inter-observer agreement (Cohen kappa = 0.70-0.90). ChT IHC was useful in unusual scenarios in which calretinin (CR) IHC failed to correctly identify patients with HSCR. In 10 cases of short-segment HSCR, abnormal ChT+ mucosal innervation was present through the entire aganglionic segment and into portions of the TZ with submucosal nerve hypertrophy. In contrast, mucosal CR IHC was retained in the TZ and adjacent aganglionic bowel, which could lead to misinterpretation of a biopsy as ganglionic bowel. Indeed, 6 such patients were identified with paradoxical CR-positive mucosal innervation in their diagnostic biopsies. ChT IHC was interpreted as unequivocal HSCR in these cases, and HSCR was confirmed on resection. In summary, ChT IHC in FFPE tissue demonstrates high positive and negative predictive values for HSCR, is superior to CR IHC in a subset of cases, and can be incorporated into routine practice without the need for specialized techniques.

Current practice patterns of rectal suction biopsy in the diagnostic work-up of Hirschsprung's disease: results from an international survey

PURPOSE

The diagnosis of Hirschsprung's disease (HD) was revolutionized by the introduction of rectal suction biopsy (RSB), allowing specimens to be taken without general anesthesia on the ward or as an out-patient procedure. However, insufficient tissue samples are not uncommon, and subsequently histopathologists often remain reluctant to confirm the presence or absence of enteric ganglion cells merely on the basis of submucosal RSBs. The aim of this study was to evaluate the current usage of RSB in the diagnostic work-up of HD based on an international survey.

METHODS

A 15-item questionnaire was distributed among participants and faculty members at the 21st International Meeting of the Pediatric Colorectal Society.

RESULTS

Eighty-seven pediatric surgeons from 30 countries completed the anonymous survey (response rate 70.2 %), grouped into 68 (78.2 %) staff surgeons and 19 (21.8 %) trainees, with a median work experience of 18 years (range 2-45 years). Of these, 74 (85.1 %) use RSB in the diagnostic work-up of patients with suspected HD, whereas 13 (14.9 %) prefer open full-thickness biopsy under general anesthesia. In total, 47 (63.5 %) respondents perform ≥20 RSBs (range 3-100 RSBs) per year. Five different RSB instruments were reported, the most common ones being rbi2 (65.0 %), Solo-RBT (15.0 %) and multipurpose suction biopsy kit (8.3 %). Only 22 (29.7 %) of the respondents use a defined negative suction pressure, with a median of 10 mL air (range 6-25 mL air). The most proximal reported biopsy site was located at a median of 2 cm (range 1-15 cm) above the pectinate line and a median of 2 (range 1-5) specimens are routinely taken, mainly from the posterior rectal wall. Insufficient tissue samples with need for repeat RSB were encountered in a median of 10 % (range 0-40 %). Most frequently used staining methods for rectal biopsies are hematoxylin/eosin (75.9 %), acetylcholinesterase (73.6 %), and calretinin (33.3 %). Overall, 36 (48.6 %) respondents had experienced RSB-related complications, including self-limiting rectal blood loss (n = 28), persistent rectal bleeding requiring blood transfusion (n = 9) and rectal perforation requiring surgical intervention (n = 7).

CONCLUSIONS

Although RSB is considered to be today's gold standard for the diagnosis of HD, many aspects of its current usage are lacking consensus. Therefore, a prospective multi-center study or larger global audit appears warranted to identify if the present survey reflects common surgical practice and to establish universal standards for RSB.

Rectal biopsy for Hirschsprung's disease: a review of techniques, pathology, and complications

BACKGROUND

Hirschsprung's disease (HD) is one of the most common congenital anomalies of colorectal function, affecting approximately 1 in 5000 live births, with a 4:1 male predominance. HD is characterized by aganglionosis that is most often limited to the rectosigmoid, but can extend proximally along the colon and, in rare instances, reach into the small intestine. A clinical history of delayed passage of meconium beyond 48 hours after birth, physical exam findings of abdominal distention and vomiting, and a contrast enema demonstrating a transition zone are highly suggestive of HD.

