Cytodiagnosis of neoplasms of the central nervous system in cerebrospinal fluid samples with an application of selective immunostains in differentiation.

In this study cytological findings in specimens of cerebrospinal fluid (CSF) of central nervous system (CNS) tumours (16 primaries, 57 metastatic and 12 suspicious) are presented, which were diagnosed over a period of 7 years in 85 patients (50 females and 35 males) with an age range of 2-76 years. The follow-up included information from clinicians and a review of medical charts, histological correlation and/or further investigations following cytodiagnosis. The patients clinically presented with signs and symptoms of meningeal involvement. The primary tumours included six medulloblastomas, eight gliomas (four glioblastomata multiforme, two anaplastic astrocytomas, and two ependymomas) and two germinomas. The metastatic tumours were 14 melanomas, 19 breast carcinomas, four leukaemias, six B-cell lymphomas, five adenocarcinomas of gastrointestinal origin, seven carcinomas of lung, one retinoblastoma and one neuroblastoma. Twelve cases were reported as suspicious. On further investigations, four of these were from a primary tumour (two glioblastomata multiforme and two anaplastic astrocytomas) while the other eight cases were of a metastasis (one B-cell lymphoma, three breast carcinomas, three melanomas and one adenocarcinoma of gastrointestinal origin). Using a panel of selective immunostains in some of the cases supported the cytological diagnosis and this was considered useful in furthering cytodiagnosis. In 75 of the patients the CSF samples were obtained on a spinal tap while in 10 patients the samples were received as ventricular CSF. There were no false-positive cases. The results of our study suggest that CSF cytology in the diagnosis of CNS tumours is quite reliable and reflects involvement of leptomeninges or the ventricles. Furthermore, the use of selective immunostains can be helpful in confirming the cytological impression and source of the tumour.     

Fine needle aspiration (FNA) cytology of pilomatrixoma

FNA smears from five histologically confirmed cases of pilomatrixoma were reviewed to delineate the cytological features helpful in diagnosis. A combination of basaloid cells, ghost cells and foreign body giant cells appeared to be necessary in FNA smear for a confident cytodiagnosis of pilomatrixoma. Presence of naked nuclei, nucleated squamous cells and calcification were additional features in favour of the diagnosis. Another 10 cases with initial cytodiagnosis of pilomatrixoma or benign skin appendage tumour were reviewed. Using the above criteria, diagnosis of pilomatrixoma was easy in five cases. One case was problematical due to presence of atypical squamous cells. Initially the cytological features were most commonly confused with epidermal inclusion cyst, giant cell lesion or a squamous cell carcinoma. The main reasons for erroneous diagnosis were lack of awareness of cytological features, predominance of one component over the others, and non‐representative FNA smears. Atypia in nucleated squamous cells, and misinterpretation of basaloid cells as malignant can lead to diagnostic dilemma. Adequate clinical data are also necessary.     

Use of monoclonal antibodies to glial fibrillary acidic protein in the cytologic diagnosis of brain tumors

Monoclonal antibodies were used to immunocytochemically demonstrate glial fibrillary acidic protein (GFAP) in 174 smear preparations of brain tumor tissue in order to investigate the presence and distribution of GFAP in a variety of intracranial tumors and to evaluate the value of this technique in the cytodiagnosis of brain tumors. GFAP-positive cells were found in the astrocytic tumors and in some of the oligodendrogliomas, ependymomas and medulloblastomas. In contrast, schwannomas, meningiomas, a primary lymphoma, a hemangiopericytoma pituitary adenomas, germinomas and metastatic tumors were negative for GFAP. The cytodiagnostic accuracy of the 174 brain tumors was raised from 90.8% to 97.1% when GFAP-immunoperoxidase staining was employed to aid the routine cytologic diagnosis. These findings indicate that immunoperoxidase staining for GFAP can be successfully applied to cytologic specimens and is a useful adjunct to routine cytologic diagnosis.     

