19세기말과 20세기초에 각각 비르효와 파파니콜로에 의해 명료하게 된 세포 병리학과 탈락세포학의 개념에서 오늘날의 암진단의 일차적인 방법이 발전해 왔다. 파파니콜로의 탈락세포학의 개념에서 1960년대 초반에 세침흡인 세포검사가 개발되었다. 이 세침흡인 세포검사는 주된 진단방법이 되어져, 절개생검을 감소하게 하고 의료비용의 효과적인 이용에 공헌하였다. 1980년대에는 면역생화학적 기술들이 암 진단에 보충역활을 하게 되었다. 단 클론 항체를 이용하는 면역과산화효소법이 먼저 암의 본성을 밝히는 보조적인 방법으로 쓰여졌다. 특정 단클론 항체들이 이용가능하게 되어 세포산물이나 표면 표지자들을 인지하는 것을 훨씬 용이하게 하였다. 예를 들면 중간세사에 대한 항체들이 분화가 나쁜 종양의 조직기원을 결정하는데 가치가 있는 것이 증명되었다. 종양표지자들은 종양존재의 생화학적 표시자로 이용될 수도 있는데 이러한 종양표지자들은 혈장이나 다른 체액들에서 검출할 수 있다. 이 종양표지자들을 농출한 것을 진단적 검사에 이용하여 이미 진단된 암의 임상 경과를 추적하고 암 발생의 위험이 있는 집단에서 특정 종양을 발견해 내기 위한 선별검사로써 이용할 수 있다. 유세포 검사는 백혈병이나 림프종 세포들의 면역표현형을 알아내고, 종양세포들의 DNA함유량을 알아내며, 세포증식율을 알아내는 등의 몇가지의 세포의 특성을 분류해내는데 유용한 도구이다. 분자생물학적 방법들은, 암 환자를 진료하는데 있어 진단, 예후평가 및 치료 등의 분야에서 일보 전진하게 하였다. 핵산교잡법이 Southern blots, Nothern blot, Dot blot 및 in situ hybridization으로 이용된다. 분자생물학 및 그 기술이 암종 생물학을 이해하고 유전자 조작을 기초로한 치료법을 계획하는데 밝은 새로운 지평선을 열어줄 수 있을 것이다.

세침흡인 검사는 촉지되거나 혹은 촉지되지 않는 양성과 악성 유방 질환을 인지하는 매우 유용한 방법이나 진단이 애매한 회색 지역이 존재한다. 1년동안 시행한 697예의 유방 세침흡인 검사 중 111예가 비정형적 혹은 악성이 의심된 다고 보고되었으며 이 중 조직학적으로 확진된 74예를 재검색하여 Masood 등 (1990)이 제안한 등급 점수표가 회색 지역을 줄이는데 유용한지 살펴보았다. 기술적 문제가 19예에서 나타났으며 나머지 55예 중 18예는 양성으로, 37예는 악성으로 조직학적으로 진단되었다. 양성 질환 중 섬유선종(5예)및 섬유선종의 성상을 지닌 섬유낭성 질환(3예)이 가장 많았고 악성은 대부분 침윤성 관암종이였으며 (29예), 관상암종(3예), 사상암종(2예) 및 점액 암종(2예) 등 분화가 좋은 암종들이 상대적으로 많았다. 등급 점수표는 회색 지역을 줄이는데 상당히 유용하여 29예의 관암종중 27예가 세포학적 악성 범주에 속했다. 그러나 분화가 좋은 암종은 7예중 2예만이 세포학적 악성 범주에 속했고 섬유선종 및 섬유선종의 성상을 지닌 섬유낭성 질환은 비교적 높은 점수를 보였다. 따라서 등급 점수표의 응용은 유방 세침흡인 검사에서 양성과 악성 병변의 감별에 매우 유용하게 이용될 수 있으나 분화가 좋은 암종들과 섬유선종의 진단에는 주의가 필요할 것으로 사료되며 유방 세침흡인 세포학적 검사에는 세포 병리 의사의 경험 및 유방질환의 세포학적 변조에 대한 친숙성이 강조되어야 할 것이다.

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs, nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma, the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ in their chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.