DATA SOURCES

We searched databases including PubMed, Google Scholar, and Scopus for the following key words: Hirschsprung's disease, rectal biopsy, pathology, ganglion cell, nerve trunk hypertrophy, pediatric constipation, and selected publications written in English that were relevant to the scope of this review.

RESULTS

Based on the data presented in the literature, we reviewed 1) biopsy techniques for the diagnosis of Hirschsprung's disease, addressed inadequate biopsies, and complications from rectal biopsy, and 2) pathologic and histologic interpretation of biopsy specimens for the diagnosis of Hirschsprung's disease.

CONCLUSION

A well-executed rectal biopsy with expert pathologic evaluation of the specimen remains the gold standard for the diagnosis of Hirschsprung's disease and is the subject of this review.

Modified Rapid AChE Method (MRAM) for Hirschsprung Disease Diagnosis: A Journey from Meier-Ruge Until Now

Hirschsprung disease (HSCR) can be diagnosed using a variety of histological and immunohistochemical methods and stains. Because of the nature of the condition and the need for a rapid diagnostic confirmation, those methods with high accuracy and fast turnaround times are preferred. The authors of this paper have used rapid acetylcholinesterase (AChE) immunohistochemistry in conjunction with standard H&E in order to optimize diagnostic accuracy, and present a modified rapid AChE method (MRAM) that has been successfully utilized for over 20 years. The authors also present a list of over 30 different methods and stains that have been proposed for Hirschsprung disease diagnosis.

Rectal suction biopsy for the diagnosis of Hirschsprung's disease: a systematic review of diagnostic accuracy and complications

PURPOSE

Rectal suction biopsy (RSB) combined with acetylcholinesterase (AChE) staining is currently the gold standard for the diagnosis of Hirschsprung's disease (HD). However, some pathologists are still reluctant to diagnose HD in RSBs as it requires thick submucosal tissue to confirm the absence of ganglion cells. Furthermore, insufficient specimens and adverse events have been reported. The objective of this study was to determine the diagnostic accuracy and incidence of complications of RSBs in patients suspected of HD based on a systematic review of the published literature.

METHODS

A literature-based search for relevant publications was conducted using multiple online databases. Staining for AChE/hematoxylin and eosin should have been used to evaluate RSBs. The number of true-positive, false-positive, true-negative and false-negative results was recorded and data on RSB-related complications was extracted. Pooled incidence rates and odds ratios (ORs) with 95% confidence intervals (CI) were calculated using standardized statistical methodology.

RESULTS

Fifty-eight studies met defined inclusion criteria, reporting a total of 14,053 RSBs. The median cohort size consisted of 72 patients (range 1-766) with a median age of 14.4 months (range 1 day-66 years) at time of biopsy. In 89.93% (CI 89.11-90.70%), RSB provided adequate tissue for the diagnosis of HD. Insufficient specimens were obtained in 10.07% (CI 9.30-10.89%) and in 8.46 % (CI 7.55-9.46%) RSB was repeated. The incidence of HD was 19.13% (CI 18.25-20.03%). Mean sensitivity of RSB was 96.84% (CI 95.57-97.47%) and mean specificity was 99.42% (CI 99.17-99.57%). The overall complication rate was 0.65% (CI 0.46-0.91%) with persistent rectal bleeding requiring blood transfusion in 0.53% (CI 0.36-0.77%), bowel perforation in 0.06% (CI 0.02-0.18%) and pelvic sepsis in 0.06% (CI 0.02-0.18%). Complications were significantly more frequent in newborns and infants compared to older children (OR 9.00 [CI 4.75-17.07], p < 0.0001).

CONCLUSIONS

RSB combined with AChE staining is a simple, safe and accurate method for the diagnosis of HD. The risk for RSB-related complications is higher in newborns and infants.

