Mixed Acinar-Neuroendocrine Carcinoma of the Pancreas with Neuroendocrine Predominance

Abstract

Background. Pancreatic tumors are rare and could arise from either the exocrine (ductal and acinar cells) or the endocrine (neuroendocrine cells) components of the pancreas. In some instances, the occurrence of pancreatic tumors comprising both acinar cells and neuroendocrine cells, with neuroendocrine cells making up more than 30% of the tumor, has been identified. This unique entity has been referred to as mixed acinar-neuroendocrine carcinoma (MANEC). Only about 20 such cases have been reported in the literature. Case Report. We report an interesting case of MANEC with neuroendocrine cell predominance in a woman presenting with epigastric pain secondary to a pancreatic mass with acinar and endocrine differentiation. She underwent surgical resection of the tumor and was offered adjuvant treatment chemotherapy with carboplatin, etoposide, and radiotherapy for positive tumor resection margins. Conclusions. Given the paucity of the cases of MANEC, continuous reporting of these cases when identified should be encouraged to aid oncologists in understanding the disease and help establish standardized management.

Pancreatic mixed acinar‐neuroendocrine carcinoma, a unique diagnostic challenge on FNA cytology: A small series of two cases with literature review

“…4 In our literature search, only nine cases were identified in which previous FNA results were reported. 3,4,6,10,15,17,22,26 Of these cases, only three were definitively diagnosed as MANEC based on the FNA specimens, having auspiciously sampled truly mixed components (see Table 2). 3,4 Our cases exhibited distinct cytomorphologic features, highlighting the variability of MANEC tumors and the difficulty of their classification (see Table 1).…”

A Pediatric Case of Mixed Acinar-Neuroendocrine Carcinoma

“…Of the 20 cases reported in the literature, most were reported in adults aged more than 60 years [1]. Most pancreatic malignancies in children are pancreatoblastomas; only a single case of MANEC has been previously reported, in an 8-year-old boy [3].…”

“…Of these, 17 cases had pancreatic masses classified as MANEC or mixed acinar ductal carcinoma [1][2][3][12][13][14][15]. In those reports, which included 5 female and 12 male patients, the mean patient age was 65.6 years and the mean mass size was 4.0 cm, with an unreported mass size in 1 case.…”

“…Neuroendocrine and acinar cell carcinomas account for approximately 7% and 1% of pancreatic cancers, respectively, whereas ductal adenocarcinomas account for more than 75%. Among the many pathological subtypes of pancreatic tumors, there are less than 20 reported cases of the mixed endocrineexocrine type in the English literature [1]. Pathologically, such tumors are termed mixed acinar-neuroendocrine carcinoma (MANEC), in which neuroendocrine cells comprise more than 30% of the tumor mass.…”

Acinar neoplasms of the pancreas—A summary of 25 years of research

“…8). In almost all cases, the acinar component predominates [39]. A few exceptional examples have shown morphologically obvious and separate components reflecting the two different cell lineages, but most mixed acinar neuroendocrine carcinomas have a more homogeneous morphology, with only subtle regional variations raising the potential of both acinar and neuroendocrine elements being present [12].…”