A Gastric Hyperplastic Polyp Observed Endoscopically Before and After Autoamputation

• Introduction
• Case Report
• Discussion
• References

Autoamputation of a gastric polyp is a relatively rare phenomenon and its precise mechanism is unclear. To learn more about the mechanism(s) involved, it is important to observe a polyp just before and just after its disappearance. We report a case of a gastric polyp that was observed endoscopically just before and then just after autoamputation. A 61-year-old woman with a thumb-sized, pedunculated hyperplastic polyp in the gastric antrum visited our institution for investigation of hematemesis. She was being treated with oral hypoglycaemic drugs for diabetes mellitus but was not taking any other medicine around that time. Emergency gastroscopy revealed a bleeding point near the polyp; gastroscopy the next day revealed that the polyp had disappeared. It was concluded that autoamputation of a gastric polyp may follow gastric injury induced by diabetes mellitus or oral antidiabetic drugs.

Introduction

Autoamputation of a gastric polyp has been reported only occasionally [1] [2] [3] [4] and the precise mechanism of the phenomenon remains unclear. It is presumed that such an event may follow twisting caused by torsion or traction [2], disturbance resulting from instrumentation or gastric biopsy [3], or necrosis and cancerous infiltration of the polyp base [5]. To find out precisely how autoamputation occurs, a polyp would need to be observed just before and just after its disappearance. To date, however, there has been no literature describing such observations. This is the first case in which a gastric hyperplastic polyp, which disappeared in the course of a day, was observed endoscopically just before and just after autoamputation.

Case Report

A 61-year-old woman visited our institution for investigation of hematemesis. She had no other symptoms apart from poor appetite which she had had since the previous day. She had been treated at another clinic for diabetes mellitus with voglibose 0.9 mg and glibenclamide 1.25 mg per day for 27 months, and her hemoglobin A_1c (HbA_1c) values ranged from 7.0 % to 8.2 %. She was not taking nonsteroidal anti-inflammatory drugs, steroids, antibiotics, or any other medication. No significant abnormality was found in the past history, in the family history, or in the physical examination. Blood chemistry examination revealed iron-deficiency anemia (hemoglobin 10.4 g/dl) and diabetes mellitus (HbA_1c 7.6 %). A gastroscopy done 4 months previously in our institution had revealed a thumb-sized pedunculated polyp on the posterior wall of the gastric antrum (Figure [1]) and a little-finger-sized, semi-pedunculated polyp, arising from the major curvature of the gastric antrum. These polyps had been diagnosed endoscopically as hyperplastic polyps. Biopsy specimens obtained at that time from the head of the pedunculated polyp also showed that the polyp was hyperplastic and that it was positive for Helicobacter pylori.

Emergency gastroscopy revealed a bleeding point near the pedunculated polyp. The polyp was dark-colored, with a long, thin stalk, and was the same size as it had been 4 months previously. We diagnosed a shallow ulcer with bleeding and the bleeding point was treated by clipping it endoscopically (Figures [2 a - c]).

When gastroscopy was repeated the next day, the polyp had disappeared (Figure [3]). As the lesion was oozing, we treated it by endoscopic argon plasma coagulation to stop the bleeding. At this point we realised that the polyp had been either completely severed or almost severed near to its original site. The color of the polyp that was not circulated was dark on the emergency gastroscopy. A gastroscopy examination 1 year later showed that the lesion had scarred over without malignancy.

Discussion

Gastric polyps disappear for two reasons: reduction in size or autoamputation. A reduction in size has sometimes been reported in hyperplastic polyps after eradication of H. pylori [6] [7] and in fundic gland polyps in the stomach [8] [9]. Autoamputation, on the other hand, is a relatively rare event [1] [2] [3] [4]. Our patient's polyp was the same size on emergency gastroscopy as it had been 4 months previously, and yet, on gastroscopy the next day, the polyp had disappeared completely. The disappearance of the polyp must therefore have resulted from autoamputation.

The precise mechanism of this phenomenon remains unclear. As mentioned above, it has been presumed that such an event may follow twisting of the pedicles [2], medical intervention [3], or necrosis and cancerous infiltration of the polyp base [5]. It is important to observe a polyp just before and just after its disappearance in order to elucidate the precise mechanism of autoamputation, but such observations have not so far been reported in the literature. Ours is the first case observed endoscopically just before and just after a polyp was severed spontaneously and therefore presents extremely valuable evidence.

