Objective : To examine the diagnostic significance of round cells with a tendency toward nuclear eccentricity in serial pancreatic juice aspiration cytologic examinations (SPACE).

Study Design : A total of 12 cases of high-grade pancreatic intraepithelial neoplasia (HGPanIN) were examined. Microscopic examinations of SPACE specimens were performed to examine the incidence, number, and architectural patterns of round cells showing a tendency toward nuclear eccentricity. Then, the nuclear irregularity of the round cells, such as increase in and uneven distribution of chromatin, variety of chromatin patterns, and nucleoli were observed. The same examinations were conducted on SPACE specimens obtained from 13 cases of chronic pancreatitis (CP) as controls.

Results : Round cells showing a tendency toward nuclear eccentricity were found in 10 out of 12 cases (83%) of HGPanIN, and 4 out of 13 cases (31%) of CP. In HGPanIN, the round cells appeared in moderate to high numbers, and the cells showed nuclear irregularities and chromatin abnormalities. In CP, on the other hand, fewer round cells were observed, and none of the cases showed uneven chromatin distribution, and a variety of chromatin patterns were observed.

Conclusion : The uneven distribution and variety of chromatin distribution patterns in the round cells with a tendency toward nuclear eccentricity may help in diagnosing malignancy.

Objective : This study was aimed at evaluating whether intracytoplasmic inclusions (IIs) that are sometimes observed in uterine cervical cytology specimens obtained from patients with chlamydia trachomatis (CT) infection are, in fact, specific for CT infection.

Study Design : We enrolled a total of 28 patients with CT infection (CT-infected group) and 30 patients without CT infection (non-CT-infected group) as confirmed by real-time PCR (qPCR). Three types of IIs were detected in the cervical cytology specimens : (1) nebular inclusion (N1), (2) intracytoplasmic inclusion (ICI), and (3) central target formation (CTF). To determine if any of the IIs were specific for genital CT infection, we performed immunocytochemistry with anti-CT antibody and calculated both the rates of detection of the IIs and the rate of immunopositivity (IMP) for CT antigen in the cervical cytology specimens of the study subjects.

Results : There were no significant differences in the rates of detection of ICI and CTF between the CT-infected and non-CT-infected groups. NI and CT IMP were detected only in the CT-infected group, at the rates of about 7.1% and 14.3%, respectively. Thus, but none of the ICI and CTF, showed CT IMP. In addition, some non-IIs-bearing cells with normal morphology detected in the CT-infected group also showed CT IMP.

Conclusion : The data suggest that while the presence of ICI and CTF in cervical cytology specimens may not be specific for CT, the significance of NI needs to be further investigated. The diagnostic ability of cervical cytology for CT infection may be limited.

Objectives : The present study was aimed at clarifying the cytological features of epithelial-mesenchymal transition (EMT) cells in effusion cytology in cases of pancreatic cancer.

Methods : We examined the features of EMT cells in the effusion cytology specimens of 33 cases of pancreatic cancer. We analyzed the immunoreactivities of the cells for EMT-related markers, such as E-cadherin, vimentin, and Zinc finger E-box binding homeobox 1 (ZEB1), and also the cytological features of the vimentin- and ZEB1-positive EMT cells in the effusion cytology specimens.

Results : Pancreatic cancer cells identified in effusion cytology were classified as the clustered type (36.3%), isolated (15.2%) or mixed type (48.5%). The EMT cells showed positive staining for E-cadherin, vimentin, and ZEB1 30 (90.9%), 6 (18.2%), and 4 (12.1%) of the effusion cytology specimens, respectively. Immunoreactivity for the EMT-related markers of E-cadherin and vimentin, but not for that of ZEB1, was closely related to the types of cells. In four of the specimens (12.1%) examined, including 2 with mixed-type cells and 2 with isolated-type cells, the EMT cells showed positive immunoreactivity for both vimentin and ZEB1. The EMT cells in the effusion cytology specimens occurred mainly as isolated, round, and or loosely aggregated clusters of cells.

Conclusions : The EMT cells in the effusion cytology specimens appeared as isolated or loosely clustered cells, and did not exhibit fibroblast-like morphological change. Therefore, it is of importance to understand the diversity of EMT cells in effusion cytology specimens.

Background : We report a case of diffuse large B-cell lymphoma (DLBCL), in which fine-needle aspiration cytology revealed a large number of multinucleated giant cells showing emperipolesis-like features.

Case : The patient was a male in his second decade of life who presented with a mass in the left neck that he had first noticed two months earlier. Findings of MRI and neck ultrasonography led to the suspected diagnosis of malignant lymphoma or schwannoma. Cytological examination revealed small- to large-sized atypical lymphocytes admixed with a large number of macrophages and multinucleated giant cells. The multinucleated cells showed intracytoplasmic inclusions containing lymphocytes, a finding that was considered as being emperipolesis-like. Similar to the cytological findings, intraoperative frozen section examination also revealed diffuse infiltration of small- to intermediate-sized lymphocytes admixed with macrophages and multinucleated giant cells. However, on permanent-section histopathology, while diffuse infiltration of lymphocytes was observed, histiocytes and multinucleated giant cells were indistinct. Immunohistochemically, the background atypical lymphocytes showed diffuse and strongly positive staining for CD 20, while the histiocytes and multinucleated giant cells showed negative staining for CD20, S-100 and CD1a, and positive staining for CD68 and CD163. Based on the findings, we made the final diagnosis of DLBCL with reactive infiltration of histiocytes and multinucleated giant cells showing emperipolesis-like features.

