The fine needle aspiration biopsy(FNAB) has become a popular method to diagnose mass lesions of the liver. Although many reports have listed FNAB criteria to be used to diagnose hepatocellular carcinoma(HCC), a diagnostic dilemma still exists at the extreme ends of the spectrum, particularly for well differentiated HCC. The authors reviewed a series of FNAB specimens of the liver to distinguish well differentiated HCC from nonneoplastic liver. Fifteen cytologic features were examined in this study: high cellularity, large sheet formation, trabecular pattern, acinar pattern, dispersed pattern, irregular arrangement, increased nuclear/cytoplasmic ratio, naked nuclei, irregular chromatin, irregular nuclear contour, multinucleation, uniform macronucleoli, multiple nuclei, uniform small cytoplasm and monotony of atypia. These features were examined in a series of 76 FNAB specimens. Fifty two specimens were from patients with HCC and 24 specimens were from patients with nonneoplastic lesion or tumors other than HCC containg adequate amount of nonneoplastic hepatocytes in smear. All specimens were coded as to the presence or absence of the above cytologic features. With the use of step-wise logistic regression analysis, three features were identified as the key cytologic features predictive of HCC: irregular chromatin, monotony of atypia and absence of large sheet formation. When these criteria were used, the sensitivity diagnosing HCC by FNAB was 94.2%, specificity 100%, positive predictive value 100% and negative predictive value was 88.9%.

Clinical lymphadenopathies are subjected to fine needle aspiration cytology(FNAC) for diagnosing not only benign lesions but also malignant ones, as the first diagnostic procedure. While the diagnostic reliability in metastatic carcinoma is high, it is difficult to differentiate malignant lymphoma from reactive conditions. We evaluated the diagnostic reliability of FNAC in lymphadenopathy, and discuss the diagnostic limitation and its place in clinical practice in this study, Over 8 years from January 1988, FNAC of 1,216 lymphadenopathies were analyzed and among them 170 cases were compared with histopathology. The results are as follows. 1. Of ail the cases, 890 cases(73.2%) were diagnosed cytologically as benign, 312 cases(25.7%) as malignant, and 14 cases(1.1%) as unsatisfactory material. Reactive hyperplasia was diagnosed in 585 cases(65.7%) of the benign lesions, and among the malignant diseases, metastatic carcinoma was diagnosed in 248 cases(79.5%), and malignant lymphoma in 62 cases(19.9%). 2. The overall diagnostic accuracy was 89.2%, and no false positive case and 9 false negative results were observed among 170 cases which were proven by histopathology. Six cases of sampling error of false negative diagnoses included 3 of metastatic carcinomas and 3 of malignant lymphomas. The causes were difference between aspiration and biopsy site, poor fixation, or scanty cellularity with bloody smear. All 3 cases of misinterpretation error were malignant lympliomas, one of mixed type on biopsy which was diagnosed as reactive hyperplasia cytologically. In summary, FNAC technique is thought to be useful in the initial diagnosis of lymphadenopathies as well as in the follow-up of patients with known malignancy. Although the results of malignant lymphoma was less accurate than other malignant lesions, the application of strict cytologic criteria or lymphoid marker studies of aspiration material will reduce the false negative rate.

The specificity of cytologic examination in effusions is high but the sensitivity is low. Therefore, various ancillary methods for the detection of malignant cells in effusions have been proposed. The presence of an aneuploid cell population is generally considered diagnostic of malignancy. The purpose of this study is to determine whether the routine use of flow cytometry adds to standard cytologic evaluation in effusions. We did flow cytometric DNA analysis in 76 effusions(28 malignant and 48 benign fluids). All the 48 benign effusions were diploid. There were 12(42.9%) aneuploid and 16(67.1%) diploid malignant effusions. Based on these results flow cytometric DNA analysis had a sensitivity of 42.9% and a specificity of 100%. These results suggest that flow cytometric DNA analysis may be a useful adjunct to conventional cytology, but its principal limitation is us relatively low sensitivity.

