Fine needle aspiration cytology of medullary thyroid carcinoma: a review of 18 cases

A series of 18 consecutive medullary thyroid carcinomas (MTC) diagnosed by fine needle aspiration cytology (FNAC) is described. The most important diagnostic cytologic criteria were the dispersed cell pattern, the polygonal appearance of the cells, binucleated cells and the presence of amyloid. Other less common cytologic features are reported and the variable microscopic appearance of MTC is pointed out. The possibility that this cytologic variability of MTC may be by itself an important diagnostic feature is proposed.     

Fine needle aspiration cytology of medullary carcinoma of the thyroid with a focus on rare variants: a review of 78 cases

S. Kaushal, V. K. Iyer, S. R. Mathur and R. Ray
Fine needle aspiration cytology of medullary carcinoma of the thyroid with a focus on rare variants: a review of 78 cases Background: The cytological features of variants of medullary carcinoma of the thyroid (MCT) are sparsely documented in the literature from case reports. Detailed cytomorphological analysis of MCT variants and features helping to distinguish them from usual MCT are presented here. Materials and methods: A total of 78 aspirates with a diagnosis of MCT over a period of 10 years were re‐evaluated. Cytomorphological details were reviewed and semiquantitatively analysed. Histology slides were reviewed in 36 cases. Results: Most aspirates showed classical features of dispersed polygonal or plasmacytoid cells with areas of spindling. In 54 aspirates, a definite cytological diagnosis of medullary carcinoma was made, which in 87.1% was based on cytomorphology alone and in 12.9% was based on immunocytochemistry for calcitonin. In 30.1% of aspirates from MCT, a guarded report of tumour was given in the absence of calcitonin immunocytochemistry. Of the 78 cases, nuclear grooves were seen in 5.1%, intranuclear cytoplasmic inclusions in 28.2%, cytoplasmic granularity in 23.1% and bizarre cells with abrupt anisocytosis in 85.9%. A follicular arrangement was seen in 14.1% and was more frequent in the follicular type (one case) and mixed follicular and medullary carcinoma (one case). Melanin production was seen in aspirates from two cases. One case of the giant cell type of MCT was seen, in which background cells showed large pleomorphic nuclei and numerous bizarre tumour giant cells, prompting a differential diagnosis with anaplastic carcinoma. One example each of the small cell type, paraganglioma‐like MCT and papillary MCT were seen. Conclusions: MCT has uniform cytological features in the majority of aspirates, including many of the histological variants. Searching for pigment in every aspirate of MCT may be rewarding. The giant cell type of MCT is rare and has to be differentiated from anaplastic carcinoma.     

Evaluation of fine needle aspiration (FNA) cytology in the diagnosis of thyroid nodules

FNA cytology of 112 patients with thyroid nodules seen in a 5-year period in a general hospital setting, and the histology obtained from the 53 operated patients, were retrospectively analysed. the inadequacy rate of FNA cytology was 11%, sensitivity was 84% (16/19), specificity was 52% (15/29), positive predictive value was 53% (16/30) and negative predictive value was 83% (15/18). Extrapolating these figures to the whole study group a negative predictive value of 95% is put forward as a more realistic figure. the results and the clinical pitfalls of the use of FNA cytology in diagnosing thyroid nodules are discussed. the authors conclude that FNA cytology is a reliable first diagnostic step in the diagnosis of thyroid nodules, even in a general hospital setting.     

The role of thyroid fine needle aspiration (FNA) cytology in a district general hospital setting

The pilot study was undertaken to evaluate the role of FNA cytology in the clinical management of patients with thyroid swelling, in a District General Hospital (DGH) setting. One hundred and eleven patients were investigated over a period of 3 years, with a total of 142 fine needle aspirations. Statistical analysis showed a sensitivity of 71%, a specificity of 91% and a false negative rate of 2.7%. These results compare very favourably with other institutions. This study therefore shows that thyroid nodule FNA cytology can be performed in a DGH with a high standard of diagnostic accuracy, the results of which play a key role in patient management.     

