Pitfalls in fine needle aspiration cytology.

A review of pitfalls encountered in fine needle aspiration cytology (FNAC) of all organs and tissues and based mainly on the author's 35-year experience of diagnostic FNAC in clinical practice is presented. Diagnostic difficulties are usually related to deviations from common cytological criteria that may occur in some lesions. Others are due to the effects of the sampling procedure or of the preparation of samples. A few basic rules are proposed, which may help to avoid some of the diagnostic pitfalls.     

Scrape cell-block technique for fine needle aspiration cytology smears

An inconclusive diagnosis on fine needle aspiration cytology (FNAC) may be due to poor spreading and presence of thick tissue fragments despite aspiration of adequate material. Repeat aspiration may not be possible especially when aspirates of deep seated organs have been obtained by image guided techniques. We have resorted to a 'scrape cell-block' (SCB) technique in such cases. In this technique the cellular material on the slides which had already been fixed and stained, was carefully removed by scraping following destaining and then processed as a cell block. SCB interpretation was then compared with the smear diagnosis and histological diagnosis, wherever available. A total of 27 cases were studied. In 12 cases SCB slides added information to the FNAC smears. In 14 cases SCB did not offer any additional information. SCB was inconclusive in one case. Final histological correlation was available in eight cases and the SCB diagnosis was confirmed in six cases, whereas in two cases SCB failed to identify the tumour. Immunocytochemistry (ICC) was done in one case. SCB is a useful technique to make the best use of the available material when reaspiration is difficult.     

Routine audit of breast fine needle aspiration (FNA) cytology specimens and aspirator inadequate rates

Routine audit of breast fine needle aspiration (FNA) cytology specimens and aspirator inadequate rates In an attempt to improve the quality of the breast FNA specimens we instigated a continuing audit of this procedure in this hospital. All FNAs since 1990 have had the following recorded: mode of aspiration, e.g. freehand or image guided, patient presentation (screening or symptomatic), patient diagnostic category, cytological diagnosis and final histological diagnosis. Aspirator performance was assessed by means of the inadequate aspiration rate (IR) of FNAs performed on patients with a final diagnosis of cancer (FDC) and diagnostic category A patients (clinically or radiologically malignant lesions). An ongoing annual review of the performance of all the aspirators was undertaken, all of whom received individual feedback. Counselling and further training were offered where indicated by poor performance. Over the period 1990–1995 a total of 13 537 FNAs were performed by 27 aspirators. The IR on category A and FDC cases over this period was 16.0% and 18.1%. The best performance achieved by an aspirator in a calendar year was an IR of 3.6% with no inadequate specimens in either FDC or category A lesions, and the best performance over the entire period was an average IR of 11.75% and 14.25% for FDC and category A groups, respectively. The overall IR on category A patients ranged from 15.9% to 23.8% and on FDC cases from 12.2% to 21.7%. There was a significant improvement in individual junior aspirator performance when their first year was compared with their last year on the unit. In some cases a deterioration in intra-aspirator performance was observed, from an IR of 6% to 33%. The overall IR rate of the unit remained stable for FDC patients, 15.5% in 1990 compared with 15.1% in 1995. This appeared to be largely due to a high proportion of the aspirations being performed by experienced personnel with consistent IRs. However, concealed within the overall rate there were some poor performers who benefited from counselling and/or further training. These results indicate an important role for audit in identifying poor aspirators who benefit from targeted training and advice, thereby improving the quality of FNA specimens, and ultimately patient care.     

Improved fine needle aspiration (FNA) cytology results with a near patient diagnosis service for breast lesions

This study is a review of the quality of FNA cytology results for breast lesions approximately 18 months before and 10 months after a change from a rapid diagnosis FNA service with consultant pathologist aspirators to a conventional FNA service with clinician aspirators of varied experience. The setting was symptomatic breast clinic in a large hospital in rural New Zealand acting as a tertiary referral centre for a population of 550,000. The results were collected retrospectively and prospectively. The quality of results for pathologist aspirators (total 810) and clinician aspirators (total 403) was compared using the definitions of the NHS Breast Screening Program Guidelines for Cytology Procedures and Reporting in Breast Cancer Screening. There were statistically significant differences in specificity (biopsy cases only) with 73% for pathologists and 49% for clinicians, specificity (full) with 74% and 56%, inadequate rate with 23% and 37%, and complete sensitivity with 76% and 67%. The use of pathologist aspirators allowed the specimens to be reported in a few minutes. Specimens taken by clinicians took at least 30 min to report. The financial aspects of the two approaches are discussed. When compared with clinician aspirators, pathologist aspirators obtained better quality results and these were reported more quickly.     

Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas

Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas This retrospective study was carried out to review the cases diagnosed as pleomorphic adenoma in major or minor salivary glands and determine the difficulties encountered on typing this tumour on fine needle aspiration cytology (FNAC). Over a 19‐year period (1982–2000) 488 pleomorphic adenomas were diagnosed on FNAC from different sites (parotid – 372 cases, submandibular – 95 cases; oral cavity – 21 cases). Histology was available in 232 cases. Twenty‐nine cases where a histological diagnosis of pleomorphic adenoma was made but the cytological diagnosis was variable were also reviewed. In 216 of the 232 cases a good cytohistological correlation was available. On review only 4 of the 16 cases initially diagnosed as pleomorphic adenoma on FNAC where the histology revealed a different tumour were categorized as pleomorphic adenoma, while 3 each were classified as adenoid cystic carcinoma and benign tumour ?type, and 2 each were diagnosed to be muco‐epidermoid carcinoma, monomorphic adenoma and acinic cell carcinoma. On review of the FNAC smears from 29 cases where a histological diagnosis of pleomorphic adenoma was available while the cytological diagnosis was variable, only 11 (38%) were categorized as pleomorphic adenoma. In the majority of the remaining cases the cytological diagnosis did not alter markedly, 7 of 10 cases where the tumour could not be typed on cytology initially could not be typed even on review. In conclusion, FNAC is an ideal, fairly accurate preoperative procedure for the diagnosis of pleomorphic adenomas. Certain diagnostic problems occur in differentiating pleomorphic adenomas from adenoid cystic carcinoma, monomorphic adenoma and mucoepidermoid carcinoma. Carcinoma ex‐pleomorphic adenoma is difficult to identify on FNAC and in our series all 4 such cases on histology were considered benign on cytology.     

Role of fine needle aspiration cytology in evaluation of paediatric lymphadenopathy

Fine needle aspiration cytology (FNAC) in children has been slow to gain acceptance as compared with its use in adults. The aim of this retrospective study is to determine the utility of FNAC in diagnosing paediatric lymphadenopathy. Six hundred and ninety-two paediatric lymph nodes were aspirated during the period from January 1996 to June 2001. Aspirated material in 32 cases (4.6%) was deemed inadequate for cytological diagnosis. In the remaining cases, 62.2% were reactive lymphadenopathy, 25.2% tuberculous lymphadenitis, 6.3% acute suppurative lymphadenitis, nine cases revealed malignancy (seven lymphoma, two metastatic deposits) and one case had Langerhan's cell histiocytosis. No significant complications were encountered in any of the cases. FNAC emerged as a safe and reliable diagnostic procedure in paediatric age group obviating the need for excision biopsy.     

UK national audit of breast fine needle aspiration cytology in 1990–91: diagnostic criteria

A survey into the practice of fine needle aspiration cytology of the breast amongst members of the British Society for Clinical Cytology in 1990 and 1991 was performed. This paper presents their reported use of diagnostic categories in reporting and the criteria found useful in the diagnosis of benign and malignant disease. A wide variety of diagnostic categories are in use. the criteria used in diagnosis largely follow recommendations found in standard textbooks, but some less well recognized features were also suggested.     

Micronucleus scoring in liver fine needle aspiration cytology

C.‐H. Wen, C.‐H. Lin, S.‐C. Tsao, Y.‐C. Su, M.‐H. Tsai and C.‐Y. Chai
Micronucleus scoring in liver fine needle aspiration cytology Objective: This study evaluated the role of the micronucleus (MN) in liver fine needle aspiration (FNA) cytology. Methods: Histological features of 75 cases of hepatocellular carcinoma (HCC), of which 25 were well differentiated, 37 moderately differentiated and 13 poorly differentiated, and 58 benign hepatic lesions (total, 133 cases) were correlated with MN expression observed in FNA smears reported as benign (n = 40), atypical (n = 14), suspicious (n = 30) and malignant (n = 49). Results: Stepwise increases in the MN score (0.4 ± 0.6, 1.2 ± 1.3, 6.3 ± 4.2 and 14.3 ± 8.8) correlated with the degree of cytological abnormality: benign, atypia, suspicious and malignant, respectively. The mean MN scores for well‐, moderately and poorly differentiated HCC were 5.4 ± 2.2, 11.5 ± 4.5 and 24.9 ± 9.1, respectively, which was significantly different between malignant and suspicious (P < 0.0001), between suspicious and atypical (P = 0.008) but not between atypical and benign. The MN scores differed significantly between all degrees of differentiation of HCC and between the HCC and benign hepatic lesions (P < 0.0001). High sensitivity, specificity and accuracy of liver FNA for diagnosing HCC (96%, 98%, and 96%, respectively) were obtained at a cutoff of three for the MN score. Conclusions: The MN score is an effective HCC biomarker and has a good potential use as an ancillary tool for diagnosing HCC using FNA cytology.     