Presence of intramucosal neuroglial cells in normal and aganglionic human colon

The enteric nervous system (ENS) is composed of neural crest-derived neurons (also known as ganglion cells) the cell bodies of which are located in the submucosal and myenteric plexuses of the intestinal wall. Intramucosal ganglion cells are known to exist but are rare and often considered ectopic. Also derived from the neural crest are enteric glial cells that populate the ganglia and the associated nerves, as well as the lamina propria of the intestinal mucosa. In Hirschsprung disease (HSCR), ganglion cells are absent from the distal gut because of a failure of neural crest-derived progenitor cells to complete their rostrocaudal migration during embryogenesis. The fate of intramucosal glial cells in human HSCR is essentially unknown. We demonstrate a network of intramucosal cells that exhibit dendritic morphology typical of neurons and glial cells. These dendritic cells are present throughout the human gut and express Tuj1, S100, glial fibrillary acidic protein, CD56, synaptophysin, and calretinin, consistent with mixed or overlapping neuroglial differentiation. The cells are present in aganglionic colon from patients with HSCR, but with an altered immunophenotype. Coexpression of Tuj1 and HNK1 in this cell population supports a neural crest origin. These findings extend and challenge the current understanding of ENS microanatomy and suggest the existence of an intramucosal population of neural crest-derived cells, present in HSCR, with overlapping immunophenotype of neurons and glia. Intramucosal neuroglial cells have not been previously recognized, and their presence in HSCR poses new questions about ENS development and the pathobiology of HSCR that merit further investigation.

Does calretinin immunohistochemistry reduce inconclusive diagnosis in rectal biopsies for Hirschsprung disease?

Many difficulties occur during the evaluation of rectal biopsies for the diagnosis of Hirschsprung disease. We investigated whether the introduction of calretinin (CR) immunohistochemistry in a diagnostic panel could decrease the rate of inconclusive results. Data from 82 patients undergoing rectal biopsies before and after CR introduction were analyzed. Inconclusive results were obtained in 17 of 45 rectal biopsies (37.8%) in the series of cases before CR introduction and in 5 of 42 rectal biopsies (11.9%) in the series of cases after CR (P < 0.006). The inclusion of CR in the histopathologic panel may improve the diagnostic accuracy of Hirschsprung disease.

Calretinin-immunoreactive mucosal innervation in very short-segment Hirschsprung disease: a potentially misleading observation

Absent calretinin-immunoreactive (CRir) mucosal innervation in aganglionic rectal biopsies is considered a useful diagnostic finding for Hirschsprung disease. Analysis of a series of rectosigmoid resections from patients with short-segment (>2-cm aganglionic, n  =  9) and very short-segment (≤2-cm aganglionic, n  =  9) Hirschsprung disease demonstrates that CRir mucosal nerves extend into the proximal 1-2 cm of aganglionic bowel, where their presence in distal rectal biopsies could complicate diagnosis of very short-segment disease. Indeed, retrospective analysis of preoperative, aganglionic, distal rectal biopsies from 4 of 9 patients with very short-segment Hirschsprung disease revealed CRir mucosal innervation. Accurate diagnosis was possible based on generous histopathological submucosal sampling to exclude ganglion cells and the presence of abundant large-caliber submucosal nerves (more than 4 nerves >30 µm thick/×200 field or more than 2 nerves >40 µm thick/×200 field). Absent CRir mucosal innervation supports the diagnosis of Hirschsprung disease, but the presence of CRir mucosal nerves does not exclude aganglionosis, especially in distal rectal biopsies from patients with very short-segment Hirschsprung disease.

Calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of Hirschsprung's disease

BACKGROUND/PURPOSE

Identifying ganglion cells by rectal suction biopsy is a basic diagnostic tool for the diagnosis of Hirschsprung's disease (HD). However, the difficult interpretation of conventionally processed slides often necessitates ancillary staining methods. The aim of this study was to evaluate the usefulness of calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of HD.

METHODS

We analyzed 52 rectal suction biopsy specimens (37 from 15 HD patients and 15 from 7 non-HD patients) for ganglion cells with calretinin and MAP-2 immunohistochemistry. We also analyzed full-thickness, frozen biopsy samples obtained from 15 HD patients who underwent surgery utilizing calretinin and MAP-2 immunohistochemistry.

