To evaluate whether different qualifications of a cytologic diagnosis of "atypical squamous cells of undetermined significance(ASCUS)" predict a greater or lesser likelihood of tissue diagnosis of uterine cervix, we compared different cytologic qualifications of ASCUS with the tissue diagnosis. One hundred twenty-two consecutive Papanicolaou smears showing ASCUS in women who had undergone cervical biopsy within nearest 30 days were collected. The 122 smears were qualified as "favor reactive"(25%), "favor low grade squamous intraepithelial lesion (LSIL)"(24%), "favor squamous intraepithelial lesion(SIL)"(16%), "favor high grade squamous intraepithelial lesion(HSIL)"(16%), and "not otherwise specified"(19%). Squamous intraepithelial or invasive lesion was pathologically confirmed by cervical biopsy in 13%, of the "favor reactive", 27% in "favor LSIL", 70% in "favor SIL", 75%, in "favor HSIL", and 35% in "not otherwise specified" smears. There were significant associations between the favor reactive smear and the benign biopsy finding and between the favor SIL smear and the biopsy shewing a squamous intraepithelial or more severe lesion. Nevertheless, most of favor LSIL smears exhibit reactive process in tissue biopsy. Conclusively, qualified ASCUS stratifies women Into different risk groups for SIL. The cytopathologist should make the cytologic diagnosis of "ASCUS, favor LSIL" circumspectly.

We evaluated the availability of toluidine blue stain in body fluids, such as peritoneal and pleural fluid and urine. Nine hundreds specimens, i.e., 400 pleural and 400 peritoneal fluids and 100 urine samples, respectively, from Jan. 1995 to May 1996 were included. We obtained the result of high sensitivity and high specificity. In toluidine blue stained body fluid in comparison with Papanicolaou stained result. Additionally, we found the diagnostically important crystals in chylothorax and some urine samples, which can not be seen in routine Papanicolaou stain. We thought the toluidine blue stain in body fluid is one of very useful diagnostic methods.

The authors analysed 2,653 cases of transthoracic fine needle aspiration cytology of the lung to evaluate the diagnostic accuracy and its limitation. A comparison was made between the original cytologic and the final histologic diagnoses on 1,149 cases from 1,074 patients. A diagnosis of malignancy was established in 38.3% benign in 48.1%, atypical lesion in 2.3%, and inadequate one in 11.9% of the cases. Statistical data on cytologic diagnoses were as follows; specificity 98.9%: sensitivity of procedure, 76.8%: sensitivity of diagnosis, 95.5%: false positive 5 cases: false negative 18 cases: predictive value for malignancy, 98.8%: predictive value for benign lesion, 79.5%: overall diagnostic efficiency, 87.5%: typing accuracy in malignant tumor, 80%.

To make the objective standard of nuclear size ingrading nuclear pleomorphism of invasive ductal carcinoma of the breast, we measured maximal nuclear diameter of tumor cells on imprint cytology slides and histologic sections from 65 cases by using computer-based image analysis system(Optimas 6.0). The maximal diameter of red blood cells were also measured to evaluate the ratio of maximal nuclear diameter of tumor cells to maximal diameter of red blood cells. The mean values of maximal nuclear diameter of tumor cells on imprint cytology slides and histologic sections were $7.56{\mu}m,\;7.53{\mu}m$ in nuclear grade 1, $8.92{\pm}0.98{\mu}m,\;9.02{\pm}0.74{\mu}m$ in nuclear grade 2, and $12.90{\pm}1.47{\mu}m,\;12.44{\pm}1.41{\mu}m$ in nuclear grade 3, respectively. There were no significant differences between values of imprint cytology and histologic section. The ratio of maximal nuclear diameter of tumor cells to maximal diameter of red blood cells were 1.3-1.4:1 in nuclear grade 1, 1.6-1.7:1 in nuclear grade 2, and 2.2-2.3:1 in nuclear grade 3. These values would be guidelines for grading nuclear pleomorphism of invasive ductal carcinoma of the breast on routine surgical pathology work.

