The role of brushing cytology in the diagnosis of gastric malignancy

The results of endoscopic biopsy and brushing cytology in 234 consecutive patients with established histologic diagnoses of discrete gastric lesions were analyzed. A histopathologic diagnosis of malignancy, established by independent means, was made in 74 patients. Brushing cytology was positive for malignancy in 63, a diagnostic sensitivity of 85%. Endoscopic biopsy was positive in 64, a diagnostic sensitivity of 86%. The sensitivity for combined cytology and biopsy was 91%, which was not significantly greater than for biopsy alone (P = .6). Cytology yielded false-positive results in 5 of 160 patients (3.1%) with confirmed benign disease. There were no false-positive biopsy reports. Although both brushing cytology and biopsy have high diagnostic sensitivities, based on the findings of this study, the routine addition of cytology to biopsy in the endoscopic evaluation of gastric lesions is not recommended. Cytology could be reserved for situations in which difficulty is encountered in obtaining adequate tissue for histologic examination and for cases with a high suspicion of malignancy that have yielded negative biopsies.     

Respiratory cytology in malignant lung disease – The thoracic oncologist’s perspective

Respiratory cytology continues to play a central role in the diagnosis and staging of thoracic malignancy, although over time indications have changed. Historically, sputum cytology and endobronchial brushings and washings figured prominently, but with the advent of endobronchial and endoscopic ultrasound much greater emphasis is placed on fine needle aspirates from lymph nodes. The advent of targeted sequencing panels for genomic profiling to identify driver mutations and PD-L1 directed immunotherapy means that there is a need to extract increasing amounts of diagnostic and predictive information from ever smaller amounts of diagnostic material. Recent work has demonstrated that cytology samples are well suited to delivering the information required, but in order to understand the limitations of clinical and laboratory techniques, a close working relationship between pathologist and thoracic oncologist is needed to optimise sample procurement and utilisation.     

Role of biliary brush cytology in primary sclerosing cholangitis

OBJECTIVE: To assess the role of brush cytology in the routine evaluation of patients with primary sclerosing cholangitis (PSC). STUDY DESIGN: From January 1995 to June 2000, 64 brush cytology specimens were obtained from 21 patients who had at least one cytologic sample obtained during endoscopic retrograde cholangiography. All patients had a diagnosis of primary sclerosing cholangitis. Cases were classified as benign, atypical or malignant according to major cytologic criteria (nuclear contour and chromatin irregularities) and minor cytologic criteria (polarity, cellularity, nuclear enlargement, mitosis, increased nuclear/cytoplasmic ratio) used by us to diagnose biliary brush cytology. Follow-up was available in all cases. RESULTS: Diagnoses were benign (13), atypical (5) and malignant (3) on cytology. Follow-up of the 13 benign cases showed bile duct stones (2), gallbladder adenocarcinoma at cholecystectomy (1), ascending cholangitis (1) and clinically/cytologically by benign follow-up (9). Five of 13 benign cases had subsequent liver transplantation for liver failure, with explants showing changes of primary sclerosing cholangitis. Of the 3 malignant cases, 1 had carcinoma in situ on biopsy, with the explanted liver showing high grade dysplasia; the second patient had cholangiocarcinoma on explant; and the third had hepatocellular carcinoma on liver five needle aspiration. The 5 patients with atypical cytology were reclassified on review as reactive (3) and atypical not otherwise specified (2). Follow-up showed benign disease in 3 of 3 atypical cases reclassified as reactive; 2 of 2 reclassified as atypical not otherwise specified showed low grade dysplasia in the explant. CONCLUSION: The overall incidence of malignancy was low (3 of 21) in patients with PSC. Bile duct brushing is a sensitive method of detecting neoplasia in the setting of PSC when well-defined cytologic criteria are applied.     

Clinical examination,xeromammography, and fine-needle aspiration cytology in diagnosis of breast tumours.

The diagnostic accuracy of clinical examination, xeromammography, and fine-needle aspiration cytology was compared with definitive histological findings in 255 breast lumps excised during one year. When suitable aspirates were obtained for cytological examination the diagnostic accuracy of aspiration cytology was higher than clinical examination or xeromammography. A diagnostic accuracy of 99% was achieved when all three screening tests were in agreement. As well as confirming a clinical diagnosis of malignancy, cytology is useful in identifying malignancy when clinical findings suggest that the tumour is benign. The availability of accurate cytology has affected patient management in many ways. Xeromammography did not enhance the diagnostic accuracy of clinical examination and aspiration cytology in patients presenting with a breast lump and, as a procedure with potential hazard, the benefit of routine xeromammography is questionable when an efficient cytological service is available.     

