Gastroenterology Research, ISSN 1918-2805 print, 1918-2813 online, Open Access
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Original Article

Volume 14, Number 5, October 2021, pages 281-289

Histologic Findings in Mucosa and Muscularis Propria Biopsied During Peroral Endoscopic Myotomy in Patients With Achalasia


Figure 1.
Figure 1. Mucosal changes in mid esophageal biopsy from one patient with achalasia who underwent peroral endoscopic myotomy. (a) Peripapillary edema (spongiosis) and ballooning are noticeable (H&E stain, × 100). (b) Intraepithelial lymphocytosis is present (H&E stain, × 200).
Figure 2.
Figure 2. Finding in muscular biopsy in achalasia. (a) Interstitial fibrosis in the muscular biopsy (H&E stain, × 100). (b) Interstitial fibrosis and elastosis and absence of ganglion cells in the muscular biopsy. The fibrosis/elastosis is accompanied by mild eosinophilic inflammation (H&E stain, × 200).
Figure 3.
Figure 3. Histologic findings in the gastric cardia in achalasia. (a) Gastric cardia with mild chronic carditis (H&E stain, × 100). (b) Moderate chronic carditis with intestinal metaplasia and focal low-grade dysplasia (H&E stain, × 100).


Table 1. Definitions of Histologic Features Evaluated in the Mucosal Biopsies
FeaturesDefinitionCutoff value
IEL: intraepithelial lymphocytosis; IELs: intraepithelial lymphocytes.
  Basal hyperplasiaThickening of basal layers of squamous epitheliumPresence or absence
  Elongation of papillaeHeight of papillae > 50% of epithelium thicknessPresence or absence
  SpongiosisWidening of intercellular spaces due to edemaPresence or absence
  Ballooning degenerationEnlarged squamous cells with intracellular edemaPresence or absence
  ParakeratosisSuperficial layers of nucleated squamous cells with dense keratinPresence or absence
  DysplasiaNeoplastic squamous epithelium confined above the basement membranePresence of absence
Inflammation within the squamous mucosa
  Peripapillary IELIELs in the first five layers of squamous epithelium surrounding the esophageal papillaeNumber of IELs per high-power field in the most densely infiltrated fields
  Interpapillary IELIELs in the squamous epithelium beyond the peripapillary regionsNumber of IELs per high-power field in the most densely infiltrated fields
  NeutrophilNeutrophils in squamous epitheliumPresence or absence
  EosinophilEosinophils in squamous epitheliumNumber of eosinophils per high-power field in the most densely infiltrated fields
ColumnarGlandular epitheliumPresence or absence
  Intestinal metaplasiaGoblet cellsPresence or absence
  Glandular dysplasiaNeoplastic glandular epithelium confined above the basement membranePresence or absence
Subepithelial fibrosisIncreased collagen deposition underneath the epitheliumPresence or absence
Submucosal inflammationInflammatory cells in the submucosaPresence or absence


Table 2. Definitions of Histologic Features Evaluated in Muscular Biopsies
FeaturesDefinitionCutoff value
Smooth muscle
  AtrophyThin and small smooth muscle fibersPresence or absence
  HypertrophyThick and large smooth muscle fibersPresence or absence
  CalcificationPurple amorphous deposition in the tissuePresence or absence
Interstitial fibrosisIncreased collagen fiberPresence or absence
Myenteric plexus
  Ganglion cellsNeuronPresence or absence
  GanglionitisLymphocytic infiltration into ganglion cell cytoplasmPresence or absence
  NeuritisInflammation within or immediately around myenteric nervesPresence or absence
  Intramuscular eosinophilEosinophilic infiltration in smooth muscle fibersPresence or absence
  Intramuscular lymphocytesLymphocytic infiltration in smooth muscle fibersPresence or absence
  Perivascular inflammationInflammatory cells in the perivascular spacesPresence or absence
  Intravascular margination of inflammatory cellsInflammatory cells in the vascular spacesPresence or absence


Table 3. Clinical Characteristics of Achalasia Patients
SD: standard deviation; PPI: proton pump inhibitor.
Gender (male/female)10:8
Age (mean, SD, range) (years)60.7 (13), 34 - 81
Duration of achalasia (mean, SD, range) (months)79 (114), 1 - 480
Type of achalasia (N = 18), N (%)
  Type I1 (5.6)
  Type II9 (50.0)
  Type III2 (11.0)
  Esophageal gastric outlet obstruction5 (27.8)
  Unspecified type1 (5.6)
Prior myotomy, N (%)2 (11.0)
Endoscopic findings (N = 18), N (%)
  Dilated esophagus only15 (83.3)
  Dilated esophagus with esophagitis2 (11.1)
  Dilated esophagus with diverticulum1 (5.6)
Timed barium study (N = 17), N (%)
  Dilated esophagus6 (35.3)
  Dilated esophagus with delayed passage of barium7 (41.2)
  Normal examination4 (23.5)
PPI use (N = 18), N (%)
  Omeprazole 40 daily6 (33.3)
  Omeprazole 40 mg bid3 (16.7)
  Lansoprazole 15 mg daily1 (5.6)
  Unspecified1 (5.6)
  None7 (38.8)


Table 4. Esophageal, Gastric Cardia, and Muscular Biopsy Findings in Patients With Achalasia Undergoing Peroral Endoscopic Myotomy
Mucosal biopsy findingsFeatureN (%)
Esophageal squamous mucosa (N = 17)Basal hyperplasia16 (92.3)
Spongiosis17 (100)
Ballooning17 (100)
Parakeratosis13 (76.5)
Intraepithelial lymphocytosis12 (70.5)
Neutrophilic inflammation4 (23.5)
Eosinophilic inflammation3 (35.3)
Gastric cardia mucosa (N = 13)Carditis9 (69.2)
H. pylori gastritis1 (7.6)
Reactive changes2 (15.4)
Intestinal metaplasia1 (7.6)
Low-grade dysplasia1 (7.6)
Muscular biopsy findings (N = 17)Absence of ganglion cells15 (88.2)
Ganglionitis1 (5.8)
Muscular atrophy9 (52.9)
Interstitial fibrosis14 (82.3)
Eosinophilic inflammation2 (11.7)