Heterotopic pancreas of the stomach: CT findings correlated with pathologic findings in six patients

A CT-based nomogram established for differentiating gastrointestinal heterotopic pancreas from gastrointestinal stromal tumor: compared with a machine-learning model

OBJECTIVE

To identify CT features and establish a nomogram, compared with a machine learning-based model for distinguishing gastrointestinal heterotopic pancreas (HP) from gastrointestinal stromal tumor (GIST).

MATERIALS AND METHODS

This retrospective study included 148 patients with pathologically confirmed HP (n = 48) and GIST (n = 100) in the stomach or small intestine that were less than 3 cm in size. Clinical information and CT characteristics were collected. A nomogram on account of lasso regression and multivariate logistic regression, and a RandomForest (RF) model based on significant variables in univariate analyses were established. Receiver operating characteristic (ROC) curve, mean area under the curve (AUC), calibration curve and decision curve analysis (DCA) were carried out to evaluate and compare the diagnostic ability of models.

RESULTS

The nomogram identified five CT features as independent predictors of HP diagnosis: age, location, LD/SD ratio, duct-like structure, and HU lesion/pancreas A. Five features were included in RF model and ranked according to their relevance to the differential diagnosis: LD/SD ratio, HU lesion/pancreas A, location, peritumoral hypodensity line and age. The nomogram and RF model yielded AUC of 0.951 (95% CI: 0.842-0.993) and 0.894 (95% CI: 0.766-0.966), respectively. The DeLong test found no statistically significant difference in diagnostic performance (p > 0.05), but DCA revealed that the nomogram surpassed the RF model in clinical usefulness.

CONCLUSION

Two diagnostic prediction models based on a nomogram as well as RF method were reliable and easy-to-use for distinguishing between HP and GIST, which might also assist treatment planning.

Duodenal Heterotopic Pancreas with a Large Retention Cyst: A Case Report and Literature Review

A 75-year-old man was referred to our hospital with a suspected pancreatic cyst. Imaging tests revealed a 3-cm cystic lesion located ventrally in the duodenal bulbus, which was suspected to be a duplication cyst with its muscularis propria contiguous to that of the duodenum. One year later, the cyst grew to 6 cm due to intracystic hemorrhaging; therefore, surgery was performed. Histopathology revealed a heterotopic pancreas (HP) in the duodenal wall. The diagnosis was a large, non-malignant retention cyst. Inflammation due to impaired outflow of pancreatic juice from the HP was identified as the cause of cyst enlargement.

Localization and Laparoscopic Excision of Gastric Heterotopic Pancreas in a Child by Endoscopic SPOT® Tattooing

Heterotopic pancreas (HP) is defined as pancreatic tissue lacking vascular or anatomic connection with the normal pancreas. Surgical resection is often indicated for symptomatic gastric HP. However, intraoperative identification of gastric HP is often difficult during laparoscopic surgery. Herein, we describe a patient with gastric HP, which was marked with SPOT^® dye (GI Supply, Camp Hill, PA, USA). The dye was seen clearly laparoscopically facilitating total excision of the lesion. The final pathology report confirmed the presence of heterotopic pancreatic tissue including pancreatic acini, small pancreatic ducts tissue with islets of Langerhans in the deep gastric submucosal area. There were no postoperative complications, and the patient was symptom-free. To the best of our knowledge, this was the first case report in the literature in which endoscopic tattooing of gastric HP before laparoscopic resection was performed. This method of localization was simple and reliable in children.

Acute Ectopic Pancreatitis Mimicking Peptic Ulcer Disease: A Case Report

BACKGROUND

Ectopic pancreas is an anatomically separate pancreatic tissue from normal glands with its own vascular and ductal system and most commonly occurs in the upper gastrointestinal tract. Ectopic pancreas is usually asymptomatic, but it can present with symptoms associated with complications, including bleeding, inflammation, and neoplasm without abnormalities in the normal pancreas.

CASE PRESENTATION

We report a 31-year-old female with acute ectopic pancreatitis involving gastric antrum and proximal duodenum mimicking peptic ulcer disease, without pancreatitis in the normal pancreas.

CONCLUSION

Ectopic pancreatitis is a rare condition and can mimic more common diseases depending on the anatomical location.

Insight into gastrointestinal heterotopic pancreas: imaging evaluation and differential diagnosis

Heterotopic pancreas (HP) is an uncommon congenital abnormality in the developmental process of the pancreas, with gastrointestinal heterotopic pancreas (GHP) being the most common HP. The clinical manifestations of GHP may have variable patterns of presentation, dictated by both the anatomic location and the functional ability of the lesion. The most common imaging modality in detecting GHP is computed tomography (CT), while gastrointestinal barium fluoroscopy, endoscopic ultrasonography, and magnetic resonance imaging (MRI) are also applied. The density and enhancement patterns of GHP are consistent with histological classifications. GHP with a predominantly acinar tissue component manifests homogeneous and marked enhancement on CT images, whereas a predominantly ductal GHP presents heterogeneous and mild enhancement. On MRI, the appearance and signal intensity of GHP were paralleled to the normal pancreas on all sequences and were characterized by T1-weighted high signal and early marked enhancement. This article provides a comprehensive review of the histopathology, clinical manifestations, imaging features of various modalities, and differential diagnosis of GHP. It is hoped that this review will improve clinicians' knowledge of GHP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate.

