Effect of cellularity on the sensitivity of detecting squamous lesions in liquid-based cervical cytology

OBJECTIVE: To evaluate the effect of cellularity on the sensitivity of both screening and diagnosis in a liquid-based cervical sample. STUDY DESIGN: SurePath samples (TriPath Imaging Inc., Burlington, North Carolina, U.S.A.) with known diagnoses were selected, including 18 negative, 16 low grade squamous intraepithelial lesion (LSIL) and 12 high grade squamous intraepithelial lesion (HSIL) cases. Through a serial dilution technique, samples of varying cellularity were prepared. The 275 slides were assigned random numbers and were routinely screened by 1 of 2 senior cytotechnologists, blinded to the reference diagnosis. Specimens with a screening diagnosis of atypical squamous cells of undetermined significance (ASCUS) or higher were reviewed by two pathologists, resulting in a final consensus diagnosis. Using a grid counting system, cellularity was determined for each slide. RESULTS: There was a clear demarcation in sensitivity between specimens with a cellularity of < 5,000 or > or = 5,000 squamous cells. This applied to both the sensitivity for screening and to the final consensus diagnosis. For cases with a reference diagnosis of LSIL+, at a cytotechnologist screening level of ASCUS or greater, sensitivity increased from 72.8% (< 5,000 cells) to 98.1% (> or = 5,000 cells) and for a reference diagnosis of HSIL from 85.7% to 100%, respectively. Similarly, for the consensus diagnosis, sensitivity rose from 78.5% (< 5,000 cells) to 96.6% (> or = 5,000 cells) for LSIL+ and from 82.9% to 100%, respectively, for HSIL. These differences were statistically significant (P < .001). CONCLUSION: A minimum cellularity of 5,000 squamous cells is recommended for SurePath liquid-based cervical preparations.     

Atypical squamous cells as a diagnostic pitfall in pulmonary Wegener's granulomatosis. A case report

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic, necrotizing, granulomatous inflammation accompanied by vasculitis. It classically involves the triad of the upper respiratory tract, lungs and kidneys. Isolated pulmonary lesions of WG may present in some patients as pulmonary masses, simulating neoplasms. The features of WG can be suggested by cytologic study. Atypical epithelial cells associated with WG have previously been reported as a cause of a false positive diagnosis of bronchoalveolar carcinoma. CASE: In this case the cytologic findings included atypical squamous cells in a background of acute, chronic and granulomatous inflammation. In several respiratory specimens the atypical squamous cells were incorrectly interpreted as diagnostic of squamous cell carcinoma. The correct diagnosis of WG was confirmed with open lung biopsy, which demonstrated necrotizing granulomatous inflammation with geographic necrosis and associated vasculitis. CONCLUSION: Markedly atypical squamous cells mimicking squamous cell carcinoma can be found accompanying the inflammatory process associated with WG and are a possible diagnostic pitfall. The possibility of WG as well as other inflammatory processes should always be considered in the differential diagnosis of squamous cell carcinoma of the lung. This case is the only reported case of WG in which atypical squamous cells were a diagnostic pitfall, initially suggesting a diagnosis of squamous cell carcinoma.     

Significance of squamous cells in fine needle aspiration cytology of the breast. A review of cases in a seven-year period

OBJECTIVE: To delineate the significance of detecting squamous cells in fine needle aspiration biopsy of breast lesions. STUDY DESIGN: The authors reviewed 15 cases of fine needle aspiration cytology of the breast with a discernible number of squamous cells from the files of Pamela Youde Nethersole Eastern Hospital, Hong Kong, during a seven-year period from the start of 1994 to the end of 2001. The cytologic features were correlated with clinical, radiologic and histologic findings, if any. RESULTS: Among the 15 fine needle aspirates of the breast with a discernible number of squamous cells, 5 of them represented metaplastic carcinoma. The remaining consisted of 3 cases of fibroepithelial tumors, 1 case of duct ectasia, 3 cases of subareolar abscess, 2 cases of sclerosed intraduct papilloma and 1 case of benign breast cyst. In general, benign squamous cells were bland looking and often associated with anucleated squames. They were mitotically inactive and could show a good maturation pattern. Tumor cell cannibalism was rare. The presence of abundant, foamy macrophages in the background suggested a benign lesion. The primary diagnosis could be deduced by recognition of other features, such as the presence of myxoid stromal tissue and papillary structures. In contrast, malignant squamous cells in metaplastic carcinoma were more pleomorphic and mitotically active. Dyskeratosis and tumor cell cannibalism were obvious. Tumor diathesis and bizarre-shaped cells were sometimes found. CONCLUSION: Squamous cells occur in fine needle aspirates from a number of benign and malignant breast lesions. Benign conditions with abundant squamous cells may sometimes mimic malignant squamous lesions and vice versa. Careful assessment of the cytologic features of squamous cells and background appearance is crucial for achieving a correct diagnosis.     