It is well known that fine needle aspiration biopsy(FNAB) is very useful and has a high accuracy rate in the diagnosis of renal neoplasms. Although there is some indecision to perform the FNAB for a rare possibility of tumor seeding along the biopsy needle tract, it tends to be used increasingly. As in the cytologic diagnosis of metastatic lesion through-out the body, renal cell carcinoma should nearly always be considered in the differential diagnosis, the precise understanding of cytologic features of renal cell carcinoma with various cell types and architectural patterns is necessarily required. In this report, we present three cases of primary renal cell tumors, two of renal cell carcinomas and one of oncocytoma, preponderantly emphasizing the cytologic differential points in the FNAB specimen.

Epstein-Barr virus(EBV) is associated with a wide spectrum of benign and malignant disorders including leukoplakia, Hodgkln's lymphoma, central nervous system lymphoma, peripheral T cell lymphoma and nasopharyngeal undifferentiated carcinoma. There are several distinctive aspects of biology of the virus that are important in investigation of virus in clinical specimens. The abundant expression of the EBER mRNA transcripts makes possible the sensitive detection of latent expression in EBV-associated tumors. Although there has been a dramatic increased interest in the direct characterization of EBV in clinical specimens, there have been few studios about the effective and reliable positive controls in performing in situ hybridization technique for EBV, especially on paraffin-em bedded tissue. We applied Burkitts lymphoma ceil line as positive control in EBV in situ hydridization using Oncor Kit. The cell block of Burkitt lymphoma cell line(CCL85 EB-3) showed strong and specific positivity for EBER in situ in nuclei of EBV infected cells.

Small cell carcinoma of the lung is characterized by cells with finely stippled chromatin and scanty cytoplasm as well as a particularly aggressive clinical course and favorable response to the chemotherapy. Recently percutaneous fine needle aspiration (FNA) biopsy has become both widely established and highly respected for the diagnosis of lung cancer. However metastatic small cell carcinoma of lymph node should be cytologically differentiated from the small round cell tumor of particular sites, especially malignant lymphoma, because small ceil carcinoma of classic oat cell type nay simulate small cell non-Hodgkin's lymphoma. We report five cases of metastatic small cell carcinoma of in-termediate cell type diagnosed by FNA of the enlarged lymph nodes of the neck and axilla. The cytologic smears contained diffuse small neoplastic cells larger than lymphocytes with dense, pyknotic nuclei and extremely scanty cytoplasm. Apparently viable large tumor cells have vesicular nuclei with granular, sometimes very coarse chromatin. The characteristic cytologic features of small cell carcinoma as compared to malignant lymphoma were as follows.: 1) small cells with dense pyknotic nuclei are evenly distributed in the background of apparently viable larger tumor cells, admixed with mature lymphocytes and phagocytic macrophages. 2) small loose aggregates of cells with nuclear melding are indicative of small cell carcinoma rather than non-Hodgkin's lymphoma. 3) the cytoplasmic and nuclear fragments of tumor necrosis are more dominant in the smears of small cell carcinoma. 4) nuclear membrane and nucleoli are generally indistinct in small cell carcinoma due to condensation of chromatin.

The cytologic samples of 26 ovarian cystic lesions from 25 women, aspirated under guide by trans-vaginal ultrasound, were evaluated for clinicopathologic correlation. Clinically 20 women were seeking medical assistance for infertility problems, and trans-vaginal cyst aspiration was done during follow-up of ovulation induction. Among them seven cases were histologically confirmed. Twenty cases of "benign cyst" in cytologic diagnosis were follicullar cyst and two cases of "endometriotic cyst" in cytology were histologically also proven in one case. One false positive diagnosis was given to corpus luteum cyst. It is emphasized that because the cysts are aspirated transvaginally and mature squamous epithelial cells occasionally could be mixed in the sample, attention should be given not to diagnose such cases as mature cystic teratoma. According to this study. ovarian aspiration cytology is useful in the management of cystic ovarian lesions, particularly in young women.

Human sparganosis is a rare parasitic disease in which the larval cestode proliferates in the various organs in the body. It usually presents as a subcutaneous or soft tissue mass. By fine needle aspiration this lesion can be diagnosed with its characteristic cytologic findings. We experienced 3 cases of sparganosis diagnosed by the fine needle aspiration. Aspirates were taken from subcutaneous mass in the abdomen and both thighs respect ively. The aspirates showed a portion of body of sparganum with numerous calcospherules, smooth muscles and tegmental cells. They also revealed granulomas with various inflammatory infiltration of eosinophils, neutrophils, lymphocytes and plasma cells.