Most of the polyps which have detached spontaneously arose from the gastric antrum and were pedunculated [1] [2] [3] [4]. Gastric perstalsis in the antrum is strong, an pedunculated polyps in the antrum may be easily distorted and are subjected to mechanical traction, particularly polyps in the bulbus. Torsion or traction may result in twisting of a polyp, causing polyp necrosis and amputation, or tearing of the polyp stalk. Our patient's polyp was also found in the antrum and was pedunculated. However, it is thought that a gastric polyp has to be twisted over a period of several hours before autoamputation occurs, because strangulated intestine does not undergo necrosis unless the intestine remains twisted for several hours. It is also believed that polyps are knocked away from their original site if they are torn off by torsion or traction. As only the polyp head had been biopsied 4 months previously, the polyp could not have been cut at its base, either then or 4 months later, as a result of the biopsy technique. The stalk was smooth and the polyp was not suspected of malignancy, either endoscopically or histologically, and no sing of malignancy was found in the scar at endoscopy 1 year later. We believe that the postulated mechanisms for the disappearance of polyps by autoamputation, which had been reported in the literature, cannot explain the disappearance of our patient's polyp.

Our patient was receiving oral antidiabetic drugs, but her HbA_1c values demonstrated that her diabetes was not under good control. The polyp remained near to its original site, which was seen to be an area of shallow ulceration of a type sometimes induced by drugs, such as the nonsteroidal anti-inflammatory drugs. It has been reported that 9.4 % of diabetic patients are diagnosed with a gastric ulcer and that they develop gastric ulcers more easily than nondiabetics [10]. It has also been reported that oral antidiabetic drugs follow nonsteroidal inflammatory drugs, steroids, and antibiotics in importance as a cause of drug-induced gastric injury, causing 10.2 % of such lesions [11]. It was reported in one study that 36.8 % of diabetic patients treated with glibenclamide were diagnosed with gastric ulcer or erosive gastritis endoscopically [10].

It is thought that diabetes mellitus and oral antidiabetic drugs can cause gastric injury and that this is due to impairment of gastric mucosal defense mechanisms, resulting from microvascular damage and an increase in harmful substances in the mucosa [10]. Our patient was positive for H. pylori, a finding closely related to the development of peptic ulcer, which increased her susceptibility to developing gastric injury. It is possible therefore, that her condition caused her to develop gastric injury at the base of the polyp and that this led to amputation of the polyp. If gastric injury was the cause of the autoamputation, this would explain why the polyp remained near the polyp base.

We believe that the most likely explanation for the autoamputation of the gastric polyp in our patient was gastric injury induced by diabetes mellitus or antidiabetic drugs.

References

• 1 Quain R. Case of polypus ejected from stomach.  Trans Pathol Soc (London). 1857;  8 219-221
  PubMedSearch in Google Scholar
• 2 Okumura H, Kanie T, Sekiya M. et al . A solitary giant polyp in the cardiac region which had fallen off spontaneously (In Japanese with English abstract).  Stomach Intest. 1969;  4 1259-1263
  PubMedSearch in Google Scholar
• 3 Tsukamoto Y, Nishitani H, Oshiumi Y, Okawa T. Spontaneous disappearance of gastric polyps: report of four cases.  Am J Roentgenol. 1977;  129 893-897
  PubMedSearch in Google Scholar
• 4 Kamiya T, Morishita T, Asakura H. et al . Histoclinical long-standing follow-up study of hyperplastic polyp of the stomach.  Am J Gastroenterol. 1981;  75 275-281
  PubMedSearch in Google Scholar
• 5 Furusawa M, Koga M, Soejima K. et al . A protruding type of advanced carcinoma of the stomach followed up as a polyp for four years: report of a case (In Japanese with English abstract).  Stomach Intest. 1973;  8 597-603
  PubMedSearch in Google Scholar
• 6 Ohkusa T, Takashimizu I, Fujiki K. et al . Disappearance of hyperplastic polyps in the stomach after eradication of Helicobacter pylori: a randomised clinical trial.  Ann Intern Med. 1998;  129 712-715
  CrossrefPubMedSearch in Google Scholar
• 7 Veereman Wauters G, Ferrell L, Ostroff J W, Heimann M G. Hyperplastic gastric polyps associated with persistent Helicobacter pylori infection and active gastritis.  Am J Gastroenterol. 1990;  85 1395-1397
  PubMedSearch in Google Scholar
• 8 Iida M, Yano T, Watanabe H. et al . Spontaneous disappearance of fundic gland polyposis: report of three cases.  Gastroenterology. 1980;  79 725-728
  PubMedSearch in Google Scholar
• 9 Hizawa K, Iida M, Matsumoto T. et al . Natural history of fundic gland polyposis without familial adenomatosis coli: follow-up observations in 31 patients.  Radiology. 1993;  189 429-432
  PubMedSearch in Google Scholar
• 10 Abe C. A study of gastric mucosal lesions in diabetes mellitus, especially treated with oral hypoglycemic agents - measuring gastric mucosal blood flow and hexosamine content in gastric mucosa (In Japanese with English abstract).  Gastroenterol Endosc. 1996;  38 271-278
  PubMedSearch in Google Scholar
• 11 Namiki M. Drug-induced acute gastrointestinal mucosal lesions (In Japanese).  Curr Ther. 1983;  11 1627-1636
  PubMedSearch in Google Scholar