RESULTS

Both calretinin and MAP-2 positively stained ganglion cells in the submucosal plexus of the ganglionic bowel but not aganglionic bowel. Calretinin usually stained ganglion cell cytoplasm and nuclei more intensely than MAP-2, which only stained cytoplasm. No nerve fiber staining in the submucosal layer was observed for either antibody. In 21.1% (11/52) of samples, calretinin and MAP-2 staining found ganglion cells which were reported not to have ganglion cells in the original surgical pathology reports. Immunohistochemical staining for calretinin using paraffin-embedded tissue sections after cryostat sections clearly demonstrated decreased staining intensity compared to MAP-2.

CONCLUSION

Calretinin and MAP-2 are useful diagnostic markers for diagnosing HD in rectal suction biopsies. These complementary methods could ameliorate the diagnostic difficulties associated with HD.

A useful panel for the diagnosis of Hirschsprung disease in rectal biopsies: calretinin immunostaining and acetylcholinesterase histochesmistry

The pathological evaluation of rectal biopsies for the diagnosis of Hirschsprung disease has been a challenging issue. We analyzed prospectively the usefulness of calretinin immunostaining and acetylcholinesterase (AChE) histochesmistry in rectal biopsies for the diagnosis of Hirschsprung disease. Frozen tissue samples from 43 patients were used for AChE histochemistry and paraffin-embedded sections for calretinin immunohistochemistry and conventional histology (hematoxylin and eosin [H&E]). Activity for AChE, was demonstrated in 13 of 43 cases, and the absence of immunoreactivity for calretinin was observed in 14 of 43 cases. Conventional histology (H&E) did not reveal ganglion cells in 24 of 43 cases. The results on calretinin were in good agreement with AChE according to the κ index (0.946; P<.001) and presented significantly higher specificity (96.7×63.3; P<.002) and accuracy (97.6×74.4; P<.003) when compared with conventional histology (H&E). The final diagnosis of Hirschsprung disease was confirmed in 13 of 43 patients who were submitted to surgical treatment. The results of the present study indicate that calretinin can be a good tool in ruling out the diagnosis of Hirschsprung disease, by showing positive staining in ganglion cells and intrinsic nerve fibers, whereas AChE is useful in confirming the diagnosis of Hirschsprung disease, by revealing activity of this enzyme in hypertrophied nerve fibers. The association between calretinin and AChE can be a useful panel for the histopathologic evaluation of rectal biopsies for the diagnosis of Hirschsprung disease.

Reoperation for Hirschsprung disease: pathology of the resected problematic distal pull-through

Hirschsprung disease, which consists of aganglionosis of the rectum and sometimes more proximal bowel, requires surgical removal of the aganglionic bowel and creation of ganglionated neorectum using proximal normally innervated bowel. The border between aganglionic and ganglionic bowel is irregular; the transition zone features variable quantities of ganglion cells and numerous large nerves. We report the histopathology of pull-through bowel segments resected because of poor postoperative outcome from 30 patients (22 boys, 8 girls). The most common indication for reoperation was severe constipation/obstruction. Transition zone (bowel with at least two nerves ≥40 µm diameter per 400× high-power field, and ganglion cells) or aganglionic bowel (bowel with at least two nerves ≥40 µm per high-power field diameter, but without ganglion cells) was found in 19/30 (63%) resections. In colons resected because of familial adenomatous polyposis, rare high-power fields showed two enlarged nerves; the mean age of those patients (135 ± 49.4 months) was significantly higher than that of the patients undergoing redo pull-through surgery (67.9 ± 42.8 months). Additional pathology included stricture and enterocolitis. Although there are multiple causes for poor outcomes following surgical therapy for Hirschsprung disease, abnormal innervation of the bowel used for pull-through is common. We recommend that intraoperative consultation at primary pull-through procedure include frozen section evaluation of the circumference of the bowel to be used for pull-through to confirm histologically the presence of both ganglion cells and normal-caliber nerves. The criteria used in this study are most suitable for infants and young children.

