Metastatic mixed acinar‐neuroendocrine carcinoma of the pancreas to the liver: A cytopathology case report with review of the literature

Abstract

A case of metastatic mixed acinar-neuroendocrine carcinoma (MANEC) of the pancreas to the liver is reported. A diagnostic percutaneous US-guided FNA and core biopsy of a liver nodule was performed. The FNA smears were cellular and showed neoplastic cells in clusters with acinar formation, isolated single cells, and scattered naked nuclei. The cytoplasm was finely granular. The nuclei were relatively uniform, some with speckled chromatin and prominent nucleoli. The immunohistochemistry performed on the cell block showed strong positivity for cytokeratin AE1/AE3, chromogranin, and synaptophysin. Furthermore, the tumor cells were weakly positive for α1-antichymotrypsin. The Ki-67 mitotic index was up to 50%. Based on the morphology and supporting immunohistochemical stains, the final cytopathologic diagnosis rendered was "Positive for malignant cells. Carcinoma with mixed acinar and endocrine features." To our knowledge, this is the first report of a metastatic MANEC to the liver diagnosed based on cytology with confirmatory histology. The difficulties in the cytopathologic diagnosis and differential diagnosis of MANEC are discussed in this article.

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

“…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). Diagnostically, both of our cases exhibited immunohistochemical evidence for both exocrine and endocrine differentiation as required in the WHO classification.…”

Metastatic mixed acinar-endocrine carcinoma of the pancreas treated with a multidisciplinary approach: a case report

“…Some pancreatic neoplasms have significant components from more than one line of differentiation and are classified as mixed acinar-endocrine carcinomas (MAEC), mixed acinar-ductal carcinomas, mixed ductal-endocrine carcinomas, or mixed acinar-endocrine-ductal carcinomas [2]. By arbitrary definition, each component must comprise at least 25% of the neoplasm [3, 12]. Only 21 cases that fit this strict definition have been reported in the English literature.…”

A Pediatric Case of Mixed Acinar-Neuroendocrine Carcinoma

“…Most pancreatic malignancies in children are pancreatoblastomas; only a single case of MANEC has been previously reported, in an 8-year-old boy [3]. MANEC is more common in women, although the number of reported cases is small [4][5][6]. Most patients present with abdominal pain and weight loss [3,7,8].…”