CT differentiation of gastric ectopic pancreas from gastric stromal tumor

Background

Gastric ectopic pancreas (GEPs) is a rare developmental anomaly which is difficult to differentiate it from submucosal tumor such as gastric stromal tumor (GST) by imaging methods. Since the treatments of the GEPs and GST are totally different, a correct diagnosis is essential. Therefore, we retrospectively investigated the CT features of them to help us deepen the understanding of GEPs and GST.

Methods

This study enrolled 17 GEPs and 119 GST, which were proven pathologically. We assessed clinical and CT features to identify significant differential features of GEPs from GST using univariate and multivariate analyses.

Results

In univariate analysis, among all clinicoradiologic features, features of age, symptom, tumor marker, location, contour, peritumoral infiltration or fat-line of peritumor, necrosis, calcification, CT attenuation value of unenhancement phase/arterial phase/portal venous phase (CTu/CTa/CTp), the CT attenuation value of arterial phase/portal venous phase minus that of unenhanced phase (DEAP/DEPP), long diameter (LD), short diameter (SD) were considered statistically significant for the differentiation of them. And the multivariate analysis revealed that location, peritumoral infiltration or fat-line of peritumor, necrosis and DEPP were independent factors affecting the identification of them. In addition, ROC analysis showed that the test efficiency of CTp was perfect (AUC = 0.900).

Conclusion

Location, the presence of peritumoral infiltration or fat-line of peritumor, necrosis and DEPP are useful CT differentiators of GEPs from GST. In addition, the test efficiency of CTp in differentiating them was perfect (AUC = 0.900).

Use of computed tomography for distinguishing heterotopic pancreas from gastrointestinal stromal tumor and leiomyoma

PURPOSE

To determine whether morphologic features and semiquantitative parameters of computed tomography (CT) could be used to distinguish heterotopic pancreas from gastrointestinal stromal tumor (GIST) and leiomyoma.

METHODS

This retrospective study evaluated CT images of heterotopic pancreases (n = 28), GISTs (n = 57), and leiomyomas (n = 26) located in the upper gastrointestinal tract. Morphologic imaging features of lesions were analyzed, including location, contour, margin, attenuation, growth pattern, enhancement type, enhancement degree, enlarged vessels feeding or draining the mass, hyperenhancement of the overlying mucosa, low intralesional attenuation, calcification, and a duct-like structure. Semiquantitative parameters included long diameter (LD), short diameter (SD), LD/SD ratio, and lesion and aorta CT values during plain CT (Lp and Ap), arterial phase (La and Aa), and venous phase (Lv and Av). Diagnostic performance of these findings and parameters were evaluated by receiver operating characteristic (ROC) analysis.

RESULTS

Morphologic CT findings (including lesion contour, margin, attenuation, growth pattern, enhancement type, and enhancement degree) and semiquantitative parameters except for LD/SD were demonstrated to be significant for differentiating heterotopic pancreas from GIST and leiomyoma (all P < 0.01). Of these, location, low intralesional attenuation, duct-like structure and LD, SD, Lv, and Sv values showed good diagnostic performance with the areas under curve (AUC) higher than 0.70. The presence of a duct-like structure demonstrated the best diagnostic ability with AUC of 0.929 [95% confidence interval (CI) 0.864-0.969], sensitivity of 5.7% (95% CI 67.3-96.0), and specificity of 100% (95% CI 95.7-100), respectively. When the three morphologic features (location, low intralesional attenuation, duct-like structure) were used in combination, the AUC was improved to 0.980 (95% CI 0.952-1).

CONCLUSION

CT features, especially the morphologic features, could be used to differentiate heterotopic pancreas from GIST and leiomyoma in the upper gastrointestinal tract and, thus, provide a more accurate method for non-invasive preoperative diagnosis. Additionally, the presence of a duct-like structure demonstrated to be a reliable indicator for heterotopic pancreas among the morphologic and semiquantitative CT features.

Intramural ectopic pancreatic tissue of the stomach: A case report of an uncommon origin of a non-cancerous gastric tumour

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Ectopic pancreatic tissue is a rare incidental finding during abdominal surgery.

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80% of the lesions are unifocal and less than 3 cm in size.

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The most frequent site is the stomach, followed by duodenum and proximal jejunum.

