A case of mixed adenoneuroendocrine carcinoma of the pancreas mimicking intraductal papillary mucinous carcinoma

Mixed neuroendocrine nonneuroendocrine neoplasms of the pancreas: a case report and literature review of pancreatic mixed neuroendocrine nonneuroendocrine neoplasm

A 36-year-old woman underwent left lateral hepatic lobectomy and tumor enucleation of the pancreatic head due to the diagnosis of mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs). Her past medical history revealed an ill-defined mass in the pancreatic uncinate (approximately 1 cm in size) and liver nodules in segment II, suggesting a pancreatic neuroendocrine tumor (pNET) and liver metastases. After the operation, pathological examination showed that the lesion in the pancreas was MiNEN. The neuroendocrine component consisted of grade 1 (G1) NETs, and the nonneuroendocrine part was well-differentiated adenocarcinoma. Additionally, in hepatic lesions, the type of pancreaticobiliary duct in moderately differentiated adenocarcinoma indicated the source of tumor cells. We present the following case in accordance with the CARE reporting checklist. MiNENs of the pancreas are extremely rare and heterogeneous malignancies. Owing to the rarity of pancreatic MiNEN, no structured guidelines on preoperative diagnostics, therapy and follow-up exist thus far. Thus, problems in differential diagnosis and appropriate therapy may arise when treating suspected MiNEN patients. We performed a rigorous search on pancreatic MiNEN via PubMed and Web of Science. In total, 167 studies were identified, and 28 cases in 15 studies about pancreatic MiNEN were assessed. All the available information was listed and fully discussed.

Presentation and outcome of mixed neuroendocrine non-neuroendocrine neoplasms of the pancreas

BACKGROUND/OBJECTIVES

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) of the pancreas and periampullary region are extremely rare and heterogeneous malignancies. Literature is sparse, clinical management is not standardized and little is known about survival outcomes. The aim of this study was to identify pathological and radiological features of MiNEN and assess the outcome of surgical management.

METHODS

Patients undergoing surgery for pancreatic and periampullary MiNEN between 2001 and 2019 were retrospectively analysed based on a prospective database. Histological, radiological and clinical features were assessed. Survival was analysed in a nested case-control study and matched-pair analyses with pure neuroendocrine neoplasms (pNEN) and ductal adeno- or acinar cell carcinomas of the pancreas. A literature review with focus on survival after surgical resection was additionally performed.

RESULTS

Of 13 patients with MiNEN, 5 had acinar-MiNEN and 8 adeno-MiNEN. Two of 5 (40%) acinar-MiNEN and one adeno-MiNEN patients had liver metastases. All but one adeno-MiNEN (88%) showed preoperative radiological features of pancreatic adenocarcinoma, 3 of 5 (60%) acinar-MiNEN exhibited mainly neuroendocrine features. No surgical mortality was observed. The 5-year overall survival rate in all MiNEN was 40%. Five-year survival rate was 58% in adeno-MiNEN and comparable to that of matched ductal adenocarcinomas (36%) and pNEN (48%). Five-year overall survival rate was 20% in acinar-MiNEN, compared to 39% in acinar carcinoma patients and 59% in matched pNEN patients.

CONCLUSIONS

MiNEN are rare and difficult to distinguish from pure adenocarcinoma or neuroendocrine neoplasm preoperatively. Surgical resection would therefore be the treatment of choice in localized tumors.

Collision of a pancreatic ductal adenocarcinoma and a pancreatic neuroendocrine tumor associated with multiple endocrine neoplasm type 1

A 54-year-old man with pancreatic head tumor had undergone pancreaticoduodenectomy and was diagnosed with pancreatic neuroendocrine tumor (P-NET) associated with sporadic multiple endocrine neoplasm type 1. Five years after the resection, P-NET recurred and liver metastases were observed. He was treated with a somatostatin analog. Eleven years after the resection, computed tomography revealed a new pancreatic hypodense and hypovascular mass adjacent to the P-NET that was diagnosed as pancreatic adenocarcinoma via endoscopic ultrasound-guided fine-needle aspiration. He underwent a total remnant pancreatectomy. Pathological examination showed that the lesion was constituted by a pancreatic ductal adenocarcinoma (PDAC) and a neuroendocrine tumor. Additionally, the invasive ductal carcinoma collided with the neuroendocrine tumor. Both PDAC and P-NET cells were observed in the collision area. We could observe the onset of PDAC during the treatment of P-NET. Moreover, we are the first to report the case of a collision of pancreatic endocrine and exocrine tumors diagnosed preoperatively.

Mixed Adenoneuroendocrine Carcinoma (MANEC) of the Gallbladder: A Systematic Review of Outcomes Following Surgical Management

BACKGROUND/AIM

Mixed adenoneuroendocrine carcinomas (MANEC) are uncommon tumors exhibiting both adenocarcinomatous and neuroendocrine differentiation. They most commonly arise in the colon, appendix, rectum or stomach, however, a limited number of MANECs have been reported to originate in the gallbladder (gMANEC). The aim of our systematic review was to accumulate the existing data on gMANEC with special attention to the clinicopathological characteristics, surgical approach, recurrence and survival rates of patients diagnosed with this rare malignancy.

MATERIALS AND METHODS

A comprehensive search of the literature was undertaken.

RESULTS

A total of 15 studies (14 case reports and 1 case series), which comprised 19 patients who successfully underwent surgical treatment for gMANEC were included in our systematic review. During a median follow-up of 8 months (range=2-48 months) the overall survival was 87% and the recurrence rate was 21%.

CONCLUSION

Achievement of complete surgical resection is the mainstay of the therapeutic management. Additionally, the stage of the disease and the histopathological mapping of these tumors affect decision-making for adjuvant chemotherapy and seem to define the prognostic course of each patient.