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.     

Rare coexistence of keratinizing squamous metaplasia with xanthogranulomatous pyelonephritis. Report of a case with the role of immunocytochemistry in the differential diagnosis

BACKGROUND: Xanthogranulomatous pyelonephritis (XPN), a rare form ofchronicpyelonephritis, is commonly associated with lithiasis and rarely leads to keratinizing squamous metaplasia. Its manifestations closely mimic those of a renal neoplasm, leading to misdiagnosis of malignancy, often resulting in radical nephrectomy. The role of immunocytochemistry in the preoperative cytologic diagnosis is assessed in the present case report. CASE: A 20-year-old male presented with fever and an enlarging mass in the right renal angle. Ultrasonography revealed a heterogeneous mass in the renal pelvis. Fine needle aspiration cytology was advised to rule out malignancy. Aspiration smears from the mass showed many dissociated cells and clusters of them with abundant vacuolated cytoplasm, vesicular nuclei and prominent nucleoli in some cells. Many desquamated metaplastic squamous cells were also seen. The background was predominantly necrotic, with inflammatory cells. The cytologic possibility of XPN with squamous metaplasia vs. renal cell carcinoma was considered. Immunocytochemical markers, epithelial membrane antigen (EMA) and CD68 (histiocytic marker) were used to determine the nature of the suspicious vacuolated cells; these cells were immunoreactive for CD68 and negative for EMA, thus confirming the cytologic diagnosis of XPN with keratinizing squamous metaplasia. CONCLUSION: The case highlights the presence of metaplastic squamous cells in XPN in smears for the first time. Immunocytochemistry is an essential tool in the preoperative cytologic diagnosis of XPN. The patient can be managed conservatively with antibiotics.     

Keratinized squamous cells in fine needle aspiration of the brain. Cytopathologic correlates and differential diagnosis

OBJECTIVE: To analyze the differential diagnosis when keratinized squamous cells are found in a brain aspirate. STUDY DESIGN: Twenty cases of brain aspirates with keratinized squamous cells were retrieved (1982-2001). Diagnoses included craniopharyngioma (CP) (n = 11), metastatic squamous cell carcinoma (SCC) (n = 5), epidermoid cyst (EC) (n = 3) and Rathke cleft cyst (RCC) (n = 1). Aspirates were obtained under stereotactic radiologic (CT) guidance. Smears were stained with Diff-Quik or Papanicolaou stain, and cell block sections were stained with hematoxylin and eosin. Radiologic and histopathologic correlation with subsequent resection specimens was performed in selected cases. RESULTS: CP showed cellular smears with numerous keratinized squamous cells in a background of degenerated cellular and keratinaceous debris. Also noted were clusters of anucleate squamous cells, multinucleated giant cells, histiocytes, calcified debris and characteristic fragments of basaloid epithelial cells. Metastatic SCC showed single cells and tissue fragments of markedly atypical and focally keratinized cells with enlarged, hyperchromatic nuclei; prominent pleomorphism in a background of necrotic cellular debris and acute inflammatory exudate. EC showed numerous isolated keratinized squamous cells often with prominent keratohyaline granules and occasional parakeratotic cells in a relatively clean background. RCC showed single cells and aggregates of benign-appearing squamous cells admixed with numerous anucleate squames and hemosiderin-laden macrophages. Glandular-type epithelium was present only rarely. CONCLUSION: Squamous cell-containing lesions in the brain present a spectrum of pathologic entities. Although they all display the common morphologic denominator of keratinizing squamous cells, subtle cytomorphologic differences exist in these lesions, permitting an accurate cytopathologic diagnosis. Clinicardiologic features and anatomic location of the tumor in the brain are additionally helpful.     