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The imaging modalities and endoscopic biopsy often remain inconclusive.

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Only resection and and histopathologic examination provide the definitve diagnosis.

Introduction

Ectopic pancreatic tissue is often incidentally encountered during abdominal surgery. We report a case of an incidental finding during a laparoscopic appendectomy, the approach to diagnosis and management of this.

The work has been reported in line with the SCARE criteria.

Presentation of case

A 32 year-old woman was diagnosed with an intramural pre-pyloric mass during a laparoscopic appendectomy. The lesion was identified on a subsequent computed tomography as a homogenous mass on the greater curvature. Upper esophagho-gastro-duodenoscopy was normal. The intramural mass was confirmed by an endoscopic sonography and the fine needle biopsy showed aspecific inflammatory cells. A laparoscopic wedge resection was realized. Histopathologic examination confirmed the diagnosis of an ectopic pancreatic tissue.

Discussion

The management of ectopic pancreas poses a medical challenge. The diagnostic quiver consists of radiologic exams and endoscopy, in combination with a direct biopsy of the lesion.

Conclusion

Despite the plethora of diagnostic modalities available, a definitive diagnosis for heterotopic pancreas often remains elusive, requiring more invasive diagnostic means. Although ample information is available in literature, there are currently no evidence-based guidelines regarding diagnosis and management of heterotopic pancreas.

Mesenteric heterotopic pancreas in a pediatric patient: A case report and review of literature

Heterotopic pancreas (HP) is a congenital anomaly defined as pancreatic tissue that has no contact with the orthotopic pancreas and its own duct system and vascular supply. The most common locations of HP are the upper gastrointestinal tract, specifically, the stomach, duodenum, and proximal jejunum. Involvement of the mesentery is rare. Here, we describe a rare case of mesenteric heterotopic pancreas (MHP) in a 12-year-old girl who presented with acute abdomen. The patient underwent emergency laparotomy, and the mass and adjacent small bowel were resected. Results of the postoperative histopathologic examination confirmed the diagnosis of MHP. Observation of the patient for 12 mo postoperatively showed no evidence of recurrence. Preoperative diagnosis of HP is difficult, even in a symptomatic patient. Increased awareness and understanding of the image characteristics of MHP will aid in correct preoperative diagnosis and appropriate patient management.

Gastric heterotopic pancreas and stromal tumors smaller than 3 cm in diameter: clinical and computed tomography findings

BACKGROUND

Identifying gastric heterotopic pancreas and stromal tumors is difficult. Few studies have reported computed tomography (CT) findings for differentiating lesions less than 3 cm in diameter. In this study, we aimed to identify clinical characteristics and CT findings that can differentiate gastric heterotopic pancreatic lesions from stromal tumors less than 3 cm in diameter.

METHODS

A total of 132 patients with pathologically confirmed gastric heterotopic pancreas (n = 66) and stromal tumors (n = 66) were included. Each group was divided into primary (n = 50) and validation cohort (n = 16). Clinical characteristics and CT findings were retrospectively reviewed. CT findings included location, border, contour, growth pattern, enhancement pattern and grade, the enhancement value of tumor, enhancement ratio of tumor, and enhancement ratio of tumor to pancreas in venous phase. The findings in the two groups were compared using the Pearson χ² test or Student t-test. Receiver operating characteristic curves were used to determine areas under the curve and optimal cut-offs.

RESULTS

Significant differences were observed between heterotopic pancreas and stromal tumors in the distribution of tumor location, border, contour (all P < 0.001), enhancement values (P < 0.001), enhancement ratios of tumors (P < 0.001), and enhancement ratios of tumors to pancreas (P < 0.001). No significant differences existed in growth pattern (P = 0.203). The area under the curve differed significantly between enhancement ratio of tumor to pancreas and enhancement ratio (P = 0.030). There were significant differences in above characteristics between two groups in validation cohort.

CONCLUSIONS

Heterotopic pancreas has characteristic CT features differentiating it from stromal tumors.

Ectopic Pancreas in the Gastric Antrum Wall Complicated by Ectopic Pancreatitis and Persistent Gastric Abscess

Ectopic pancreas is an uncommon finding in the stomach. Complications are rare but can lead to significant morbidity and even mortality. We report a 49-year-old man who presented with upper abdominal pain, vomiting, and weight loss and was found to have a gastric wall abscess that developed a few weeks after endoscopic biopsy of a gastric ulcer. After medical treatment failed to resolve his symptoms, he underwent distal gastrectomy with Roux-en-Y gastrojejunostomy. Postoperatively, the gastric wall abscess was determined to have derived from a focus of ectopic pancreatic tissue with evidence of ectopic chronic pancreatitis.

Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications

Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery. ^© RSNA, 2017.