The report of aspiration cytologic findings of epithelial-myoepithelial carcinoma(EMC) in the salivary gland is extremely rare. We present a case of fine needle aspiration cytology(FNAC) from EMC in the right submandibular gland of a 46 years old male patient. Neck CT scan revealed a confined lesion in the submandibular gland without enlargement of the regional lymph node. FNAC from the tumor showed several three-dimensional cellular clusters with admixed normal acinar cells. They frequently formed blanching tubular structures composed of two type of cells; darker cells haying eosinophilic scanty cytoplasm with round dense nuclei and clear cells having abudant pale cytoplasm with vesicular nuclei at the periphery of clusters. The tumor cells of both types did not show pleomorphism or mitoses. The resected submandibular gland showed an ill-defined whitish firm tumor, measuring $2{\times}1.5{\times}2cm$. The histology revealed an infiltrative tumor showing characteristic two cell types in a duct-like arrangement surrounded by thin basement menbrane. An inner layer of darker cells and outer layer of clear cells were postive for cytokeratin in the former and S-100 protein in the taller on the immunohistochemical stain.

Malignant rhabdold tumor is a distinct renal tumor in the pediatric age group. It was originally described as a rhabdomyosarcomatold variant of Wilms' tumor. However, subsequent studies fatted to confirm myogenous differentiation, so it is now considered to be a distinct and unique type of highly malignant tumor, histogenetically unrelated. Although extrarenal forms of this tumor are rare, several examples have been described in other sites, especially the liver, prostate, paravertebral area, urinary bladder and soft tissue. We experienced a case of malignant rhabdiod tumor located in the intraabdominal cavity in a 10 month-old boy. Smear of peritoneal fluid showed round, polygonal and irregular shaped cells with large nuclei, ample cytoplasm containing light pink to purple cytoplasmic inclusions, and one or a few prominent nucleoli. Immunocytochemistry revealed positivity to cytokeratin, epithelial membrane antigen and vimentin, and negativity to desmin and neuron-specific enolase. These distinct cytologic appearance and immunophenotypes were most consistent with a diagnosis of extrarenal malignant rhabdoid tumor. The cytoplasmic inclusions were correlated with eosinophilic inclusions seen in histologic section and electron microscopy confirmed this interpretation, showing filamentous aggregations in the cytoplasms of the tumor cells.

We experienced a case of infiltrating lobular carcinoma of the breast in the ascitic fluid. The patient was a 49 year-old woman who presented with a palable mass of 3 months duration in the left upper quadrant of the abdomen and abdominal distension. Five years ago, she had undergone left radical mastectomy with chemotherapy and radiotherapy for infiltrating lobular carcinoma of the breast. The ascitic fluid smears revealed singly scattered small round to elliptical cells, many of which were arranged in characteristic indian-file patterns consisting of 3 to 5 cells. The tumor cells had scanty cytoplasm, rare cytoplasmic vacuoles and marked chromatin clumping with small, but prominent nucleoli.

Gaucher's disease is an autosomal recessive disorder resulting from mutation at the glucocerebrosidase locus on chromosome 1q21. As a result, glucocerebroside accumulates principally in the phagocytic cells known as Gaucher cells. In our case, a five-year old girl was admitted with seven days' history of fever and abdominal distension. At physical examination the patient had hepatosplenomegaly. Laboratory tests revealed a hemoglobin concentration of 2.8g/L: platelet counts of $23,000/{\mu}l$: normal range of white cell and differential counts, and negative Coombs' test. Liver enzymes were normal. For the evaluation of hepatosplenomegaly, fine needle aspiration was performed blindly against the palpable spleen. Wet-fixed hematoxylin and eosin-stained smears are made. The smears from the spleen showed predominantly macrophages with abundant cytoplasm and rather small, uniform, often eccentric nuclei with small nucleoli. The multinucleated cells were often found. The cytoplasm was pale, with more or less distinct fibrillarity. The cells had the characteristic appearance of Gaucher cells. Gaucher cells were also found in the tissue section from the liver, spleen and lymph node and the bone marrow aspirate. The diagnosis was later confirmed by determination of bela-glucosidase activity in peripheral blood leucocytes. Fine needle aspiration of the spleen is considered as a convenient procedure with a low complication rate for the diagnosis of lysosomal storage disease.

