Split sample comparison of ThinPrep and conventional smears in endoscopic retrograde cholangiopancreatography-guided pancreatic fine-needle aspirations

Fine-needle aspiration (FNA) of pancreatic lesions is a common procedure to establish a tissue diagnosis before chemotherapy or surgery. In this study, the authors attempt to compare the diagnostic value of the ThinPrep (TP) method with conventional smears (CSs) in samples obtained by endoscopic retrograde cholangiopancreatography (ERCP)-guided pancreatic FNAs. Material obtained, prospectively, from ERCP-guided pancreatic FNAs was split to prepare CSs (2-5 slides) first, the remainder being rinsed in PreservCyte, and in the laboratory, 1 TP slide was prepared. The diagnostic categories of unsatisfactory, benign, reactive, suspicious for malignancy, and malignant were compared. Fifty-one pancreatic FNAs prepared by split sample method yielded the following results: TP yielded unsatisfactory, 6 cases; benign, 3 cases; reactive, 5 cases; suspicious for malignancy, 11 cases; and malignant, 26 cases; in contrast, CS yielded unsatisfactory, 13 cases; benign, 4 cases; reactive, 3 cases; suspicious for malignancy, 13 cases; and malignant, 18 cases. Histological follow-up was available in 21 cases (reactive, 8 cases; suspicious for malignancy, 1 case, and malignant, 12 cases). The foregoing data indicate a higher sensitivity in detection of pancreatic adenocarcinoma by the TP method (TP, 91% vs. 58% CS) with equivalent specificity (100%). In addition, TP provides better preservation and cytological detail.     

Diagnostic value of telomerase expression in breast fine-needle aspiration biopsies

Fine-needle aspiration biopsy (FNAB) of breast is a minimally invasive sampling procedure with a proven value in the initial evaluation of patients with palpable breast lesions. FNAB is a simple, cost-effective, and relatively nontraumatic procedure that has replaced open surgical biopsy in majority of academic institutions across the world. There are, however, inherent limitations in the ability of FNAB to reliably diagnose small percentage of cases that are difficult to diagnose by cytomorphology alone and require excisional biopsy. This shortcoming may be minimized if the morphology can be complemented by a reliable diagnostic adjunct. This retrospective study was designed to assess the added value of telomerase immunostain in interpretation of breast FNABs. Telomerase is a ribonucleoprotein enzyme that has been shown to be activated in different malignant tumors, including breast cancer. Immunocytochemical detection of this molecular marker on cytologic smears and cellblocks may be helpful for interpretation of FNAB specimens. In our retrospective study, we found that 56% of the malignant breast cases (28/50) showed positive telomerase immunostaining while only 4% of the negative cases (2/50) stained with telomerase (positive predictive value: 93%, negative predictive value: 69%). Expression of telomerase on highly suspicious breast fine-needle aspirations may upgrade the diagnosis to malignancy. However, a negative telomerase cannot exclude the possibility of carcinoma.     

Routine use of ThinPrep method in fine-needle aspiration material as an adjunct to standard smears

The purpose of this study was to evaluate the efficacy of routine use of ThinPrep® in fine‐needle aspiration (FNA) material as an adjunct to standard smears. We reviewed 50 consecutive, satisfactory‐for‐evaluation FNA materials in which ThinPrep® slides were obtained. In each case, Diff‐Quik‐stained and Papanicolaou‐stained smears were initially prepared, and the ThinPrep® slide was made from the needle/syringe rinse. Smears and ThinPrep® slides were evaluated for the presence of diagnostic material. In addition, the following questions were addressed: could the final diagnosis be made based on smears only, and did the ThinPrep® method add any additional information to the diagnosis? Smears were satisfactory for evaluation in 49/50 cases, and in one case diagnostic material was present on the ThinPrep® slide only. Thirty‐two out of 50 ThinPrep® slides contained material sufficient for evaluation. In 46/50 (92%) cases, final diagnoses could be made based on smears only. In 2 cases, ThinPrep® slides showed additional diagnostic material, and in another 2 cases were critical for the diagnosis. The routine use of ThinPrep® as an adjunct preparatory method to FNA material is not justified, and is associated with an additional, potentially nonreimbursable cost. Diagn. Cytopathol. 2001;25:101–103. © 2001 Wiley‐Liss, Inc.     

