Mixed adenoneuroendocrine carcinoma (MANEC) is defined as a tumor that has morphologically recognizable both adenocarcinoma and neuroendocrine carcinoma components comprising at least 30% of either components. MANEC occurring in the ampulla of Vater is extremely rare, and only 16 cases have been reported in the English language literature. In the present report, we describe the first case of MANEC of the ampulla of Vater with immunocytochemical analyses. An 82-year-old Japanese male was incidentally found to have a tumorous lesion in the ampulla of Vater. Endoscopic ultrasound-fine needle aspiration (EUS-FNA) of the tumor was performed. The Papanicolaou smear demonstrated the presence of different three components. The most dominant component was cohesive clusters of small round cells with round to oval nuclei with powdery chromatin and scant cytoplasm, which corresponded to small cell carcinoma. The second component was an adenocarcinoma, which was composed of irregularly overlapping clusters of tall columnar cells with large round to oval nuclei containing conspicuous nucleoli. The third component was an adenoma, which was comprised of flat cohesive clusters of columnar cells without atypia. Immunocytochemical analyses demonstrated that synaptophysin was expressed in the small round cells, and cdx-2 was expressed in all three components. Accordingly, a cytodiagnosis of MANEC with adenoma component was made. Preoperative diagnosis of ampullary MANEC is difficult. However, this report clearly demonstrates three different components in the EUS-FNA cytological specimen. Therefore, we suggest that cytological examination is a useful method for diagnosis of MANEC of the ampulla of Vater.

Infarction after the fine-needle aspiration (FNA) procedure is a well-recognized phenomenon of salivary gland lesions. Though extremely rare, spontaneous infarction without previous FNA can occur in pleomorphic adenoma (PA). The present report describes a fourth cytological case of spontaneous infarction of PA of the parotid gland using immunocytochemical analysis, to the best of our knowledge, for the first time. A 57-year-old Japanese female presented with persistent swelling of the right neck region. Physical examination revealed a tumour in the right parotid gland, and FNA examination of the tumour was performed following surgical resection. The Papanicolaou smear demonstrated the presence of fully necrotic cell clusters of varying sizes in a necrotic background. Only a few viable cell clusters were observed. These cells were polygonal to spindle-shaped, and exhibited large round to oval nuclei with a conspicuous nucleoli. Although nuclear pleomorphism was noted, the nuclear chromatin was fine. No neoplastic myoepithelial cells were observed. Therefore, it was suspected that these cells were malignant. Immunocytochemical analysis indicated that these atypical cells were positive for p40. Histopathological examination of the resected parotid gland tumour revealed infarcted PA. Our study revealed that the presence of atypical squamous metaplastic cells in a necrotic background was a characteristic cytological feature of infarcted PA, and that these atypical squamous cells can have large nuclei with conspicuous nucleoli and exhibit pleomorphism. Although cytological diagnosis of infarcted PA is difficult, pathologists and cytopathologists must consider the presence of atypical metaplastic squamous cells in benign salivary gland tumours, including infarcted PA.

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Hepatoid adenocarcinoma is defined as an extrahepatic malignant neoplasm showing morphological and immunohistochemical resemblance of hepatocellular carcinoma. The occurrence of this type of tumor in the gallbladder is extremely rare. In this study, we report the first cytological case of hepatoid adenocarcinoma of the gallbladder. An 80-year-old Japanese female was found to have a tumorous lesion in the gallbladder. Papanicolaou smear of the ascites demonstrated a few epithelial cell clusters composed of round to oval neoplastic cells with distinct cell border and large centrally-located nuclei. Tumor touch smear of the resected tumor revealed the presence of two distinct neoplastic components. The first component was composed of clusters or sheets of epithelial cells with distinct cell border, relatively rich clear cytoplasm, and centrally-located nuclei, as seen in the ascites specimen. The other component was composed of tall columnar cells with large basally-oriented nuclei, and glandular formation was noted as well. Immunocytochemical analyzes of the touch smear material demonstrated that the former component was positive for HepPar1, thus it was considered as a hepatoid adenocarcinoma, and the latter component deemed as a typical adenocarcinoma. Histopathological and immunohistochemical examination of the resected gallbladder tumor confirmed a diagnosis of hepatoid adenocarcinoma. The characteristic cytological features of hepatoid adenocarcinoma are the presence of sheets or clusters of neoplastic cells with distinct cell border and centrally-located nuclei. Immunocytochemical analysis for HepPar1 may help its diagnosis. Demonstration of hepatoid adenocarcinoma is important in the cytological specimen because this type of tumor shows an aggressive clinical course.