Histochemical staining for intestinal dysganglionosis: over 30 years experience with more than 1,500 biopsies

PURPOSE

Intestinal dysganglionosis are a group of anomalies of the enteric nervous system that constitute infrequent but severe forms of constipation. Histochemical stainings are the gold standard diagnostic procedure for intestinal dysganglionosis. This study describes our experience with histochemistry in a large series of patients.

METHODS

Between 1977 and 2010, 1,589 biopsies from children with persistent chronic constipation were studied. The specimens were snap frozen, sectioned and stained with acetylcholinesterase (AChE), acetylcholinesterase counterstained with hematoxilin and succinic dehydrogenase (SDH) histochemical stainings.

RESULTS

Among the 1,589 biopsies, 946 (59.5%) were rectal biopsies, 242 (15.2%) were internal sphincter biopsies, 346 (21.8%) were intestinal mapping studies and 42 (2.7%) of them were colon specimens from surgical resections. From the rectal biopsy group, 544 (57.5%) patients were reported as normal. Hirschsprung disease was found in 163 (17.2%) patients with a median age at diagnosis of 8 months and a male to female ratio of 3:1. Intestinal neuronal dysplasia was found in 162 (17.2%) patients, hypoganglionosis in 3 (0.3%) of them and ganglioneuromatosis in 1 (0.1%). In 73 (7.7%) patients, the biopsy was not conclusive for different reasons. 34 out of the 42 resected colon specimens were Hirschsprung disease. Intestinal neuronal dysplasia was found in the proximal segment of the aganglionic bowel in 15 out of 34 (44%) patients. All the aganglionic resected colon specimens had a previous aganglionic rectal biopsy. There were no false positive results in this group.

CONCLUSIONS

Histochemical stainings continue to be the gold standard in the diagnosis of intestinal dysganglionosis. The combination of two histochemical staining techniques provides a high level of accuracy in the diagnosis of intestinal dysganglionosis.

Total colonic aganglionosis: case report, practical diagnostic approach and pitfalls

Hirschsprung disease remains a challenging diagnosis for many pathologists. The disease is characterized by a lack of ganglion cells in the myenteric and submucosal plexus, associated with increased numbers of acetylcholinesterase-positive nerve fibers. Hypertrophic nerve fibers are present in most but not all patients. Total colonic aganglionosis (TCA) is an uncommon form of Hirschsprung disease with clinical, histologic, and genetic differences and is even more difficult to diagnose and manage. This case illustrates some of the difficulties frequently faced by the pathologists dealing with total colonic aganglionosis. Suction rectal biopsy specimens often lack significant nerve hypertrophy and positive acetylcholinesterase staining, which aid in the diagnosis. Pathologists have to depend mainly on the lack of ganglion cells in adequate submucosa to establish the diagnosis. Transition zone is often long in total colonic aganglionosis and interpretation of frozen sections can be difficult. The presence of several uniformly distributed clusters of mature ganglion cells and lack of nerve hypertrophy are required to avoid connections at the transition zone.

Pathology of Intestinal Motor Disorders in Children

Varied intestinal neuromuscular pathologies are responsible for Hirschsprung disease and other forms of chronic pseudo-obstruction that are encountered in pediatrics. Pathologically distinct subtypes discussed in this review include aganglionosis, hypoganglionosis, neuronal intranuclear inclusion disease, ganglionitis, degenerative neuropathy, diffuse ganglioneuromatosis, neuronal dysplasia, malformations of the muscularis propria, degenerative leiomyopathy, leiomyositis, and mitochondriopathies. Emphasis is given to the histopathologic features that distinguish these conditions and their differential diagnoses.