Benign and malignant papillary neoplasms of the breast may be difficult to distinguish in both cytologic and histologic preparations. To define the cytologic features of benign and malignant papillary lesions, we retrospectively reviewed 18 cases of fine needle aspirates from histologically confirmed cases of papilloma or papillary carcinoma of the breast. This study included 3 intraductal papillary carcinomas, 3 invasive papillary carcinomas, and 12 intraductal papillomas. Ail cases were evaluated for presence or absence of papillary fragments, bloody background, apocrine metaplasia, macrophages, and degree of cellularity, atypia, and single isolated columnar epithelial cells. Papillary fragments were present in all cases. The background of the smear was bloody in all 6 carcinomas, but in only 7 out of 12 papillomas. Markedly increased cellularity was present in 4 carcinomas(67%) and 7 papillomas(58%). Single cells were present in 5 carcinomas(83%) and 8 papillomas(67%). The majority of papillomas and papillary carcinomas had mild to moderate atypia, and severe atypia was noted in one case of intraductal papillary carcinoma and one case of invasive papillary carcinoma. Apocrine metaplasia was absent in all cases of papillary carcinomas, but present in 8 papillomas(57%). Macrophages were noted in 4 carcinomas and were present in all cases of papillomas. The constellation of severe atypia, bloody background, absence of apocrine metaplasia and/or macrophages were features to favor carcinoma. Malignant lesions tended to show higher cellularity and more single isolated cells. The cytologic features mentioned above would be helpful to distinguish benign from malignant papillary lesions of the breast. However, because of overlapping of cytologic features, surgical excision should be warranted in all cases on papillary lesions of the breast to further characterize the tumor.

The accuracy of fine needle aspiration cytology(FNAC) of the lymph node was investigated through a review of 176 FNAC cases and the corresponding biopsies. We chose 157 FNAC cases after the exclusion of 19 inadequate ones. Sensitivity of malignancy was 94.0%, specificity 100%, false negativity 6.0%, and false positivity 0.0%. The overall diagnostic accuracy was 96.8%. Sensitivity of metastatic carcinoma was 98.0% and that of malignant lymphoma was 87.9%. False negative cases included one metastatic carcinoma and four malignant lymphomas. The aspirates of metastatic carcinoma with false negativity exhibited a diffuse smear of keratin debris without viable cells, which led to the difficulty in differentiation from benign epithelial cyst. The cases of malignant lymphoma with false negative diagnosis were two Hodgkin diseases, one Lennert's lymphoma, and one peripheral T cell lymphoma in the histologic sections. On the analysis of 39 cases of tuberculosis, 17 cases(43.6%) were diagnosed as tuberculosis, 4(10.3%) as granulomatous lymphadenitis, 3(7.7%) as necrotizing lymphadenitis, and 15(38.5%) as reactive hyperplasia or pyogenic inflammation. Sensitivity of tuberculosis was 53.9%. In conclusion, lymph node FNAC is an excellent non-invasive diagnostic tool for the diagnosis of metastatic carcinoma. The diagnostic accuracy of malignant lymphoma could be improved with flow cytometry or polymerase chain reaction for antigen receptor genes. For the FNAC diagnosis of tuberculosis, AFB stain, culture, and PCR would be helpful as adjuvant techniques.

We retrospectively reviewed the results of 1,850 fine needle aspiration cytology(FNAC) of thyroid nodules performed from 1990 to 1991 in the Department of Pathology, Seoul National University Hospital. Among 1,528 cases and 322 cases aspirated by clinicians and a pathologist, 465 cases(30.4%) and 13 cases(4.0%) of the aspirates were inadequate, respectively. In 227 cases, correlation of the FNAC diagnosis and histologic diagnosis was done. Excluding the inadequate cases, the sensitivity nor the detection of neoplasm(malignancy together with follicular adenoma) was 86.4% and the specificity was 70.7%. The overall diagnostic accuracy was 79.0%. There were 16 false-positive cases(7.0%), and 19 false-negative cases(8.4%). The predictive value of each cytologic diagnosis was 92% in papillary carcinoma, and 100%, in Hashimoto's thyroiditis. The expectancy of malignancy was 52.8% in "suspicious malignancy" and 26.7% in "atypical lesion".