Pitfalls in the diagnosis of herpes simplex infection in respiratory cytology

OBJECTIVE: To evaluate the prevalence and potential pitfalls in making an accurate diagnosis of respiratory herpetic infection. STUDY DESIGN: Eighteen cases with the diagnosis of herpes simplex virus (HSV) infection were identified from a total of 7,501 (0.24%) respiratory specimens. All cases were evaluated for classic cytomorphologic features of HSV infection and associated cytologic findings. The parameters studied included number of cells with HSV cytopathic effect, intranuclear inclusions, multinucleation, presence of atypical squamous cells, reparative changes, presence and degree of inflammation and associated obscuring factors. RESULTS: Only a minority of cases (28%) had numerous cells with classic viral cytopathic change. Four (22%) of 18 cases showed atypical squamous cells, and 5 (28%) revealed reparative changes. The majority of the cases were associated with inflammation, which was severe in 4 cases (22%). Blood and degenerative changes obscured the cytologic findings in 3 cases (17%). One case showed a necrotic background. CONCLUSION: Due to the low prevalence of HSV infection in respiratory cytology, a high index of suspicion is necessary for an HSV diagnosis. Pitfalls for a false negative diagnosis include limited number of cells with viral cytopathic change, only mononuclear cells with viral changes and obscuring inflammation or blood. Pitfalls for a false positive diagnosis of malignancy include atypical keratinized squamous cells, atypical repair, cellular degeneration and necrotic background.     

Significance of bizarre cells in cervical screening liquid‐based cytology: A prospective study of 15 cases

Objective

The aim of this study was to assess the significance of bizarre cells (cells of squamous origin with a superficial squamous cell‐type cytoplasm and characterised by multinucleation that produces bizarre nuclear shapes) in liquid‐based cytology (LBC) Papanicoaou (pap) smears with clinical and histological follow‐up correlation.

Methods

Fifteen patients, all with LBC samples containing bizarre cells, were identified in routine ThinPrep^® LBC workload. HPV testing was performed in each case using residual LBC material. Cytological‐histological correlations were reviewed.

Results

All 15 LBC samples contained bizarre cells and tested positive for high‐risk HPV types. Ten of the 15 cases were identified as atypical squamous cells ‐ cannot exclude an HSIL (ASC‐H) with secondary diagnosis of low‐grade squamous intraepithelial lesion (LSIL), while five cases were identified as high‐grade squamous intraepithelial lesion (HSIL), and a subsequent biopsy was recommended. Additionally, 13/15 cases underwent cone biopsy or hysterectomy within 1‐11 months, of which 10 showed histologically confirmed HSIL end‐points. LSIL was present in three cases. Bizarre cells were identified in the HSIL epithelium of five cone biopsies.

Conclusions

Identification of bizarre cells in LBC is straightforward and may facilitate diagnosis. The cytology of bizarre cells is associated with HSIL in cone biopsies. We recommend assigning LBC samples containing bizarre cells as ASC‐H with secondary diagnosis of LSIL.     

Intraobserver and interobserver variability in the quality assessment of cervical smears

Intraobserver and interobserver variability in assessing the quality of cervical smears, as measured by the presence or absence of endocervical columnar cells and squamous metaplastic cells, was evaluated. In total, 180 cervical smears representing the most important cytologic diagnoses were anonymously rescreened twice by 19 observers with an interval of six months. An absence of endocervical columnar cells was proven to correlate with a high percentage of false-negative diagnoses. Intraobserver agreement on the presence or absence of endocervical columnar cells was 85.7% between the two screenings. A predictive value of 57.7% was found for a negative scoring (absence of these cells) while the predictive value of a positive scoring (presence of endocervical cells) was 87.3%. Of the observer scorings, 83.9% concurred with the final diagnosis; there was no significant correlation between that concurrence and the number of years of experience in cytopathology of the observer. For squamous and squamous metaplastic cells in the cervical smear the predictive value of a negative scoring (absence) was only 20.6%. Compared to the final diagnosis, 69.5% of these scorings matched. A significant and relatively high correlation with the experience of the observer was found for the scoring for the presence of metaplastic cells. Even though the predictive values of these quality scorings were relatively low a significantly higher risk for false diagnoses was established when negative scorings were given. It is therefore advisable to have smears with negative scorings for endocervical columnar cells and squamous metaplastic cells always rescreened by another observer.     