Comparison of cytohistologic techniques in diagnosis of gastroesophageal malignancy

OBJECTIVE: To evaluate the diagnostic performance of various endoscopic cytologic techniques, namely, brushing cytology, touch smear cytology and crush cytology, and comparison with concurrent biopsy results in diagnosis of gastroesophageal malignancy. STUDY DESIGN: This prospective study was conducted on 100 patients, with 78 clinically suspected cases of esophageal malignancy and 22 cases of gastric malignancy. RESULTS: The diagnostic accuracy of touch smear in esophageal malignancy was significantly higher (94.12%) than brushing and crush smears (89.71% each), and endoscopic biopsy had the diagnostic accuracy of 88.24%. The diagnostic accuracy of combined brushing and biopsy was 100%; it was 97.06% for touch smears combined with biopsy. In comparison, the diagnostic accuracy in gastric malignancy was 75% for brushing alone, which was significantly lower than touch smear (87.5%) and endoscopic biopsy (87.5%). The diagnostic yield for crush smear was 81.25%. A combination of touch smears and biopsy had a diagnostic yield of 100%; it was 93.75% for combined brushings and biopsy. CONCLUSION: A combination of cytohistologic techniques resulted in a statistically significant increase in the diagnostic yield of gastroesophageal malignancies and thus cytologic techniques may act as adjunct to biopsy histology to increase the diagnostic efficiency.     

Assessing HER-2 status in fresh frozen and archival cytological samples obtained by fine needle aspiration cytology

Determination of HER-2 status is an essential prerequisite in considering a patient's eligibility for anti-HER-2 therapy; few studies have focused on its evaluation on cytological material. We present a new method of assessing HER-2 status on cytological samples, by fluorescence in situ hybridization (FISH) with an automated detection system, using fresh frozen (FF) and May–Grünwald–Giemsa (MGG) stained smears, and we evaluate the reliability of HER-2 determination on fine needle aspiration cytology (FNAC). The pre-treatment protocol for FF smears is easier and faster than for MGG stained slides. However, with the described procedure, FISH is also feasible on archival MGG stained slides. We conclude that with this method, cytological samples obtained by FNAC, either FF or MGG, are a reliable option for assessing HER-2 status.     

Value of endoscopic retrograde cholangiopancreatography-guided brushings in preoperative assessment of pancreaticobiliary strictures: what's new?

Brush cytology plays a prominent role in confirming the presence of extrahepatic biliary tract malignancy. However, its value is limited by its relatively low and widely variable sensitivity values. Various factors seem to influence the accuracy of cytologic diagnosis and are attributed to sampling, technical and interpretation errors. Ancillary methods, such as immunocytochemistry, flow cytometry, image analysis, fluorescence in situ hybridization (FISH) and the newly discovered method of global analysis of gene expression are helpful in resolving cases with inconclusive cytology and are vigorously investigated for their value in assessing the expression of novel tumor markers for the diagnosis and prognosis of pancreatic and bile duct carcinomas. However, their routine use in clinical practice remains in doubt. To increase the sensitivity of brush cytology and strengthen its role in the preoperative assessment of patients with pancreaticobiliary malignancies, the following are of the utmost importance: improvement of current sampling and cytopreparation techniques, introduction of a uniform system for reporting epithelial abnormalities based on strict and clearly distinct morphologic criteria for each pathologic entity and incorporation of experience and knowledge derived from standard cytologic methods and novel diagnostic technologies in clinical practice without compromising the high specificity associated with brush cytology.     

Cytologic studies of the fallopian tube in patients undergoing salpingo-oophorectomy

Background

Mounting evidence suggests the fallopian tube as the origin for ovarian high grade serous carcinoma (HGSC). We attempted to identify the tubal cytological features that allow us to distinguish malignant from benign conditions.

Methods

Tubal specimens (n = 56) were collected from patients who underwent bilateral salpingo-oophorectomy (BSO) due to various clinical indications. A standard procedure to collect fallopian tube brushings from freshly received surgical specimens was developed. Cytological diagnoses were classified into three categories: benign, atypical, and suspicious for malignancy/malignant. Cytological variables of individual cells and epithelia were subjected to statistical analysis. The fallopian tube histology was used as diagnostic reference for confirmation of cytology diagnosis.