Cytopathology of Follicular Tumours of the Thyroid With Clear Cell Change

A retrospective cytological study of nine follicular tumours of the thyroid with clear cell change was undertaken. In five clear cell adenomas and one moderately differentiated clear cell follicular carcinoma the epithelial cells occurred singly or in sheets and clusters; they sometimes assumed a trabecular or follicular pattern. The cells usually had pale diffusely vacuolated cytoplasm with ill-defined boundaries, a variable degree of anisonucleosis, nucleolar enlargement, and nuclear overlapping. Smears from a signet-ring cell adenoma contained in addition a few cells with large cytoplasmic vacuoles and compressed eccentric nuclei. In these cases a cytological diagnosis of 'follicular lesion' (or follicular neoplasia), clear cell type or signet-ring cell type, was given. A cytodiagnosis of 'carcinoma' was made only in the poorly differentiated follicular carcinoma-clear cell variant studied which showed unequivocal features of malignancy. Features suggestive of thyroid cyst, nodular goitre, Hashimoto's thyroiditis, and cell hyperactivity (marginal vacuoles, 'fire flare') were also found in the aspirated specimens of these cases of clear cell tumour of the thyroid.     

Does Microhistology Improve the Cytological Diagnosis of Liver and Pancreatic Tumours?

Guided percutaneous fine needle aspiration cytodiagnosis of the liver, retroperitoneum and pancreas was performed in 197 patients. In 42 cases, material left after the smears were prepared was embedded in paraffin wax for histological examination. Six liver tumours and seven pancreatic tumours were identified in this material. In two cases the diagnosis of liver cell carcinoma was made only after microhistological examination. Re-examination of the cytological material in both cases disclosed features of liver cell carcinoma which were underestimated in the first examination and diagnosed only broadly as cancer cells. On the other hand, in another case cancer cells were present only in the smear and absent in the microhistological preparation. Diagnosis of pancreatic tumours was generally not improved by microhistological examination. In one case cancer cells were present only in the cytological material. In another case a cytological diagnosis of suspected cancer was confirmed as adenocarcinoma by microhistology. The diagnosis of non-neoplastic material in the remaining 29 cases were identical by cytopathology and microhistology. It is concluded that the microhistology of needle aspirate material complements cytological examination and can refine diagnosis although it increases cost.     

A simple intraductal aspiration method for cytodiagnosis in nipple discharge

OBJECTIVE: To increase cytodiagnostic accuracy for women with spontaneous nipple discharge using a simple intraductal aspiration method. STUDY DESIGN: We compared the cytodiagnostic accuracy of the conventional squeezing collection method and intraductal aspiration by intravenous catheter in a total of 146 women with spontaneous nipple discharge in a single duct without a mass; they had been pathologically identified at Kaohsiung Medical University Hospital. RESULTS: Adequate specimens were collected in 96.6% (141/146 cases) of the sample by the intraductal aspiration method as compared to 76.0% collected by the conventional squeezing method (P < .05). An adequate specimen should consist, at a minimum, of six cohesive clusters of well-preserved epithelial cells, with each cluster composed of at least five cells other than foam cells. The cytologic diagnosis was divided into five categories: positive in 9 cases, suspicious in 10, negative with atypical findings in 59, negative in 33 and inadequate specimens in 35 cases that employed the squeezing method. These results were less satisfactory than with the intraductal aspiration method: the smears were positive in 17 cases, suspicious in 14, negative with atypical findings in 78, negative in 32 and inadequate specimens in 5. Our results showed a sensitivity of 92.3% and specificity of 93.9% for the intraductal aspiration method as compared to a sensitivity of 52.9% and specificity of 89.3% for the squeezing method. Among the 27 cancers in this series, correct cytodiagnosis, including suspicious cases, was made in 24 cases by intraductal aspiration, with an accuracy of 88.9%, as compared to the 33.3% (9/27) accuracy of the squeezing method (P < 0.5). CONCLUSION: For patients with spontaneous nipple discharge, the intraductal aspiration method provides much more accurate cytodiagnosis than does the conventional squeezing method.     

Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan

Objective:  Pulmonary hamartomas have a characteristic heterogeneous radiological appearance. However, when composed predominantly of undifferentiated mesenchymal fibromyxoid component, their homogeneous appearance on computed tomography is indeterminate for malignancy. Rendering an accurate preoperative diagnosis in these cases can alter management. The aim of this study was to determine the incidence and accuracy of cytodiagnosis for hamartomas 'indeterminate' by imaging.
Methods:  We retrospectively reviewed records for hamartomas diagnosed by transthoracic fine needle aspiration (FNA) including immediate impressions and final diagnoses. Cytological features evaluated included the presence of fibromyxoid stroma, bronchioloalveolar cell hyperplasia, fibroadipose tissue, cartilage and smooth muscle.
Results:  Eighteen (1.3%) hamartomas were identified from 1355 transthoracic FNAs. The immediate impression was hamartoma in 13 (72%), carcinoid in one (6%), mucinous bronchioloalveolar carcinoma in two (11%) and non-diagnostic in two (11%). The final diagnosis of hamartoma in cases diagnosed as carcinoid, mucinous bronchioloalaveolar carcinoma and non-diagnostic on immediate impression was rendered following assessment of all cytological material.
Conclusion:  Overall, FNAs are highly reliable for diagnosing hamartomas even when composed principally of undifferentiated mesenchymal fibromyxoid stroma, especially with the aid of all available preparations including Diff-Quik smears, Papanicolaou smears, ThinPreps and cell block material.     