双向凝胶电泳-飞行时间质谱技术鉴定食管上皮细胞癌变时14-3-3 protein ε、S100A9的表达

[摘要] 目的：分析食管鳞癌和正常食管上皮细胞蛋白质的表达差异,获取鉴别两者的分子标志物。方法：通过激光捕获显微切割技术分离ESCC肿瘤细胞和癌旁上皮细胞,通过双向电泳和质谱技术鉴定表达异常的蛋白,并通过蛋白免疫印记证实部分差异蛋白的表达。结果：建立了食管癌组织和正常食管上皮蛋白的双向凝胶电泳图谱,通过质谱技术鉴定出14-3-3 protein ε、S100A9等蛋白在食管癌变时差异表达,蛋白印记结果证实14-3-3 protein ε、S100A9的表达量在食管癌变时分别上调和下调。结论：激光捕获显微切割是蛋白质组研究中的一个突破性的技术,可以有效地解决组织异质性的问题;本实验检测到的差异蛋白例如14-3-3 protein ε、S100A9可能成为鉴别食管癌组织和正常食管上皮特异性的分子标记物。     

Comparison of Cytobrush sampling, spatula sampling and combined Cytobrush-spatula sampling of the uterine cervix

Since the introduction of the Cytobrush for sampling the uterine cervix, some practitioners have ceased taking a concomitant cervical scraping using a spatula. To examine whether Cytobrush sampling alone is adequate for the diagnosis of cervical lesions, the Cytobrush and spatula samples in 444 smears (most with original diagnoses of at least mild dysplasia) were analyzed separately for the presence of diagnostic cells, endocervical cells and squamous cells. Of the 412 smears showing pathologic findings (mild to severe dysplasia or worse), diagnostic cells were present in 400 Cytobrush samples and in 369 spatula samples; the combination of both samples thus gave a 3% gain in correct diagnoses as compared to use of the Cytobrush samples alone. Another 18 smears would have been underdiagnosed based only on the Cytobrush samples. Endocervical cells were present in 95.3% of the Cytobrush samples and 83.8% of the spatula samples; squamous cells were present in 93.9% of the Cytobrush samples and 96.8% of the spatula samples. Analysis confirmed that it is important that the smear should contain both endocervical and squamous cells. A positive relationship between the absence of squamous cells in the Cytobrush sample and the probability of a false-negative assessment was suggested. It thus seems inadvisable to replace the combination sampling method by Cytobrush sampling alone, which may lead to a false-negative diagnosis.     

Nuclear DNA in histologic sections from squamous-cell carcinoma and adenocarcinoma of the lung

The nuclear DNA content in morphologically identified tumor cells was analyzed in 4-micron histologic sections from 58 patients with lung carcinoma who survived for at least five years. Thirty-three of the carcinomas were invasive squamous bronchial carcinomas and 25 were pulmonary adenocarcinomas. In all squamous carcinomas, the majority of tumor cells were found to exhibit DNA values exceeding the normal tetraploid and/or diploid region. In contrast, some of the pulmonary adenocarcinomas were found to be composed of a majority of tumor cells with DNA values in the normal diploid region. The results indicate that invasive squamous bronchial carcinomas, in general, are tumors with aneuploid DNA patterns indicative of a high malignant potential and that malignancy grading based on DNA measurements does not add any significant prognostic information to that obtained by morphologic diagnosis.     

Evaluation of PAPNET-assisted cervical rescreening

Evaluation of PAPNET-assisted cervical rescreening
We have compared the results of targeted manual rescreening of 1211 randomly selected smears with the results of PAPNET-assisted rescreening of 1613 cervical smears, containing at least 6.3% low-grade squamous intraepithelial lesion (SIL). PAPNET diagnosis and the targeted rescreening diagnosis were compared with the initial report, issued on the corresponding smear. Reproducibility scores for inadequacy, presence of endocervical and endometrial cells, specific infections and squamous cell abnormalities were determined. The reproducibility scores for the diagnosis of inadequate smears and specific infections were lower with the PAPNET-assisted rescreening. The detection of squamous cell abnormalities was excellent for both methods (>0.95), with a higher detection rate for false-negative smears with the PAPNET testing system.     