Diagnostic performance of stomach CT compared with endoscopic ultrasonography in diagnosing gastric subepithelial tumors

PURPOSE

To evaluate the diagnostic ability of multi-detector computed tomography (MDCT) compared to endoscopic ultrasonography (EUS) as a standard reference, and investigate the factors influencing the detection of small gastric subepithelial tumors (SETs) (<5 cm) on MDCT with stomach protocol.

METHODS

We retrospectively investigated 70 patients who were suspected with gastric SETs on esophagogastroduodenoscopy (EGD), and underwent both EUS and computed tomographic (CT) scanning. EUS was performed by two gastroenterologists, and location, size, echotexture, echogenicity, and layer of origin were described when gastric SETs were detected on EUS. MDCTs were reviewed based on consensus of two radiologists blinded to the EUS result. Size, location, enhancement pattern, and contour of the lesion detected on CT were described. We calculated the diagnostic ability of CT compared to EUS with respect to detection of gastric SETs, and investigated the factors influencing detection of SETs on CT. We also used receiver operating characteristic (ROC) curve to obtain optimal cut-off size for predicting CT visibility of small SETs.

RESULTS

Of the 70 patients, who underwent both CT and EUS due to suspicious presence of SET on EGD, EUS detected 56 probable cases of SET and 14 cases of external compression. CT led to detection of 39 cases of SET out of the 56 cases. Sensitivity and specificity of CT was 69.6% and 100.0%, respectively. Positive predictive value (PPV) and negative predictive value (NPV) of CT were 100.0% and 45.2%, respectively. There was a significant difference in mean size of CT-detected lesions compared to CT-invisible lesions (14.36 mm vs. 8.52 mm, p < 0.001), but no significant differences in terms of layer of origin and location between these two groups (p > 0.5) were observed. The ROC analysis revealed that the optimal cut-off value, also referred to prediction of CT visibility, was 10 mm. Out of 70 cases, 26 cases (37.14%) were identified as external compression or insignificant lesions such as lipoma, hemangioma, lymphangioma, or gastritis cystica on CT, and do not require regular follow-up.

CONCLUSIONS

Stomach CT shows good feasibility with respect to depiction of small SETs, especially in cases where size is larger than 10 mm. Henceforth, it is proposed that stomach CT would be a complimentary or problem-solving tool for SET in evaluating the presence of external compression and characterization of tumors.

Beyond gastric adenocarcinoma: Multimodality assessment of common and uncommon gastric neoplasms

Despite advances in molecular biology, imaging, and treatment, gastric neoplasms remain a significant cause of morbidity and mortality; gastric adenocarcinoma is the fifth most common malignancy and third most common cause of death worldwide (Brenner et al., Methods Mol Biol 472:467-477, 2009; Howson et al. Epidemiol Rev 8:1-27, 1986; Roder, Gastric Cancer 5(Suppl 1):5-11, 2002; Ferlay et al., GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. International Agency for Research on Cancer, 2013). Because of both the frequency at which malignant gastric tumors occur as well as the worldwide impact, gastric neoplasms remain important lesions to identify and characterize on all imaging modalities. Despite the varied histologies and behaviors of these neoplasms, many have similar imaging features. Nonetheless, the treatment, management, and prognosis of gastric neoplasms vary by pathology, so it is essential for the radiologist to make every effort to differentiate between these lesions and raise the less common entities as differential diagnostic considerations when appropriate.

Heterotopic pancreatic pseudocyst radiologically mimicking gastrointestinal stromal tumor

Heterotopic pancreas is a relatively common variant of foregut embryologic dystopia that can be described as pancreatic tissue found outside the normal anatomic location, being independent from vascular supply of normal pancreas. Having all features of pancreatic tissue except for the major duct structures, this ectopic tissue may be clinically recognized when pathologic changes take place. Inflammation, hemorrhagic or obstructive states, and eventually malignancy-related problems may become a diagnostic challenge for clinician and finally lead to consequences of misdiagnosis. In this article we will discuss a case of heterotopic pancreatic tissue located in gastric cardia, which was diagnosed preoperatively as gastrointestinal stromal tumor.

Inflammatory fibroid polyps of the gastrointestinal tract: a 14-year CT study at a single institution

PURPOSE

To investigate the computed tomography (CT) features of pathology-proven inflammatory fibroid polyps (IFPs) in the gastrointestinal tract.

METHODS

This retrospective series study included 27 patients with pathology-proven IFPs in the stomach (n = 16), small (n = 9), and large (n = 2) intestine, who underwent contrast-enhanced CT. Two radiologists reviewed the CT images of the patients to determine in consensus the long diameter, shape, margin, contour, and growth pattern of the lesions, the presence of an ulcer and overlying mucosal hyperenhancement, the lesion enhancement patterns including the homogeneity and the degree of contrast enhancement, and the presence of intussusception and obstruction. The CT results and clinical data of the gastric and intestinal lesions were compared.

