Carcinoma ex pleomorphic adenoma (CXPA) of the salivary glands is a relatively rare carcinoma. The detection rate of the carcinoma component in the cytological specimens is not high and may be challenging in cytological examination. The purpose of the present study was to analyze the cytological specimens of CXPA with emphasis on the detection of the carcinoma component. We reviewed the cytological characteristics of patients histopathologically diagnosed with CXPA who underwent preoperative cytological examination. Of the 10 patients enrolled in the study, 8 had tumors located in the parotid gland, and 2 in the submandibular gland. A review of the cytological specimens revealed the presence of the carcinoma component in all 10 cases and the pleomorphic adenoma (PA) component in 6 cases, although initial cytodiagnosis detected the carcinoma component in 8 cases. The cytological feature of this component was the presence of variable‐sized clusters of polygonal cells with relatively rich cytoplasm and large round to oval nuclei in a necrotic background. Interestingly, carcinoma cells mixed with the PA component were also present. On histopathological analysis, 7 cases were intracapsular, and the remaining 3 cases were widely invasive CXPA. Further, 9 cases had salivary duct carcinoma as carcinoma component. In conclusion, these findings show that careful detection of the carcinoma cells, particularly within the PA component, is crucial for early detection of CXPA, and the presence of necrosis might help with the detection of the carcinoma component.

Secretory carcinoma (SC) of the salivary gland is a rare distinct clinicopathological entity characterized by the presence of the ETV6‐NTRK3 fusion. Although the characteristic cytological features of SC have been recognized, its cytodiagnosis, especially differentiating SC from acinic cell carcinoma, is challenging. Recent studies have revealed that immunohistochemistry for pan‐tyrosine receptor kinase (Trk) and nuclear receptor subfamily 4 group member 3 (NR4A3) are specific for SC and acinic cell carcinoma, respectively. However, the usefulness of immunocytochemical detection of these markers in the diagnosis of SC has not been addressed. Hence, the present study aimed to analyze the usefulness of immunocytochemical staining for pan‐Trk and NR4A3 in the cytodiagnosis of SC. We enrolled eight patients with a histopathological diagnosis of SC who underwent preoperative fine‐needle aspiration cytological examination. The cytological characteristics were reviewed and immunocytochemical staining for pan‐Trk and NR4A3 was performed. The characteristic cytological features noted in the patient cohort included neoplastic cell clusters with a sheet‐like and papillary cluster arrangement as well as single cells. Additionally, neoplastic cells with mild to moderately enlarged nuclei and small nucleoli, multi‐vacuolated cytoplasm, and intracytoplasmic mucin were also observed. The immunocytochemical analyses clearly demonstrated that all eight specimens showed positive nuclear staining for pan‐Trk, but were negative for NR4A3 expression. Although all cases of SC do not always show positive immunoreactivity for pan‐Trk, immunocytochemical analysis for pan‐Trk may be useful for the cytodiagnosis of SC along with assessment of the characteristic cytological features.

Background Recently, there have been reports of endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) cytology being used for the diagnosis of various kinds of tumors. This method has also been adopted in the diagnosis of gastric submucosal tumors (SMTs). The aim of this study was to analyze the utility of EUS‐FNA cytological examination in rapid on‐site evaluation (ROSE) for gastric SMTs. Methods Retrospective analyses of the cytological specimens of EUS‐FNA in ROSE for gastric SMTs and determination of the diagnostic accuracy of EUS‐FNA combined with immunohistochemical analysis of cell blocks and surgically resected specimens were performed. Results A total of 110 patients were enrolled in this study. The most common cytodiagnosis was spindle cell tumor (62 patients, 55.5%), followed by negative for tumor (34 patients), and malignant lymphoma and adenocarcinoma (five patients each). Cell blocks were prepared for 60 of the patients (96.8%), cytologically diagnosed with spindle cell tumor. Immunohistochemical analyses using cell block revealed gastrointestinal stromal tumor (GIST, c‐kit+/desmin−, 49 patients) and leiomyoma (desmin+/c‐kit−, five patients). Thus, using EUS‐FNA specimens, 83.1% of GIST patients were pre‐operatively diagnosed. Conclusions EUS‐FNA cytological examination in ROSE for gastric SMTs aided in the collection of sufficient amounts of tumor tissues for preparing cell blocks. This method led to a high rate of accurate pre‐operative diagnosis in patients with gastric SMTs.

This study highlights the cytomorphological features of atypical polypoid adenomyoma (APAM). Squamous morules and/or short fascicles of spindle cells were found in five of the six cases. A combination of cytomorphological features can lead to a suspicion of APAM and avoid an overdiagnosis as endometrioid carcinoma.

Olfactory neuroblastoma (ONB) is a rare malignant neuroectodermal tumor. Due to the rarity, there are scarce reports describing the cytological features of ONB. Thus, we aimed to analyze these cytological features and discuss their differences depending on the histological grading of ONB. Patients with a histopathological diagnosis of ONB who underwent fine‐needle aspiration cytology were enrolled in the study. The cytological features, including arrangement and shape of neoplastic cells, nuclear features, and presence of rosettes, were analyzed. Eight patients with ONB were enrolled; cytological specimens of seven patients were obtained from metastatic lesions and that of one patient were obtained from the nasal cavity tumor. The cytological specimens demonstrated variable‐sized clusters of neoplastic cells and single cells. Two‐cell pattern, composed of large‐sized viable neoplastic cells and small‐sized apoptotic cells, was noted in 3 of 4 high‐grade ONBs but in none of 4 low‐grade ONBs. This reflects that the presence of the two‐cell pattern may represent higher proliferation in neoplastic cells. The neoplastic cells had scant cytoplasm and round to oval nuclei containing fine to granular chromatin without conspicuous nucleoli. Rosettes and paranuclear blue bodies were observed in one patient. Most cytological specimens of ONB were obtained from metastatic lesions, especially from the cervical lymph node. Thus, ONB should be differentiated from malignant lymphoma and small cell neuroendocrine carcinoma. Recognition of these cytological features of ONB while considering patient history can aid in correctly diagnosing ONBs. Moreover, the presence of two‐cell pattern might reflect high‐grade histology of ONB.