[The pathology of insulinoma and gastrinoma. The location, size, multicentricity, association with multiple endocrine type-I neoplasms and malignancy]

Solid pancreatic masses in children: A review of current evidence and clinical challenges

Pancreatic tumors in children are infrequently encountered in clinical practice. Their non-specific clinical presentation and overlapping imaging characteristics often make an accurate preoperative diagnosis difficult. Tumors are categorized as epithelial or non-epithelial, with epithelial tumors further classified as tumors of the exocrine or endocrine pancreas. Although both are tumors of the exocrine pancreas, solid pseudopapillary neoplasm is the most prevalent solid pancreatic tumor in children, while pancreatoblastoma is the most common malignant tumor. Insulinoma is the most common pediatric pancreatic tumor of the endocrine pancreas. Malignant tumors require a complete, often radical, surgical resection. However, pancreatic parenchyma-sparing surgical procedures are utilized for benign tumors and low-grade malignancy to preserve gland function. This review will discuss the epidemiology, pathophysiology, clinical and diagnostic characteristics, and management options associated with both common and rare solid pancreatic masses in children. We will also discuss current challenges encountered in their evaluation and treatment.

Progesteron receptor expression in insulin producing cells of neuroendocrine neoplasms

Progesterone receptor (PgR) inhibits cell proliferation in pancreatic neuroendocrine neoplasms (PanNEN). In non-neoplastic pancreas, loss of PgR induces β-cell proliferation and insulin production. However, detailed association between PgR and insulin producing PanNENs is poorly understood. Insulin, proinsulin, and PgR were immunolocalized in 82 PanNENs (54 non-functioning PanNENs: NF-PanNENs and 28 insulinomas). The status of immunoreactivity was compared to the clinicopathological factors of the patients. Immunoreactivity was also confirmed by employing the double-immunohistochemistry. These results were also compared with those in non-neoplastic Langerhans islets. PgR immunoreactivity was significantly higher in insulinomas than that in NF-PanNENs (p < 0.001). Insulin and proinsulin immunoreactivity was also detected in 20 (37 %) of (single cell) insulin positive NFs (Ins^pos-NF-PanNEN), in which PgR expression was higher than in insulin negative NF-PanNENs (Ins^neg-NF-PanNEN, p = 0.03). The ratio of PgR-insulin double positive cells to overall insulin positive cells, as well as PgR-proinsulin double positive cells to proinsulin positive cells, was detected to the same degree in insulinoma (PgR-insulin 70 %, PgR-proinsulin 66 %), Ins^pos-NF-PanNENs (PgR-insulin 65 %, PgR-proinsulin 68 %) and normal islet (PgR-insulin 80 %, PgR-proinsulin 72 %). PgR and insulin expressing cells colocalize in tumor cells of the PanNENs regardless of the hormone-related symptoms of the patients. Inhibitory effect of PgR on tumor cells might be associated with the favourable clinical outcome of insulinoma patients.

The Adult Pancreas in Trauma and Disease

The spectrum of traumatic and natural disease that can affect the adult pancreas is multiple and varied. Some entities are more commonly encountered in routine forensic pathology practice and the forensic pathologist needs to be very familiar with their pathological features and development from a pathophysiological perspective. However, many of the conditions are extremely rare and may never be encountered in the professional lifetimes of an individual pathologist. Still, forensic pathologists need to be aware of them in case they are one day faced with these entities as possible diagnoses to be established at postmortem examination. This can be the result of clinical concerns raised in life, potential natural disease explanations for unexpected biochemical results, and sudden, unexpected or otherwise unexplained deaths where criminal concern about the exogenous administration of a substance must be considered. Acad Forensic Pathol. 2018 8(2): 192-218.

[Surgical treatment of benign, premalignant and low-risk tumors of the pancreas : Standard resection or parenchyma preserving, local extirpation]

Cystic neoplasms and neuroendocrine adenomas of the pancreas are detected increasingly more frequently and in up to 50 % as asymptomatic tumors. Intraductal papillary mucinous neoplasms, mucinous cystic neoplasms and solid pseudopapillary neoplasms are considered to be premalignant lesions with different rates of malignant transformation. The most frequent neuroendocrine adenomas are insulinomas. Neuroendocrine adenomas are considered to be potentially malignant, inherent to the lesion and development is unpredictable. Standard surgical treatment for pancreatic tumors are the Kausch-Whipple resection, left hemipancreatectomy and total pancreatectomy depending on the location; however, the application of standard surgical procedures, which are usually multiorgan resections for benign, premalignant and low-risk cancers of the pancreas have to be balanced against the risk for early postoperative morbidity, hospital mortality of 1.5-7 % and loss of endocrine and exocrine pancreatic functions in 12-30 %. Tumor enucleation, pancreatic middle segment resection and duodenum-preserving total pancreatic head (DPPHR-T/S) resection are parenchyma-preserving, local resection procedures, which are associated with a low early postoperative rate of severe complications, hospital mortality up to 1.3 % and maintenance of exocrine and endocrine pancreatic functions in more than 90 %. Tumor enucleation bears the risk of pancreatic fistulas (<33 %) and a limitation is proximity to the pancreatic main duct. The main risk for pancreatic middle segment resection is early postoperative pancreatic fistulas (up to 40 %), early postoperative intra-abdominal hemorrhage and a reintervention frequency up to 15 %. The DPPHR-T/S resection is applied for cystic neoplastic lesions in 90 %, severe postoperative complications are below 15 % and the 90-day hospital mortality is 0.5 %. Pancreatic fistulas are observed in less than 20 % with a recurrence rate of <1 %. These facts and maintenance of exocrine and endocrine pancreatic functions are advantages compared with the Kausch-Whipple resection of the pancreatic head. The use of tumor enucleation, particularly for neuroendocrine tumors and pancreatic middle segment resection as well as total DPPHR resection should replace the pancreatoduodenectomy for lesions in the pancreatic head and hemipancreatectomy for lesions in the pancreatic body and tail.