RESULTS

The IFPs typically manifested as well-defined (89%), round or ovoid (81%), slightly lobulated-contoured (70%) masses with a purely endoluminal growth pattern (96%) and an overlying mucosal hyperenhancement (67%). Lesion homogeneity and the degree of contrast enhancement varied. The intestinal IFPs were significantly larger (3.5 vs. 2 cm), more symptomatic (82% vs. 19%), and more frequently associated with intussusception (73% vs. 0%) and obstruction (46% vs. 6%) than the gastric lesions (p ≤ 0.027).

CONCLUSIONS

The characteristic CT features of IFPs were well-defined, round or ovoid, lobulated-contoured, and endoluminal masses with overlying mucosal hyperenhancement and various enhancement patterns. IFP should be included in the differential diagnosis of patients with a soft-tissue mass in the gastrointestinal tract, especially if a large endoluminal mass in the small intestine is accompanied by intussusception.

[Gastric adenomyoma clinically simulating hypertrophic pyloric stenosis]

Gastric adenomyomas are extremely uncommon benign tumors in children. On histologic examination, these tumors have an epithelial component similar to pancreatic ducts. We present a case of a pyloric adenomyoma that clinically simulated hypertrophic pyloric stenosis in a newborn girl. Imaging tests, fundamentally magnetic resonance imaging, were very important in the characterization and diagnosis of this entity.

Heterotopic pancreas of the jejunum: associations between CT and pathology features

PURPOSE

To investigate the computed tomography (CT) features of heterotopic pancreas of the jejunum (HPJ) and to assess their associations with HPJ pathology features.

METHODS

In this retrospective series analysis, two radiologists reviewed the CT images of 17 patients with surgically proven HPJ in order to determine in consensus the location, long diameter, margin, shape, contour, and growth pattern of the lesions, the presence of a duct-like structure, the lesion enhancement patterns, including the homogeneity, and the degree of contrast enhancement compared with that of the main pancreas. The pathology features of the surgical specimens were reviewed and their associations with the CT features were assessed.

RESULTS

On CT, the HPJs typically appeared as a small (<3 cm), well-defined, ovoid or flat-shaped mass in the proximal jejunum with multiple and tiny lobulations. The growth pattern varied and the duct-like structure was rarely visible. The HPJs mostly appeared to be homogeneous and exhibited hyper- or isoattenuation compared to the main pancreas in the arterial and portal phases. However, these enhancement patterns varied slightly depending on the microscopic composition of the lesions (i.e., acinar vs. ductal predominance). Most HPJs comprised histologically of large acini, some ducts, and small islet cells, and had ductal communication with the jejunum.

CONCLUSIONS

HPJs typically manifested as small, well-defined, ovoid or flat-shaped, homogeneous, and well-enhancing masses with a microlobulated contour in the proximal jejunum on CT, and their enhancement patterns associated with their microscopic composition. The pathology features of HPJs generally mimic those of the normal pancreas.

Gastric subepithelial masses: evaluation of multidetector CT (multiplanar reconstruction and virtual gastroscopy) versus endoscopic ultrasonography

OBJECTIVES

To assess the role of multidetector computed tomography (MDCT) with multiplanar reconstruction (MPR) and virtual gastroscopy (VG) for detection and differentiation of gastric subepithelial masses (SEMs) by comparison with endoscopic ultrasonography (EUS).

METHODS

Forty-one patients with a suspected SEM were evaluated using EUS and MDCT. MDCT findings were analyzed based on the consensus of two radiologists who were blinded to the EUS findings. The analysis of the CT features included the location, size, and contours of the tumor, the presence of central dimpling, as well as the growth pattern, enhancement pattern, and enhancement degree. The long diameter (LD) and the short diameter (SD) of each lesion were measured and the LD/SD ratios were calculated. EUS and MDCT results were compared with histopathology for the pathologically proven lesions. For the non-pathologically proven lesions, MDCT results were compared with EUS.

RESULTS

Among the 41 patients, 34 SEMs were detected using EUS. For the detection of SEMs with MDCT, a sensitivity of 85.3%, a specificity of 85.7%, a positive predictive value of 96.7%, and a negative predictive value of 54.5% were calculated. The overall accuracy of MDCT for detecting and classifying the SEMs was 85.3 and 78.8%, respectively.

CONCLUSIONS

MDCT with MPR and VG is a valuable method for the evaluation of SEMs. Specific MDCT criteria for various SEMs may be helpful in making an accurate diagnosis.

