Inflammatory myofibroblastic tumor‐like stromal proliferation within gastric inverted hyperplastic polyp

Abstract

Inflammatory myofibroblastic tumor-like stromal proliferation within gastric inverted hyperplastic polypTo the Editor: Gastric inverted hyperplastic polyp (IHP), a rare type of gastric polyp, is a downward-growing lesion composed of the proliferative gastric mucosal components of foveolar-, pyloric-, fundic-, or mixed-type epithelium that protrudes into the submucosal layer, mimicking a submucosal tumor. The pathogenesis of gastric IHP remains to be elucidated, although several hypotheses have been suggested. To date, 40 cases, including the case described in this report, have been reported. 1-4 We experienced an extremely rare histopathological transformation of a gastric IHP: an inflammatory myofibroblast tumor (IMT) arising within a gastric IHP, defined as a 'IMT-like stromal proliferation within gastric IHP', indicating a clinically borderline tumor, in an adult patient. We describe the characteristics of this lesion and provide a review of the relevant literature.A 58-year-old female patient was admitted to the department of internal medicine for assessment of the physical check-up abnormality of a submucosal tumor. She had no noticeable symptoms or medical or operational history with the exception that she was a 5 pack-years smoker. Her clinical physical examination was unremarkable and labora-

Gastric hamartomatous inverted polyp: Report of three cases with a review of the endoscopic and clinicopathological features

“…An EUS has been routinely performed for the qualitative diagnosis of SMT or to determine the depth of invasion of gastric tumors and has often revealed the presence of a multilocular anechoic region in the second or third layer of the gastric wall of the GHIP. 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 However, no specific features of GHIPs have been identified, and in the present series, the EUS revealed an atypical image of a cyst with partition walls and a hyperechoic nodule. In addition, previous reports showed that an EUS was performed in 25 patients (including six patients with adenocarcinoma components); however, no significant differences were noted in the EUS features of a GHIP with or without adenocarcinoma.…”

“…An EUS has been routinely performed for the qualitative diagnosis of SMT or to determine the depth of invasion of gastric tumors and has often revealed the presence of a multilocular anechoic region in the second or third layer of the gastric wall of the GHIP 7–27 . However, no specific features of GHIPs have been identified, and in the present series, the EUS revealed an atypical image of a cyst with partition walls and a hyperechoic nodule.…”

“…To the best of our knowledge, only 41 previously reported patients with GHIP have been reported in the English‐language literature (41 patients, 42 tumors because 1 patient had 2 GHIPs 6 ). 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 Only 9 patients with GHIPs, 24 patients with inverted hyperplastic polyps (1 patient had 2 lesions), and 8 patients with similar lesions given other names have been reported. Table 3 summarizes the clinicopathological and endoscopic features of these patients (Table S3 shows the detailed clinicopathological and endoscopic characteristics of the 42 tumors).…”

“…In addition, previous reports showed that an EUS was performed in 25 patients (including six patients with adenocarcinoma components); however, no significant differences were noted in the EUS features of a GHIP with or without adenocarcinoma. 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 Therefore, while an endoscopic diagnosis of a GHIP using the findings of EUS alone may not be possible, the EUS may be useful in determining whether an endoscopic resection may be performed. In the present study, only three patients had all the tumors endoscopically resected because one patient presented with hematemesis and anemia (Patient 1).…”

Gastric Inflammatory Myofibroblastic Tumor with Fludeoxyglucose (18F, FDG) Uptake on Positron Emission Tomography (PET): A Case Report and Literature Review

“…There is no radiological sign that serves as a diagnostic basis for gastric IMT [40][41][42][43][44][45]. Gastric IMTs have been reported to present as heterogeneous, lobar, calcified, cystic lesions on ultrasound and non-enhanced abdominal CT examinations [1], though they may manifest as homogeneous or heterogeneous lesions with central delayed enhancement and peripheral early filling [45,46].…”