Practical pathology and genetics of Hirschsprung's disease

Diagnosis and management of Hirschsprung's disease (HSCR) requires understanding of the malformation's anatomic features and multigenic nature. Rectal biopsies, intraoperative frozen sections, and resection specimens provide invaluable information. Extraction of these data requires thoughtful biopsy technique, adequate histologic sections, histochemistry, and collaboration of surgeon and pathologist. Critical consideration of transition zone anatomy and published studies of "transition zone pull through" indicate that more research is needed to determine how much ganglionic bowel should be resected from HSCR patients. Many HSCR-susceptibility genes have been identified, but mutational analysis has limited practical value unless family history or clinical findings suggest syndromic HSCR.

Gastrointestinal neuromuscular pathology: guidelines for histological techniques and reporting on behalf of the Gastro 2009 International Working Group

The term gastrointestinal neuromuscular disease describes a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular, including interstitial cell of Cajal, dysfunction. Such disorders commonly have impaired motor activity, i.e. slowed or obstructed transit with radiological evidence of transient or persistent visceral dilatation. Whilst sensorimotor abnormalities have been demonstrated by a variety of methods in these conditions, standards for histopathological reporting remain relatively neglected. Significant differences in methodologies and expertise continue to confound the reliable delineation of normality and specificity of particular pathological changes for disease. Such issues require urgent clarification to standardize acquisition and handling of tissue specimens, interpretation of findings and make informed decisions on risk-benefit of full-thickness tissue biopsy of bowel or other diagnostic procedures. Such information will also allow increased certainty of diagnosis, facilitating factual discussion between patients and caregivers, as well as giving prognostic and therapeutic information. The following report, produced by an international working group, using established consensus methodology, presents proposed guidelines on histological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology. The report addresses the main areas of histopathological practice as confronted by the pathologist, including suction rectal biopsy and full-thickness tissue obtained with diagnostic or therapeutic intent. For each, indications, safe acquisition of tissue, histological techniques, reporting and referral recommendations are presented.

Calretinin immunohistochemistry versus acetylcholinesterase histochemistry in the evaluation of suction rectal biopsies for Hirschsprung Disease

Diagnosis of Hirschsprung disease (HSCR) relies on histologic and/or histochemical staining of sections from suction rectal biopsies. Acetylcholinesterase histochemistry (AChE) facilitates diagnosis but is not universally employed, in part because it requires special tissue handling. Calretinin immunohistochemistry (IHC) may be a useful alternative, because loss of calretinin immunoreactive nerves reportedly correlates spatially with aganglionosis. We investigated the patterns of calretinin IHC in suction rectal biopsies from HSCR and non-HSCR patients and compared the diagnostic value of calretinin IHC with a widely used rapid AChE method. In suction rectal biopsies that contain ganglion cells, small nerves in the lamina propria, muscularis mucosae, and superficial submucosa contain granular aggregates of calretinin immunoreactivity. Immunolabeling of these nerves is completely absent in the aganglionic biopsies of HSCR patients. Multiple observers independently reviewed calretinin IHC and AChE sections of suction rectal biopsies from 14 HSCR patients and 17 non-HSCR controls. Five observers, blinded to the correct diagnosis, scored each patient's calretinin IHC and AChE slides as HSCR, not HSCR, or equivocal. The frequencies of major and minor discrepant diagnoses were compared. Calretinin IHC yielded no misdiagnoses or major discrepancies between observers. In contrast, 2 misdiagnoses and significantly more interobserver disagreement resulted from the AChE-stained sections. Calretinin IHC appears to be a reasonable, and potentially superior, alternative to AChE as an adjunctive diagnostic method for evaluating suction rectal biopsies for HSCR.

