<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> The interobserver agreement was moderate in the JLCS-JSCC (<i>k</i> = 0.499) and PSC (<i>k</i> = 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. <b><i>Conclusions:</i></b> 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.

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. Meth

BACKGROUND. Patients with noninvasive, small‐sized primary adenocarcinomas of the lung have excellent prognosis after lobectomy. Several researchers have suggested that limited resection could be an acceptable alternative for these patients. Therefore, a preoperative or intraoperative judgment of invasiveness would be one of the critical determinants of the surgical procedure in each case. Cytopathologic findings that can distinguish invasive from noninvasive adenocarcinomas remain to be elucidated. METHODS. Imprint smears were obtained from 60 resected adenocarcinomas with nonmucinous bronchioloalveolar features. Thirteen cytologic factors were evaluated: the presence of necrosis, fibrovascular tissue, proportion of macrophages, the presence of large tumor cell clusters, nuclear grooves, nuclear overlapping, variation in nuclear size, chromatin pattern, presence of a nucleolus, intranuclear inclusions, multinucleated cells, spindle cells, and mitosis. Each factor was examined by univariate analysis for correlation with the presence of histopathologic invasion. RESULTS. In the univariate analysis, 5 cytologic factors—presence of tumor cell clusters consisting of more than 50 tumor cells (P < .001), nuclear overlapping in more than 3 layers (P < .001), presence of nuclear grooves (P = .007), more than 3‐fold variation in nuclear size (P < .001), and 1 mitotic cell per 1000 tumor cells (P = .035)—were associated significantly with invasion. Among these, nuclear overlapping in more than 3 layers (P = .003) and more than 3‐fold variation in nuclear size (P = .005) were found to be independent predictive factors for invasion by multivariate analysis. CONCLUSIONS. Using imprint smears, the presence of invasion in small‐sized primary adenocarcinomas of the lung is predictable by the 2 above‐mentioned cytologic findings. Imprint smear cytology may effectively aid intraoperative judgement of invasion in cases where frozen section histology is difficult to interpret. Cancer 2006. © 2006 American Cancer Society.

Ectopic meningioma is a generally rare type of benign tumor that very rarely occurs in the lung. Here, we report the cytological findings of a primary pulmonary meningioma with a particular focus on immunohistochemical (IHC) assessment. A healthy 60‐year‐old woman visited our hospital with an asymptomatic nodule in the right lower lung lobe. She had no particular past‐history and no other tumors in the central nervous system or elsewhere according to an imaging examination. Transbronchial fine‐needle aspiration cytology revealed clusters of spindle cells in a whorled formation and psammoma bodies. The tumor cells exhibited spindle‐shaped cytoplasm, small fusiform or round nuclei and numerous intranuclear cytoplasmic inclusions. IHC staining of the cytological specimen revealed that the tumor cells were positive for epithelial membrane antigen, negative for thyroid transcription factor‐1 and p40, and equivocal for claudin‐1. Progesterone receptor immunoreactivity of cytology specimen resulted negative at first by manual method but retrieved positive by an autostainer. Following segmentectomy, the pathological diagnosis was a meningothelial meningioma. The patient has remained well without recurrence for 36 months postoperatively. Because the cytological preparation exhibited characteristic findings of meningioma, a correct diagnosis based on pre‐operative cytological findings with appropriate IHC would be possible. Here, we report the cytological and IHC features of this case and highlight the importance of IHC‐quality assurance.

Signet-ring cell carcinoma (SRCC) and goblet-cell-type adenocarcinoma (GCA) are mucin-producing lung adenocarcinomas. Primary SRCC shows an aggressive clinical course, whereas GCA shows infrequent distant metastasis, but more frequent intrapulmonary metastases resembling lobar pneumonia. To distinguish SRCC from GCA, this study investigated the respective cytological features of these lesions. We selected 10 cases each of SRCC and GCA from the archival imprint smears. We assessed them for the following 10 cytological features. Necrosis/debris was observed in 60% of the SRCC and 90% of the GCA. A mucinous background was observed in 10% of the SRCC and 90% of the GCA. Significant inflammation was observed in none of the SRCC and 80% of the GCA. Stromal cluster was observed in 30% of the SRCC and 70% of the GCA. Nuclear overlapping was observed in 50% of the SRCC and in all of the GCA. Single tumor cells were observed in 80% of the SRCC and 10% of the GCA. Honeycomb-like cluster was observed in none of the SRCC and 80% of the GCA. Prominent nucleolus was observed in 50% of the SRCC and 40% of the GCA. Nuclear membrane irregularity was observed in 70% of SRCC and 60% of the GCA. Nuclear pleomorphism was observed in all of the SRCC and none of the GCA. The cytological features of SRCC were the presence of single tumor cells and nuclear pleomorphism, whereas that of GCA were the presence of abundant mucin and significant inflammation in the background, and a honeycomb-like cluster.