To analyze the accuracy and usefulness of sputum cytology as a screening method, 103 cases of histologically proven lung cancer registered from 1998 to 2000 at Kangbuk Samsung Hospital were retrospectively examined. We reviewed the original cytologic and surgical diagnoses for the cases, and the cytology slides of all cytologically negative cases. The overall sensitivity of sputum cytology was 0.83 ; the sensitivity of prebronchoscopy sputum cytology for bronchogenic carcinoma was 0.87. Central tumor location (P=0.002), tumor size (>2.4 cm), (P=0.027) and the number of sputum samples $(\geq3)$ (P=0.001) were associated with a positive cytologic diagnosis. Of the 18 cytologically negative cases, 9 cases(38% of smears) were determined to be insufficient for diagnosis, due strictly to low cellularity and saliva. After a review of the cytology slides of cytologically negative cases, we identified several atypical clusters in one case of bronchioloalveolar carcinoma. This negativity was thus attributed to an interpretation error (1/18, 5.6%). Our results suggest that its sensitivity is more strongly related to the specimen adequacy and the times of sampling than to interpretation error. In terms of sensitivity, specificity, accessibility, cost, and morbidity associated with the screening tests, sputum cytology was found to be an accurate effective screening method for lung cancer.

Postmenopausal squamous atypia (PSA) is a phenomenon characterized by cellular alterations mimicking condyloma in the uterine cervix of postmenopausal women. It is not associated with human papillomavirus (HPV) infection. The aim of this study is to correlate findings with HPV infection and the cytohistologic findings of PSA. Eighty-three smears from postmenopausal women, initially interpreted as ASCUS and low-grade squamous intraepithelial lesions(LSIL), were reviewed according to the criteria of PSA. Fifty-eight cases were subsequently reclassified as PSA. Forty cases categorized as PSA were available for HPV-DNA detection by a nested polymerase chain reaction. Eight of these 40 cases(20%) showed biopsy-proven LSIL lesions. The HPV-DNA was detected in 42.5%(17/40), compared to 25%(5/20) of control cases. The HPV-DNA detection rate of biopsy-proven LSIL was 62.5%(5/8). It has been concluded that cytologic differential diagnosis of PSA from LSIL is difficult due to because of poor histologic and viral correlation.

Liquid-Based Uterine Cervicovaginal Cytology is known to be a sensitive and effective screening method for cervical neoplasm $MonoPrep^{TM},\;ThinPrep^{TM},\;and\;SurePath^{TM}$ methods have been recently used as Liquid-Based Uterine Cervicovaginal Cytology techniques, and the $SurePath^{TM}$ method has been used in Sung-Yoon Reference Laboratory since 2003. The goal of Liquid-Based Uterine Cervicovaginal Cytology is to separate cervical epithelial cells from non-target cells, red blood cells and neutrophils. This report describes a study which evaluated cellularity, stainablilty, and cellular changes of epithelial cels in samples processed using a manual technique as compared to samples processed using $SurePath^{TM}$ automated method. The samples processed by means of a manual technique contained a cellularity of epithelial cells similar to that of the samples processed using the $SurePath^{TM}$ automated method. In addition, we compared variable density gradient reagents, including dextran, dextrose, and sucrose, to $SurePath^{TM}$ gradient media in order to evaluate cell fractionation and cellularity of epithelial cells. 10% dextran of gradient media shows good fractionation. The samples processed with 10% dextran demonstrated sufficient cellularity of epithelial cells and shows the fewest cellular changes. In conclusion, using a manual technique on these samples is easier to read than those results obtained using the $SurePath^{TM}$ automated method.

Due to insufficient clinical information, most cervicovaginal smears from pregnant or postpartum women have been screened without regard to pregnancy-related cytological changes. Here, we have reviewed 116 abnormal cervicovaginal smears from 103 pregnant and postpartum women. Initial cytological diagnoses revealed the following: 9 cases of high-grade squamous intraepithelial lesions (HSIL), 8 cases of low-grade squamous intraepithelial lesions (LSIL), 85 cases of atypical squamous cells of undetermined significance (ASCUS), and 14 cases involving atypical glandular cells of undetermined significance (AGUS). 31 cases upon review, involved pregnancy-related cytological changes, comprising 25 cases of decidua cells, 4 cases of Arias-Stella reaction, and 2 cases of cedidual cells coupled with Arias-Stella reaction. Interpretation errors were detected in 14 cases: 13 cases of decidual cells interpreted as either ASCUS favor reactive or ASCUS ruled out HSIL, and one case of Arias-Stella reaction was interpreted as ASCUS ruled out HSIL. Decidual cells and degenerated glandular cells with Arias-Stella reaction can result in diagnostic mistakes. In order to avoid misdiagnosis and unnecessary surgeries, both clinicians and pathologists must be aware of the pregnancy-related cytological changes. The clinician should also always inform the pathologist on the pregnancy status of the patient.