T. Nakajima, M. D.

Department of Gastroenterology · Niigata Central Hospital

1-18 Shinko-chou · Niigata City · Niigata 950-8556 · Japan

Fax: + 81-25-283-7203

Email: oide-oide@nyc.odn.ne.jp

References

• 1 Quain R. Case of polypus ejected from stomach.  Trans Pathol Soc (London). 1857;  8 219-221
  PubMedSearch in Google Scholar
• 2 Okumura H, Kanie T, Sekiya M. et al . A solitary giant polyp in the cardiac region which had fallen off spontaneously (In Japanese with English abstract).  Stomach Intest. 1969;  4 1259-1263
  PubMedSearch in Google Scholar
• 3 Tsukamoto Y, Nishitani H, Oshiumi Y, Okawa T. Spontaneous disappearance of gastric polyps: report of four cases.  Am J Roentgenol. 1977;  129 893-897
  PubMedSearch in Google Scholar
• 4 Kamiya T, Morishita T, Asakura H. et al . Histoclinical long-standing follow-up study of hyperplastic polyp of the stomach.  Am J Gastroenterol. 1981;  75 275-281
  PubMedSearch in Google Scholar
• 5 Furusawa M, Koga M, Soejima K. et al . A protruding type of advanced carcinoma of the stomach followed up as a polyp for four years: report of a case (In Japanese with English abstract).  Stomach Intest. 1973;  8 597-603
  PubMedSearch in Google Scholar
• 6 Ohkusa T, Takashimizu I, Fujiki K. et al . Disappearance of hyperplastic polyps in the stomach after eradication of Helicobacter pylori: a randomised clinical trial.  Ann Intern Med. 1998;  129 712-715
  CrossrefPubMedSearch in Google Scholar
• 7 Veereman Wauters G, Ferrell L, Ostroff J W, Heimann M G. Hyperplastic gastric polyps associated with persistent Helicobacter pylori infection and active gastritis.  Am J Gastroenterol. 1990;  85 1395-1397
  PubMedSearch in Google Scholar
• 8 Iida M, Yano T, Watanabe H. et al . Spontaneous disappearance of fundic gland polyposis: report of three cases.  Gastroenterology. 1980;  79 725-728
  PubMedSearch in Google Scholar
• 9 Hizawa K, Iida M, Matsumoto T. et al . Natural history of fundic gland polyposis without familial adenomatosis coli: follow-up observations in 31 patients.  Radiology. 1993;  189 429-432
  PubMedSearch in Google Scholar
• 10 Abe C. A study of gastric mucosal lesions in diabetes mellitus, especially treated with oral hypoglycemic agents - measuring gastric mucosal blood flow and hexosamine content in gastric mucosa (In Japanese with English abstract).  Gastroenterol Endosc. 1996;  38 271-278
  PubMedSearch in Google Scholar
• 11 Namiki M. Drug-induced acute gastrointestinal mucosal lesions (In Japanese).  Curr Ther. 1983;  11 1627-1636
  PubMedSearch in Google Scholar

T. Nakajima, M. D.

Department of Gastroenterology · Niigata Central Hospital

1-18 Shinko-chou · Niigata City · Niigata 950-8556 · Japan

Fax: + 81-25-283-7203

Email: oide-oide@nyc.odn.ne.jp