Evaluation of nine sets of PCR primers in the RNA dependent RNA polymerase region for detection and differentiation of members of the family Caliciviridae, Norwalk virus and Sapporo virus

Norwalk virus and Sapporo virus were approved as type species of the genus "Norwalk-like viruses" and the genus "Sapporo-like viruses," respectively, in the family Caliciviridae. A total of 116 stool specimens containing Norwalk virus (NV) or Sapporo virus (SV) were tested by RT-PCR and Southern hybridization to evaluate nine sets of PCR primers and seven internal oligonucleotide probes in the RNA dependent RNA polymerase region of NV and SV for detection and differentiation of viruses in the NV and SV. Fifty-five stool samples were collected from 11 outbreaks of NV and/or SV gastroenteritis in an infant home, where residents were infants under 2 years of age, in Sapporo, Japan. Sixty specimens were obtained in Sapporo from sporadic cases in children, mainly under 6 years of age, of acute gastroenteritis due to small round structured viruses detected by EM. There is no single primer pair to detect all NV and SV, and at least three primer pairs, G1 set, G2 set and Sapp35/Sapp36, are required to detect viruses in the NV and SV clades. Many NV and SV strains were successfully classified into one of the NV/genogroup I, NV/genogroup II and SV by single-round RT-PCR and Southern hybridization. The new detection method for SV reported in this study combined with those for NV previously reported may elucidate the importance of Norwalk virus and Sapporo virus as a cause of viral gastroenteritis in all age groups in the world.     

The value of lymph node imprint cytodiagnosis: an assessment of interobserver agreement and diagnostic accuracy

The value of lymph node imprint cytodiagnosis: an assessment of interobserver agreement and diagnostic accuracy
The aim of this study was to assess the reliability of cytodiagnosis of lymph node imprints without fixed tissue sections. One hundred randomly selected archival cases were used in the study. These air‐dried May–Grünwald–Giemsa imprint slides were assessed independently and blind by three pathologists. Cases were assigned to one of four diagnostic categories: reactive changes, non‐Hodgkin's lymphoma (NHL), Hodgkin's disease (HD) and secondary malignancy. Each broad diagnosis was compared with the 'correct' reviewed histological diagnosis to calculate interobserver agreement and diagnostic accuracy. The overall κ score (+0.59) was indicative of moderate agreement. The mean pathologist diagnostic accuracy was 78%, with complete agreement with the histological diagnosis in 61% of cases. The main diagnostic difficulties were in the distinction between reactive changes and NHL and distinguishing NHL from HD. Further diagnostic classification, e.g. typing of lymphomas and subclassification of Hodgkin's disease, was not found to be reliable using the imprints alone. With these limitations in mind, pathologists should be able to use lymph node imprints for cytodiagnosis in selected cases. The study also emphasized the utility of imprints as a corollary to the histology and as a tool for cytology training and continuing education.     

Cytological diagnosis of basal cell carcinoma and actinic keratosis, using Papanicolaou and May–Grünwald–Giemsa stained cutaneous tissue smear

