A gigantic ectopic pancreatic lesion in the upper body of the stomach

Abstract

Endoscopy and radiography lead to the correct diagnosis in most patients with ectopic pancreas. Gastric lesions are found at the antrum in 85% to 95% of patients, either on the posterior or anterior wall, most commonly along the greater curvature.1Chandan V.S. Wang W. Pancreatic heterotopia in the gastric antrum.Arch Pathol Lab Med. 2004; 128: 111-112PubMed Google Scholar The most common characteristic gross feature is a central depression, which corresponds to a ductal orifice.2Christodoulidis G. Zacharoulis D. Barbanis S. et al.Heterotopic pancreas in the stomach: a case report and literature review.World J Gastroenterol. 2007; 13: 6098-6100Crossref PubMed Scopus (110) Google Scholar Histopathologic diagnosis is straightforward when pancreatic acini, ducts, islets of Langerhans, and intervening connective tissue are present. Here we report a case of a large, ectopic, pancreatic mass, about 7 cm in size, which was incidentally found in an unusual location during screening gastroscopy. To our knowledge, this is the first description of such a large, ectopic, pancreatic lesion in an unusual location.Case reportA 33-year-old man was referred to us with a large, unusually shaped, gastric mass lesion. The patient had no symptoms and no relevant medical history. Results of physical examination and laboratory testing performed on admission were normal. Endoscopic examination revealed a large, oddly shaped lesion on the anterior wall of the upper body of the stomach along the greater curvature (Fig. 1). The lesion resembled entangled tree roots, and the surface was covered with intact mucosa coated with sticky mucus. EUS revealed an approximately 5-cm, heterogeneous, hypoechoic lesion with anechoic spaces, which were traced as tubular structures inside the lesion (Fig. 2). No lymph node enlargement was detected, and the lesion did not invade the mucosal layer. CT revealed an approximately 7-cm, low attenuated lesion with rim enhancement in the gastric wall (Fig. 3). We performed a mucosectomy to obtain sufficient tissue to determine the nature of the lesion. Pathologic examination revealed definite ectopic pancreatic tissue including ductal and acini components (Fig. 4). We decided to follow-up the lesion at 6-month intervals after discussing this issue with the patient.Figure 2Radial endoscopic US findings (5 MHz). An approximately 5-cm (white dotted-line and white arrows), ill-defined, heterogeneous, hypoechoic lesion with anechoic spaces was observed. The lesion originated from the submucosal layer (third layer) and did not invade the mucosal layer.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3CT revealed an approximately 7-cm, low attenuation, longitudinal lesion with radiolucent internal components and rim enhancement in the gastric wall (black arrows).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 4Pathologic examination. Acini and ductal components were observed, suggesting ectopic pancreas (H&E, orig. mag. ×200).View Large Image Figure ViewerDownload Hi-res image Download (PPT)DiscussionThe term ectopic pancreas generally refers to well-developed and normally organized pancreatic tissue outside the pancreas, without anatomic or vascular connections with the true pancreas. The most common location is the stomach, accounting for 25% to 38% of cases, then the duodenum (17%-36%) and the jejunum (15%-21.7%). Ectopic pancreatic tissue is found rarely in the esophagus, gallbladder, common bile duct, spleen, mesentery, mediastinum, and fallopian tubes. The frequency of ectopic pancreas has been estimated as 1 case per 500 explorations of the upper abdomen or 0.6% to 13.7% of autopsies.3De Castro Barbosa J.J. Dockerty M.B. Waugh J.M. Pancreatic heterotopia: review of the literature and report of 41 authenticated surgical cases, of which 25 were clinically significant.Surg Gynecol Obstet. 1946; 82: 527-542PubMed Google Scholar, 4Dolan R.V. ReMine W.H. Dockerty M.B. The fate of heterotopic pancreatic tissue: a study of 212 cases.Arch Surg. 1974; 109: 762-765Crossref PubMed Scopus (267) Google ScholarThe case described here was unusual in 3 ways. First, the lesion was quite large, approximately 7 cm on CT. Ectopic pancreas sizes have been reported to be up to 2 cm.5Chen S.H. Huang W.H. Feng C.L. et al.Clinical analysis of ectopic pancreas with endoscopic ultrasonography: an experience in a medical center.J Gastrointest Surg. 2008; 12: 877-881Crossref PubMed Scopus (31) Google Scholar Second, the shape of the lesion differed from the typical presentation of ectopic pancreas. Ectopic pancreas in the stomach generally appears as a submucosal tumor with a central depression, which corresponds to the opening of a duct. However, the ectopic pancreas in our patient had a complicated, tangled tree root–like appearance, and it was covered with mucosa coated with mucus. Finally, the location was atypical. Gastric ectopic pancreas masses are discovered in the antrum in 85% to 95% of cases, either on the posterior or anterior wall, most commonly along the greater curvature.1Chandan V.S. Wang W. Pancreatic heterotopia in the gastric antrum.Arch Pathol Lab Med. 2004; 128: 111-112PubMed Google Scholar In our case, ectopic pancreas was located at the anterior side of the upper body of the stomach along the greater curvature. We suspected combined malignancy in this bizarre lesion,6Mizuno Y. Sumi Y. Nachi S. et al.Acinar cell carcinoma arising from an ectopic pancreas.Surg Today. 