Schwannoma is a benign encapsulated nerve sheath tumor and is histologically characterized by a mixture of Antoni type A and B tissue. A preoperative diagnosis of schwannoma by fine needle aspiration cytology or by any other means is important a preserve clinically important nerves. Therefore, it is necessary to make a specific cytological diagnosis of nerve sheath tumor. However, there are a few reports regarding cytological features of schwannoma in Korea. We experienced seven cases of solitary schwannoma and here we report their characteristic cytological features with a review of literatures. The characteristic features of schwannoma on cytology were the presence of both Antonl type A and B tissue. The cytologic findings common to all cases of schwannoma generally corresponded to the histologic findings of Antoni type A tissue, consisting of fragments of tightly cohesive fascicles with variable cellularity. Dense fibrillary substances were found, along with palisading nuclei and Verocay bodies. Individual tumor cells consisted of cohesive cells haying spindle or oval nuclei, with pointed ends and Indistinct cell borders. Variation in nuclear size and shape was also present. The Antoni type B consisted of scattered wavy or short spindle cells and some histiocytes and lymphocytes in the abundant myxoid background with formation of microcysts. Immunohistochemistry for S-100 protein revealed a uniformly strong positive reaction and was helpful to make more accurate diagnosis of schwannoma.

Angiosarcomas are rare tumors, seen most commonly in the skin and soft tissue of head and neck legion. But it has been described in numerous body sites including thyroid, breast, liver, spleen, bone, etc.. Their biological behaviors depend on the microscopic grade, site of origin, and multifocality. We report the unique cytological features of an angiosarcoma in pleural fluid. A 61-year-old woman presented with a 6 month history of dyspnea on exertion and chest pain. Chest computerized tomography(CT) revealed multiple subpleural small nodules in the right lung and widespread all space consolidation and pleural effusion in the left lung. CT of liver revealed multiple small low attenuated lesion. The smears obtained from pleural fluid showed hypocellularity with a hemorrhagic background. The tumor cells were highly pleomorphic oval or spindle in shape and presented singly, in loose groups, in knitted syncytial aggregates, and in acinar pattern. Their nuclei had vesicular chromatin with delineated, thick nuclear membranes and occasionally a large eosinophilic, prominent nucleolus. The cytoplasm was plump, thin or protected in spindly fashion. Almost ail tumor cells showed variable sized intracytoplasmic vacuoles and their nuclei were sometimes crescentic by a huge vacuole. Occasional binucleated tumor cells and mitotic figures were present. Cellular debris and streaky materials were identified. Needle biopsy specimen from the pleura revealed anastomosing slit-like spaces lined by pleomorphic tumor cells. The tumor cells showed a strong reactivity for CD31 and vimentin and focal weak reactivity for factor VIII-related antigen.

We report a case of 53-year-old man with plasmacytold transitional cell carcinoma of the urinary bladder, which may be confused with plasmacytoma. The patient initially presented with gross hematuria and dysuria for two months. Cystoscopy and radiologic studios revealed multiple intraluminal protruding masses on the urinary bladder invading perivesical fat tissue. After urinary cytologic examination and cystoscopic biopsy, radical cystectomy and pelvic lymph node dissections were done. Urine cytology showed single cells and poorly cohesive cells with round eccentric nuclei, bi-or multi-nucleation, indistinct nucleoli, coarse chromatin, and abundant basophilic cytoplasm within relatively clear background. The cytologic findings of tumor cells were similar to the plasma cells seen in plasmacytoma. The tumor of the bladder was composed on discohesive, individual cancer cells with diffuse pattern that simulated lymphoma or plasmacytoma. Immunohistochemical and electron microscopic studies clearly established the epithelial nature of the neoplasm. Recognition of this plasmacytoid type of transitional cell carcinoma of the urinary bladder can avoid the misdiagnosis.

