Discriminant analysis between malignant mesothelioma and reactive mesothelium using nuclear three-dimensional analysis is useful for morphologically suspicious cases.

OBJECTIVE: Morphological discrimination between malignant mesothelioma (MM) and reactive mesothelium (RM) is often difficult. Stereological analysis of nuclear luminance using centrifuged smear samples from coelomic fluid and discriminant analysis based on Mahalanobis distance may help to more accurately discriminate between MM and RM. In the present study, discriminant analysis was conducted on cytological specimens using the auto-smear method in a blinded manner with regard to histological results. STUDY DESIGN: Coelomic fluid samples of 28 cases, cytologically diagnosed using the auto-smear method, were analyzed to determine pixel counts, the number of focus layers, 3-dimensional variation in the coefficient of variation of nuclear luminance between the focus layers as well as roundness in about 30-50 atypical cell nuclei per case. These measurements were employed to determine malignancy based on Mahalanobis distance. RESULTS: Discrimination rates were as high as 91.7% for MM and 82.7% for RM. The discrimination rates of MM with histology were >80% in 8 of 10 suspicious cases with the initial cytology. CONCLUSION: Our method allowed accurate discrimination between MM and RM and provides a useful alternative for the diagnosis of suspicious cases where morphological diagnosis of malignancy is difficult.

Differential diagnosis of reactive mesothelial cells and malignant mesothelioma cells using the cell proliferation markers minichromosome maintenance protein 7, geminin, topoisomerase II alpha and Ki-67.

OBJECTIVE: The aim of this study was to evaluate whether the immunocytochemical expression of cell proliferation markers, such as minichromosome maintenance protein 7 (MCM 7), geminin, topoisomerase II alpha (topo IIα) and Ki-67, which are different types of cell proliferation markers, could be useful for their differential diagnosis in reactive mesothelial cells and malignant mesothelioma cells obtained from body cavity fluids. STUDY DESIGN: Samples diagnosed and later histologically confirmed as reactive mesothelial cells (39 cases) or malignant mesothelioma (32 cases) in body cavity fluids were examined. Immunocytochemical staining of MCM 7, geminin, topo IIα and Ki-67 was performed with the immunoperoxidase polymer method. RESULTS: Labeling indices (LIs) of MCM 7 (cutoff value 20.0%; sensitivity 100%; specificity 100%), geminin (cutoff value 4.5%; sensitivity 88.0%; specificity 70.0%), topo IIα (cutoff value 11.0%; sensitivity 88.0%; specificity 92.0%) and Ki-67 (cutoff value 15.3%; sensitivity 78.0%; specificity 79.0%) of malignant mesothelioma cells were significantly higher than those of reactive mesothelial cells. CONCLUSION: LIs of MCM 7, geminin and topo IIα can be reliable tools for the differential diagnosis of reactive mesothelial cells and malignant mesothelioma cells.

Cytology Reporting System for Lung Cancer from the Japan Lung Cancer Society and the Japanese Society of Clinical Cytology: An Extensive Study Containing More Benign Lesions.