Fine needle aspiration (FNA) cytological examination is an appropriate method for the evaluation of pulmonary nodules. In major types of lung cancer, Its diagnostic accuracy is quite high. However, it is sometimes difficult, using this technique, to differentiate between some unusual phenotypes including adenosquamous carcinoma, bronchioloalveolar carcinoma (BAC), neuroendocrine tumor, mucoepidermoid carcinoma, and sclerosing hemangioma. Here, we present a case involving extremely well differentiated adenosquamous carcinoma, mimicking benign lesions, such as pulmonary scar and adenomatoid malformation with squamous metaplasia. The patient was a 68-year-old man presenting with a solitary pulmonary nodule$(1.6\times1.6cm)$, which was incidentally found at the periphery of the right lower lobe. FNA revealed some clusters of glandular cells with minimal atypia, in addition to squamous cells at a nearly full maturational state. Histological examination verified the cytological diagnosis on a lobectomy specimen. The tumor exhibited a well differentiated adenocarcinoma component, mimicking the bronchioles in scarred lung tissue. and a well differentiated squamous cell carcinoma component, mimucking the squamous cell nests of adenoacanthoma, in the other organs. In the present case, the possibility of adenosquamous carcinoma should have been considered if squamous cells were seen in the FNA from the peripheral pulmonary nodule, even though they appeared to be benign.

Invasive micropapillary carcinoma (IMPCa) is a rare variant of invasive ductal carcinoma of the breast. This variant is associated with a set of peculiar cytological findings and aggressive biological behaviors. In most reported cases, IMPCa has involved massive axillary lymph node metastases at the time of diagnosis. We experienced four cases of cytological features of IMPCa, all of which were verified by histological examination. Fine needle aspiration cytology (FNAC) revealed malignant epithelial cells, which formed small, oval to angulated papillary clusters, which lacked central fibrovascular cores. The histological findings of the four cases revealed both pure and mixed forms of IMPCa, composed of cohesive malignant epithelial cells, surrounded by distinctive clear spaces and separated by thin fibrous septa. All patients evidenced axillary lymph node metastases at the time of diagnosis. It is important to identify the peculiar cytological findings which would differentiate IMPCa from other diseases.

Lymphoproliferative disorders, manifesting either as a primary lesion or as part of a generalized process, rarely involve the breast. The primary malignant lymphoma of the breast is rare. The cytologic features of this neoplasm have not been reported in Korea thus far. We described a case of primary malignant lymphoma of the breast, as diagnosed by fine needle aspiration cytology (FNAC) in an 84-year-old female. FNAC smears showed high cellularity. The main cytologic feature observed was a carpeting of monotonous, atypical, enlarged lymphoid cells. These lymphocytes showed relatively round elliptical nuclei with some indentation. One or more prominent nucleoli were seen. Biopy from the breast mass revealed diagnostic features of non-Hodgkin's lymphoma, diffuse large B-cell type.

Primary clear cell adenocarcinoma of uterine cervix is rare and cytomorphology in the vaginal smear have not been previously described in Korean literatures. The cytologic characteristics of clear cell adenocarcinoma of the uterine cervix include : malignant cells with abundant, finely vacuolated cytoplasm ; hobnail appearance, and distinctive basement membrane-like hyaline materials within cellular aggregates. A 36-year-old woman presented with vaginal bleeding. Cytologic examination of vaginal smear and histopathologic examination of a radical hysterectomy specimen allowed the diagnosis of hemorrhagic tumor in the uterine cervix as a clear cell adenocarcinoma. Cytologic findings were very characteristic. The tumor cells had abundant, pale, finely vacuolated cytoplasm with indistinct cytoplasmic membrane. The nuclei were round to oval with finely dispersed chromatin. Extracellular basement membrane-like hyaline substance, which stained a light green color in Papanicolaou's preparation, was frequently observed within the cancer cell clusters.

Ewing's sarcoma (ES)/PNET is common in both axial and appendicular skeletons, but is extremely rare in the talus. Here, we report a case of ES/PNET of the left talus in a 29-year-old male patient diagnosed by fine needle aspiration cytology, and review the literature on similar cases. The cytological smears were composed of individually dispersed small round cells and occasional clusters of loosely cohesive cells. The tumor cells were fragile, frequently exhibiting naked nuclei. Two distinct types of cells were observed. The light (chief) cells displayed round or slightly oval nuclei with frequent indentations, generally inconspicuous nucleoli, and a thin rim of cytoplasm, which sometimes harbored small vacuoles. The dark cells were smaller, displaying scanty cytoplasm with dense hyperchromatic nuclei, intermixed with chief cells, and often manifesting as small molded groups. However, no significant nuclear pleomorphisms or mitoses were noted. Tumor cells in the ceil block revealed positive cytoplasmic glycogen, as determined by a PAS stain with diastase control, and also exhibited positive immunoreactivity for CD99.

Granular cell tumor is characterized by large eosinophilic cells with granular appearances. These are mostly benign. Approximately $1\sim2%$ are malignant, and establishment of reliable criteria for diagnosing malignant granular cell tumor has been difficult to establish because oi the rarify. Reports on the cytologic features of this neoplasm are hardly found in Korea. We report a case of rarely-occurring granular cell tumor in the lower leg of a 40-year-old male, diagnosed on fine needle aspiration cytology, together with a review of the literature regarding significant adverse histology and prognostic factors. The aspirates revealed cellular smears of isolated cells, syncytial clusters, and occasionally stripped nuclei in a nine, bluish-purple, granular background. Tumor cells were polygonal, rounded, or slightly spindled, and showed ill-defined granular cytoplasm. Nuclei were small and round or oval, with inconspicuous or small, prominent nucleoli. The nuclei showed rare intranuclear cytoplasmic invagination. Occasionally, there were mild to moderate nuclear pleomorphisms with vesicular nuclei, with large, prominent nucleoi, but no mitosis. The immunocytochemical stain for S-100 was strongly positive in the cytoplasm of tumor cells with occasional nuclei.