Pneumocystis carinli is an established cause of pulmonary infections in immuno-compromised hosts. Several cytoiogical stains, such as Papanicolaou, Gomori methenamine sliver(GMS) and Diff-Quik have been used for detection of the organism, but occasionally can be laborious and, due to a degree of nonspecificity, may be misleading. We evaluated the diagnostic utility of immunocytochenmical stains that recognize P. carinii in bornchoalveolar lavage from experimentally Induced P. carinii pneumonia rats(n=15). In audition to routine stains for diagnosis by morphologic recognition of P. carinii on Papanicolaou, GMS and Diff-Quik stains, bronchoalveolar lavage samples were reacted with immunocytochemical stains using monoclonal antibodies(MAB) 092 and 902. In bronchoalveolar lavage P. carinii organisms were detected In 9 of 10 cases(90%) using each MAB 092 and 902, whereas GMS and Diff-Quik stains demonstrated P. carinii in 13(86%) and 11(73%) of 15 cases respectively. In lung tissue specimens(n=15) P. carinii organisms were well identified on GMS stain and immunohistochemical stains using MAB 092 and 902 in ail cases. We believe that the immunocytochemical staining using MAB 092 and/or 902 is a very useful and diagnostic tool In addition to GMS and Diff-Qulk stain to detect P. carinii organisms in bronchoalveolar lavage.

The authors reviewed 167 malignant effusions from 110 patients, of which the primary site was established on the basis of either biopsy or surgical resection of the primary neoplasm. Main factors analysed were the distribution of primary organs and the cytohistoiogic correlation of body cavity effusions. The 167 fluid specimens from 110 patients consisted of 90 cases(53.9%) of pleural, 68(40.7%) of peritoneal, and 9(5.4%) of pericardial origins. Histologically they consisted of 82 cases(74.5%) of adenocarcinoma, 8(7.3%) of malignant lymphoma, 6(5.5%) of squamous ceil carcinoma, and 3(2.7%) of small cell carcinoma. The most common site among the primary lesions was the stomach in 25 cases(22.7%) followed by the lung in 21(19.1%), ovary on 17(15.5%), and breast in 7(6.4%). As for the distribution of primary tumors in adenocarcinoma, the most common site was lung un 16 cases (48.5%) in pleural fluid and stomach in 22(48.9%) in peritoneal fluid. In pericardial effusions, all 5 cases were from the lung. As a whole, the cytologic findings of malignant effusion were fairly representative of histologic characteristics of primary lesions. Thus, when the primary lesion Is unknown, careful evaluation of effusion cytology is presumed to be a helpful tooi for tracing the primary tumor.

Patients with rheumatoid arthritis of any degree of severity or duration may develop necrotizing granulomatous pleuritis, a morphologic replica of the inflammatory reaction characteristic of rheumatoid synovitis and rheumatoid nodules. The principal feature is the background composed of granular, amorphous, particulate material or debris of various hues. The material is sometimes eosinophilic sometimes more cyanophilic, or even green in the Papanicolaou stain. Within this background are elongated, fibroblast-like epithelioid cells, numerous multinucleated giant cells and degenerating leukocytes. The combination of the debris, spindle epithelioid ceils, and multinucleated giant cells in fluid is pathognomonic for rheumatoid pleuritis. We experienced a hcase of rheumatoid pleuritis showing these characteristic cytologic findings. The patient was a 63 year-old man with positive rheumatoid factor. The pleual fluid specimen revealed elongated epithelioid cells and multinucleated giant cells on a background of amorphous granular material.

Oxyphilic (Hurthle) cells have abundant eosinophilic granular cytoplasms and occur in both benign and malignant neoplasms of the thyroid gland. Most published studies described mainly oxyphilic tumors of follicular type, and reports on oxyphilic papillary thyroid carcinomas are rare. The oxyphilic variant of papillary carcinoma differs from the classic papillary carcinoma in its more aggressive biological behavior. We report a case of oxyphilic papillary carcinoma exhibiting exclusively oxyphilic cells in a follicular pattern without papillary structures. The pattern of papillary carcinoma was confirmed by fine needle aspiration material and lymph nodal metastasis, both of which revealed typicaled papillary structures with characteristic nuclear features, psammoma bodies, and oxyphilic cytoplasm.

