Characteristic CT features of heterotopic pancreas of the mesentery: “another pancreas” in the mesentery

Pancreatic congenital anomalies and their features on CT and MR imaging: a pictorial review

OBJECTIVE

To review the congenital anomalies of the pancreas with their main clinical manifestations and key imaging findings on CT and MRI.

BACKGROUND AND CLINICAL SIGNIFICANCE

Anomalies of pancreatic development are frequent and generally asymptomatic, but can mimic and predispose individuals to pancreatic or peripancreatic pathologies, such as pancreatitis or malignancy. Their correct diagnosis may help avoid unnecessary further investigations and procedures, or establish adequate treatment when they manifest clinically. Differentiating pancreatic congenital anomalies from their main radiological mimics constitutes a challenge for the radiologist and requires familiarity with key imaging findings.

CONCLUSION

The imaging findings of CT and MRI are essential for the correct diagnosis of congenital pancreatic anomalies.

The tale of 2 pancreases: Jejunal mesenteric ectopic pancreas causing recurrent ectopic pancreatitis

Ectopic pancreas, or the presence of pancreatic tissue separate from the anatomic pancreas, is rarely reported in locations other than the stomach or duodenum. A 43-year-old female was found to have a large jejunal mesenteric ectopic pancreas causing ectopic pancreatitis during workup for frequent episodes of abdominal pain. We present the imaging findings and postresection pathology findings of a rare jejunal ectopic pancreas and discuss the potential complications of this unique condition.

Pancreatic heterotopia in mesentery

INTRODUCTION

The pancreatic heterotopia of fortuitous operational discovery remains rare because of the medical imagery progress. We report a mesenteric localisation of aberrant pancreas identified during the assumption of responsibility of an abdominal emergency.

OBSERVATION

A 26-year-old man was allowed with the urgencies for an acute obstruction of the small bowel. Surgical exploration revealed a distal support an ileo-parietal adherence near to an inflammatory hearth of appendicular origin. We noted, in addition to the mesentery of the first jejunal loop, a bilobate mass of glandular-like tissue with a pancreatic aspect. The adjacent jejunal handles were macroscopically healthy. The Pathological examination of the mass confirmed the existence of a mixed glandular exocrine and endocrine origin of pancreatic tissue, type I of the Heinrich's classification.

CONCLUSION

This rare topographic entity of fortuitous discovery underlines the need for a meticulous surgical exploration of the abdominal cavity particularly in urgency when a summarized radiological assessment does not permit a complete morphological study.

Heterotopic pancreas adenocarcinoma in the stomach: A case report and literature review

BACKGROUND

Heterotopic pancreas is a common lesion found in the gastrointestinal tract and is usually considered a benign disease. Reports of malignant change of heterotopic pancreas are scarce.

CASE SUMMARY

A 44-year-old Chinese female underwent a gastroscopy to assess abdominal distension that had persisted for 2 months. A protruding lesion in the gastric antrum was revealed but no malignant tissue was found in the biopsy specimen. The patient's symptom persisted and progressed to repeated vomiting. Endoscopy after 4 months revealed obstruction of the gastric outlet caused by the protruding lesion. A distal gastrectomy was performed. Histopathological examination of the surgical specimen showed the malignant transformation of aberrant pancreas in the stomach. Chemotherapy consisting of folinic acid, fluorouracil, and oxaliplatin was administered for three cycles, and was changed to gemcitabine monotherapy because of adverse effects and increased serum tumor marker levels. The patient remained asymptomatic during a 12-month follow-up.

CONCLUSION

Pancreatic heterotopy should be considered as source of a potentially malignant lesion, and early treatment or close monitoring for aberrant pancreas is recommended.

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.

CT features of asymptomatic heterotopic pancreas in jejunal mesentery

Heterotopic pancreas (HP) is localized pancreatic tissue that has no relation to orthotopic pancreas and has its own channel and vascular structures. Usually, the submucosa is located in the upper gastrointestinal tract; mesenteric placement is rarely reported. It is frequently asymptomatic and is detected incidentally in imaging, laparotomies, or autopsies. Rarely, pancreatitis may be the cause of small bowel obstruction, massive gastrointestinal bleeding, and malignant transformation. However, this has usually been reported in localized submucosal HP cases. The imaging findings are typical, and the diagnosis can be verified without the need for a histopathological diagnosis. In this case report, we aimed to present the imaging findings of asymptomatic HP located in the proximal jejunum mesentery of a 44-year-old woman. To avoid unnecessary surgical procedures, the characteristic imaging findings of HP are understood and should be considered in the differential diagnosis of masses seen in the mesentery.

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.

Acute Clinical Manifestation of Mesenteric Heterotopic Pancreatitis: A Pre- and Postoperative Confirmed Case

Heterotopic pancreas is a relatively uncommon congenital anomaly, defined as pancreatic tissue in ectopic sites without an anatomic and vascular continuity with the main body of the pancreas. We report the case of a 58-year-old woman who was admitted to the hospital with the clinical suspicion of a mild, acute pancreatitis. Computed tomography, magnetic resonance imaging, transabdominal ultrasound, and endoscopic ultrasound revealed a normal orthotopic pancreas and the suspicion of a large heterotopic pancreas in the small bowel mesentery with signs of acute inflammation. The diagnosis of mesenteric heterotopic pancreatitis was preoperatively confirmed by endoscopic ultrasound-guided fine-needle aspiration and consequently histologically established after surgical resection.

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.