Results

Among the 56 fallopian tube specimens, 2 (3.7 %) showed inadequate cellularity preventing further evaluation, 11 (20.4 %) were diagnosed as malignant or suspicious of malignancy, 7 were atypical, and 36 were benign. The presence of three dimensional clusters (p < 0.0001, Fisher’s Exact Test), or prominent nucleoli (p = 0.0252, Fisher Exact test) was highly correlated with the diagnosis of malignancy. The suspicious malignant/malignant cytological diagnosis was also highly correlated with presence of HGSC with or without serous tubal intraepithelial carcinoma (STIC).

Conclusions

Tubal cytology may be useful for ovarian cancer screening and early detection.

     

Conventional respiratory cytology versus fine needle aspiration cytology in the diagnosis of lung cancer

The results of 184 fine needle aspiration (FNA) cytologic examinations were compared with the findings of "conventional" respiratory cytology (on sputums, bronchial brushings and bronchial washings) and histology (on biopsy and autopsy samples) and with the medical records. Positive cytologic results were obtained in 6 (10%) of 60 sputums, 17 (21%) of 80 brushings, 16 (19%) of 84 washings and 82 (44%) of 184 aspirates. These positive results were confirmed by biopsy for 6 of 6 sputums, 16 of 17 brushings and 15 of 16 washings. Among the 82 patients with a positive FNA cytology, malignancy was confirmed by lung biopsy in 39 and by autopsy in 2; the cytologic diagnosis was supported by clinical and radiographic findings in all but 1 of the remaining 41 patients. Using transbronchial lung biopsy, autopsy and medical records as final standards, the positive predictive values were 100% for sputum, 94.1% for brushings, 93.0% for washings and 98.6% for FNA samples. The high positive predictive values of FNA and the other cytologic procedures indicate that these diagnostic modalities provide simple, rapid and reliable methods for the diagnosis of lung cancer.     

Prospective comparison of the value of brushings before and after biopsy in the endoscopic diagnosis of gastroesophageal malignancy

The hypothesis that the cytodiagnostic results on endoscopic brushings obtained before biopsy may be superior to those brushings obtained after biopsy, but with the accuracy of the subsequent biopsy reduced, was examined for 300 consecutive patients, including 256 with esophageal or gastric carcinomas. Following stratification by site and endoscopic appearance of their lesions, the patients were randomized to undergo brushing either before or after forceps biopsy. The accuracy of brushing cytology in patients with carcinoma was significantly higher when the brushing was performed before biopsy than after biopsy (93.5% versus 82.6%; P less than .01). The diagnostic yield of the biopsy was not significantly different whether the lesions were brushed before or after the biopsy (92.7% versus 93.2%; P less than .5). The diagnostic superiority of brushings obtained before biopsy did not relate to the site or endoscopic appearance of the tumor. There were no false-positive cytologic or histologic reports. For all 256 carcinomas, the cumulative accuracy (brushing cytology plus biopsy) reached 98.8% and was significantly better (P less than .001) than that of biopsy alone (93.9%) or cytology alone (87.9%). Apart from reinforcing the belief that the combined application of brushing and biopsy is mandatory for achieving optimal results, this study indicated that the brushing should be performed before the biopsy.     

Imprint cytology of vacuum-assisted breast biopsy specimens: a rapid diagnostic tool in non-palpable solid lesions

Objective:  Imprint cytology provides a rapid preliminary diagnosis shortly after the completion of breast biopsy. This study aims to assess the validity of imprint cytology for the pre-operative diagnosis of non-palpable mammographic solid lesions excised by vacuum-assisted breast biopsy (VABB).
Methods:  Seventy-two women with non-palpable Breast Imaging Reporting and Data System 3 and 4 mammographic solid lesions without microcalcifications underwent VABB on the stereotactic Fischer's table with 11-G Mammotome vacuum probes. Imprint samples were examined (Diff-Quick stain, modified Papanicolaou stain and May-Grünwald–Giemsa). The cores were dipped into a CytoRich Red Collection fluid for a few seconds in order to obtain samples with the use of the specimen wash. After the completion of cytological procedures, the core was prepared for routine pathological study. The pathologist was blind to the preliminary cytological results. The cytological and pathological diagnoses were comparatively evaluated.
Results:  The sensitivity of the cytological imprints for cancer was 90%. The specificity of the method for cancer diagnosis was 100%. Two precursor lesions were present in the material: one case of atypical ductal hyperplasia, which was successfully detected, and one case of lobular neoplasia, which escaped detection. The cytological imprints were inadequate in four out of 72 cases (5.6%), but none of them were included within the malignant subgroup.
Conclusions:  Imprint cytology seems to be an important adjunctive tool in the management of patients with non-palpable mammographic solid lesions. Its very satisfactory sensitivity and optimal specificity could establish its use in general clinical practice.     