Variability of acetylcholinesterase hyperinnervation patterns in distal rectal suction biopsy specimens in Hirschsprung disease

Variability in cholinergic innervation may contribute to false-negative and false-positive evaluations for Hirschsprung disease (HD). We compared intraspecimen variability of histochemical acetylcholinesterase (ACE) activity in 62 distal rectal mucosal biopsy specimens from 33 patients with short-segment HD (SSHD), 14 patients with short-segment HD/Down syndrome (SSHD/DS), 10 patients with total colonic aganglionosis (HDTC), and 45 ganglionated control specimens obtained because of clinical suspicion for HD. Specimens were evaluated in 1-mm linear segments for abnormal distribution and abnormal intensity of staining reaction in the lamina propria (LP), muscularis mucosae (MM), numerical excess of small submucosal nerves (SSN), and presence or absence of large submucosal nerves (LSN) defined as >35 microns in diameter. Patients with HD and controls were predominantly infant males. Aggregate length of specimens was 186 mm in HD and 136 mm in controls. We defined multiple patterns and relative frequencies of normal and abnormal ACE reactivity in the muscularis mucosae, submucosal nerves, and innervation in the lamina propria. We verified a hyperinnervation pattern more common in neonates within each subset of HD. Large submucosal nerves >35 microns in diameter are relatively less common in SSHD/DS and HDTC. Eleven of 57 patients with HD had at least 1 mm of normal muscularis mucosae accounting for 19/186 mm examined. Ten percent of control mm had at least 1 submucosal nerve >35 microns in diameter. Intraspecimen variability in ACE patterns, when extreme, can usually be resolved by findings elsewhere in an adequate specimen, minimizing the need for repeat procedures.

Histochemical staining of rectal suction biopsies as the first investigation in patients with chronic constipation

Rectal suction biopsy (RSB) is the gold standard diagnostic procedure for disorders of bowel motility. This study describes our experience with RSB stained with histochemistry as the first diagnostic approach in a large series of patients presenting with chronic constipation. Between 1993 and 2005, 766 children underwent RSB for persistent chronic constipation. The specimens were snap frozen, sectioned and stained with conventional hematoxylin and eosin (H&E) and with nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and acetylcholinesterase (AChE) histochemical stainings. Adequate amount of submucosa was present in 655 (85.5%) out of 766 cases and formed the basis of this study. RSB in 540 (82%) patients were reported as normal. Hirschsprung's disease was found in 47 (7.2%) patients with characteristic features of absence of ganglion cells, increased AChE activity in the lamina propria and muscularis mucosae, thick nerve fibers in the submucosa, and a lack of NADPH-d-positive fibers in muscularis mucosae. RSB in 59 (9%) patients presented features of intestinal neuronal dysplasia such as submucosal hyperganglionosis, giant ganglia, ectopic ganglia and increased AChE activity in lamina propria. Hypoganglionosis was suspected in nine (1.3%) children because of sparse or absent ganglion cells and low AChE and NAPDH-d activity in muscularis mucosae. Three patients (0.4%) developed bleeding following RSB, requiring diathermy of the bleeding point. Thus, we conclude that RSB is a simple and safe method when used as the first diagnostic approach in patients with chronic constipation. The combination of two histochemical stainings techniques provides a high level of accuracy in the diagnosis of intestinal dysganglionosis.

At what age is a suction rectal biopsy less likely to provide adequate tissue for identification of ganglion cells?

OBJECTIVE

The objective of this study was to determine at what age suction rectal biopsy is less likely to provide adequate tissue to detect submucosal ganglion cells in a child being evaluated for Hirschsprung disease.

PATIENTS AND METHODS

Children > or =1 year of age undergoing a rectal biopsy at a single children's hospital had 1 biopsy each obtained simultaneously with a suction biopsy device and a grasp biopsy forceps. The biopsies were examined by 2 pathologists for adequacy of the submucosa (none, scant, adequate, or ample) and the presence of ganglion cells. The 2 specimens were compared with each other.

RESULTS

One hundred fifty-two children 1 to 17 years of age were included. Fifty-three were female. Subjects were grouped into 4 age categories: 1 to 3 years (group A), 4 to 6 years (group B), 7 to 9 years (group C), and > or =10 years (group D). Similar numbers of patients were recruited for each group. Ganglion cells were identified in 73% and 90% by the suction and grasp devices, respectively, in group A. In groups B through D, ganglion cells were identified in 50% to 53% vs 92% to 97% of the suction and grasp biopsies, respectively (P < 0.001). Submucosa was present in 88% (suction) vs 98% (grasp) in group A, 70% vs 95% in group B, 69% vs 94% in group C, and 45% vs 92% in group D.