Benign cystic neoplasm and endocrine tumours of the pancreas--when and how to operate--an overview

BACKGROUND

The recent evolution of limited local operative procedures for benign pancreatic lesions shifted surgical treatment options to the application of local techniques, although major resections of pancreatic head and left resection are still the standard.

OBJECTIVES

To evaluate the level of evidence of tumour enucleation (EN), pancreatic middle segment resection (PMSR) and duodenum preserving total/subtotal pancreatic head resection (DPPHRt/s), we focus based on present knowledge on indication to surgical treatment evaluating the questions, when and how to operate.

RESULTS

Tumour enucleation is recommended for all symptomatic neuro-endocrine tumours with size up to 2-3 cm and non-adherence to pancreatic main-ducts. EN has been applied predominantly in neuro-endocrine tumours and less frequently in cystic neoplasms. 20% of enucleation are performed as minimal invasive laparascopic procedure. Surgery related severe post-operative complications with the need of re-intervention are observed in about 11%, pancreatic fistula in 33%. The major advantage of EN are low procedure related early post-operative morbidity and a very low hospital mortality. PMSR is applied in two thirds for symptomatic cystic neoplasm and in one third for neuro-endocrine tumours. The high level of 33% pancreatic fistula and severe post-operative complications of 18% is related to management of proximal pancreatic stump. DPPHRt/s is used in 70% for symptomatic cystic neoplasms, for lesions with risk for malignancy and in less than 10% for neuro-endocrine tumours. DPPHRt with segment resection of peripapillary duodenum and intra-pancreatic common bile duct has been applied in one third of patients and in two thirds by complete preservation of duodenum and common bile duct. The level of evidence for EN and PMSR is low because of retrospective data evaluation and absence of RCT results. For DPPHR, 7 prospective, controlled studies underline the advantages compared to partial pancreaticoduodenectomy.

CONCLUSION

The application of tumour enucleation, pancreatic middle segment resection and duodenum preserving subtotal or total pancreatic head resection are associated with low level surgery related early post-operative complications and a very low hospital mortality. The major advantage of the limited procedures is preservation of exo- and endocrine pancreatic functions.

Islet cell tumor arising from a heterotopic pancreas in the duodenal wall with ulceration

A rare case of symptomatic islet cell tumor arising from heterotopic pancreas in the duodenum with ulceration is described. Gastrointestinal bleeding was the only sign observed in this patient. Tagged red blood cell scan, upper endoscopy, and computed tomography scan showed active bleeding ulcer from a periampullary mass. Removal of the submucosal tumor was done to prevent future re-bleeding. Histologic and immunohistochemical characterization of the tumor showed an endocrine tumor that expressed a variety of endocrine peptides.

Morphological and functional investigations of neuroendocrine tumors of the pancreas

Neuroendocrine tumors of the pancreas are rare neoplasms arising predominantly from the pancreatic islets of Langerhans and are thus known as islet cell tumors. More than the half of all neuroendocrine tumors are called functioning islet cell tumors because they secrete one or more biologically active peptides that may produce clinical symptoms. Clinical diagnosis of non-functioning, i.e., biologically inactive, tumors is often delayed and patients tend to present with advanced tumors (size greater than 5 cm) that are easily localized by using conventional imaging modalities. On the other hand, symptoms of functioning islet cell tumors usually appear early in the clinical course, rendering the preoperative localization of these small hormone-producing tumors (size less than 2 cm) difficult with non-invasive methods. Since functioning islet cell tumors can often be cured by surgical resection, invasive procedures are warranted when necessary for localization diagnosis. Failure to search for, detect, and resect these small tumors will invariably result in persistent symptoms. Regarding the unsatisfactory results of morphological imaging methods, functional studies, especially arterial stimulation with hepatic venous samplings, may provide a preoperative regionalization of the pancreatic adenoma, regardless of its size.

Islet cell tumor

A case of islet cell tumor occurring in a patient with the multiple endocrine neoplasia type I syndrome is reported. Immunostaining for insulin was strongly positive in the tumor cells. Numerous dense-core granules of endocrine caliber were identified ultrastructurally. Morphometric analysis of the secretory granules in 20 islet cell tumors gave a granule size of 182 +/- 52 nm (mean +/- standard deviation).