Calcium oxalate crystals in thyroid fine needle aspiration cytology

OBJECTIVE: To determine the occurrence, distribution and location of calcium oxalate crystals (COCs) in thyroid fine needle cytology specimens. STUDY DESIGN: Thyroid tissues from 60 fine needle aspiration cytology specimens (31 benign and 29 malignant lesions) were reviewed. These lesions were also histologically examined, and their pathologic diagnosis was confirmed. The cytologic slides were examined by normal and polarized light microscopy to determine their size, shape, occurrence, distribution and location. RESULTS: The size and shape of COCs varied from case to case. The total incidence was 45% (benign diseases, 68%; malignant lesions, 21%). No significant relationship between age and occurrence of COCs was found. Benign diseases showed more multifocal than focal distribution of COCs, unlike malignant diseases. Twenty-three (85%) of 27 cases with COCs revealed background location of COCs, especially within thyroid colloid. CONCLUSION: The occurrence of COCs in thyroid fine needle cytology was lower than that in histologic specimens reported in the literature, and COCs were more often identified in benign than malignant lesions. The presence of COCs may be a clue to benign lesions if their distribution is taken into consideration.     

Renal fine needle aspiration cytology

OBJECTIVE: To audit and evaluate the pitfalls in renal fine needle aspiration (FNA) cytology. STUDY DESIGN: A retrospective analysis of 180 renal FNAs from 163 patients, encountered at Canberra Hospital, Australian Capital Territory, between June 1989 and July 1997 was undertaken. The FNA procedures had been performed by radiologists under computed tomography (CT) or ultrasound (US) guidance. The study correlated the FNA results with biopsy findings and clinical outcome. RESULTS: The initial cytologic diagnoses included 84 (47%) benign, 6 (3%) atypical, 7 (4%) suspicious, 70 (39%) malignant and 13 (7%) inadequate. Six of the 13 cytologically inadequate group, on further investigation, had malignant histology. The benign cytologic categories contained 79 benign conditions and 5 cases with a malignant outcome. The atypical cytologic group contained 5 benign and 1 malignant case. All nine cytologically suspicious cases had malignant histology. The cytologically malignant group contained 62 malignant, 7 benign and 1 patient lost to follow-up. The sensitivity was 92.5%, specificity was 91.9%, positive predictive value was 89.9%, negative predictive value was 94.0%, and efficacy of the test was 92.2%. CONCLUSION: Renal FNA can provide an accurate diagnosis in most instances; however, aspiration cytology of the kidney has limitations and pitfalls. Low grade renal cell carcinoma has to be differentiated from oncocytoma, angiomyolipoma, renal infarct and reactive conditions. Renal FNA has a high negative predictive value, which is useful in reassuring patients with radiologically and cytologically benign lesions. Negative FNA does not exclude malignancy in the presence of a radiologic suspicion.     

Actinomycosis in fine needle aspiration cytology

Four cases of actinomycosis were diagnosed by fine needle aspiration (FNA) cytology and eight more cases were detected during a review of FNA smears reported as inflammatory. the age of these 12 cases ranged from 20 to 61 years with a median of 35 years. the male to female ratio was 3:1. the common regions of involvement were cervicofacial in seven cases (58.3%), thoracic in three (25.0%) and abdominal in two (16.7%). Four of the seven cervicofacial cases presented with intra-oral masses; the thoracic lesions were pulmonary in location, and the abdominal lesions presented as bowel masses. the possibility of actinomycosis was not considered clinically in any case. the main reason for missed cytodiagnosis in two thirds of the cases appeared to be observer error. It is suggested that when the aspiration smear from a mass is found to be an inflammatory exudate rich in neutrophils, special efforts must be made to look for this microorganism.     

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.     