Myxopapillary ependymoma generally arise in the conus medullaris and filum terminale of adult spinal cord. These tumors are readily recognized due to unique histopathologic features, however, their cytologic features are not well described. When only a tiny sample is obtained, cytologic examination using crush preparation may be a useful diagnostic tool to help appropriate intraoperative diagnosis. We present the crush cytologic features of myxopapillary ependymoma arising in thoracic and lumbar spinal cord of a 13-year-old boy. The patient had complained of paraparesis and back pain for 1 month. The MRI image revealed a relatively well demarcated intramedullary mass in T11-L1 levels. Crush preparation for cytology were peformed by biopsy material. Crush cytologic findings revealed high cellularity and small sized branching papillary clusters on fibrillary or mucinous background. The tumor cells had uniform round or elongated nuclei. The cytoplasmic process of tumor cells were attached to the vascular wall. Between the tumor cells and vascular walls, the perivascular collar of globoid acellular stroma with metachromatic reaction on toluidin blue stain was noted. The crush preparation of myxopapillary ependymoma is considered as a simple and highly accurate diagnostic tool for differentiation from other intramedullary neoplasms of central nervous system.

Osteoclast-like giant cell tumor of the liver is an extremely rare malignancy with poor prognosis. To our knowledge, 5 cases have been reported in English literatures, but there was no report about fine needle aspiration cytologic(FNAC) features. We experienced a case of osteoclast-like giant cell tumor of the liver obtained by computed tomography(CT)-guided FNAC and needle biopsy. The cytologic findings mimicked slant cell tumor of the bone. A large hepatic mass of the left lobe with abdominal wall invasion was found by CT in a 46- year-old female complaining of epigastric pain. The FNAC showed moderately cellular smears consisting of osteoclast-like giant cells and mononuclear cells, which were individually scattered or intermingled in clusters. The osteoclast-like giant cells had abundant cytoplasms and multiple small round nuclei with fine chromatin and distinct nucleoli. The mononuclear cells had moderate amount of cytoplasm and relatively bland-looking oval nuclei with single small nucleoli. All of the cytologic features recapitulated the histologic findings of bland-looking osteoclast-like multinucleated giant cells evenly dispersed throughout the background of mononuclear cell. The immunohistochemical study showed positive reaction for CD68 and vimentin, but negative for cytokeratin in both osteoclast-like slant cells and mononuclear cells.

An extremely unusual case of epidermoid cyst showing diffuse parakeratosis and aggressive clinical behavior is presented. A destructive bone lesion with surrounding ill-defined soft tissue lesion was found by computed tomography in a 63 year-old man complaining of painful swelling of the right buttock. He had a history of surgical excision twice for epidermoid cysts of soft tissue of the right hip during recent one year On aspiration cytology, the aspirate was highly cellular and mostly composed of desquamated nucleated squamous cells. Operation finding revealed that the iliac bone was Irregularly destroyed and filled with gray-white cheesy material and necrotic bone bedris. Adjacent gluteus muscle showed scattered gray-white lesions. The curettage specimen showed bone necrosis and desquamated squamous cells filling the marrow spaces. The lesion within muscle revealed epidermoid cyst with diffuse parakeratosis.

Sometimes a pilomatrixoma on upper neck can be misdiagnosed as primary salivary gland tumor, skin adnexal tumor or metastatic carcinoma. On fine needle aspiration cytology(FNAC), characteristic features are ghost cells, basaloid cells, and calcium deposits, among which presence of ghost cells seems to be the key to recognize it. Here we present a cytologically misdiagnosed case of pilomatrixoma. A 32-year-old man presented a subcutaneous mass on the right posterior neck. It has grown slowly for 1 year, and was nontender, well circumscribed, hard, and movable mass. An Initial FNAC yielded only monomorphic population of highly mitotic basaloid cells, without anucleated ghost cells, chronic inflammatory cells or foreign-body giant cells, suggestive of a poorly differentiated carcinoma. However, that was inconsistent with patient's clinical findings. For further correct diagnosis, FNAC was repeated, which yielded the basaloid cells and foreign-body giant cells. The diagnosis of pilomatrixoma could be made and the mass was excised. This case demonstrates that the pilomatrixoma should be considered in the differential diagnosis of subcutaneous aspirates containing not ghost cells but a dominant population of basaloid cells.