GRP78在食管鳞状细胞癌、不典型增生及正常食管鳞状上皮组织中的表达

目的：检测葡萄糖调节蛋白78（glucose—regulated proteins78,GRP78）在同一食管癌患者食管的鳞状细胞癌、不典型增生及正常鳞状上皮组织中的表达,研究GRP78与食管鳞状细胞癌发生发展的关系。方法：取90例食管鳞状细胞癌患者的病变组织,其病理切片中正常鳞状上皮组织、不典型增生组织和鳞状细胞癌组织均存在,用免疫组化的方法,检测GRP78在3种不同组织中表达的情况,分析G史P78与性别、年龄、浸润深度、分化程度、分期及淋巴结转移等参数之间的关系。结果：GRP78在食管正常鳞状上皮组织、不典型增生组织、鳞状细胞癌组织中的阳性表达率分别为7．8％、85．6％、47．8％,GRP78在正常食管组织、不典型增生组织、食管鳞癌组织3组中表达的差异有显著性意义（P〈0．01）。鳞状细胞癌组织中GRP78表达阴性者,年龄较阳性者大;GRP78表达与肿瘤分化程度、分期、淋巴结转移等有明显相关性。结论：GRP78在食管正常细胞向恶性细胞转化的过程中可能扮演了重要角色,检测GRP78的表达可能有助于对食管鳞状细胞癌的预防及早期诊断。     

Cytologic diagnosis of laryngeal and hypopharyngeal squamous cell carcinoma in sputum

A prospective study of the value of sputum cytology in the diagnosis of squamous cell carcinoma of the larynx and hypopharynx is reported. Sputum cytology established the diagnosis in 63.5% of the patients with laryngeal lesions and in 77.4% of the patients with hypopharyngeal lesions. In laryngeal cancer, a positive diagnosis by sputum cytology was related to clinical T factors (according to the TNM classification): while only 29.4% of T1 lesions were positively detected by sputum cytology, 63.3% of T2 lesions, 69.7% of T3 lesions and 79.2% of T4 lesions were so detected. In hypopharyngeal cancer, there was no discernible relationship between sputum cytodiagnosis and clinical T factors. Generally, there was only a small number of cancer cells present in the sputum in these cases. Some of the squamous cancer cells were not very conspicuous and would require careful screening of the sputum specimens to be detected.     

Diagnosis of a case of pulmonary carcinosarcoma by detection of rhabdomyosarcoma cells in sputum

Cytologic examination of sputum samples from an elderly patient revealed the presence of two cell populations: squamous cell carcinoma cells and rhabdomyosarcoma cells. The abnormal squamous cells showed both keratinizing and nonkeratinizing forms while some of the rhabdomyosarcoma cells showed cross striations. Sputum cytology was thus able to suggest a diagnosis of pulmonary carcinosarcoma. Histologically, the tumor was composed mainly of sarcomatous tissue showing various kinds of cells: fusiform or fibrous cells, round anaplastic cells, spindled cells with typical cross striations and myoblastic cells. A partially myxomatous degeneration was present. In addition, squamous cell carcinoma proliferated along the bronchi and formed small invasive cell nests in the sarcomatous tissue. No transition between the two components was noted. Both cellular constituents had metastasized to an interlobar lymph node.     

Interobserver concordance in the assessment of features used for the diagnosis of cervical atypical squamous cells and squamous intraepithelial lesions (ASC‐US,ASC‐H,LSIL and HSIL)

G. Bigras, J. Wilson, L. Russell, G. Johnson, D. Morel and M. Saddik
Interobserver concordance in the assessment of features used for the diagnosis of cervical atypical squamous cells and squamous intraepithelial lesions (ASC‐US, ASC‐H, LSIL and HSIL) Objectives: Given the well‐known poor reproducibility of cervical cytology diagnosis, especially for atypical squamous cells of undetermined significance (ASC‐US) and low‐grade squamous intraepithelial lesion (LSIL), this study surveyed reproducibility in the assessment of individual cytomorphological features. Methods: One hundred and fifty cells or groups of cells, with a variety of morphological appearances, including normal cells, high‐grade squamous intraepithelial lesion (HSIL), LSIL, ASC‐US and ASC cannot exclude HSIL (ASC‐H), were precisely marked on 150 different liquid‐based cytological preparations. They were analysed by 17 observers who assessed 17 cytological features including nuclear features (chromatin texture, nuclear outline, nuclear shape, etc.), cytoplasmic features (cell shape, cytoplasmic staining, cytoplasmic clearing, etc.) and group characteristics (nuclear polarity, cellular density, etc.). A total of 43 350 data scores were collected in a database using a web‐based survey. Kendall’s W and relative entropy indexes were utilized to compute concordance indexes of respectively ordinal and nominal variables. Results: Nuclear features have significantly lower reproducibility (0.46) compared with other cytological features (0.59). The feature with least agreement is assessment of chromatin texture. A small but significant difference in concordance was found between two subsets of observers with different levels of experience. Conclusion: Most previous studies assessing reproducibility of cytological diagnoses show, at best, moderate reproducibility among observers. This study focused on agreement regarding the presence of constituent morphological features used to recognize dyskaryosis and various grades of squamous intraepithelial lesions. A map of reproducibility indexes is presented that highlights, for daily practice or teaching, the robustness of features used for cytological assessment, recognizing that diagnosis is always based on a combination of features.     