2007; 37: 704-707Crossref PubMed Scopus (46) Google Scholar but there was no evidence of cancer. Endoscopists should be aware that ectopic pancreatic lesions can present as very large and unusually shaped tumors in uncommon locations along the GI tract.DisclosureAll authors disclosed no financial relationships relevant to this publication. Endoscopy and radiography lead to the correct diagnosis in most patients with ectopic pancreas. Gastric lesions are found at the antrum in 85% to 95% of patients, either on the posterior or anterior wall, most commonly along the greater curvature.1Chandan V.S. Wang W. Pancreatic heterotopia in the gastric antrum.Arch Pathol Lab Med. 2004; 128: 111-112PubMed Google Scholar The most common characteristic gross feature is a central depression, which corresponds to a ductal orifice.2Christodoulidis G. Zacharoulis D. Barbanis S. et al.Heterotopic pancreas in the stomach: a case report and literature review.World J Gastroenterol. 2007; 13: 6098-6100Crossref PubMed Scopus (110) Google Scholar Histopathologic diagnosis is straightforward when pancreatic acini, ducts, islets of Langerhans, and intervening connective tissue are present. Here we report a case of a large, ectopic, pancreatic mass, about 7 cm in size, which was incidentally found in an unusual location during screening gastroscopy. To our knowledge, this is the first description of such a large, ectopic, pancreatic lesion in an unusual location. Case reportA 33-year-old man was referred to us with a large, unusually shaped, gastric mass lesion. The patient had no symptoms and no relevant medical history. Results of physical examination and laboratory testing performed on admission were normal. Endoscopic examination revealed a large, oddly shaped lesion on the anterior wall of the upper body of the stomach along the greater curvature (Fig. 1). The lesion resembled entangled tree roots, and the surface was covered with intact mucosa coated with sticky mucus. EUS revealed an approximately 5-cm, heterogeneous, hypoechoic lesion with anechoic spaces, which were traced as tubular structures inside the lesion (Fig. 2). No lymph node enlargement was detected, and the lesion did not invade the mucosal layer. CT revealed an approximately 7-cm, low attenuated lesion with rim enhancement in the gastric wall (Fig. 3). We performed a mucosectomy to obtain sufficient tissue to determine the nature of the lesion. Pathologic examination revealed definite ectopic pancreatic tissue including ductal and acini components (Fig. 4). We decided to follow-up the lesion at 6-month intervals after discussing this issue with the patient.Figure 3CT revealed an approximately 7-cm, low attenuation, longitudinal lesion with radiolucent internal components and rim enhancement in the gastric wall (black arrows).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 4Pathologic examination. Acini and ductal components were observed, suggesting ectopic pancreas (H&E, orig. mag. ×200).View Large Image Figure ViewerDownload Hi-res image Download (PPT) A 33-year-old man was referred to us with a large, unusually shaped, gastric mass lesion. The patient had no symptoms and no relevant medical history. Results of physical examination and laboratory testing performed on admission were normal. Endoscopic examination revealed a large, oddly shaped lesion on the anterior wall of the upper body of the stomach along the greater curvature (Fig. 1). The lesion resembled entangled tree roots, and the surface was covered with intact mucosa coated with sticky mucus. EUS revealed an approximately 5-cm, heterogeneous, hypoechoic lesion with anechoic spaces, which were traced as tubular structures inside the lesion (Fig. 2). No lymph node enlargement was detected, and the lesion did not invade the mucosal layer. CT revealed an approximately 7-cm, low attenuated lesion with rim enhancement in the gastric wall (Fig. 3). We performed a mucosectomy to obtain sufficient tissue to determine the nature of the lesion. Pathologic examination revealed definite ectopic pancreatic tissue including ductal and acini components (Fig. 4). We decided to follow-up the lesion at 6-month intervals after discussing this issue with the patient. DiscussionThe term ectopic pancreas generally refers to well-developed and normally organized pancreatic tissue outside the pancreas, without anatomic or vascular connections with the true pancreas. The most common location is the stomach, accounting for 25% to 38% of cases, then the duodenum (17%-36%) and the jejunum (15%-21.7%). Ectopic pancreatic tissue is found rarely in the esophagus, gallbladder, common bile duct, spleen, mesentery, mediastinum, and fallopian tubes. The frequency of ectopic pancreas has been estimated as 1 case per 500 explorations of the upper abdomen or 0.6% to 13.7% of autopsies.3De Castro Barbosa J.J. Dockerty M.B. Waugh J.M. Pancreatic heterotopia: review of the literature and report of 41 authenticated surgical cases, of which 25 were clinically significant.Surg Gynecol Obstet. 