Role of fine needle aspiration cytology in the diagnosis of soft tissue tumours

Fine needle aspiration cytology (FNAC) is a widely accepted safe, simple and rapid diagnostic procedure used in the examination of neoplastic and non‐neoplastic lesions of various locations. Since its introduction, FNAC has developed into an effective diagnostic tool practiced in a large majority of medical centres evaluating and treating oncological patients. The role of FNAC has been limited in the examination of primary soft tissue lesions, however, as many physicians working in this area recommended against using FNAC. An increasing use of minimally invasive diagnostic procedures in the last decade has resulted in a better acceptance of FNAC as a first‐line approach or as a complementary tool to core needle biopsy in the diagnosis of musculoskeletal lesions. This review discusses the role and value of FNAC in the evaluation and treatment of soft tissue tumours based on the experience gathered over the course of 48 years at the Sarcoma Center in Lund, Sweden. FNAC reports most often provide diagnostic information allowing the initiation of treatment or, when definitive diagnosis cannot be rendered from a cytological examination, guiding the continued diagnostic investigation. The main advantages of soft tissue FNAC are good sensitivity and specificity, low morbidity, speed of diagnosis, and low cost/benefit ratio. The most important disadvantages stem from limited experience in cytological diagnosis of soft tissue tumours and a lack of standardised and uniform reporting system for soft tissue FNAC.     

Fine needle aspiration (FNA) in the diagnosis of soft tissue tumours; a review of 22 years experience

FNA plays an important role in preoperative diagnosis of soft tissue tumours. A close clinical/morphologic cooperation is essential. FNA should be performed on the most accessible part of the tumour, avoiding penetration of the deep portions of the tumour. Needles 0.7 mm (22 G) are recommended. For deep lesions, needles with a stylet should be used. After the FNA, tattooing of the aspiration channel is recommended, and the channel is surgically removed together with the tumour, if a sarcoma. Material from the FNA can be used for additional examinations, i.e. electron microscopy, immunohistochemistry, DNA ploidy analysis and chromosomal analysis. Those techniques are of great importance in the differential diagnosis, particularly in the paediatric small/round cell tumours. the majority of sarcomas can be defined as low grade or high grade malignant in FNA. For malignancy grading the following parameters are used: cellularity, pleomorphism, chromatin pattern, nucleolar structure, mitotic figures and necroses. Cytodiagnostic details of the most common soft tissue tumours and their differential diagnoses are presented.     

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.     

Cytological diagnosis of soft tissue tumours

Cytological diagnosis of soft tissue tumours The aims of this study were to determine the patterns of soft tissue tumours and also to try to assess the utility of fine needle aspiration cytology (FNAC) in diagnosing soft tissue tumours. Of 15 361 patients who visited the cytology diagnostic service of the Pathology Department, Medical Faculty, Addis Ababa University, 623 (4.1%) cases with a diagnosis of soft tissue tumours were retrieved from the department's records for the years 1991-96. Fifty-three soft tissue tumours (25 benign and 28 malignant tumours) with combined FNAC and surgical biopsy results were traced for cyto-histological correlations. Twenty-two out of 25 benign soft tissue tumours were correctly diagnosed, with three false cytologic diagnoses where one mesenchmal neoplasm, one haemangioma, and one haemorragic lesion were identified; and out of 28 malignant soft tissue, 23 were correctly diagnosed however, the five false cytological diagnoses were one soft tissue sarcoma, one dermatofibrosarcoma, one malignant mesenchymal neoplasm, one spindle cell neoplasm and one menechymal neoplasm. Thus, in this study a sensitivity and specificity of 88.5% and 81.5% respectively for the diagnosis of soft tissue tumours were reported. In conclusion, FNAC of soft tissue tumours is a fast, effective and reliable diagnostic tool that may help in categorizing soft tissue tumours into benign and malignant groups for clinical management.     

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.     

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.     

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.     

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.     

Fine needle aspiration cytology of solitary fibrous tumours of the pleura

OBJECTIVE: To analyse fine needle aspirates from solitary fibrous tumour (SFT) of the pleura and to elucidate the cytological features unique to these tumours and differential diagnostic findings of benign and malignant SFTs. METHODS: Fine needle aspiration (FNA) cytology slides from eight cases of SFT of the pleura, including six benign and two malignant SFTs, were reviewed. The subsequent histological slides were also examined. RESULTS: Cytological diagnoses from six histologically proven cases of benign SFTs were low-grade sarcoma (one), non-small cell carcinoma (one), malignant tumour (1) and benign (three). Two cases of malignant SFTs were cytologically diagnosed as malignancy. The aspirates showed a varying degree of cellularity. Most smears were composed of single, scattered fusiform cells, and irregular loose aggregates of oval to spindle cells intimately admixed with dense collagenous stroma. Two malignant SFTs had a greater number of cells in clusters, and displayed mitotic activity, without significant cytological atypia. CONCLUSIONS: The diagnosis of SFT may be suggested by a combination of cytological and radiological findings. The precise determination of malignancy for SFT, however, is not usually straightforward on the basis of cytological features alone. The findings of highly cellular clusters and mitotic activity in the FNA cytological smear can help differentiate malignant from benign SFTs.     

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.     