Importance of guided fine needle aspiration cytology (FNAC) for the diagnostics of thyroid nodules - own experience

The aim of our study was to assess the accuracy and limitations of ultrasound guided fine-needle aspiration cytology (FNAC) of thyroid nodules. METHODS: The usg-FNAC results of 245 patients with thyroid nodules, who afterwards underwent thyroid surgery or who died, and autopsies were carried out, and compared retrospectively with cytologic results. Patients with malignant cytologic conclusion without histological confirmation after surgery or autopsy were excluded from the study (9 persons). The usg-FNAC results were divided as follows: group 1: diagnosis of malignancy (n = 30), group 2: suspicion of malignancy (n = 28), group 3: benign (n = 126), group 4: inconclusive (n = 29). RESULTS: Assuming the cytologic results of group 1 and group 2 were interpreted as being malignant and those of group 3 as being benign, the sensitivity, specificity and accuracy of usg-FNAC were 90 %, 85 % and 86 % respectively. Comparing the cytologic conclusions between a group of patients with follicular lesions and a subgroup of other lesions a statistically significant difference (p < 0,01) between both subgroups using Fisher's test was found. Sensitivity, specificity and diagnostic accuracy in subgroup of follicular lesions were low (71 %, 63 %, 67 %), while in the subgroup of other lesions were high (94 %, 86 %, 88 %). FNAC can specify the nature of focal lesion with high sensitivity, specificity and diagnostic accuracy in the cases of non-follicular lesions. Histological evaluation is required to specification of the nature in cases in which cytology is indicative of follicular proliferation.     

Endoscopic ultrasound-guided fine needle aspiration of the pancreas. Diagnostic utility and accuracy

OBJECTIVE: Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) is regarded as a safe and reliable procedure for diagnosing and staging of pancreatic neoplasms. This study retrospectively evaluated both the diagnostic utility and accuracy of pancreatic EUS-FNABs and potential cytologic pitfalls when using Diff-Quik stain for on-site evaluation. STUDY DESIGN: Pancreatic EUS-FNABs performed between 1995 and 1998 were identified from the files of the Department of Pathology. All patients were studied via a linear-array ultrasound endoscope with an FNAB device. Immediate evaluation of the specimen by a pathologist using air-dried slides and Diff-Quik stain was done on all cases. An average of five passes (range, three to nine) were performed. Five cytologic categories were identified: nondiagnostic, benign, atypical, suspicious and malignant. EUS disease staging, histologic correlation and clinical follow-up were reviewed. RESULTS: Sixty-nine consecutive pancreative FNABs were evaluated in the study period. The patients comprised 38 females and 31 males with a mean age of 65 years (range, 36-83). Histologic correlation was available on 40 patients, and follow-up was available on the remaining 29. The cytologic diagnoses included: 31 malignant, 8 suspicious, 6 atypical, 20 benign and 4 nondiagnostic. Forty-three cases were true positive, 9 were true negative, 2 were false positive, and 11 were false negative. The overall sensitivity was 80% and specificity was 82%. CONCLUSION: The study showed that cytologic evaluation of pancreatic EUS-FNABs has 80% sensitivity and 82% specificity. False negative diagnosis was usually due to sampling error. A nondiagnostic cytologic diagnosis should be rendered in the absence of adequate sampling of a lesion. On-site cytologic evaluation of EUS-FNABs aids in guaranteeing specimen adequacy, and the pathologist should be trained to evaluate Diff-Quik-stained samples.     

Diagnostic pitfalls in the evaluation of fine needle aspiration cytology of the thyroid: correlation with histopathology in 260 cases

Objectives:  Fine needle aspiration cytology (FNAC) of the thyroid is a non-invasive, cost-effective screening procedure that is valuable for distinguishing neoplastic lesions from non-neoplastic nodules. The aim of this study was to determine the diagnostic accuracy of FNACs performed at our institution by correlating FNAC results with histopathological diagnoses.
Methods:  Two hundred and seventy-one aspiration cytology specimens followed by thyroidectomy were included in the study, and the results of 260 adequate FNACs were compared with their histological diagnoses.
Results:  The sensitivity and specificity of thyroid FNAC for detecting neoplasia were 92.6% and 91.6%, respectively. There were 15 (5.7%) false positives and six (2.3%) false negatives.
Conclusions:  The results showed that follicular cells that exhibit some of the features of papillary carcinoma could be observed in a cytology slide of Hashimoto's thyroiditis, leading to a diagnostic pitfall. In addition, cellularity and overlapping cytological criteria in hyperplasia might lead to a false diagnosis.     