Cytology of colorectal adenomas

A study of the cytological appearances of benign and malignant colorectal adenomatous polyps is reported. The aim of the study was to characterize the cytological features of adenomatous polyps and predict the likelihood of malignancy using cytology. A five grade classification of colorectal cytology has been developed and the characteristic appearances of cells from adenomatous polyps are described. The reproducibility of cytological diagnosis based on this classification has been tested in 120 smears from normal mucosa and adenomatous polyps (including polyp cancers). Correlation with histology was achieved in 88% and correlation of the cytological diagnosis between two observers was achieved in 84%. We conclude that cytology can be used reliably as an adjunct to histology in the assessment of malignancy of adenomatous polyps.     

Detection of bladder cancer by multitarget multicolour FISH: comparative analysis on archival cytology and paraffin-embedded tissue

Detection of bladder cancer by multitarget multicolour FISH: comparative analysis on archival cytology and paraffin-embedded tissue We have evaluated the possibility of using the same specimen for both cytological diagnosis and multitarget multicolour FISH (MtMcFISH) analysis in order to determine whether the routinely processed specimens used for diagnosis were also suitable for this ancillary procedure. For this purpose 18 positive samples (11 voided urine and seven bladder washings) were selected, together with a representative section of the corresponding immediately previous or subsequent histological specimens. Two negative cytology slides were added as negative controls. FISH analysis revealed a normal pattern for each probe in the two negative controls and an abnormal pattern in the 18 positive cases. In the latter the same FISH alterations were found in the cytology samples and in the corresponding histological sections, and superimposable cytological/histological features were observed in two cases where two different histology samples were analyzed. The results clearly show that MtMcFISH may be successfully applied to destained routinely processed cytology slides.     

Non-computer-assisted liquid-based cytology for diagnosis of oral squamous cell carcinoma

Abstract

The development of oral squamous cell carcinoma (OSCC) occasionally follows the neoplastic progression of other premalignant lesions. Although biopsy is the definitive diagnostic method, liquid-based cytology is an adequate method for screening suspicious lesions. We compared liquid-based cytology to histology for diagnosis of OSCC in patients with oral lesions that raised clinical suspicion of malignancy. Our sample consisted of 48 patients. Cytological samples were obtained by scraping the lesion superficially using Cytobrush^®. We conducted cytological and histopathological evaluation of all preparations. We estimated sensitivity and specificity levels as well as positive and negative predictive values. The degree of inter-observer agreement for both methods was assessed using the kappa index. Twenty-eight (58.3%) of the cases finally were diagnosed with OSCC and 20 (41.7%) were determined to be premalignant lesions. We observed eight false negatives and no false positives; OSCC prevalence was 56.5%. The values for diagnostic indices were: sensitivity, 69% (CI 95%, prevalence 51.87); specificity, 100%; positive predictive value, 100%; negative predictive value, 71% (CI 95% 54.82). A kappa index of 0.622 (CI 95% 0.93, 0.39) was observed.     

Cellular cohesiveness in benign and malignant thyroid follicular tumours varies significantly,but the difference is not useful in diagnosis of individual cases