Objective:  Cytology may become the diagnostic method of choice with the advent of new non-invasive treatments for non-melanoma skin cancer, as the sampling technique for cytology entails little tissue disfiguration. The aim of this study was to compare and evaluate the diagnostic performance of scrape cytology using two different cytological staining techniques, and to evaluate additional touch imprint cytology, with that of histopathology of basal cell carcinoma (BCC) and actinic keratosis (AK).
Methods:  We investigated 50 BCC and 28 AK histologically verified lesions, from 41 and 25 patients, respectively. Two separate skin scrape samples and one touch imprint sample were taken from each lesion. The smears were stained with Papanicolaou (Pap) or May–Grünwald–Giemsa (MGG) stains. All cytological specimens were examined in random order by pathologists without knowledge of the histology. Cytodiagnostic results were compared with the histopathological report.
Results:  Scrape cytodiagnosis agreed with histopathology in 48 (Pap) and 47 (MGG) of the 50 BCC cases, and in 26 of 28 (Pap) and 21 of 26 (MGG) AK cases, yielding sensitivities of 96%, 94%, 93% and 81%, respectively. No significant difference in sensitivity between the two staining methods was found but a trend towards higher Pap sensitivity for AK was noted ( P  =   0.10). Touch imprint cytology confirmed histopathology in 38 of the 77 cases of BCC and AK.
Conclusion:  Cytological diagnosis with either Pap or MGG stain for BCC and AK is reliable, and differentiates well between BCC and AK. Imprint cytology proved to be non-diagnostic in half of the examined cases.     

Fine needle aspiration (FNA) of synovial sarcoma—a comparative histological–cytological study of 15 cases, including immunohistochemical, electron microscopic and cytogenetic examination and DNA‐ploidy analysis

A retrospective study of 25 FNAs (11 aspirates from primary tumours and 14 from recurrencies and metastases) from 15 synovial sarcomas was performed. The cytological findings were correlated with the histopathology and the value of immunohistochemical and electron microscopic examination as well as DNA‐ploidy and cytogenetic analysis for diagnosis were assessed. A reproducible cellular pattern with a reliable diagnosis of spindle cell sarcoma was possible provided that the aspirates were cell rich. However, a true biphasic pattern indicative of synovial sarcoma was only seen in one of the 25 specimens. Electron microscopic examination of the aspirates was a valuable adjunctive diagnostic method, whereas immunocytochemistry and DNA‐ploidy analysis were not. Immunohistochemical, electron microscopic and cytogenetic analysis were all valuable ancillary methods when performed on surgical specimens. Malignant haemangiopericytoma and fibrosarcoma were the most important differential diagnoses in the FNA specimens.     

Inflammatory Lesions of the Breast: Diagnosis By Fine Needle Aspiration

Amongst 1061 breast lesions diagnosed by fine needle aspiration (FNA) over a period of 6 years (1985-1990), 128 were reported to be showing changes consistent with an inflammatory lesion. On review, the cytodiagnosis was found to be inaccurate in 31 cases. The cytological features of the 97 cases that were correctly reported are described in this report. The cytological diagnoses issued in these 97 cases were acute mastitis or breast abscess (57 cases) and tuberculous mastitis (30 cases). Non-specific chronic mastitis and miscellaneous conditions accounted for four and six cases respectively. Acid fast bacilli (AFB) were demonstrated in 28.0% of tuberculous mastitis cases and 10.0% of those diagnosed as acute mastitis or breast abscess. FNA cytology was found to be useful for the diagnosis of inflammatory lesions of breast and their classification, as only five out of 57 cases of acute mastitis/breast abscess and one out of 30 tuberculous mastitis cases were suspected on clinical grounds.     

Cytodiagnosis of malignant non-Hodgkin's lymphomas in effusions (author's transl)

Body cavity effusions in malignant non-Hodgkin's lymphomas, particularly in the early stages of those neoplasms, are rare in comparison to the far more common effusions in other malignant diseases and in inflammatory processes. Therefore, the cytological differential diagnosis is of great importance. Of 7,000 pleural and 1,700 ascitic effusions, only 42 cases were malignant non-Hodgkin's lymphoma and in 30 lymphoma was suspected. When lymphoma is suspected, particularly low-grade lymphoma, there are great difficulties in making a differential diagnosis. Using the more or less typical cellular and nuclear criteria of the various lymphoma types, an attempt was made to classify the unequivocal lymphomas according to the Kiel classification of malignant non-Hodgkin's lymphomas. In principle these criteria are the same in cytological and histological examinations. In 31 cases the lymphoma subtype could be specified and confirmed in part by subsequent histological examination. Apart from the suspect lymphoma cases (40%), cases of a low grade of malignancy were predominantly observed (28%). Lymphomas with a high grade of malignancy were less frequently encountered (15%), a proportion similar to that of unclassifiable lymphomas (16%). Apparently the cytological and karyological criteria are not yet adequate to classify lymphomas from conventionally prepared cytological specimens with a higher degree of accuracy.     