Fine needle aspiration cytology of the thyroid: a comparison of 5469 cytological and final histological diagnoses

OBJECTIVE: We evaluated the efficacy of fine needle aspiration cytology (FNAC) of the thyroid in a series of 5469 lesions with histological control and studied the causes of, and the possibility of reducing the limitations of the method. METHODS: FNAC was always performed by a pathologist under the guidance of a clinician, using a 22-gauge needle. Generally two aspirations were carried out, and usually four slides were obtained for each nodule; they were then stained with May-Grünwald-Giemsa and with Papanicolaou. The cytological diagnoses were classified in four groups: inadequate, benign, suspicious and malignant. RESULTS: We obtained a complete sensitivity of 93.4%, a positive predictive value of malignancy of 98.6%, and a specificity of 74.9%. At histological control, the cytological diagnosis of Hurthle cell neoplasm corresponded to a significantly higher incidence of malignant neoplasms than the diagnosis of non-Hurthle cell follicular neoplasm (32.1% versus 15.5%). There were 66 false-negative findings, the main cause of diagnostic error (24 cases) being failure to recognize the follicular variant of papillary carcinoma. The number of inadequate FNACs was low (4.2%). CONCLUSION: Our study confirmed the great efficacy of thyroid FNAC. A cytological diagnosis of Hurthle cell neoplasm should be considered an indicator of high risk. Awareness that failure to recognize the follicular variant of papillary carcinoma was the main problem in the interpretation of thyroid FNAC should lead to a decrease of false-negative diagnoses. The inadequate rate was very low, as it was the pathologist personally who performed the needle aspiration.     

Audit of fine needle aspiration cytology of 120 renal lesions

Solid renal masses in 120 patients were assessed by percutaneous fine needle aspiration cytology, performed under radiographic guidance. Follow-up was obtained in all but seven cases. Diagnostic sensitivity for 83 tumours in the series was 91.6%, while two false positive reports resulted in a specificity of 93.8%. Positive and negative predictive values were 97.4% and 81.1% respectively. One advantage of the procedure was the ability to cell type neoplasms accurately, which enabled administration of pre-operative chemotherapy in childhood tumours, and selection of appropriate surgical procedures in adults. The technique offered a non-surgical means of confirming primary renal tumours in patients presenting initially with distant metastases, and documenting renal secondaries in cases with malignancy at other sites. The diagnosis of benign or inflammatory lesions permitted institution of definitive therapy.     

Pitfalls in the diagnosis of Wegener''s granulomatosis on fine needle aspiration cytology

OBJECTIVE: To review the clinical and pathological findings in six suspected cases of Wegener's granulomatosis (WG) and highlight the diagnostic difficulties faced by the cytopathologist. METHODS: Retrospective review of records of the Cytopathology Department to identify patients who underwent image-guided transthoracic pulmonary fine needle aspiration cytology (FNAC) for pulmonary lesions of suspected WG and those who were subsequently confirmed to have WG. Detailed evaluation of cytomorphological features was carried out. RESULTS: A total of six cases were identified in whom the initial procedure to obtain a pathological diagnosis was transthoracic FNAC. In one case, atypical squamous cells on cytology initially suggested a diagnosis of squamous cell carcinoma while in another a diagnosis of WG was made on cytology; however, a subsequent lung biopsy revealed silicosis. CONCLUSION: Acute inflammation and necrosis are the most consistent cytopathological findings in WG. In selected cases FNAC can provide supportive pathological evidence to establish a diagnosis of WG.     

United Kingdom national audit of breast fine needle aspiration cytology in 1990–91-organization and level of activity

A survey amongst members of the British Society for Clinical Cytology (BSCC) was performed in 1990 and 1991 into their experience of fine needle aspiration (FNA) cytology of the breast. Here we present the findings of that part of the survey covering organizational aspects of the service and methods of specimen handling. the replies demonstrate differences in approach to many of the topics covered. There is a preference for the examination of direct smears (rather than cytospins) with air dried Giemsa staining and wet fixation Papanicolaou staining finding nearly equal favour. Some perceived problems were highlighted, including availability and funding of training and quality assurance as well as facilities for liaison between pathologists, clinicians and radiologists.     