A primary squamous cell carcinoma of the thyroid is extremely rare disease. We evaluated this disease by fine needle aspiration cytology in a 43 year-old female. On physical examination, the thyroid was moderately enlarged and palpated with hard consistency. The cytologic aspirate revealed nests of squamous cells, malignant squame and thyroid follicular cells in the necrotic background. We diagnosed this tumor as squamous cell carcinoma with cytologic evidence. Surgically resected thyroid revealed well differentiated squamous cell carcinoma. Immunohistochemical staining for antithyroglobulin proved that this tumor was primary in origin and clinical study confirmed this lesion to be of primary thyroid origin rather than metastasis or direct invasion from contiguous structures.

Acinic cell carcinoma is a slow-growing solid neoplasm of salivary gland. Although their cytological and histological finding is bland-looking, their biological behavior is unpredictable. We experienced two cases of acinic cell carcinoma of the salivary gland diagnosed by fine needle aspiration biopsy and confirmed by tissue examination. They showed different clinical courses. We compared their cytologic and histologic findings. The first case was a right preauricular mass in a 58 year-old female of 3 years duration. The cytologic smear revealed sheets or small clusters of monotonous cells mimicking normal serous acinar cells with little cellular pleomorphism. She underwent superficial parotid lobectomy. The tumor was a well demarcated 1.5cm sized nodular mass without infiltration into surrounding parenchyme. The second case was a left submandibular mass in a 23 year-old male of 4 years duration. The smear showed more severe pleomorphism of the tumor cells than those of previous case. Excisional biopsy was done. The excised tumor was $5.5{\times}3.5{\times}3cm$ sized multilobulated solid mass with invasion into surrounding parenchyme. The tumor recurred after 20months, thus total excision of the mass and modified radical neck dissection was carried out. From the above findings, cytologic atypism, infiltrative growth pattern and type of initial therapy may be correlated with biologic behavior.

Well differentiated fetal adenocarcinoma of the lung Is a subtype of pulmonary blastoma. In this report, CT-guided fine needle aspiration smears were performed at the right upper lobe of the lung in a 45 year-old male patient who had the smoking history of one pack per day for 25 years. The smears disclosed round, papillary, and tubular patterns of cell clusters. The individual cells had relatively uniform, small to medium sized nuclei without nucleoli, and showed vesicular or eosinophilic cytoplasm with Indistinct cell border. The morules were seen in the central area of papillary clusters. They were composed of two cell types, outer single layered cuboidal cellular lining and central three-dimensional cluster of cells simulating fetal lung. These cytologic features need to be differentiated from usual pulmonary adenocarcinoma, carcinoid, and pulmonary blastoma. On histologic findings, the tumor arised in the bronchial epithelium. And the tumor cells had abundant intracytoplasmic glycogen with neuroendocrine feature on histochemical study. In addition, the multiplicity of this tumor is the unique point comparable to the previous reports.

Two cases of pulmonary atypical carcinoid tumor were diagnosed by fine needle aspiration cytology. Although the cytologic features of atypical carcinoid tumor have been relatively well described, it is easy to confuse atypical carcinoid tumor with typical carcinoid tumor, small cell carcinoma and adenocarcinoma of the lung. Atypical carcinoid tumor has been recognized as a distinct variant of pulmonary neuroendocrine carcinoma, with characteristic histopathologic and clinical features that separate it from both carcinoid and small cell carelnoma. The distinction of atypical carcinoid tumor from small cell carcinoma has important prognostic and therapeutic implications. The cytologic characteristics of atypical carcinoid tumor included polygonal to fusiform cells with a variable amount of lacy cytoplasm, oval nuclei with coarsely dispersed chromatin and frequent nucleoli, and mild pleomorphism. The malignant cells were arranged either in acinus-like clusterg or in epithelial sheets.