Heterotopic Pancreas of the Jejunum Incidentally Detected by Preoperative Abdominal CT: Report of Two Cases and Review of the Literature

Heterotopic pancreas (HP) is typically an asymptomatic malformation that can present anywhere along the gastrointestinal tract. It is often detected incidentally on surgery for other diseases or autopsy. We encountered 2 patients with jejunal HP incidentally detected by computed tomography (CT) performed for close evaluation of other diseases. In a 57-year-old woman diagnosed with reactive lymphoid hyperplasia on the dorsal portion of the pancreas head, CT detected a 15 mm oval-shaped submucosal lesion at the jejunum. In an 87-year-old woman diagnosed with type 2 adenocarcinoma occupying the sigmoid colon, CT detected a round-shaped submucosal tumor 15 mm in diameter in the jejunum. Both cases were histologically diagnosed as type 1 HP according to the classification by Heinrich. Contrast-enhanced CT revealed that the CT analyses of HP and pancreatic parenchyma were nearly identical in the arterial phase, but in the equilibrium phase, contrast enhancement persisted longer in HP than in the pancreatic parenchyma. There has been no report of asymptomatic jejunal HP preoperatively diagnosed by CT. These cases are presented with a review of the literature, particularly focusing on CT findings.

Upper gastrointestinal tract heterotopic pancreas: findings from CT and endoscopic imaging with histopathologic correlation

OBJECTIVE

To evaluate and describe computed tomographic (CT) and endoscopic (ES) imaging findings in patients with pathologically confirmed upper gastrointestinal (GI) tract heterotopic pancreas (HP).

METHODS

Findings from imaging examinations in 11 patients with pathologically confirmed HP were retrospectively reviewed (CT images obtained from 11 patients and ES images from 6 patients were available for review). Two radiologists evaluated lesion location, size, shape and border as well as growth pattern, enhancement pattern, enhancement grade and number of tumors. The presence of surface dimpling, prominent enhancement of overlying mucosa, and low intralesional attenuation were also evaluated.

RESULTS

HP in the upper GI tract showed typical features in CT imaging: submucosal masses, ill-defined borders, endoluminal growth patterns, bright enhancement similar to the normal pancreas, surface dimpling and low intralesional attenuation. Endoscopic photographs manifested an endoluminal, ill-defined, submucosal mass in the upper GI tract wall, typically with central umbilication. The LD (long diameter)/SD (short diameter) ratios were found to be significantly different between HP in the stomach and HP in the duodenum (P<.05 for each finding). In addition, HP in the duodenum tended to be small and round.

CONCLUSIONS

HP exhibits typical pancreatic pathologic features. Images showed characteristic features in CT imaging: submucosal masses, ill-defined lesions with an endoluminal growth pattern, bright enhancement similar to the normal pancreas, surface dimpling and low intralesional attenuation. ES imaging showed an endoluminal, ill-defined, submucosal mass, typically with central umbilication.

Glomus tumor of the stomach: a clinicopathologic analysis of 10 cases and review of the literature

Background/Aims

Gastric glomus tumors are extremely rare, and presurgical confirmation is often impossible. The identification of clinical and radiologic characteristics of this tumor type is important for preoperative diagnosis and treatment planning.

Methods

In this study, we analyzed 10 cases of gastric glomus tumors resected at a single institute over 9 years.

Results

Eight of the patients were men and 2 were women, with a mean age of 49 years. Five patients presented with abdominal discomfort or pain, 1 presented with anemia, and the remaining 4 cases were found incidentally during endoscopic examinations. The most common location of the tumor was the antrum (n=7), followed by the low (n=2) and high body (n=1). Although the endoscopic ultrasonography findings were variable, contrast-enhanced computed tomography generally showed a strong homogeneous enhancement. The resected tumors were well-demarcated solid masses with sizes ranging from 1.0 to 3.6 cm. Microscopically, the masses were composed of abundant vascular channels with clusters of uniform and round glomus cells. There was no evidence of recurrence after complete surgical resection.

Conclusions

Gastric glomus tumors are unusual, distinct lesions that should be considered in the differential diagnosis of a gastric submucosal mass. Unlike their deep soft tissue counterparts, most glomus tumors in the stomach are benign.

Hypervascular subepithelial gastrointestinal masses: CT-pathologic correlation

Although the vast majority of gastrointestinal (GI) masses are epithelial neoplasms, a variety of subepithelial masses are infrequently encountered during endoscopic or radiologic examination. A subepithelial mass, which was previously called a submucosal mass, is defined as a mass covered with normal-appearing mucosa, whether the underlying process is intramural or extramural in origin. At contrast material-enhanced computed tomography (CT), hypervascular subepithelial masses are usually detected more easily than isoattenuating or hypovascular masses. Entities that appear as intramural hypervascular subepithelial lesions include neuroendocrine tumors, GI stromal tumor, glomus tumor, hemangioma, angiosarcoma, Kaposi sarcoma, nerve sheath tumors, hypervascular metastases, heterotopic tissues, and vascular structures. Entities that appear as extramural hypervascular subepithelial lesions include Castleman disease, solitary fibrous tumor, inflammatory myofibroblastic tumor, and actinomycosis. Some rare gastric cancers resemble subepithelial tumors. In comparison with endoscopic ultrasonography, CT is of limited value in differentiating the layers of the GI wall and determining the origin of mass lesions. However, recent advances in multidetector CT with multiplanar reformation allow one to determine whether a GI mass is of epithelial, intramural subepithelial, or extramural subepithelial origin. Furthermore, the full extent of tumors can be delineated, and local invasion and distant metastases can be identified. Familiarity with the characteristic CT appearances of hypervascular subepithelial masses of the GI tract will help radiologists make a more confident diagnosis.