1946; 82: 527-542PubMed Google Scholar, 4Dolan R.V. ReMine W.H. Dockerty M.B. The fate of heterotopic pancreatic tissue: a study of 212 cases.Arch Surg. 1974; 109: 762-765Crossref PubMed Scopus (267) Google ScholarThe case described here was unusual in 3 ways. First, the lesion was quite large, approximately 7 cm on CT. Ectopic pancreas sizes have been reported to be up to 2 cm.5Chen S.H. Huang W.H. Feng C.L. et al.Clinical analysis of ectopic pancreas with endoscopic ultrasonography: an experience in a medical center.J Gastrointest Surg. 2008; 12: 877-881Crossref PubMed Scopus (31) Google Scholar Second, the shape of the lesion differed from the typical presentation of ectopic pancreas. Ectopic pancreas in the stomach generally appears as a submucosal tumor with a central depression, which corresponds to the opening of a duct. However, the ectopic pancreas in our patient had a complicated, tangled tree root–like appearance, and it was covered with mucosa coated with mucus. Finally, the location was atypical. Gastric ectopic pancreas masses are discovered in the antrum in 85% to 95% of cases, either on the posterior or anterior wall, most commonly along the greater curvature.1Chandan V.S. Wang W. Pancreatic heterotopia in the gastric antrum.Arch Pathol Lab Med. 2004; 128: 111-112PubMed Google Scholar In our case, ectopic pancreas was located at the anterior side of the upper body of the stomach along the greater curvature. We suspected combined malignancy in this bizarre lesion,6Mizuno Y. Sumi Y. Nachi S. et al.Acinar cell carcinoma arising from an ectopic pancreas.Surg Today. 2007; 37: 704-707Crossref PubMed Scopus (46) Google Scholar but there was no evidence of cancer. Endoscopists should be aware that ectopic pancreatic lesions can present as very large and unusually shaped tumors in uncommon locations along the GI tract. The term ectopic pancreas generally refers to well-developed and normally organized pancreatic tissue outside the pancreas, without anatomic or vascular connections with the true pancreas. The most common location is the stomach, accounting for 25% to 38% of cases, then the duodenum (17%-36%) and the jejunum (15%-21.7%). Ectopic pancreatic tissue is found rarely in the esophagus, gallbladder, common bile duct, spleen, mesentery, mediastinum, and fallopian tubes. The frequency of ectopic pancreas has been estimated as 1 case per 500 explorations of the upper abdomen or 0.6% to 13.7% of autopsies.3De Castro Barbosa J.J. Dockerty M.B. Waugh J.M. Pancreatic heterotopia: review of the literature and report of 41 authenticated surgical cases, of which 25 were clinically significant.Surg Gynecol Obstet. 1946; 82: 527-542PubMed Google Scholar, 4Dolan R.V. ReMine W.H. Dockerty M.B. The fate of heterotopic pancreatic tissue: a study of 212 cases.Arch Surg. 1974; 109: 762-765Crossref PubMed Scopus (267) Google Scholar The case described here was unusual in 3 ways. First, the lesion was quite large, approximately 7 cm on CT. Ectopic pancreas sizes have been reported to be up to 2 cm.5Chen S.H. Huang W.H. Feng C.L. et al.Clinical analysis of ectopic pancreas with endoscopic ultrasonography: an experience in a medical center.J Gastrointest Surg. 2008; 12: 877-881Crossref PubMed Scopus (31) Google Scholar Second, the shape of the lesion differed from the typical presentation of ectopic pancreas. Ectopic pancreas in the stomach generally appears as a submucosal tumor with a central depression, which corresponds to the opening of a duct. However, the ectopic pancreas in our patient had a complicated, tangled tree root–like appearance, and it was covered with mucosa coated with mucus. Finally, the location was atypical. Gastric ectopic pancreas masses are discovered in the antrum in 85% to 95% of cases, either on the posterior or anterior wall, most commonly along the greater curvature.1Chandan V.S. Wang W. Pancreatic heterotopia in the gastric antrum.Arch Pathol Lab Med. 2004; 128: 111-112PubMed Google Scholar In our case, ectopic pancreas was located at the anterior side of the upper body of the stomach along the greater curvature. We suspected combined malignancy in this bizarre lesion,6Mizuno Y. Sumi Y. Nachi S. et al.Acinar cell carcinoma arising from an ectopic pancreas.Surg Today. 2007; 37: 704-707Crossref PubMed Scopus (46) Google Scholar but there was no evidence of cancer. Endoscopists should be aware that ectopic pancreatic lesions can present as very large and unusually shaped tumors in uncommon locations along the GI tract. DisclosureAll authors disclosed no financial relationships relevant to this publication. All authors disclosed no financial relationships relevant to this publication.