Ultrasound-guided fine needle aspiration cytology in the diagnosis and management of thyroid nodules

OBJECTIVE: To examine the accuracy of fine needle aspiration cytology (FNAC) in the diagnosis of thyroid nodules and compare the inadequacy rates for ultrasound-guided and freehand FNAC. METHODS: A retrospective study of 434 patients with thyroid nodules who underwent diagnostic FNAC over a 2-year period. Cytological diagnoses have been compared with the histological assessment of resection specimens in 69 cases. RESULTS: The inadequacy rate was significantly lower from ultrasound guided FNAC (24/373 cases, 6.4%) than from freehand FNAC (8/61 cases, 13.1%) (P = 0.043). Seventy-six percentage of patients had a non-neoplastic cytological diagnosis and, after multidisciplinary review, the patients were reassured and assigned to clinical follow-up. Sixty-seven patients had a resection for cytological appearances consistent with non-neoplastic disease (n = 34), suspicious of follicular neoplasia (n = 23), or suspicious of malignancy (n = 10), and two patients had resections following inadequate cytology with ultrasound appearances suspicious of a neoplasm. The overall accuracy of FNAC analysis for malignancy was 97.0%, with sensitivity 83.3%, specificity 98.0%, positive predictive value 71.4% and negative predictive value 98.4%. The overall accuracy of FNAC analysis for the prediction of neoplasia was 97.5%, with sensitivity 80.5%, specificity 97.8%, positive predictive value 89.2% and negative predictive value 95.9%. Difficulties in cytological diagnosis were associated with lymphoid infiltrates and with degenerative changes in follicular adenomas. CONCLUSION: Ultrasound-guided FNAC has a significantly lower yield of inadequate aspirates than palpable FNAC. The ability of FNAC to predict neoplasia in 89% patients and to exclude neoplasia in 95.9% patients makes an important contribution to the multidisciplinary assessment of patients.     

Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology

U. Handa, S. Chhabra and H. Mohan
Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology Objective: Plasma cell tumours represent autonomous proliferation of plasma cells and can manifest as multiple myeloma, monoclonal gammopathy of undetermined significance, variants of plasma cell myeloma or plasmacytoma. Methods: We report 12 cases of plasma cell tumours, which were initially diagnosed as plasmacytoma on fine needle aspiration cytology (FNAC). The patients were further subjected to bone marrow examination, serum electrophoresis, urine examination for Bence–Jones proteins, and x‐ray examination of the skeleton. Results: The cytological smears from all cases were cellular and showed numerous plasma cells in varying degrees of maturity. Subsequent to investigations, five cases were labelled as multiple myeloma with secondary extramedullary plasmacytoma, three as solitary bone plasmacytoma and two as primary extramedullary plasmacytoma. In the remaining two cases, bone marrow and urine examination findings were not available, so a conclusive diagnosis of multiple myeloma or solitary plasmacytoma could not be made. Conclusion: The study highlights the role of FNAC in the diagnosis of plasma cell tumours. Subsequent work‐up and follow‐up of these patients is important to rule out the presence of multiple myeloma.     

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.     

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 ancillary techniques in diagnosing and subclassifying non-Hodgkin''s lymphomas on fine needle aspiration cytology

Non-Hodgkin's lymphomas (NHL) are tumours of the lymphoid cells. During the process of development of lymphoid cells, neoplasia may evolve at any point. Neoplastic cells usually carry the imprint of cell of origin at the stage of origin. Various types of NHL may have similar morphology with wide variation in origin, immunophenotype and other biological features. Different ancillary laboratory techniques may help to overcome the limitations of morphology in this aspect. The commonly used ancillary techniques in lymphomas are immunocytochemistry (IC), flow cytometry, Southern blot (SB) technique, polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH). In addition, laser scanning cytometry (LSC) and DNA microarray technologies are in the research phase. Various laboratory techniques are used for immunophenotyping, demonstration of monoclonality, identification of chromosomal translocation, assessment of cell kinetics and expression of mRNA in the tumour cells. Flow cytometry helps in rapid immunophenotying of NHL and it has an added advantage over IC in recognizing the co-expression of CD markers. Fine needle aspiration cytology (FNAC) combined with flow immunophenotyping may help us to diagnose and subclassify certain NHLs, such as follicular lymphoma and mantle cell lymphoma, which were previously recognized as pure morphological entities. Loss of morphology is one of the important limitations of flow cytometry. LSC can overcome this limitation by studying morphology along with the immunophenotyping pattern of individual cells. Chromosomal changes in NHL can be identified by SB, PCR and FISH. Molecular diagnosis of NHL helps in diagnosis, subclassification, prognostic assessment and even in planning of therapy. DNA microarray is a relatively newer and promising technology. It gives information about the expression of several thousands of genes in a tumour in a single experiment. In the near future, FNAC combined with ancillary techniques may play a major role in diagnosis, subclassification and management of lymphomas.     

Transbronchial fine needle aspiration cytology in the diagnosis of mediastinal/hilar sarcoidosis

OBJECTIVE: The diagnostic value of transbronchial/transtracheal fine needle aspiration (TBFNA) cytology in the patients with mediastinal and/or hilar lymphadenopathy has been investigated. METHOD: Out of 116 patients with mediastinal/hilar lymphadenopathy, the diagnosis of sarcoidosis was established in 88 (75.9%). One hundred and seventy-one TBFNAs from different lymph node stations were performed using a cytological 26-gauge needle. Adequate lymph node samples were obtained in 157 of 171 (91.8%) TBFNA and 14 of 171 (8.2%) TBFNA samples were inadequate. RESULTS: Cytological findings consistent with sarcoidosis were found in 79 of 88 (89.77%) patients and 133 of 157 (84.71%) samples. The sensitivity of TBFNA cytology in sarcoidosis presenting as mediastinal/hilar lymphadenopathy was 78.7%, specificity 92.3%. CONCLUSIONS: Overall diagnostic accuracy of TBFNA cytology in the diagnosis of sarcoidosis was 86.2%, and cytological findings consistent with sarcoidosis were the only morphological diagnosis of sarcoidosis in 63.6% of patients.