Cystic lesions of the gastrointestinal tract: multimodality imaging with pathologic correlations

The cystic lesions of the gastrointestinal (GI) tract demonstrate the various pathologic findings. Some lesions may present a diagnostic challenge because of non-specific imaging features; however, other lesions are easily diagnosed using characteristic radiologic features and anatomic locations. Cystic masses from the GI tract can be divided into several categories: congenital lesions, neoplastic lesions (cystic neoplasms, cystic degeneration of solid neoplasms), and other miscellaneous lesions. In this pictorial review, we describe the pathologic findings of various cystic lesions of the GI tract as well as the radiologic features of GI cystic lesions from several imaging modalities including a barium study, transabdominal ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging.

Pancreatic intraductal papillary mucinous neoplasm with concomitant heterotopic pancreatic cystic neoplasia of the stomach: a case report and review of the literature

A 60-year-old Caucasian male underwent a total pancreatectomy for a mixed type pancreatic intraductal papillary mucinous neoplasm (IPMN) arising in the main and secondary pancreatic ducts. During surgery, a subserosal polypoid mass was noted at the greater curvature of the gastric antrum and was enucleated. This mass was proven to be heterotopic pancreatic tissue with cystic neoplasia of the IPMN histologic subtype. Through an extensive search of the literature, we found that this is the first case ever reported with simultaneous existence of IPMN changes, in the main and secondary ducts of the orthotopic pancreas and in the heterotopic pancreatic tissue of the gastric wall.

Duodenal stenosis caused by cystic dystrophy in heterotopic pancreas: report of a case

We herein describe the first reported case of duodenal stenosis caused by cystic dystrophy in heterotopic pancreas (CDHP) in Asia. A 63-year-old man was admitted to the hospital presenting with nausea and vomiting of 2 days' duration. Laboratory examinations showed an elevation in both the serum amylase level (275 IU/l) and white blood cell count (13 600/microl). A 3-cm-diameter tumor close against the duodenum was pointed out from the results of computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP); the tumor contained a cystic and solid component. Endoscopic examinations and an upper gastrointestinal series showed stenosis of the second portion of the duodenum without any mucosal change. The tumor was considered to be located at the submucosal layer of the second duodenum. The biopsy specimen of the duodenum revealed no malignancy. We strongly doubted the presence of a malignant submucosal tumor in the duodenum based on the findings of diagnostic imaging, and a pancreaticoduodenectomy was thus performed. Histopathologically, the lesion was diagnosed to be CDHP. The postoperative course was uneventful. The patient was symptomatic but was free of any symptoms after surgery. He continues to be regularly followed up on an outpatient basis and has had no recurrence of symptoms. This case demonstrates the need to consider CDHP in the differential diagnosis as a rare cause of duodenal stenosis.

CT findings of an ectopic pancreas in the anterior mediastinum

We report here on a rare case of an ectopic pancreatic tissue in the anterior mediastinum. A 32-year-old woman without any symptoms was transferred to our hospital because of an abnormal large mediastinal shadow on her chest radiograph during a checkup. The computed tomography (CT) scan revealed a giant cystic-solid mass that measured 16 × 13 × 8 cm and it was located in the center of the anterior mediastinum and it symmetrically grew to two sides. On enhanced CT scans, the solid component of the mass showed marked enhancement. We performed total surgical resection of the mass and complete pancreatic tissues were verified on the pathological examination.

Ectopic pancreas: CT findings with emphasis on differentiation from small gastrointestinal stromal tumor and leiomyoma

PURPOSE

To describe the computed tomographic (CT) findings of ectopic pancreas and to identify the features that differentiate it from other similarly manifesting gastric submucosal tumors such as gastrointestinal stromal tumor (GIST) and leiomyoma, which are the most common gastrointestinal submucosal tumors.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and did not require informed consent. CT images of pathologically proved ectopic pancreases (n = 14), GISTs (n = 33), and leiomyomas (n = 7) in the stomach and duodenum were retrospectively reviewed. Analysis of the CT findings included evaluation of the location, contour, growth pattern, border, enhancement pattern, and enhancement grade of the tumor, as well as the presence of surface dimpling, prominent enhancement of overlying mucosa, and low intralesional attenuation. The attenuation of each lesion, the long diameter (LD), the short diameter (SD), and the LD/SD ratio were measured. Among these findings, statistically significant variables were determined by using the chi(2) test (to compare the categoric variables), the Student t test (for quantitative analysis), and the receiver operating characteristic curve (to determine the optimal cutoff of the LD/SD ratio).