INTRODUCTION: The Japan Lung Cancer Society (JLCS) and the Japanese Society of Clinical Cytology (JSCC) have proposed a new four-tiered cytology reporting system for lung carcinoma (JLCS-JSCC system). Prior to the proposal, the Papanicolaou Society of Cytopathology (PSC) had proposed a revised reporting system (PSC system), which comprises the "neoplastic, benign neoplasm, and low-grade carcinoma" category (N-B-LG category), in addition to the 4 categories of the JLCS-JSCC system. This study aimed to evaluate the interobserver agreement of the JLCS-JSCC system with an additional dataset with more benign lesions in comparison with the PSC system. METHODS: We analyzed 167 cytological samples, which included 17 benign lesions, obtained from the respiratory system. Seven observers classified these cases into each category by reviewing one Papanicolaou-stained slide per case according to the JLCS-JSCC system and PSC system. RESULTS: The interobserver agreement was moderate in the JLCS-JSCC (k = 0.499) and PSC (k = 0.485) systems. Of the 167 samples, 17 samples were benign lesions: 7 pulmonary hamartomas, 5 sclerosing pneumocytomas, 2 squamous papillomas, one solitary fibrous tumor, one meningioma, and one lymphocytic proliferation. There were diverse sample types as follows: 11 touch smears, 3 brushing smears, 2 aspirations, and one sputum sample. Fourteen samples (82.3%) were categorized into "negative" or "atypical" by more than half of the observers in the JLCS-JSCC system. Conversely, 3 samples were categorized as "suspicious" or "malignant" by more than half of the observers in the JLCS-JSCC system. On the other hand, 11 samples (64.7%) were categorized into the N-B-LG category by more than half of the observers in the PSC system. CONCLUSIONS: The concordance rate in the JLCS-JSCC system was slightly higher than that in the PSC system; however, the interobserver agreement was moderate in both the JLCS-JSCC and PSC systems. These results indicate that both the JLCS-JSCC and PSC systems are clinically useful. Therefore, both systems are expected to have clinical applications. It may be important to integrate the 2 systems and construct a universal system that can be used more widely in clinical practice.

Immunohistochemical, molecular, and clinicopathological analyses of urothelial carcinoma, micropapillary variant.

The prognosis of urothelial carcinoma, micropapillary variant (MPV), of the bladder has been shown to be worse than that of the conventional urothelial carcinoma (UC). However, it remains to be clarified why the MPV is more aggressive. We therefore here focused on the correlation between clinical features and histological, immunohistochemical and molecular findings for eight MPV and 35 UC, evaluating expression of MUC1, Ki-67, p53, CD147, CD34, D2-40, and extracellular matrix proteins. The Ki-67 labeling index was significantly higher in UC than in MPV but densities of venous and lymphatic tumor emboli were significantly higher in the MPV cases and lymph node metastasis was more frequent, with a poorer prognosis. Tenascin-C and fibronectin also showed significantly greater expression in MPV than in UC at the epithelial-mesenchymal interfaces. Direct sequencing showed point mutations of KRAS exon 1 in three MPV with significantly more frequency compared to UC. Occupation rate of the MPV area in the tumor showed significant inverse correlation with overall survival. Thus our histopathological findings provide clues to explaining why prognosis is poorer in the MPV than UC.

Cytology Reporting System for Lung Cancer from the Japan Lung Cancer Society and Japanese Society of Clinical Cytology: An Interobserver Reproducibility Study and Risk of Malignancy Evaluation on Cytology Specimens.

INTRODUCTION: The classification of lung carcinoma is based on small biopsies and/or cytology in 80% of patients with non-small cell carcinoma. However, there is no widely accepted classification system for respiratory cytology. The Japan Lung Cancer Society (JLCS) and Japanese Society of Clinical Cytology (JSCC) have proposed a new four-tiered cytology reporting system for lung carcinoma with the following categories: (1) "negative for malignancy," (2) "atypical cells," (3) "suspicious for malignancy," and (4) "malignancy." OBJECTIVE: The aim of this work was to perform an interobserver reproducibility study to confirm the utility of the four-tiered reporting system on respiratory cytological samples. METHODS: We analyzed 90 cytological samples obtained with bronchoscopy. Seven observers classified these cases into each category by reviewing one Papanicolaou-stained slide per case according to the three-, four-, and five-tiered reporting systems. RESULTS: The interobserver agreement was fair in the three- (κ = 0.50), four- (κ = 0.45), and five-tiered (κ = 0.45) reporting systems. However, the four-tiered reporting system provided more precise information than the three-tiered reporting system in patient management. The risk of malignancy in the four-tiered reporting system was also stratified well: 19.3% for "negative for malignancy," 45.6% for "atypical cells," 74.7% for "suspicious for malignancy," and 88.1% for "malignancy." CONCLUSIONS: The reporting system proposed by the JLCS and JSCC was designed to enhance the communication between clinicians and pathologists and among different institutions. It is simple and applicable to cytological diagnosis of any respiratory diseases. We propose establishing an international classification for respiratory cytology, harmonizing the reporting systems proposed by different countries.