Conclusion : Multinucleated giant cells showing emperipolesis-like features is a rare, but possible finding in DLBCL.

Background : Combined small cell carcinoma is the generic term used to refer to small cell carcinoma occurring concomitantly with NSCLC, and small cell carcinoma occurring concomitantly with carcinosarcoma is rare. Herein, we report a case of combined small cell carcinoma of the lung with carcinosarcoma.

Case : The patient, in his 50 s, presented with bloody sputum and cough, and imaging chest computed tomography (CT) a 10 cm-sized tumor in the right upper lobe. Biopsy suggested the diagnosis of sarcomatoid carcinoma, and lobectomy was performed. Histopathology of the resected tumor revealed the diagnosis of combined small cell carcinoma with carcinosarcoma. Imprint cytology revealed adenocarcinoma cells, spindle-shaped mesenchymal cells, and a small number of small cell carcinoma cells.

Conclusion : It is difficult to make a diagnosis of combined small cell carcinoma by cytology alone. It is necessary to accumulate cytological data from these rare cases to enable cytological diagnosis.

Background : Small cell carcinoma (SCC) of the prostate is a rarely encountered entity, and it is even rarer for tumor cells to appear in the urine. We report the case of a patient in whom SCC of the prostate was detected based on the findings of urinary cytology during endocrine therapy for adenocarcinoma of the prostate.

Case : A male in his sixties was diagnosed as having prostatic adenocarcinoma based on a high serum level of prostate-specific antigen (PSA) and imaging findings. Thirteen months after the initiation of endocrine therapy, the serum PSA decreased to within the normal range, and both the primary and metastatic foci decreased in size. However, 24 months later, SCC was suspected based on the findings of urinary cytology and confirmed by biopsy of the prostate. Urinary cytology showed isolated or small aggregates of small atypical cells with a high N/C ratio in a clean background. The tumor cells contained hyperchromatic nuclei, inconspicuous nucleoli and scant cytoplasm, with nuclear molding and formation of rosette-like structures.

Conclusion : When urinary cytology shows atypical cells with a high N/C ratio during or after endocrine therapy for prostate adenocarcinoma, it is important to consider the possibility of SCC transformation of the adenocarcinoma.

Background : Meningeal melanomatosis is an extremely rarely encountered condition in pediatric practice. Herein, we report a case of pediatric meningeal melanomatosis in which atypical melanocytic cells were detected in the cerebrospinal fluid.

Case : A 4-year-old boy was admitted to our hospital with a history of dysstasia, vomiting and altered consciousness, and was suspected as having encephalitis. After admission, the findings of MRI suggested the possibility of leptomeningeal melanosis, and cerebrospinal fluid (CSF) cytology and brain biopsy were performed. CSF cytology showed atypical cells with intracytoplasmic melanin, and brain biopsy revealed atypical cells containing melanin proliferating under the arachnoid membrane and invading the cerebral parenchyma. Finally, the diagnosis of meningeal melanomatosis was established.

Conclusion : Meningeal melanomatosis is extremely rare. Neither the symptoms nor the imaging findings are specific, and it is often difficult to distinguish this condition from other diseases of the nervous system, like meningitis. CSF cytology has an important role in the diagnosis.

Background : The cell transfer technique is a useful method for performing immunostaining when the amount of cytology material is limited. We report a case with a metastatic tumor in which the primary lesion could be identified by immunostainings performed using the cell transfer technique.

Case : The patient, a woman in her 80 s, had been diagnosed as having lung adenocarcinoma two years prior to the present consultation. During the course of radiation therapy, a swelling was detected in her left neck. PET-CT scan and ultrasonography revealed a mass lesion in both the left cervical lymph node and the left thyroid. The cytological findings of the thyroid lesion were interpreted as atypical follicular epithelial cells of undetermined significance, because of intranuclear inclusion-like structures. Cytological examination of the lymph node specimens showed some atypical cells with intranuclear cytoplasmic inclusions. Metastatic thyroid papillary carcinoma was suspected, however, the patient had a past history of lung adenocarcinoma, cytologic features of which could overlap those of papillary carcinoma. To identify the primary site, immunostainings were performed using the cell transfer technique. The tumor cells were positive for TTF-1, thyroglobulin, and PAX8, suggesting metastasis from papillary thyroid carcinoma.

Conclusion : We reported a case of metastatic tumor in which the primary lesion could be identified by immunostainings using the cell transfer technique, but failed to be diagnosed by Papanicolaou staining alone.