Ectopic pancreas tissue in the posterior mediastinum

The occurrence of ectopic pancreas in the mediastinum is rare. Herein, we report a 22-year-old female who presented with right shoulder pain, dysphagia, fever and headaches. Chest computer tomography revealed a mass in the posterior mediastinum with accompanying signs of acute mediastinitis. Needle biopsy and fine-needle aspiration revealed ectopic gastral tissue and ectopic pancreas tissue, respectively. Surgical resection was attempted due to recurring acute pancreatitis episodes. However, due to chronic-inflammatory adhesions of the mass to the tracheal wall, en-bloc resection was not possible without major tracheal resection. Since then, recurring pancreatitis episodes have been treated conservatively with antibiotics. We report this case due to its differing clinical and radiological findings in comparison to previous case reports, none of which pertained a case of ectopic pancreas tissue in the posterior mediastinum with recurring acute pancreatitis and mediastinitis.

Ectopic insulinoma: a systematic review

Knowledge of ectopic insulinomas comes from single cases. We performed a systematic review through PubMed, Web of Science, Embase, eLibrary and ScienceDirect of all cases reported in the last four decades. We also describe one unreported patient. From 28 patients with ectopic insulinoma, 78.6% were female and mean age was 55.7 ± 19.2 years. Hypoglycaemia was the first symptom in 85.7% while 14.3% complained of abdominal pain or genital symptoms. Median tumour diameter was 27.5 [15-52.5] mm and it was localised by CT (73.1%), MRI (88.9%), [68Ga]Ga-DOTA-exedin-4 PET/CT (100%), 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC (100%), somatostatin receptor scintigraphy (40%) and endoscopic ultrasound (50%). Ectopic insulinomas were located at duodenum (n = 3), jejunum (n = 2), and one respectively at stomach, liver, appendix, rectum, mesentery, ligament of Treitz, gastrosplenic ligament, hepatoduodenal ligament and splenic hilum. Seven insulinomas were affecting the female reproductive organs: ovary (n = 5), cervix (n = 2) and remaining tumours were at retroperitoneum (n = 3), kidney (n = 2), spleen (n = 1) and pelvis (n = 1). 89.3% underwent surgery (66.7% surgery vs. 33.3% laparoscopy) and 16% underwent an ineffective pancreatectomy. 85.7% had localized disease at diagnosis and 14.3% developed distant metastasis. Median follow-up time was 14.5 [4.5-35.5] months and mortality was reported in 28.6% with median time until death of 60 [5-144] months. In conclusion, ectopic insulinomas are presented as hypoglycaemia with female preponderance. Functional imaging [68Ga]Ga-DOTA-exedin-4 PET/CT and 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC have very high sensitivity. Clinicians should be alert to the possibility of extra-pancreatic insulinomas when classic diagnostic tests and intraoperative pancreas exploration failed to locate the tumour.

[Mature teratoma of the anterior mediastinum with a predominance of the pancreatic component and signs of focal nesidioblastosis]

A case of a mature anterior mediastinal teratoma with a predominance of the pancreatic component (80% of the tumor) and signs of nesidioblastosis in a 46-year-old woman is presented. During histological examination, all components of the pancreatic parenchyma were determined - acini with interlobular and intralobular ducts, endocrine cells and islets of Langerhans of various sizes and shapes, as well as islet-duct complexes scattered in the acinar tissue. In addition to pancreatic tissue, cartilage, bronchial respiratory epithelium, small intestine tissue, hair follicles, and sebaceous glands were found in the neoplasm. Immunohistochemical examination revealed signs of focal nesidioblastosis. In the islets, insulin-positive β-cells (80.0% of the volume of the islets), as well as endocrine cells expressing glucagon and somatostatin (10.0% of the volume of the islets) were determined. By 2020, only 4 such cases have been published in the English-language literature.

Benign lesions of the mediastinum: A review with emphasis on cytology and small biopsy specimens

This review focuses on the diagnosis of select benign processes, ranging from reactive entities to heterotopic tissues to neoplasms, which may occur in the mediastinum. Currently, the mediastinum can be evaluated and biopsied with endoscopic procedures. Therefore, cytopathology specimens, fine needle aspirations, and small biopsies play an important role in the diagnosis of these lesions. In this review, an emphasis is given to relevant clinical presentations, histologic and cytologic findings, differential diagnoses, ancillary testing, and interpretation. Pitfalls are reviewed and discussed in each section. It is important for both surgical pathologists and cytopathologists to be familiar with these entities and their cytologic and histologic features that may be helpful in reaching a diagnosis.

Aberrant pancreatic tissue in a giant mediastinal cyst: an uncommon entity

Background

Heterotopia of pancreatic tissue in the thorax and mediastinum is uncommon, although, a common developmental anomaly in the gastrointestinal tract where the aberrant tissue is a component of gastrointestinal duplication cysts, intralobular pulmonary sequestration or teratomas.

Case presentation

We report a case of an ectopic pancreas located in a giant mediastinal cyst in a 2-year old girl who presented with severe dyspnoea due to external compression of the intra-thoracic structures, mainly the right main bronchus. Surgical resection was carried out with complete relief of symptoms. The cyst was confirmed histopathologically to contain pancreatic tissue. Literature review showed that this is an uncommon presentation hence the need to report the case.

Conclusion

Heterotopia of the pancreas although, an uncommon occurrence in the thorax and mediastinum, should be considered when dealing with cystic lesions of the mediastinum and surgery plays an important role in its management.

Trial registration

JUTH/DCS/ADM/127/XXV/203. Registered 2nd September 2018.

Resection of anterior mediastinal ectopic pancreas by right thoracoscopy: A case report

Ectopic pancreas is uncommon in the anterior mediastinum. Herein, a 32-year-old woman presented to our institution for investigation of an abnormal mediastinal shadow on chest computed tomography. The patient underwent complete surgical resection of the anterior mediastinal mass by right thoracoscopy, and the postoperative pathology examination confirmed the diagnosis of ectopic pancreas. There were no clinical signs of pancreatitis. No recurrence or metastasis was observed during a follow-up period of 3 years. English language medical literature was also searched in order to identify other case reports describing this rare condition and identified 17 papers describing 20 cases of anterior mediastinal ectopic pancreas, which were all confirmed at surgery. All clinical characteristics in these cases were reviewed.

Mediastinal Ectopic Pancreas with Abundant Endocrine Cells Coexisting with Mediastinal Cyst and Thymic Hyperplasia

Mediastinal ectopic pancreas is a rare condition with only 28 cases reported in the literature. Here we report a 21-year-old female patient who presented with dyspnea and intermittent severe chest pain of 7 years' duration. Computerized tomography scan (CT-scan) of the chest revealed a mediastinal cyst. The cyst was resected and it demonstrated on histopathological examination the presence of pancreatic tissue with increased number of islets of Langerhans, coexistent with mediastinal cyst and thymic hyperplasia. We made a review of all previously reported cases of this entity.

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.