Case Report
Iron Deficiency Anemia Masking Adenomyoma of the Jejunum
Mary Dougherty1, Muhammad Bader Hammami2,3, Anuj Chhaparia2, Jinping Lai4, Christine Hachem1,2
1Department of Gastroenterology, 2Department of Internal Medicine, 3Division of Gastroenterology and Hepatology, 4Department of Pathology, Saint Louis University, Saint Louis University School of Medicine, St. Louis, MO, USA

Corresponding Author
Dr Anuj Chhaparia


Intestinal adenomyomas, also known as myoepithelialhamartomas, are benign non-neoplastic tumor-like lesions characterized by glandular structures lined by cuboidal or tall columnar epithelium and surrounded by smooth muscle bundles. Reported cases of adenomyoma of the gastrointestinal tract have been largely confined to the stomach and duodenum, with lesions distal to the duodenum occurring less frequently. Here we report a case of adenomyoma of the jejunum that presented with anemia, along with a review of the literature.

Case Report 

A 62 year old woman with history of heartburn and cholecystectomy presented for bronchial thermoplasty for treatment of asthma. She was incidentally found to have iron deficiency anemia. Anemia was evaluated with upper and lower endoscopy, and findings were negative for suspicious pathology or source of bleeding. Capsule video endoscopy revealed a pedunculated 10 mm polyp in the distal jejunum/proximal ileum. Endoscopic removal of the polyp was completed by double balloon enteroscopy. Grossly, the lesion was polypoid shaped measuring 0.9x0.8x0.6 cm (Figure 1). Microscopically, it was a well-circumscribed submucosal lesion composed of variably sized glandular structures surrounded by smooth muscle bundles. The glandular structures showed pyloric morphology and were lined by cuboidal or columnar epithelium with interspersed goblet cells and occasional Paneth cells (Figure 2). Immune-stains were performed with appropriate controls. The lesional epithelial component was strongly and diffusely positive for CK7 and CK19 and weakly positive for CDX2, but negative for CK20 (Figure 3). The smooth muscle component was positive for desmin and alpha-SMA. Ki-67/MIB-1, highlighting rare lymphocytes in the lesion and basal cells of the small intestinal mucosal epithelium (Figure 4). All pathologic features supported a final diagnosis of adenomyoma. The patient’s postoperative course was complicated by transient abdominal pain and bloating after the procedure. Abdominal X-ray was negative for free intra-abdominal air or perforation. Her pain resolved overnight and she was discharged the following morning. Upon follow-up one year later, she continues to do well, and the anemia has resolved.


Myoepithelialhamartoma of the gastrointestinal tract was first described by Clarkein 1940.5 While the incidence of small intestine adenomyoma is relatively rare, the actual incidence is unclear because very few cases have been reported. Review of the literature reveals 34 reported cases in the small intestine,3,5-13,15-21,23-34  including the duodenum, ampulla of Vater, and ileum, with 11 well-documented cases reported in the jejunum (Table 1).3,5,9-10,16-17, 20-21,29,31,34 Of these cases, the patients were between the ages of three to eighty one years old, with six women and five men. While they are typically asymptomatic, symptoms of intestinal adenomyoma vary depending on the size, location of the lesion, and patient age.  In the periampullary region, adenomyoma typically presents with biliary obstruction or abdominal pain, with reported cases of acute pancreatitis.14,22 Lesions in the ileum and jejunum have presented with intussusception and intestinal obstruction,29 but many reported cases have been incidentally detected. In the small intestine, intussusception is its most common complication, reported in 19 cases.1-3,6-8,11-13,15-20,24-25,27,32-33 Anemia has been reported in 11.7% of the cases described (4 cases).  Most cases were surgically removed (26 cases), which may be attributed to a high number of laparotomies due to the adenomymoma presenting with intussusception, and a small percentage were removed endoscopically (3 cases).   Microscopically, intestinaladenomyomas are submucosal tumors characterized by glandular structures lined by cuboidal or tall columnar epithelium and surrounded by bundles of smooth muscle.21 The differential diagnosis of this pathological presentation includes: enteritis cysticaprofunda, hamartomatous polyps in Peutz-Jeghers syndrome, adenocarcinoma, and pneumatosiscystoides. The pathogenesis of adenomyoma remains unclear, but the most widely accepted hypothesis is that it represents either a form of myoepithelialhamartoma or pancreatic heterotopia.26  The term ‘hamartoma’ refers to a focal but excessive overgrowth of cells indigenous to the particular site, while the term ‘heterotopia’ refers to microscopically normal cells that are present in an abnormal location.  Clarke suggested that the classification of ‘adenomyoma’ be used only for lesions with exocrine-type ducts without ectopic pancreatic acini or islets surrounded by smooth muscle, and that the term ‘pancreatic heterotopia’ should refer to lesions with ectopic pancreatic acini or islets.5 In our case, we performed immunohistochemical testing in an attempt to increase our understanding of the origins of the adenomyoma. We detected the expression of CK7 and CK19, weak expression of CDX2, and the absence of CK20 expression. In general, CK7 is distributed in the pancreatic duct epithelium but is essentially absent in GI epithelium. CK20 is distributed in the GI epithelium but is absent in pancreatic duct epithelium.4 Thus, theimmunohistochemical features of the lesion are similar to that of the pancreatic duct epithelium and appear to support the heterotopic pancreas hypothesis. However, most reported cases of adenomyoma, including our present case, do not contain pancreatic tissue. In fact, the glandular structures showed pyloric morphology and were lined by cuboidal or columnar epithelium with interspersed goblet cells and occasional Paneth cells, suggesting a pyloric origin. Qing et al.(2009) and Tomibayashi et al. (2011) also reported cases of adenomyoma of the jejunum with goblet cells. Goblet cells were also found in a case of adenomyoma in a Meckel’s diverticulum.33


Adenomyoma of the small intestine is an extremely rare tumor largely unknown to most clinicians. While typically asymptomatic, symptoms of intestinal adenomyoma vary depending on size, location, and patient age. In our patient this lesion was likely the source of chronic GI bleeding manifesting as anemia. The prognosis of adenomyoma is excellent, with no evidence of recurrence or metastatic transformation in reported cases. Treatment of asymptomatic or bleeding adenomyomas is simple resection. Nevertheless, the pathogenesis of small bowel adenomyoma is not well understood due to its rarity, making further studies necessary. 

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