CONCLUSION

The suction rectal biopsy is less likely to provide adequate submucosa for identification of ganglion cells after 3 years of age.

[Hirschsprung's disease: practical considerations]

Hirschsprung's disease (1/5000 live births) is defined by the congenital absence of neuronal cells in the nervous plexuses in the distal part of the digestive tract. The disease affects the rectum and sigmoid colon in 80% of cases, or is more extensive. Hirschsprung's disease is suspected in cases of low gastrointestinal obstruction in the neonatal period, or in cases of chronic severe constipation in childhood. It is diagnosed by pathological examination of rectal biopsies that include the submucosa. After standard staining, multiple sections are scrutinized for neuronal cells. Acetylcholinesterase staining is performed on a frozen fragment to demonstrate the hyperplasia of cholinergic fibers that is very suggestive of Hirschsprung's disease. This hyperplasia decreases from the rectum to the splenic flexure of the colon. Hyperplasia of extrinsic nerve fibers and rarefaction of neuromuscular junctions in Hirschsprung's disease may be demonstrated immunohistochemically. Differential diagnosis includes chronic intestinal pseudo-obstructions. The treatment for Hirschsprung's disease is, most often, anastomosis of the normally innervated gut to the anal canal. Peri- or pre-operative biopsies assist surgery, but their interpretation is difficult in the transitional zone. The examination of the surgical specimen allows measurement of the aganglionic segment and transitional zone. Different genes (RET, most often) may be involved in sporadic or familial Hirschsprung's disease. Hirschsprung's disease is associated with other digestive or extra-digestive abnormalities in 5 to 30% of patients. Associated abnormalities may delay the diagnosis and treatment of Hirschsprung's disease.

Anomalies d’expression de la synaptophysine dans la maladie de Hirschsprung

Hirschsprung's disease is defined by the congenital absence of ganglion cells in enteric plexuses. Immunostaining of synaptophysin after formalin fixation may be used to identify hyperplasia of nerve fibers and rarefaction of neuromuscular junctions in Hirschsprung's disease. The aim of the study was to evaluate semi-quantitatively the expression of synaptophysin in Hirschsprung's disease, in correlation with morphologic features. This retrospective study included 3 controls, 42 surgical rectal biopsies performed for suspicion of Hirschsprung's disease in children presenting with lower digestive occlusion or severe chronic constipation, including 18 Hirschsprung's disease, and 23 surgical specimens of Hirschsprung's disease. In the absence of Hirschsprung's disease, synaptophysin-positive fibers were numerous but thin in the muscularis mucosae, thin and scarce in the mucosa and submucosa. Neuromuscular junctions were thin and numerous in the muscularis propria. In Hirschsprung's disease, synaptophysin-positive fibers were coarse, and increased in number on each side of the muscularis mucosae. Plexuses were enlarged, weakly stained, and associated in the connective tissue of the muscularis propria with coarse and intensely stained fibers. In conclusion, staining for synaptophysin could be useful to demonstrate abnormalities of enteric innervation in rectal biopsies performed for suspected Hirschsprung's disease in the absence of acetylcholinesterase staining on frozen sections, in transmural biopsies performed for guiding surgery in Hirschsprung's disease, and in cases of extensive Hirschsprung's disease.

Detection of ganglion cells in the colonic plexuses by immunostaining for neuron-specific marker NeuN: an aid for the diagnosis of Hirschsprung disease

The majority of ganglion cells in the colonic plexuses can be easily and specifically identified by immunostaining for neuronal marker NeuN. The distance between the neighboring solitary ganglion cells or groups of ganglion cells varied from 0.18 to 4.0 mm, average 1.0 mm, in ganglionic segments of colons of patients with Hirschsprung disease, and from 0.3 to 6.3 mm, average 1.43 mm, in colons of pediatric patients with chronic constipation of various etiologies. No ganglion cells were detected in aganglionic colonic segments of patients with Hirschsprung disease by this method.