T. Rozkos, A. Ryska, J. Cap, F. Sobande and J. Laco
Cellular cohesiveness in benign and malignant thyroid follicular tumours varies significantly, but the difference is not useful in diagnosis of individual cases Introduction: The aim of our study was to search for new, readily available and statistically reliable cytological markers for differentiating benign and malignant follicular thyroid neoplasms pre‐operatively. Methods: Cohesiveness of tumour cells in cytology slides from a series of 58 follicular tumours diagnosed between 1998 and 2004 inclusive was studied, including 48 follicular adenomas, and eight minimally invasive and two widely invasive follicular carcinomas. Photomicrographs of the cytology slides were taken and the digital images were analysed using computer image analysis software. We evaluated the relative proportions of cells arranged in groups of various sizes. The cohesiveness of the cells in cytological smears was then correlated with the immunohistochemical expression of E‐cadherin in corresponding histological slides. Results: Cases from 15 men (26%) and 43 women (74%) with a mean age of 50 years (range, 19–79) were analysed. In follicular adenomas and carcinomas, respectively, isolated cells were seen in 16.8% and 24.7% (P = 0.028), groups of two to five cells in 9.7% and 11.5% (P = 0.145) and groups of more than five cells in 73.5% and 63.8% (P = 0.041). The mean cell count in groups with more than five cells was 46.5 and 27.0 in adenomas and carcinomas, respectively (P < 0.001). Cell cohesiveness, either as percentage of cells in groups of more than five (R² = 0.026) or as mean cell count per group of more than five (R² = 0.005), was not found to be dependent on the expression of E‐cadherin. Using a threshold of 13% isolated tumour cells in cytological smears, follicular adenomas and carcinomas could be distinguished with 90% sensitivity and 41% specificity. Conclusions: Although we demonstrated a statistically significant difference in cell cohesion between follicular adenomas and carcinomas, these could not be distinguished in the clinical setting by evaluation of the percentage of isolated cells in cytological smears because the specificity was too low. The absence of correlation of cellular cohesiveness with E‐cadherin expression indicates that other factors are probably responsible for the loss of cohesiveness observed in follicular thyroid malignancy.     

Brush cytology of gastric malignancies

OBJECTIVE: To compare endoscopic biopsy and cytology versus biopsy alone in the diagnosis of gastric malignancies. STUDY DESIGN: This prospective study included 229 cases referred for endoscopy for visible gastric lesions during a four-year period (1996-2000). Both biopsy and brush cytology were performed, and all the slides were screened by a cytotechnologist and reviewed by a pathologist. RESULTS: Of the 229 cases, 97 (42.4%) were proven to be malignant and 132 (57.6%) definitely benign. Biopsy was positive in 90 patients (92.7%), while brush cytology was positive in 85 (87.1%). Combined use of biopsy and brush cytology yielded higher diagnostic sensitivity (100%). CONCLUSION: Brush cytology is a safe, easy and rapid method of diagnosing gastric malignancies. Brush cytology is a useful adjunct in the diagnosis of gastric malignancies and should be considered a routine method in combination with biopsy. Multiple repeated endoscopies are recommended in cases of positive cytology and negative biopsy to rule out or confirm malignancy.     

Is CSF cytology a useful diagnostic procedure in staging paediatric CNS tumours?

Objectives:  To evaluate whether there are any factors that predict malignant cells being found in paediatric cerebrospinal fluid (CSF) samples. To determine whether CSF provides useful staging information not provided by magnetic resonance imaging (MRI) in paediatric patients with primary central nervous system (CNS) malignancy.
Methods:  We compared the CSF cytology and spinal MRI staging results in paediatric patients with primary CNS malignancy at a UK tertiary referral centre, over a decade.
Results:  Of 159 CSF samples, 72 samples were from 72 patients with primary CNS malignancy with spinal MRI available for comparison. Eight of these 72 had positive cytology (seven malignant and one suspicious). All had a high clinical suspicion of tumour at the time of sampling. Of the 72 patients, only two had evidence of CSF spread on MRI spinal staging and CSF cytology; ten had MRI without cytological evidence and six had cytological without MRI evidence.
Conclusions:  In paediatric patients with primary CNS tumours, CSF cytology provides useful staging information. Spinal MRI alone may miss some patients with CSF spread who would be identified with CSF cytology.     

Multicolor fluorescence in situ hybridization (M-FISH) on cells from urine for the detection of bladder cancer