Improving diagnostic yield of biliary brushings cytology for pancreatic cancer and cholangiocarcinoma

Biliary brushings are currently the best accepted method to obtain a cytological diagnosis of pancreatic cancer or cholangiocarcinoma. The technique has good specificity but poor sensitivity. Two dedicated pathologists reviewed 137 consecutive biliary brushings from 127 patients between February 1997 and February 2000. The ultimate diagnosis was determined by review of radiology, operative diagnosis and patient outcome. The sensitivity, specificity, positive predictive value and negative predictive value of the original results and the review results were calculated and compared. Additional diagnostic categories 'suspicious' and 'atypical possibly benign' were included on review. After review, the sensitivity improved from 49.4% to 89.0% and the specificity remained 100%. The use of the additional diagnostic category 'suspicious' increased the sensitivity to 90.4%, at the expense of a fall of the specificity to 66.7%. We conclude that review by two dedicated pathologists and additional diagnostic categories can improve the diagnostic accuracy of biliary brushings.     

Evaluation of accuracy of fine needle aspiration cytology for diagnosis of canine mammary tumours: comparative features with human tumours

OBJECTIVE: The authors evaluated the accuracy of the fine needle aspiration cytology technique in the diagnosis of 77 canine mammary gland tumours using the same cytological and histological criteria currently applied to the diagnosis of human breast cancer. METHODS: The study was performed in 73 pure or mixed-breed female dogs submitted to surgical resections of 'mammary tumours'. All cytological smears were stained by routine May-Grunwald-Giemsa and Papanicolaou stains. RESULTS: We obtained a correct cyto-histological correlation in 52/77 cases (67.5%) when all cytopathological examinations were considered, and in 52/56 cases (92.9%) when the inconclusive cases were excluded from the analysis. CONCLUSION: Our results demonstrate that, because of the similarity of the cytological findings in the human and canine mammary gland tumours, it is possible to use the same cytological criteria applied in human pathology for the diagnosis of canine mammary gland tumours.     

Fine needle aspiration cytology of minor salivary gland tumours of the palate

Fine needle aspiration cytology of minor salivary gland tumours of the palate This retrospective study was carried out to review aspirates from minor salivary gland tumours of the palate and to assess the problems encountered in their diagnosis, especially the cytological diagnosis of newer entities such as polymorphous low grade adenocarcinoma (PLGA). Fifty-five cases of palatal salivary gland tumours aspirated over a period of 16 years were reviewed. Histology was available in 26 cases. Pleomorphic adenoma (27 cases) was the most common benign cytodiagnosis. Eleven aspirates were malignant tumours of which eight cases were adenoid cystic carcinoma and three cases were mucoepidermoid carcinoma. Seven cases were diagnosed on fine needle aspiration as suggestive of PLGA. However histological confirmation was available in only one of these cases. Concordance between the initial and revised typings of the tumours was seen in only 28 cases (54%) in the present study. Initially 18 of the 51 tumours (35.3%) could not be typed; and after review, only three could not be typed. Three cases of oncocytoma could be diagnosed on review only. Palatal salivary gland tumours, although relatively uncommon, are difficult to diagnose cytologically. This is more so in cases of newer entities such as PLGA, as their cytological diagnosis is still not well characterized.     

Immunofluorescent staining of metastatic carcinoma cells in serous fluid with carcinoembryonic antibody, epithelial membrane antibody, AUA-1 and BER-EP4

Using an indirect immunofluorescence technique, we assessed the accuracy and clinical usefulness of a panel of monoclonal and polyclonal antibodies. the panel consisted of carcinoembryonic antibody (CEA) and epithelial membrane antibody (EMA), AUA-1, and Ber-EP4 conjugated with fluorescein isothiocyanate. Twenty-six specimens from pleural, peritoneal or pericardial effusions known to contain carcinoma cells (adenocarcinoma or large cell anaplastic carcinoma) and 16 specimens without carcinoma were first examined. the sensitivity and specificity for each of the antibodies were as follows: CEA, 71% and 75%; EMA, 96% and 81%; AUA-1, 80% and 100%; and Ber-EP4, 85% and 100%, respectively. the panel of antibodies was then applied to a group of 14 'problematic' fluids. These had been identified as causing dilemmas in interpretation, either because the cells in the fluids were of equivocal appearance on light microscopy, or the cytological diagnosis was different from that expected in the light of the clinical condition of the patient. Insufficient cellular material was present in one specimen. In five (39%) of the cases the immunochemical staining supported the light microscopic diagnosis. In four (30%) cases, however, the results indicated that the original light microscopic report was incorrect. Two of these were examples of large cell carcinoma of the lung, in which false negative reports had been issued on pleural fluids. the other two were cases of benign ovarian tumours in which a false positive report had been issued. the immunostaining also clarified the final diagnosis in the three patients (23%) on whom 'suspicious' cytological reports had previously been issued. the remaining case, fluid from a patient with a high grade mixed Mullerian tumour of the ovary, was unresolved. We conclude that immunofluorescent staining by AUA-1, EMA and Ber-EP4 is an aid in the cytological interpretation of serous fluids. CEA is much less helpful.     