Effect of ultrasound transmission gel on ultrasound‐guided fine needle aspiration cytological specimens of thyroid

A. Lalzad, D. Ristitsch, W. Downey, A. F. Little and M. E. Schneider‐Kolsky
Effect of ultrasound transmission gel on ultrasound‐guided fine needle aspiration cytological specimens of thyroid Objective: To investigate prospectively the diagnostic impact of ultrasound coupling gel on thyroid specimens obtained under ultrasound guidance. Methods: Patients presenting for ultrasound‐guided fine needle aspiration (USG‐FNA) of the thyroid were invited to participate in the study. Four specimens per nodule were collected: two using chlorhexdine wash and two using sterile, colourless ultrasound gel as couplant according to routine protocol. All slides were analysed in a blinded fashion by two senior cytologists for the presence or absence of ultrasound gel‐induced artefacts. The presence of gel‐induced artefacts between the two groups was analyzed using Pearson’s chi‐square test. Kappa statistics were used to measure the inter‐rater agreement between the cytologists. Results: Twenty thyroid nodules comprising 80 specimen slides were collected. On slides collected with gel, cytological artefacts were detected in 60–65% of cases compared with 10–15% of cases without gel (P < 0.001). The inter‐rater agreement between the two observers was very good (κ = 0.84). Two of the 14 patients required repeat FNA due to non‐diagnostic cytology results caused by inadequate sampling and gel‐induced artefacts. Conclusions: Clinical cytopathologists, radiologists and sonographers should be aware of the potential for ultrasound gel to cause significant artefacts on cytological specimens. Our findings suggest that staff involved in USG‐FNA cytology should remove the gel carefully before taking the aspirate.     

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.     

Initial axillary staging of breast cancer using ultrasound‐guided fine needle aspiration: a liquid‐based cytology study

A. Schiettecatte, C. Bourgain, C. Breucq, N. Buls, V. De Wilde and J. de Mey
Initial axillary staging of breast cancer using ultrasound‐guided fine needle aspiration: a liquid‐based cytology study Objective: To evaluate the preoperative detection of axillary metastasis combining ultrasound (US)‐guided fine needle aspiration cytology (FNAC) and liquid‐based cytology (Surepath^®) to reduce sentinel node procedures. Methods: In total, 148 patients with clinically negative lymph nodes and no preoperative therapy were included. All patients underwent preoperative ultrasound of the axilla with FNAC if suspicious lymph nodes were found. Complete axillary lymph node dissection was performed at primary surgery when FNAC was positive. All other patients underwent a sentinel node procedure. Results: US‐guided FNAC of the axilla revealed metastasis in 34 (23.0%) of the 148 patients. These 34 patients were 53.1% of all patients (n = 64) with proven axillary lymph node involvement. In 66 patients (44.6%), both ultrasound and histopathology were negative. Overall sensitivity of US‐guided FNAC was 50.0%, specificity 100%, positive predictive value 100% and negative predictive value 70.2%. In T1 tumours, all patients referred for sentinel node procedure were node‐negative. The correlation between malignant FNAC and histopathology was 100%. US‐guided liquid‐based FNAC in patients with no clinically positive lymph nodes reduced the necessity for a sentinel node procedure by 23.0%. Conclusions: We advocate that US‐guided fine needle aspiration (FNA) combined with liquid‐based cytology of axillary lymph nodes should be included in the preoperative staging of breast cancer.     

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.     