Bladder cancer is the fifth most common cancer in adults. Because of the high recurrence rate (up to 70%) new tumor markers for urine are necessary for monitoring patients. In this study, we investigated the value of M-FISH on cells from urine for the detection of bladder cancer. Urine samples from 141 patients suspicious of bladder cancer were analyzed in this study. Cells were isolated from urine before surgical therapy. For FISH analysis, a commercial kit (UroVysion) containing hybridization probes for chromosomes 3, 7, 9p21 and 17, was used. Twenty-five cells were analyzed in each case by two observers. A FISH result was obtained in 121 cases. Overall, sensitivity was 60% and specificity reached 82.6%. Sensitivity and specificity by cytology were 24.1% and 90.5%, respectively. Analyzing results concerning T-category, sensitivity of FISH and cytology was 36.1% and 15% in pTa, 65.2 and 25.7% in pT1, 100% and 66.7% in pT2-3 tumors, respectively. Concerning tumor grade, similar results were obtained: sensitivity was 37% and 14% in G1, 65.4% and 40% in G2, 91.7% and 50% in G3 tumors, for FISH and cytology, respectively. In conclusion, FISH on cells from urine has been shown in all studies to be highly sensitive and specific for detection of bladder cancer. Sensitivity of FISH is higher than conventional cytology and can be used in routine diagnosis additionally to conventional cytology especially in doubtful or negative cases. FISH can detect recurrence earlier than other methods like cytology, cystoscopy or biopsy histological examination.     

Diagnostic value of nucleolar organizer regions (AgNORs) in brush biopsies of suspicious lesions of the oral cavity.

OBJECTIVE: The aim of this retrospective study was to report on the diagnostic accuracy of AgNOR-analysis as an adjunctive diagnostic tool of conventional oral exfoliative cytology taken from suspicious lesions in our clinic. STUDY DESIGN: Cytological diagnoses obtained from brush biopsies of macroscopically suspicious lesions of the oral mucosa from 75 patients (final diagnoses: 53 histologically proven squamous cell carcinomas, 11 leukoplakias and other inflammatory oral lesions) and from 11 patients with normal mucosa as a negative control group were compared with histological and/or clinical follow-ups. Five smears were doubtful and seven suspicious for tumor cells in the cytologic report. Number of AgNOR's were counted in 100 squamous epithelial cell-nuclei per slide after silver-restaining. RESULTS: Sensitivity of our cytological diagnosis alone on oral smears for the detection of squamous carcinomas was 92.5%, specificity 100%, positive predictive value was 100% and negative 84.6%. The best cut-off value of the mean number of AgNOR dots per nucleus distinguishing benign from malignant cells was 4.8. The percentage of nuclei with more than three AgNORs had a cut-off level of 70%. Applying these methods to twelve doubtful or suspicious cytological diagnoses we were able to correctly establish the diagnosis of malignancy in ten cases of histologically proven cancers and to reveal benignity in two histologically proven cases. Thus we achieved a positive and negative predictive value of 100% each. CONCLUSIONS: Smears from brushings of visible oral lesions, if clinically considered as suspicious for cancer, are an easily practicable, non-invasive, painless, safe and accurate screening method for detection of oral cancerous lesions. We conclude that AgNOR-analysis may be a useful adjunct to other methods in routine cytological diagnosis of oral cancer that can help to solve cytologically suspicious or doubtful cases.     

Cytologic evaluation of bronchoalveolar lavage specimens in immunosuppressed patients with suspected opportunistic infections

The role of bronchoalveolar lavage cytology in the diagnostic evaluation of immunosuppressed patients with suspected opportunistic pulmonary infections was evaluated by comparing two groups of patients who underwent fiberoptic bronchoscopy. Bronchoalveolar lavage specimens were compared with other available diagnostic techniques, including bronchial washings, bronchial brushings, transbronchial lung biopsies and open lung biopsy. Prior to the initiation of a protocol for bronchoalveolar lavage, a specific etiology for the pulmonary infiltrate using the above combined modalities was identified in 23 of 47 cases, for an overall diagnostic rate of 49%. The combined bronchial washings and brushings (cytologic procedures) identified a specific etiology in 9 of 47 (19%) of the cases. There were ten cases in which a cytologically identifiable organism (Pneumocystis, virus or fungus) was not present in the bronchial washings and brushings and one missed case of malignancy, for a false-negative rate of 23%. With the addition of the lavage technique and better sampling of the distal airways, a specific etiology for the pulmonary infiltrate was identified in 32 of 48 (67%) of the cases. This is comparable to the values of 40% to 65% cited in the literature for diagnosis of infectious disease by open lung biopsy. The lavage cytologic procedure identified a specific etiology in 22 of 48 (46%) of the cases, and the false-negative rate was reduced to 6%. With the excellent sampling of the bronchoalveolar lavage and the improved cytology results, the need for transbronchial or open lung biopsy has been eliminated in immunosuppressed patients with suspected opportunistic pulmonary infections. This allows these patients to be studied on an outpatient basis.