Ciliated muconodular papillary tumors of the lung: Cytologic features and diagnostic pitfalls in intraoperative examinations.

Ciliated muconodular papillary tumors (CMPTs) of the lung are rare, likely benign neoplastic lesions. Here we describe a case of a CMPT, focusing on its cytologic features, which to our knowledge have not been reported previously. Owing to dull back pain, a 69-year-old male non-smoker underwent CT, which revealed a 1.3 × 1.3-cm solid nodule in the peripheral field of the left lower lung lobe. A wedge resection of the nodule was performed, with the provisional diagnosis being primary lung cancer. Macroscopic examination of a resected specimen showed a 1.2-cm grayish nodule. Touch imprint smear cytology revealed ciliated columnar cells and mucous cells, as well as abundant extracellular mucin on inflammatory background of lymphocytes and histiocytes. Histologic examination revealed a nodular papillary tumor composed of ciliated columnar cells, mucous cells, and basal cells surrounded by a mucin pool. No nuclear atypia or mitotic figures were identified. The final diagnosis was CMPT. The postoperative course was uneventful, with no recurrence at 8 months after surgery. Although a CMPT is a rare lung tumor, it should be considered when cytological or histological examination of a solitary peripheral lung nodule shows non-atypical ciliated cells and mucous cells surrounded by mucin.

Cell cannibalism and nucleus-fragmented cells in voided urine: useful parameters for cytologic diagnosis of low-grade urothelial carcinoma.

OBJECTIVE: To clarify whether the 3 parameters of cell clusters, cell cannibalism and nucleus-fragmented cells could improve diagnostic accuracy for grade 1 urothelial carcinoma (G1UC). STUDY DESIGN: A total of 52 voided urine samples from 31 patients histologically diagnosed as having G1UC were reviewed. In addition, 10 voided urine samples from cases with grade 3 demonstration urothelial carcinoma (G3UC) and 30 voided urine samples from 25 patients with a histologic diagnosis of chronic inflammation of the bladder were evaluated for comparison. Areas of tumor cells with cannibalism were measured. RESULTS: Cell cannibalism was evident in 12 of 31 G1UC cases (38.7%), significantly less often than with G3UC, but never identified in the control group. Mean areas of tumor cells featuring cannibalism were significantly smaller in G1 UC than in G3UC cases. Nucleus-fragmented cells were also less frequent in G1UC than in G3UC, but more common than in the control group. CONCLUSION: Cell cannibalism and nucleus-fragmented cells in voided urine with special attention to areas of tumor cell with cannibalism could be applied as a parameter to improve diagnostic accuracy for G1UC.

Basement membrane-like substance in cytologic diagnosis in clear cell adenocarcinoma of the minor salivary gland of the palate. A case report.

BACKGROUND: Clear cell adenocarcinoma (CCA) of the minor salivary gland accounts for < 1% of all tumors of the salivary gland. CASE: A 32-year-old woman with a history of papillary carcinoma of the thyroid 1 year earlier complained of pain on the left side of the neck. After a detailed examination, the patient underwent the resection of a tumor located at the palate. Imprint cytology of the tumor revealed cohesive tumor cells of uniform size containing an abundant clear cytoplasm and round nuclei with extra but fine granular chromatin and conspicuous nucleoli. A basement membrane-like substance (BMS) was stained in light green with Papanicolaou staining and was positive for laminin with immunohistochemical staining. Histopathologic analysis confirmed the trabecular or nest-like arrangement of the cells with the clear cytoplasm and BMS substance surrounded by tumor cells, which were positive for laminin and AE1 immunohistochemically. CONCLUSION: Although CCA of the palate is extremely rare, an accurate cytologic diagnosis can be made if the characteristic findings of CCA, including BMS, are imaged.

Cytological significance of abnormal squamous cells in urinary cytology.