Follow‐up of atypia and follicular lesions of undetermined significance in thyroid fine needle aspiration cytology

N. Dincer, S. Balci, A. Yazgan, G. Guney, R. Ersoy, B. Cakir and G. Guler
Follow‐up of atypia and follicular lesions of undetermined significance in thyroid fine needle aspiration cytology Objective: To report our experience of atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS) rate and outcome. Methods: Among 7658 patients with 19 569 nodules, 524 (2.7%) nodules were diagnosed as AUS/FLUS on fine needle aspiration (FNA). After exclusion of patients with simultaneous nodules that were suspicious for follicular neoplasm or malignancy or that were malignant, 368 (4.8%) patients were diagnosed as AUS/FLUS. The outcome of 146 patients who had undergone surgery or repeated fine needle aspirate at the time of preparation of this study was evaluated. The original FNAs were matched to repeated FNAs and thyroidectomy or diagnostic lobectomy specimens. Results: Seventy‐two (19.6%) of the 368 patients had directly undergone surgery, either a lobectomy or a thyroidectomy: of these, 27 (37.5%) had neoplastic nodules (21 were malignant). Seventy‐four (20.1%) of the 368 patients had repeat FNA. On second FNA, 47 of 74 (63.5%) were benign, three were suspicious for follicular neoplasm, one was malignant and 23 (31.1%) were non‐diagnostic. Four patients had a third FNA: two were AUS/FLUS, one was malignant and one non‐diagnostic. One patient had a fourth FNA, which was diagnosed as AUS/FLUS. Sixteen (21.6%) of 74 patients with repeat FNA had surgery: three of these had neoplastic nodules (two were malignant). Overall, 88 of the 368 (23.9%) patients had a thyroidectomy of which 30 (34.1%) were neoplastic and 23 (26.1%) malignant. The neoplastic rate for patients who were once diagnosed with AUS/FLUS was 8.2% and the malignancy rate 6.3%. The malignancy rate for patients on follow‐up at the time we prepared the study was 15.7% (23/146); 222 remained on follow‐up without surgery or repeat FNA or were managed elsewhere. Conclusions: Although in this category repeat FNA is expected rather than excision, we suggest evaluation of all AUS/FLUS patients in multidisciplinary meetings to decide management and recommend follow‐up of all patients with this diagnosis.     

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.     

Inter- and intraobserver reproducibility of thyroid fine needle aspiration cytology: an analysis of discrepant cases

OBJECTIVE: To determine the inter- and intraobserver reproducibility and analyse the discrepant cases of fine needle aspiration cytology (FNAC) of the thyroid. METHODS: Cases of thyroid FNAC with a corresponding histological diagnosis were reviewed regarding the original cytological diagnoses by two observers. The final cytological diagnoses (FCD) included both concordant and consensus diagnoses. The inter- and intraobserver reproducibility and efficacy of thyroid FNAC were calculated based on the FCD. RESULTS: A total of 97 FNAC cases with corresponding histopathological specimens were analysed. Although inter- and intraobserver disagreement in the cytological diagnoses occurred in about one-quarter of the cases analysed (24.7% and 23.7%, respectively), a substantial level of diagnostic interobserver (kappa = 0.71) and intraobserver (kappa = 0.66) reproducibility was observed. The efficacy of the method was 94.4%. Disagreement in the diagnosis was detected in 24 cases (24.7%), most of them (41.7%) for follicular lesions. Discordant cytological diagnoses between the two observers were represented by six (16.2%) of the 37 cases with an FCD of colloid nodule, five (41.7%) of the 12 cases of cellular follicular lesion, all three cases of follicular neoplasm, in two (6.3%) of the 32 cases of PTC, one (16.7%) of six cases of follicular neoplasm with a predominance of Hürthle cells and in one case of poorly differentiated neoplasia. Similarly, major disagreement in intraobserver cytological diagnoses was observed for the diagnosis of follicular lesions: 18 (78.3%) of a total of 23 discordant cases. CONCLUSION: As discrepancies in the cytopathological diagnosis can have repercussions in the management of patients, all cases with a cytological diagnosis of follicular lesions/neoplams should be reviewed in multidisciplinary meetings thus minimizing interobserver variability.