**7. Modalities for detection of HGMP**

#### **7.1 High definition endoscopy**

Use of high definition endoscopy will improve the clarity and definition and can differentiate HGMP/CIP from the squamous mucosa.

#### **7.2 Narrow band imaging**

Narrow band imaging (NBI) which utilizes different light wavelengths has been reported to improve the detection rate of HGMP/CIP (Hori et al., 2010; Ohara, 2010). NBI allows better visualization of the more superficial features of mucosa. In NBI, the HGMP/CIP appears a grayish pink patch surrounded by greenish hued squamous cell mucosa. Occasionally area where the thickness of squamous cell layer is less, it can also give the similar appearance but in this case, mucosal vessels, greenish in appearance, can still be seen coursing through the area. In HGMP/CIP, vessels are not seen.

#### **7.3 Chromoendoscopy**

HGMP/CIP can also be visualized with chromoendoscopy. Both Lugol's solution and methylene blue can be used to identify HGMP/CIP. Lugol's solution is iodine based and has affinity that has affinity for glycogen in non-keratinized squamous cell epithelium of the esophagus. HGMP/CIP will not stain and appear lighter shade compared to the surrounding esophagus. Methylene blue will stain HGMP/CIP blue in colour. However, this procedure requires the spraying of dye and to do this in the proximal esophagus may induce cough reflex causing discomfort to the patient (Dib & Ortiz, 2009).

#### **7.4 Wired guided examination**

Use of wire guided examination has also been reported to improve the yield. The endoscope is withdrawn into the mid-esophagus and a guide wire is threaded through into the esophagus. The endoscope is then slowly withdrawn while examining the proximal esophagus and crico-pharyngeal area (Bhasin et al., 2006).

in patients with multiple patches, they tend to be found in close proximity, above or below forming columns or on the opposite side (kissing patches). It is uncertain whether the size of HGMP/CIP may change with time. One study reported that the size of a HGMP/CIP decreased during subsequent endoscopy whilst on acid suppression treatment (Chong & Jalihal, 2006). Healing of surrounding inflammation may account for this observation. Associated findings include elevated whitish nodules that do not have the characteristic salmon colored mucosa. In elderly patients, venous bled or hematoma can also be found. To date, the profiles of HGMP/CIP have not been properly studied. Interestingly, HGM can also be found in other parts of the esophagus, mid esophagus and above the gastroesophageal junction (Borhan-Manesh & Franum, 1991; Katsanos et al., 2010) (Figure 7e). It is likely that the overall acid production from the HGMP/CIP is less than that seen in gastroesophageal reflux disease affecting the gastroesophageal junction. Acid related injuries can be seen in the patch and the surrounding esophageal squamous mucosa. Inflammatory macroscopic changes visible during endoscopy or microscopic changes only visible on histological examinations resembling those seen in reflux esophagitis have been

Use of high definition endoscopy will improve the clarity and definition and can

Narrow band imaging (NBI) which utilizes different light wavelengths has been reported to improve the detection rate of HGMP/CIP (Hori et al., 2010; Ohara, 2010). NBI allows better visualization of the more superficial features of mucosa. In NBI, the HGMP/CIP appears a grayish pink patch surrounded by greenish hued squamous cell mucosa. Occasionally area where the thickness of squamous cell layer is less, it can also give the similar appearance but in this case, mucosal vessels, greenish in appearance, can still be seen coursing through the

HGMP/CIP can also be visualized with chromoendoscopy. Both Lugol's solution and methylene blue can be used to identify HGMP/CIP. Lugol's solution is iodine based and has affinity that has affinity for glycogen in non-keratinized squamous cell epithelium of the esophagus. HGMP/CIP will not stain and appear lighter shade compared to the surrounding esophagus. Methylene blue will stain HGMP/CIP blue in colour. However, this procedure requires the spraying of dye and to do this in the proximal esophagus may

Use of wire guided examination has also been reported to improve the yield. The endoscope is withdrawn into the mid-esophagus and a guide wire is threaded through into the esophagus. The endoscope is then slowly withdrawn while examining the proximal

induce cough reflex causing discomfort to the patient (Dib & Ortiz, 2009).

esophagus and crico-pharyngeal area (Bhasin et al., 2006).

described.

**7. Modalities for detection of HGMP** 

area. In HGMP/CIP, vessels are not seen.

differentiate HGMP/CIP from the squamous mucosa.