RESULTS

The typical location (prepyloric antrum and duodenum), endoluminal growth pattern, ill-defined border, prominent enhancement of overlying mucosa, and an LD/SD ratio of greater than 1.4 were found to be significant for differentiating ectopic pancreas from other tumors (P < .05 for each finding). When at least two of these five criteria were used in combination, the sensitivity and specificity for diagnosing ectopic pancreas were 100% (14 of 14) and 82.5% (33 of 40), respectively. When four of these criteria were used, a sensitivity of 42.9% and a specificity of 100% were achieved.

CONCLUSION

By using specific CT criteria, ectopic pancreas can be differentiated from small GIST or leiomyoma with a high degree of accuracy.

Characteristics of ectopic pancreas in dynamic gadolinium-enhanced MRI

The characteristics of jejunal ectopic pancreas in dynamic gadolinium-enhanced magnetic resonance imaging are described in a 40-year-old man with bowel obstruction. The pre-contrast signal intensity and post-contrast enhancement pattern of ectopic pancreas are the same as those of the pancreas.

Role of EUS and MDCT in the diagnosis of gastric submucosal tumors according to the revised pathologic concept of gastrointestinal stromal tumors

Gastric submucosal tumors (SMTs) consist of various lesions arising from the deep layers of the stomach. Gastrointestinal stromal tumors (GISTs) are undoubtedly the commonest malignant SMTs of the stomach, and therefore the attitude towards the general diagnostic approach for GISTs defines the extended diagnostic plan for SMTs. Two recent consensus meetings were assembled concerning the classification and therapeutic plans for GISTs. These meetings shed light upon the need for the modification of the current role of imaging modalities, including endoscopic ultrasound (EUS) and computed tomography (CT). According to the revised concepts of GISTs, the most important and plausible current role of imaging for the diagnostic approach of gastric SMTs is to differentiate GISTs from other gastric SMTs. This review discusses the newly established diagnostic role of radiology according to the revised classification of GISTs and provides the differential diagnoses based on EUS and CT findings.

Cystic lesion mimicking intraductal papillary mucinous tumor arising in heterotopic pancreas of the stomach and synchronous intraductal papillary mucinous adenocarcinoma of the pancreas

This article presents the study of a 66-year-old man with an asymptomatic pancreatic mass detected incidentally 4 months earlier. A magnetic resonance imaging scan revealed 2 distinct cystic masses in the pancreas and the gastric antrum. Microscopically, the pancreatic lesion showed dilated cysts containing papillary structures lined by mucinous epithelium, which showed a loss of polarity, an increased nucleus-to-cytoplasm ratio, a prominent nucleolus, and high proliferation on immunostaining for Ki-67. The gastric lesion was composed of heterotopic pancreatic tissue surrounding a large dilated cyst that was lined with mucinous epithelium and contained a few intraluminal papillae.

[Aberrant pancreas and duodenal diaphragm: an exceptional association]

Aberrant pancreas of the duodenal wall (APD) and duodenal diaphragm (DD) are two rare entities, which developed during duodenal embryogenesis. Occurrence, diagnosis and therapeutic approach of these lesions are different. Herein, we report the first case of this exceptional association in a man who had no symptoms. A surgical resection of both lesions was performed and the outcome was uneventful. Embryogenesis, morphological characteristics and treatment are discussed.

[Aberrant pancreas: report of five cases]

We herein report five cases of heterotopic pancreas localized on common bile duct, gastric antrum, duodenum (two cases including one with cystic dystrophy), and jejunum. The choledocal localization was revealed by jaundice. The duodenal localization with cystic, diagnosed by endoscopic ultrasound, was revealed by onsets of acute pancreatitis. All localizations were treated by resection: antrectomy, bowel resection, and pancreaticoduodenectomy. Postoperative course was uneventful. Review of the literature shows that, even in uncomplicated cases, resection is usually performed.

Imagerie en coupes de l’estomac et du duodénum

Imaging of the stomach and duodenum provides an abundant semiology, which allows precise diagnosis. In this chapter we will review specific considerations related to CT, MRI and US imaging of the stomach and duodenum. Normal imaging features as well as the main gastric and duodenal diseases will be described and illustrated.

Obstructing gastric heterotopic pancreas: case report and literature review

Heterotopic pancreas (HP) is generally an asymptomatic lesion and is a rare cause of gastric outlet obstruction. We report such a case in which both upper gastrointestinal series and abdominal computerized tomography (CT) demonstrated an antral mass; surgical and histological results are also reported.