The aim of this study was to evaluate the significance of abnormal squamous cells (ASCs) in urinary cytology to clarify whether finding of ASCs could improve diagnostic accuracy. A total of 3,812 urine specimens were reviewed. We focused on three parameters of ASCs, necrotic debris, and ASC clusters, and linked them to histological diagnosis and clinical information. ASCs were identified in 34 (0.9%) specimens from 21 different patients. The incidence of ASCs was higher in females than in males. The 34 urine specimens were categorized as voided urine (16 cases), bladder-catheterized urine (17 cases), and bladder-washed fluid (1 case). Six (28.6%) of 21 patients were histologically diagnosed as having combined urothelial carcinoma and squamous cell carcinoma (SCC). Eight patients (38.1%) were histologically diagnosed as having SCC originating from sites other than the urinary tract; those urine specimens showed ASCs that were likely to have been exfoliated from malignant lesions. Necrotic debris and ASC clusters were identified in 12 specimens (35.3%) from 11 patients and 4 specimens (11.8%) from 4 patients, respectively, from a total of 34 specimens. Our results indicate that a great amount of care is needed for cytological diagnosis when attempting to recognize ASCs in urine specimens because ASCs were identified in not only SCC of the bladder but also in carcinoma or nonmalignant lesions of nonurinary tracts. Necrotic debris was found not only in patients who had malignant bladder tumors but also in those who had malignant lesions in locations other than the bladder.

Comparative image analysis of cells in voided and catheterized urine.

OBJECTIVE: To objectively evaluate the difference in cytologic findings between specimens of voided and catheterized urine by using a comparative image analysis device, CAS200. STUDY DESIGN: Cells in voided and catheterized urine from 13 patients with transitional cell carcinoma (TCC), including 3 with grade 1, 6 with grade 2 and 4 with grade 3, were compared cytologically. The cellular area, nuclear area, nuclear/cytoplasmic ratio and nuclear density of both types of cytologic specimen were measured using CAS200. RESULTS: Cell area and nuclear area of grade 1 TCCs were significantly greater in voided urine than in catheterized urine. In contrast, cell area and nuclear area of grade 3 TCCs were significantly smaller in voided urine than in catheterized urine (P < .01), and nuclear density of grade 3 TCCs was higher in the latter than in the former. CONCLUSION: The cellular findings in voided urine were different from those in catheterized urine from the same patient. Thus, the method selected for obtaining urine specimens will affect the findings in urinary cytology.

Diagnostic findings of bronchial brush cytology for pulmonary large cell neuroendocrine carcinomas: comparison with poorly differentiated adenocarcinomas, squamous cell carcinomas, and small cell carcinomas.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) of the lung has been proposed as a new disease entity. To establish diagnostic features, bronchial brush cytologic findings were evaluated. METHODS: Bronchial brush cytology material of 20 LCNECs was evaluated by light microscopy and stained immunocytochemically with protein gene product 9.5 (PGP9.5), neuron-specific enolase, and neural cell adhesion molecule antibodies. The findings were compared with those for 19 poorly differentiated adenocarcinomas (ACs), 18 poorly differentiated squamous cell carcinomas (SCCs), and 20 small cell lung carcinomas (SCLCs). RESULTS: Frequently observed characteristic cytologic findings of LCNECs were necrotic background (90.0%), large tumor cell size (90.0%), naked nuclei (90.0%), and nuclear streaking (90.0%). Nuclei in all LCNECs showed a fine granular chromatin pattern and possessed one or a few nucleoli. Indian-filing and rosette arrangements were observed in less than one-half of the LCNECs. In poorly differentiated ACs and SCCs, these features were less frequent, whereas thick nuclear membranes were observed more often. In SCLCs, tumor cell adhesions and Indian-filing or nuclear molding were observed more frequently than in LCNECs, whereas a necrotic background, tumor cell clusters, large tumor cells, and nucleoli were less prominent. The majority of LCNECs (80.0%) had a positive immunocytochemical reaction for PGP9.5, in contrast to the low positive reactions for ACs (42.1%) and SCCs (30.8%). CONCLUSIONS: Large cell neuroendocrine carcinomas can be diagnosed preoperatively by bronchial brush cytology using reliable parameters, including tumor cell size, naked nuclei, thin nuclear membranes, nuclear streaking, high PGP9.5 positivity, and a necrotic background.