Fine needle aspiration cytologic findings in metastatic basaloid squamous cell carcinoma of the head and neck.

Basaloid squamous cell carcinoma of the head and neck is a variant of squamous carcinoma the cytomorphology of which has not been examined previously. The cytologic features of metastatic basaloid squamous cell carcinoma in fine needle aspiration specimens from nine patients are described. The primary tumors, when known, were located in the base of the tongue, tonsil, epiglottis, nasopharynx, hypopharynx and false vocal cord. Each neoplasm had large fragments or clusters of crowded cells and scattered single cells in the cytologic smears. The cells had round or oval, hyperchromatic nuclei that often had single, small nucleoli. The nuclei usually were small or medium sized, but six tumors had a few cells the nuclei of which were large and pleomorphic. The cytoplasm was typically scant, and only three cases had occasional keratinized cells. Necrosis was present in six neoplasms. Three neoplasms, originally diagnosed as small cell undifferentiated carcinoma, contained numerous single cells and small clusters of cells with nuclear molding. On review, however, smears from these neoplasms also contained a few large fragments of tightly cohesive cells with larger, vesicular nuclei. Another basaloid squamous cell carcinoma had been interpreted elsewhere as an adenoid cystic carcinoma because of the presence of pseudoglandular structures with stromal cores. Although the cytologic features of basaloid squamous cell carcinoma may mimic those of other poorly differentiated carcinomas in fine needle aspiration specimens, they are sufficiently distinctive that a diagnosis of this variant of squamous cell carcinoma can be suggested for a patient whose primary neoplasm is located in the upper aerodigestive tract.     

The application of visual cell profiles in the study of premalignant atypias in sputum

Because the diagnosis of squamous-cell carcinoma of the lung by routine cytologic screening of sputum is often inconclusive, our laboratory is studying the use of cytomorphologic profiles as a reliable diagnostic aid. This study reports the analysis of the profiles of 75 subjects, both cigarette-smoking volunteers and hospitalized patients suspect for lung cancer. Twenty-five of the subjects had been classified as having squamous metaplasia, 25 as having atypias and 25 as having squamous-cell carcinoma. Four slides were made for each subject, with 100 random fields viewed on each slide. The frequency of free alveolar macrophages, metaplastic squamous cells, epithelial atypical cells and malignant squamous cells were noted for each field. The results indicated that, although there were large differences between individual profiles within each diagnostic category, there were significant differences between the average profiles for each diagnostic category. Furthermore, although there were differences in cell frequencies from slide to slide and within slides, the differences were constant across diagnostic categories. The results are supportive of the progressive-atypia hypothesis for squamous-cell carcinoma of the lung and provide a baseline for comparison with subsequent individual profiles.     

Aspiration cytology of the conjunctival surface

OBJECTIVE: To evaluate a method of obtaining conjunctival cells that utilizes aspiration of the conjunctival surface. STUDY DESIGN: Eighteen eyes from 16 patients with epibulbar lesions underwent aspiration of the conjunctival surface using a tuberculin syringe without a needle. The aspirated cells were prepared by the cytocentrifuge or Millipore filter technique. The lesions were subsequently biopsied, and the cytologic and histologic diagnoses were compared. RESULTS: Diagnoses of the conjunctival lesions, in decreasing order of frequency, were conjunctival intraepithelial neoplasia (dysplasia, carcinoma in situ), squamous cell carcinoma, squamous metaplasia, nevus, lymphoma and inflammation. In this feasibility study, the cytologic diagnosis accurately correlated with the histologic diagnosis in most cases. There were two cases in which the cytologic diagnosis led to the correct histologic diagnosis. CONCLUSION: Aspiration cytology of the conjunctival surface is useful in obtaining diagnostic material and may be used as a guide to where a biopsy should be performed. Limitations include inadequate samples and lack of observer experience.