**7.1 High definition endoscopy** 

**7.2 Narrow band imaging** 

**7.3 Chromoendoscopy** 

**7.4 Wired guided examination** 

Fig. 7. Endoscopic images showing different HGMPs; a) a large depressed patch with coarse surface texture with another patch located on the opposite wall, b) two small patch with smooth surface texture, one elevated and the other flat, c) a large slightly depressed patch with coarse surface texture on the right lateral wall, d) two round elevated patch with white edges and smooth surface and associated venous bled, and e) a small flat round patch with smooth surface texture located above the gastroesophageal junction. All the patches shown stained positive for CK7 and CK20 with characteristics pattern

Heterotopic Gastric Mucosal Patch of the Proximal Esophagus 137

Use of proximal pH monitoring can also provide clue to the presence of HGMP/CIP. Presence of acid pH detected in the proximal esophagus without acidic pH detected in the distal esophagus suggests the presence of HGMP/CIP. However, both gastroesophageal reflux and proximal acid reflux secondary to HGMP/CIP may co exist. Endoscopic imaging will still be required to confirm the presence of HGMP/CIP. Use of confocal microendoscopy

Complications of HGMP/CIP are those cases classified under the clinico-pathological classification as types III to V (von Rahden et al., 2004). To date, there have been around thirty cases of cervical esophagus adenocarcinoma (type V) reported (Abe et al., 2004 ; Alaani et al., 2007 ; Alrawi et al., 2005 ; Balon et al., 2003; Berkelhammer et al., 1997; Carrie, 1950; Chatelain et al., 2002; Christensen & Sternberg, 1987; Clemente, 1974; Danoff et al., 1978; Davis et al., 1969; Goëau-Brissonnière et al., 1985; Haruki et al., 2008 ; Hirayama et al., 2003; Ishii et al., 1991; Kammori et al., 1996; Kamiya et al., 1983; Klaase et al., 2001; Lauwers et al., 1998 ; Morson & Belcher, 1952; Noguchi et al., 2001 ; Pai et al., 1997; Pech et al., 2001; Raphael et al., 1966; Sakamoto et al., 1970; Schmidt et al., 1985; Sperling & Grendell, 1995; Takagi et al., 1995; von Rahden et al., 2004 & 2005; Yoshida et al., 1986; Yoshida et al., 2010) in the literature. Other non-malignant complications (types III and IV) have been reported in both children and adults and are shown in Table 1 (Sauvé et al., 2001; Mion et al., 1996; Steadman et al., 1988; Yarborough et al., 1993; Bosher & Taylor, 1951; Powell & Luck, 1988; Karnak et al., 1999; Buse et al., 1993; Waring & Wo, 1997; Weaver, 1979; Bataller et al., 1995; Kohler et al., 1988; Garcia et al., 2002; Daher et al., 2010; Sánchez-Pernaute et al., 1999; Righini et al., 2007 ; Chatelain et al., 1998; Oguma et al., 2005 ; Rana et al., 2006 ; Schulewitz et al., 2007). Proximal esophageal web or stricture associated with Plummer-Vinson or Paterson-Kelly-Brown syndrome associated with sideroblastic anemia is now believed to complication of HGMP/CIP (Ainsley, 2011). Table 3 shows the listed of reported

Other conditions reported to be associated with laryngopharyngeal reflux include chronic obstructive airway disease exacerbations, obstructive sleep apnea and laryngopharyngeal neoplasms (Eryuksel et al., 2009; Wise et al., 2006; Copper et al., 2000). Indirectly, there may

The management of patients with HGMP/CIP depends on the presence of symptoms or complications following the clinico-pathological classification proposed by von-Rahden. For the majority of patients, HGMP/CIP are detected incidentally (type I) and as such do not require any treatment, follow up or surveillance. For patients with acid related symptoms, treatment with acid suppression with or without pro-kinetic and antacid will suffice. For majority, a short course of treatment will be adequate. However, for a proportion, prolonged acid suppression similar to patients with significant gastro-esophageal reflux

**7.7 Others** 

**8. Complications** 

for the diagnosis has also been reported.

complications associated with HGMP/CIP.

**9. Treatment/management** 

disorders may be required.

**8.1 Other possible associated with HGMP/CIP** 

be association with HGMP/CIP (Basseri et al., 2009; Satoh et al., 2007).