Randomized study comparing endoscopic ultrasound-guided Trucut biopsy and fine needle aspiration with high suction

H. Gerke, M. K. Rizk, A. D. Vanderheyden and C. S. Jensen
Randomized study comparing endoscopic ultrasound-guided Trucut biopsy and fine needle aspiration with high suction
Objectives:  Endoscopic ultrasound (EUS)-guided Trucut biopsy (TCB) enables acquisition of tissue cores for histological assessment. Because of the rigid needle and the spring mechanism, tissue acquisition can be difficult from regions that require sharp angulation of the echoendoscope. Fine needle aspiration with high suction (FNAHS) has been proposed as a method to obtain histological tissue cores while affording the flexibility to obtain specimens even with extreme endoscope angulation. The objective was to compare prospectively these two methods in their ability to obtain specimens for histological assessment and in their diagnostic accuracy, including cytological diagnosis when achieved.
Methods:  Eighty lesions in 77 patients were amenable to transoesophageal, transgastric or transrectal biopsy and were randomized to TCB ( n  = 44) or FNAHS ( n  = 36). Each specimen was assessed for adequacy (scoring system where a score of 0 was no material, 1–2 was considered cytological, and 3–5 was considered histological). Follow-up information was obtained to establish a gold standard final diagnosis.
Results:  The median histological scores for FNAHS and TCB were 2 and 5, respectively. Histological cores were obtained in 95.3% of TCB, as opposed to 27.8% in the FNAHS group ( P  < 0.0001). Although the diagnostic accuracy for TCB was greater than that for FNAHS (88.3% and 77.8%, respectively), this was not statistically significant ( P  = 0.24).
Conclusion:  If histological information is required, TCB is superior to FNAHS. The difference in diagnostic accuracy did not reach statistical significance due to low numbers and the fact that FNAHS often enabled a cytological diagnosis.     

P-cadherin expression in glandular lesions of the uterine cervix detected by liquid-based cytology

OBJECTIVE: To study P-cadherin aberrant expression as a possible marker for cervical adenocarcinomas in cytological samples. METHODS: We studied P-cadherin immunoexpression in liquid-based cervical cytology samples of biopsy-proven cervical lesions. RESULTS: We found a statistically significant correlation between P-cadherin expression and a cytological diagnosis of malignancy, either glandular or squamous (P < 0.0001). Twenty-two of 33 malignant cases showed P-cadherin membrane staining. None of the 30 benign cases tested showed membrane staining, but three of them displayed an aberrant nuclear P-cadherin expression. CONCLUSIONS: We concluded that P-cadherin can be used to discriminate between malignant and benign cervical cytological specimens, but not to discriminate glandular from squamous lesions.     

Telecytologic diagnosis of breast fine needle aspiration biopsies. Intraobserver concordance

OBJECTIVE: To determine the intraobserver concordance between telecytologic and glass slide diagnosis of breast fine needle aspirates. STUDY DESIGN: Twenty-five cases, originally received in consultation, were each examined by three cytopathologists. An average of seven compressed digital images per case were presented, together with a brief clinical history, using the http protocol and an internet browser. RESULTS: Agreement between the telecytologic and glass slide diagnosis ranged from 80% to 96%. Nevertheless, two cases that had been unequivocally diagnosed as malignant based upon video images were considered to be benign by the same pathologist when reviewing the glass slides. Both diagnostic confidence and self-concordance were higher for one pathologist having significant previous video microscopy experience. CONCLUSION: Although intraobserver concordance between telecytologic and glass slide diagnoses of breast fine needle aspirates is high, refinement of existing criteria for diagnosis of malignancy, taking account of the particular limitations associated with telecytologic diagnosis, may be prudent prior to widespread use of telecytology for fine needle aspiration evaluation.