Diagnosis of Mesenteric Ectopic Pancreas by Secretin-Enhanced Magnetic Resonance Cholangiopancreatography

Ectopic pancreas (EP) is defined as pancreatic tissue found outside its usual anatomical position, with no ductal or vascular communication with the native pancreas.We report the case of a 59-year-old woman with a mesenteric jejunal EP initially suspected on computed tomography and confirmed by secretin-enhanced magnetic resonance cholangiopancreatography.Mesenteric EP is a very rare finding with nonspecific clinical presentation, so that, classic radiological findings have not been well described previously.

Heterotopic Pancreas of the Gastrointestinal Tract and Associated Precursor and Cancerous Lesions: Systematic Pathologic Studies of 165 Cases

Heterotopic pancreas (HP) can be detected by accompanying symptoms or incidentally during gastrointestinal (GI) tract tumor resection. We compared clinicopathologic features among 165 resected HPs (57 gastric [35%], 56 duodenal [34%], 30 omental [18%], and 22 jejunal [13%]). Symptomatic HPs (79/135 GI tract wall HPs, 59%) were larger (P=0.05), more common in younger patients and in a gastric location (both P<0.001), and more frequently associated with lymphoid cuffs (P=0.03) than incidentally found HPs. Gastric/jejunal HPs were more frequently symptomatic (P<0.001), deeply located (P=0.03), and associated with lymphoid cuffs (P=0.008) and pancreatic intraepithelial neoplasia/intraductal papillary mucinous neoplasms (PanIN/IPMN; P=0.001) than duodenal HPs. HP was frequently associated with acinar-ductal metaplasias (117/135 GI tract wall HPs, 87%) and PanINs/IPMNs (68/135, 50%); those with PanINs/IPMNs were larger (P<0.001), more frequently located in stomach (P=0.001), had deeper wall involvement (P=0.03), and more often showed infiltrative growth (P<0.001) and lymphoid cuffs (P=0.02). Four HPs containing PanINs abutted adenocarcinomas, all expressing wild-type KRAS and intact SMAD4/DPC4 expression. Thus, symptomatic HP is associated with younger age, larger size, gastric location, and lymphoid cuffs. HPs containing PanINs/IPMNs (usually low grade) are larger and more common in stomach, have deeper wall location, and show infiltrative growth and lymphoid cuffs. Adenocarcinomas are rarely observed adjacent to HPs with PanINs/IPMNs. KRAS mutational and SMAD4/DPC4 immunohistochemical studies can discriminate between adenocarcinoma derived from HP and concurrent adenocarcinoma with HP.

Heterotopic pancreatic rests: imaging features, complications, and unifying concepts

OBJECTIVE

The spectrum of pancreatic heterotopia will be reviewed, including clinical features, potential complications, and imaging manifestations. This will also include a review of various entities associated with pancreatic heterotopia such as groove pancreatitis and cystic dystrophy of gastroduodenal heterotopic pancreas. These entities were previously thought of as distinct histopathologic entities but now appear to represent manifestations of pancreatic heterotopia.

CONCLUSION

Pancreatic heterotopia and heterotopic pancreatitis can have a wide range of appearances. Several entities, which were previously thought to be distinct, can be considered manifestations of pancreatic heterotopia and heterotopic pancreatitis.

Ektopinė (heterotopinė) kasa plonosios žarnos pasaite: klinikinio atvejo pristatymas ir literatūros apžvalga

Ektopinė kasa (EK) – reta įgimta anomalija, kai normalus kasos audinys yra už kasos ribų. Heterotopinis kasos audinys plonosios žarnos pasaite yra ypač retai sutinkamas EK tipas. EK dažniausiai aptinkama įvairiose virškinamojo trakto dalyse atsitiktinai.

Paprastai EK yra simptomų nesukelianti anomalija, tačiau kliniškai gali pasireikšti atsiradus komplikacijoms, tokioms kaip uždegimas, kraujavimas, obstrukcija ar supiktybėjus. Simptomų išsivystymas priklauso nuo EK dydžio, lokalizacijos bei patologinių audinio pokyčių, kurie taip pat būdingi ir normaliam kasos audiniui. Operacinis gydymas nėra indikuotinas, nebent esant komplikacijoms, todėl labai svarbi tiksli priešoperacinė diagnozė siekiant išvengti nereikalingų intervencijų.

Mes pristatome retą klinikinį atvejį, kada EK lokalizavosi plonosios žarnos pasaite. Pateikiame paciento kompiuterinės tomografijos tyrimo vaizdus. Šis klinikinis atvejis parodo, kad ektopinis kasos audinys visada turėtų būti įtrauktas į gastrointestinių navikų diferencinę diagnostiką.

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.

Gastroscopy and endoscopic ultrasonograhpy for diagnosis of heterotopic pancreas in the stomach

AIM: To investigate the value of gastroscopy, endoscopic ultrasonography (EUS) and multi-slice spiral computed tomography (MSCT) in the diagnosis of heterotopic pancreas (HP) in the stomach.

METHODS: Clinical data (including endoscopic manifestations and pathological findings) of 268 patients diagnosed with HP by gastroscopy, biopsy, EUS or MCST at our hospital from January 2005 to September 2013 were retrospectively analyzed.

RESULTS: Of all the patients, 84 were diagnosed with HP by gastroscopy and 26 of them were pathologically confirmed (26/84, 31.0%); 7 were diagnosed by both biopsy and pathology (7/7, 100%); 174 were diagnosed by EUS and 151 of them were confirmed by pathology (151/174, 86.8%); 3 were diagnosed by MSCT, but only 1 was confirmed by pathology (1/3, 33.3%).

CONCLUSION: EUS is a useful technique for diagnosing HP in the stomach and it is the first choice for diagnosis of HP.