Cytologic features of the fine needle aspiration of metastatic epithelioid sarcoma are presented. The patient was a 48 year-old male who had been sufferring from recurrent and metastatic tumors of the right upper extremity for 6 years. The aspirate from the axillary mass cytologically consisted of isolated large polygonal cells with abundant, cyanophilic, slightly granular cytoplasm. Eccentrically located large round nuclei showed finely dispersed chromatin, small nucleoli, occasional convolution and folding of nuclear membrane, and frequent binucleation. Although both histologic and cytologic similarity of epithelioid sarcoma to squamous cell carcinoma is well known, findings of cyanophilic granular cytoplasm, convoluted nuclei, and binucleation appeared to be the differential points.

A primary squamous cell carcinoma of the breast was evaluated by fine needle aspiration cytology in a 60 year-old female. Squamous cell carcinoma is a rarely encountered lesion in the breast and nine cases of cytologic findings of mammary squamous cell carcinoma have been reported in the world literature. Our case appears to be one of these rare pure squamous cell tumors. The cytologic diagnosis was possible because of the well defined characteristics of the malignant squamous cells, similar to those found in other locations. Thorough examination of the patient did not reveal squamous cell carcinoma elsewhere.

Extrathoracic metastases of thymomas are extremely rare, occurring in less than 2% of cases. We present a case of metastatic thymoma in the liver diagnosed by aspiration biopsy. A fine-needle aspirate from a hepatic mass of a 65-year old man who had a history of malignant thymoma locally invading pericardium was examined. Nests of epithelial cells with few scattered lymphocytes were present. The nuclei of the epithelial cells were round to oval and appeared relatively uniform and regular, with fine chromatin pattern. They had one or two, small but lather conspicuous nucleoli. Unlike previous reports on the findings of the aspiration cytology of thymomas, the characteristic biphasic pattern was not present in this case.

Fine needle aspiration cytology of a pulmonary mass was performed on a 51-year-old man who had a left testicular mass. Cytologic features were composed of a homogeneous population of malignant cells associated with a background of foamy and lacelike material. The cellular features were characterized by monomorphous cell proliferation of relatively regular large cells, generally isolated or grouped. Occasionally, fine blanching stroma with large tumor cells and scanty lymphocytes were noted. The tumor cells had a round, regular nucleus, prominent round nucleoli, and a thin rim of cytoplasm containing large vacuoles or lacunae filled with glycogen. The fine needle aspiration cytologic diagnosis was highly consistent with metastatic seminoma from testis and less likely primary or other metastatic carcinoma. The diagnosis of resected testicular mass was classic seminoma. Despite the fact that cytopathologists were not familial with diagnosis of seminoma due to clinician's lack of interest in fine needle aspiration cytology of germ cell tumors including seminoma, it appears that a diagnosis of this tumor should not be problematic in cytologic material if specific histologic criteria are applied.

Although exfoliative colonic cytology for the diagnosis of colorectal cancer has been largely abandoned due to the widespread use of colonoscopy, some authors still insiston the usefulness of colon lavage fluid. We tried evaluating the diagnostic feasibility of colon lavage fluid cytology using an orally administered balanced electrolyte solution. We collected colon lavage fluids in 106 patients prior to colonoscopy and reviewed the slides. Cytologic examination revealed neoplastic cells in 7 of 16(44%) cases of endoscopically proven adenocarcinoma patients. Therefore, we thin cytologic study of colon lavage fluid may be considered as one of the noninvasive diagnostic tools in colorectal cancer.

Cytologic findings of 2 cases of metastatic leiomyosarcoma diagnosed by fine needle aspirtion cytology are reported. Case 1 is pleomorphic leiomyosarcoma which had metastsized to the liver from the stomach of a 54-year-old male patient. The cytologic features showed highly cellular aspirates with nuclear pleomorphism and interlacing pattern. Case 2 is low grade leiomyosarcoma that occurred in the uterus of a 43-year female patient and metastsized to both lungs. The aspirates were less cellular than that of case 1, and showed spindle cells with minimal pleomorphism, but ceil block revealed interlacing patterns of smooth muscle cells with occasional mitosis.