Signet ring cell carcinoma is a variant of adenocarcinoma and has been rarely reported in the lung as a primary site. Recently, we experienced two cases of primary signet ring cell carcinoma in the lung without any other extrapulmonary lesion. Sputum cytology was performed and the tumor cells which have eccentrically located nuclei and abundnat mucinous cytoplasm were dispersed in diffuse sheets. On resected specimen, the signet ring cells occupied about $50{\sim}80%$ of all tumor cell nests. Histochemical staining revealed that the mucin produced by tumor cells was mostly carboxylated acid mucins. Ultrastructurally, the tumor cells contained variable sized membrane-bound mucin granules with weak central osmilophilic density and showed numerous surface microvilli, which represented that tumor cells arose from bronchial epithelial cells. In general, this tumor has diffusely infiltrative nature and the prognosis is fatal due to widespread metastasis before clinical discovery.

Reports on the cytologic or histopathologic findings of inflammatory pseudotumors are relatively infrequent and most of them have dealt with those involving the lung, liver, genitourinary tract, alimentary tract, spleen, mediastinum, retroperitoneum, etc. Moreover there have not been any cytologic studios of those involving lymph nodes. We present fine needle aspiration cytologic features of inflammatory pseudotumor occurring in a lymph node in a 64 year-old man. The aspirate consisted of proliferating spindle cells and admixed histiocytes, fibroblasts, lymphocytes, and plasma cells. Histiocytes were present either singly or in loosely cohesive small clusters. A few multinucleated giant cells were present as well. However, tuberculosis could be excluded by the absence of typical granuloma, caseation necrosis, or characteristic mixed spindle and inflammatory cell components. Other benign and malignant lymphadenopathies could also be differentiated based on cytologic findings.

A case of cervical chordoma diagnosed by fine needle aspiration is discussed. A 41year-old male was admitted due to dyspnea on neck flexion. Radiologic image revealed a retrotracheal superior mediastinal solid mass. Aspiration cytology showed many clusters of oval or large polygonal cells having abundant eosinophilic or bubbly cytoplasm in an amorphous blue-gray mucoid background. The nuclei were round and showed size variation, coarse granular chromatin, and indistinct nucleoli. Some cells contained brown granular pigments in the cytoplasm. Mitoses were rarely found. The cytoplasm was strongly positive for PAS stain. Immunohistochemical stains using cell block revealed positive reaction for cytokerain, EMA, vimentin, and S-100 protein. The confirmative diagnosis was made by following excisional biopsy. Electron microscopic study revealed large pools of intracytoplasmic glycogen and microfilaments. This is the first case of cervical chordoma diagnosed by aspiration cytology to our knowledge in Korean literature.

Sinonasal undifferentiated carcinoma(SNUC) is a distinct, relatively rare neoplasm arising in the nasal cavity and paranasal sinuses composed of undifferentiated epithelial cells and clinically characterized by a fulminant course. We report a case of SNUC in a 56-year old man who have had bilateral neck masses since one month ago before coming to our hospital. The paranasal computed tomography showed soft mass density in the left maxillary sinus and the nasal cavity with bone destruction in the anterior medial and the inferior maxillary sinus wall. This mass was extruded into the left orbital wall. Biopsy of the nasal mass and fine needle aspiration(FNA) of the neck mass were done. FNA revealed medium-sized neoplastic cells forming clusters or individually dispersed. Nuclei were round to oval, slightly to moderately pleomorphic, and hyperchromatic. Chromatin was finely granular, but occasionally was coarsely granular. Nucleoli varied from large to inconspicuous and the cytoplasm was scanty.

저자들은 최근 면역기능이 저하되지 않은 50세 남자환자의 폐장에 국한되어 발생한 효모균증을 세침흡인 도말소견으로 진단하고 이의 세포도말 소견을 보고하는 바이다. 세침흡인 도말배경내에는 녹색 내지는 염색되지 않으며 굴절되어 보이는 다양한 크기의 둥글거나 난원형이면서 그 주변에 투명한 운륜을 갖는 균체가 다수 산재되어 관찰되었다. 균체의 크기는 $5{\sim}15{\mu}m$이었으며 Gomori methenaminesilver 염색상 발아성 홀씨가 잘 관찰되었다. Mucicarmine 염색상 피막은 연분홍색으로 염색되었다.