Pleomorphic adenoma of salivary gland: to what extent does fine needle aspiration cytology reflect histopathological features?

OBJECTIVE: The histological diversity encountered in pleomorphic adenoma may cause diagnostic difficulty in fine needle aspiration (FNA) cytology due to limited and selective sampling. The present study based on 25 histologically confirmed pleomorphic adenoma cases attempts to find out to what extent FNA cytology reflects the histopathological features. METHODS: May-Grunwald-Giemsa and Papanicolaou stained smears, and haematoxylin and eosin stained paraffin sections of 25 pleomorphic adenomas of parotid and submandibular glands were reviewed. The cellularity, which was assessed in a sliding scale of 1+ to 4+, and proportions of epithelial to mesenchymal components in FNA smears and histology was determined and compared. The frequency of morphological features such as squamous metaplastic cells, cells with oncocytic change, acinus formation, mucus globules, papilla formation, giant cells, myxoid and chondroid matrix as well as specific nuclear features was compared between the two diagnostic methods, and the statistical significance was determined using Fisher's exact test of probability. RESULTS: There was complete concordance between cytology and histology with respect to overall cellularity in 14 (56.0%) cases and in the proportions of epithelial to mesenchymal components in 13 (52.0%). Epithelial cells and myxoid matrix were present in all cases. There was no significant difference between smear and tissue section with respect to frequency of squamous metaplasia, oncocytic change, acinus formation, papilla formation, mucus globules, giant cells, nuclear pleomorphism, nuclear chromatin pattern, and mitotic figures. Morphological parameters that were significantly higher in FNAC compared with histology included intranuclear cytoplasmic inclusions (36.0% versus 8.0%, p = 0.0374), nuclear grooves (84.0% versus 48.0%, p = 0.0090), and reniform nuclei (20.0% versus 0.0%, p = 0.0502). Chondroid matrix was the only parameter which was significantly more common in histology than in cytology (44.0% versus 4.0%, p = 0.019). CONCLUSION: FNA cytology demonstrates well most of the histological features of pleomorphic adenoma of salivary gland and may be considered a useful tool in initial assessment of the tumour.     

Signet ring cells in fine needle aspiration cytology of breast carcinomas: review of the cytological findings in ten cases identified by histology

Objective:  To establish whether the presence of signet ring cells (SRCs) in histology sections of breast carcinoma cases was reflected by their presence in fine needle aspiration cytology (FNAC) smears, correlating to the histological type of breast carcinoma.
Methods:  We reviewed the FNAC findings of ten cases that had been diagnosed as primary breast carcinoma with SRCs on histological sections between 1998 and 2007. Slides and histological sections were obtained from the archives of Ege University Hospital.
Results:  FNA smears were reviewed for the following cytomorphological features: background, cellularity, architecture, nuclear pleomorphism and the presence of SRCs. The background was bloody in eight cases, necrotic in one, and clean in one. There was no mucinous material in any of the cases. Cellularity was prominent in five cases (hypercellular), moderate in three (cellular) and low in two (hypocellular). Loosely cohesive groups of tumour cells of varying size were observed in all cases. A plasmacytoid appearance to some of the tumour cells was seen in all cases and discohesive tumour cells were present in eight. Nuclear pleomorphism was high in six cases and moderate in four. SRCs were observed in seven of the ten cases. Two of these seven cases also had a tubular pattern and one had tumour giant cells.
Conclusions:  FNAC should be evaluated carefully regarding the presence of SRCs when cells with a plasmacytoid appearance are observed in either hyper- or hypocellular smears. The presence of single SRCs in FNACs with hypercellularity, high nuclear grade and tubular formation or tumour giant cells may be a clue in favour of ductal carcinoma. The presence of single SRCs in FNACs with hypocellularity and mild to moderate nuclear grade may be suggestive of lobular carcinoma. However, larger studies would be needed to establish the predictive value of the presence of SRCs on FNAC.     