Osteoclastomalike anaplastic carcinoma of the thyroid. Diagnosis by fine needle aspiration cytology

Fine needle aspiration (FNA) of a neck mass yielded cytologic specimens containing two cell populations: multinucleated giant cells and smaller, round-to-oval, undifferentiated malignant cells. The giant cells were frequently so numerous as to obscure the other cells. The FNA cytodiagnosis of a rare anaplastic thyroid carcinoma containing osteoclastic giant cells was substantiated by the subsequent exploratory surgery and biopsy specimen. Immunohistochemical staining suggested a dual origin of the two cell populations.     

Follicular variant of papillary thyroid carcinoma: diagnostic limitations of fine needle aspiration cytology

OBJECTIVE: To study the diagnostic sensitivity and specificity of fine needle aspiration cytology (FNAC) offollicular variant of papillary thyroid carcinoma (FVPTC). STUDY DESIGN: The study group consisted of 390 papillary thyroid carcinoma (PTC) cases diagnosed histologically with thyroidectomy specimens. The FNAC and histopathologic classification were compared in terms of the appearance of FVPTC and non-FVPTC statistically with the chi squared test. Also, several features of the cytologic smears of FVPTC were reviewed. RESULTS: Twelve of the 390 PTC cases were classified as FVPTC histologically. Five of the 12 cases were also reported as FVPTC in the diagnosis by FNAC and the other 7 as the usual type of PTC (UTPTC). There was 1 case classified as UVPTC histologically but FVPTC cytologically. If we use histologic diagnosis as the gold standard, the sensitivity and specificity of FNAC diagnosis of FVPTC were 42% and 83%, respectively. CONCLUSION: FNAC may be a good tool for diagnosing PTC, but it is unreliable to differentiate between FVPTC and UTPTC.     

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.     

Diagnostic associations of p53 immunostaining in fine needle aspiration cytology of the breast

Duplicate cytospin preparations were made from 46 symptomatic breast fine needle aspirates. One of each pair was assigned to benign or malignant categories by one experienced observer as part of the 'triple approach'patient assessment. the other was immunostained with DO7, a monoclonal antibody to recombinant p53 protein, and rated by another observer as positive or negative for nuclear staining, unaware of the cytodiagnosis. Positive controls included carcinomas known to have mutant p53, while negative controls were of the reagent substitution type. of the 26 aspirates with a benign cytodiagnosis (verified by the triple approach), 23 were p53 protein-negative and three positive. of the 20 with a malignant cytodiagnosis (histologically confirmed), six were p53 protein-negative and 14 positive (exact P <0.0001). As a diagnostic test this would give 70% sensitivity and 88% specificity.     

Diagnostic efficacy of immunocytochemistry on fine needle aspiration biopsies processed by thin-layer cytology

OBJECTIVE: To evaluate the efficacy of immunocytochemistry (ICC) performed on smears processed by thin-layer cytology (TLC). STUDY DESIGN: During the period January 2001-September 2003, 3,573 consecutive fine needle aspiration biopsies were processed with both conventional smears (CSs) and TLC diagnosed by a single pathologist; 113 required immunocytochemical study. CSs were fixed in ethanol whereas TLC slides were processed with the ThinPrep 2000 method (Cytyc Co., Marlborough, Massachusetts, U.S.A); both were stained with Papanicolaou stain. ICC staining was carried out on only TLC slides. RESULTS: The 113 cytologic cases were grouped as follows: 32 thyroid nodules with 16 histologic controls (HCs), 24 lymph nodes (regardless of location) with 15 HCs, 18 liver and pancreatic lesions (3 HCs), 11 lung nodules (6 HCs), 5 kidney and adrenal gland lesions (1 HC), 6 abdominal (2 HCs) and 4 mediastinal masses (1 HC), 6 salivary gland tumors (3 HCs), 4 bone masses (2 HCs) and 3 subcutaneous lesions (1 HC). ICC contributed to the diagnosis in 104 cases (92%), whereas it was inconclusive in 9. The cytologic diagnoses were histologically confirmed in 46 of 50 cases (92%). CONCLUSION: ICC can be successfully applied on TLC slides with better results than on CSs, and its yield can be useful in making the correct diagnosis on fine needle aspiration biopsy.     

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.