Fine needle aspiration cytology of suspected tuberculous lymphadenitis

Fine needle aspiration cytology of suspected tuberculous lymphadenitis The aims of this cross-sectional study were to describe the distributional patterns of tuberculous lymphadenitis and to assess the correlation between fine needle aspiration cytology (FNAC) and the Ziehl Neelsen staining technique in diagnosing tuberculous lymphadenitis. Romanowsky's method (Wright's stain) for cytological diagnosis and Ziehl Neelsen (hot method) for the identification of acid-fast bacilli were utilized. Out of one hundred and twenty-eight consecutive patients attending the cytological diagnostic service of the Department of Pathology within Jimma University, 89 (69.6%) of the patients were younger than 30 years of age. The male to female ratio was 1.3 : 1. The cervical region was the most common site and involved 95 cases (74.2%), followed by the axillary and inguinal lymph node regions (20.3% and 4.3%, respectively). The Wright's-stained cytology smears were grouped into three categories: epithelioid granulomas without necrosis, epithelioid granulomas with caseous necrosis and necrosis without epithelioid granulomas. The Ziehl Neelsen stains were undertaken on separate slides: 20.0% of the cases showing epithelioid granulomas without necrosis, 61.9% of those with epithelioid granulomas with necrosis/abscesses and 69.7% of those with necrosis without granulomas were found to be positive for acid-fast bacilli. The overall positivity for the ZiehlNeelsen stained cases was 59.4%. It can therefore be concluded that FNAC is a reliable diagnostic tool in helping to avert the more invasive surgical procedures undertaken in the diagnosis of tuberculous adenitis. The ZiehlNeelsen stain for identification of acid-fast bacilli should be incorporated as an adjunct to increase the diagnostic accuracy of tuberculous lymphadenitis.     

Evaluation of aspiration cytology of ovarian masses with histopathological correlation

T. Sood, U. Handa, H. Mohan and P. Goel
Evaluation of aspiration cytology of ovarian masses with histopathological correlation Objectives: To evaluate the efficacy and diagnostic accuracy of fine needle aspiration cytology (FNAC) in distinguishing non‐neoplastic and neoplastic ovarian lesions and to determine reliable cytological criteria for typing neoplastic ovarian masses into benign and malignant tumours and their subtypes. Methods: FNAC was performed on 50 patients diagnosed as having an ovarian mass clinically and/or ultrasonographically. Detailed history, clinical examination and ultrasound findings in each case were recorded. The cytological diagnoses were categorized as neoplastic and non‐neoplastic and further into benign and malignant neoplasms. These cytological diagnoses were then compared subsequently with the histopathological diagnoses. Results: The study material consisted of 57 aspirates from 50 patients. A comparison of cytological findings with the histological diagnosis was possible in 53 aspirates; in the remaining four cases (7%) the smears were acellular. On cytology, 31 lesions were diagnosed as neoplastic and 22 as non‐neoplastic. The overall sensitivity of cytology in diagnosing neoplastic and non‐neoplastic ovarian lesions was 93.9% and the specificity was 100%. The positive predictive value was 100% and negative predictive value 90.9%. The overall diagnostic accuracy was 96.2 %. Conclusion: FNAC of ovarian masses is a minimally invasive procedure that can differentiate neoplastic from non‐neoplastic ovarian lesions. It may help avoid unnecessary operations and preserve the reproductive ability in young patients. Furthermore, it also enables a satisfactory sub‐categorization of ovarian tumours, which facilitates the choice of appropriate therapy.     

Fine needle aspiration cytology of mammary hamartoma: a review of nine cases with histological correlation

Mammary hamartoma is a breast lesion rarely reported by fine-needle aspiration cytology (FNAC). We report on our experience of FNAC in nine cases confirmed by biopsy. We searched hospital case files for mammary hamartoma or similar lesions (fibrolipomas, lipomas, fibromas, etc.), and cases included were only those in which both FNAC and a histopathological study had been performed. The cytological features that were analysed included epithelial components, mesenchymal fragments and isolated cells dispersed in the background. The patients ranged in age from 25 to 58 years (mean 40 years), and the lesions were predominantly in the right breast and upper outer quadrant. The duration varied from 1 to 20 years. Mammographic features were characteristic revealing well-circumscribed masses of heterogeneous radiodensity and by ultrasonography were hypoechoic without calcification. Grossly, these lesions were oval to round, well-demarcated masses, ranging in diameter from 10 to 80 mm. The tumours were firm, rubbery and white, consisting largely of dense fibroconnective tissue with variable amounts of adipose tissue and glandular elements. Cytological samples showed two components, epithelial and mesenchymal. The cellularity was variable and was composed of lobular cells forming acini, ductal cells, occasional apocrine and foamy cells; myoepithelial cells and isolated naked nuclei were also observed. Adipose tissue and dense fibrous tissue were observed, occasionally with epithelial cells attached, and this finding was an important feature for diagnosis. We considered that the cytological findings could help to diagnose mammary hamartoma, FNAC making a rapid and very important technique for the diagnosis of this pathology.