Stromal infiltration as a predictor of tumor invasion in breast fine-needle aspiration biopsy

Clinical management of in situ carcinoma of the breast is different from invasive carcinomas. Thus, it is important to find cytomorphologic criteria to distinguish between these two entities. The current study is designed to assess whether, by applying strict cytologic criteria, the status of stromal invasion can be predicted. In this retrospective study, 223 consecutive nonpalpable tumors sampled by ultrasound-guided breast fine-needle aspirates with diagnosis of in situ and invasive carcinoma with histologic follow-up evaluation were retrieved. Ten cytologic parameters were evaluated, which included cellular clustering, eosinophilic differentiation, necrosis, tubular structures, dirty background, nuclear anisonucleosis, cellular pleomorphism, cribriform pattern, tubular structures, and stromal infiltration. Among all the parameters examined, stromal infiltration was the most powerful predictor of status of invasion. Stromal infiltration was significantly higher in invasive (88%) than in situ (11%), P < 0.0001. In contrast, cribriform pattern (16% vs 36%) and necrosis (19% vs 59%) were more frequently seen in situ than in invasive carcinomas with P-values of 0.0008 and <0.0001, respectively. This study demonstrates that stromal infiltration defined by strict criteria may predict the status of tumor invasion in breast fine-needle aspirates. The combination of stromal infiltration and cribriform pattern and necrosis in aspirates may provide an opportunity in introducing a "predictive index" to differentiate between an in situ versus an invasive process.     

Sclerosing lobular hyperplasia of the breast: fine-needle aspiration cytology findings--a case report

Sclerosing lobular hyperplasia (SLH) is an uncommon benign lesion seen in the juvenile breast. It presents as a palpable, firm, circumscribed nodular lump in the breast of a young woman. Histologically, it is characterised by prominent lobular hyperplasia and sclerosis of the intralobular connective tissue. We discuss the cytomorphology and differential diagnosis. A 16-yr-old female patient presented with a painless, firm, nodular, mobile mass in the right breast measuring 4 x 4 cm. The clinical and radiological diagnosis was fibroadenoma. Fine-needle aspiration smears showed round to oval ductal epithelial cells in flat sheets and round clusters with an acinar arrangement. A few bare nuclei were seen dispersed in a clean background but no stroma was visualised. A combination of clinical findings, imaging, and cytological features of SLH can help to differentiate this condition from other palpable juvenile breast diseases.     

Plasmablastic lymphoma involving breast: a case diagnosed by fine-needle aspiration and core needle biopsy

Plasmablastic lymphoma (PBL) is a rare lymphoma originating from B-cells with terminal differentiation. Most common anatomic site involved by PBL is the oral cavity. Involvement of other body sites has only rarely been reported. Herein, we report a rare case of EBV-negative PBL involving the breast of an HIV positive 47-year-old woman. The patient presented with decreased vision and photophobia. During physical examination, she was found to have bilateral breast masses and multiple lymphadenopathy. Fine-needle aspiration of one of the breast masses showed large malignant cells with plasmacytoid features. Immunohistochemical studies performed on the core biopsy showed that the tumor cells were positive for common leukocyte antigen CD45 and plasma cell marker CD138, but negative for the pan-B cell markers CD20 and CD79a. Molecular genetic studies showed clonal rearrangement of the immunoglobulin kappa light chain gene. This is the first case of PBL involving the breast reported in English cytological literature.     

A comparative analysis of core needle biopsy and fine-needle aspiration cytology in the evaluation of palpable and mammographically detected suspicious breast lesions

The present study was undertaken to compare the efficacy of needle core biopsy (NCB) of the breast with fine-needle aspiration cytology (FNAC) in breast lesions (palpable and non-palpable) in the Indian set-up, along with the assessment of tumor grading with both the techniques. Fifty patients with suspicious breast lesions were subjected to simultaneous FNAC and ultrasound-guided NCB following an initial mammographic evaluation. Cases were categorized into benign, benign with atypia, suspicious and malignant groups. In cases of infiltrating duct carcinomas, grading was performed on cytological smears as well as on NCB specimens. Both the techniques were compared, and findings were correlated with radiological and excision findings. Out of 50 cases, 18 were found to be benign and 32 malignant on final pathological diagnosis. Maximum number of patients with benign diagnosis was in the fourth decade (42.11%) and malignant diagnosis in the fourth as well as fifth decade (35.48% each). Sensitivity and specificity of mammography for the diagnosis of malignancy was 84.37% and 83.33%, respectively. Sensitivity and specificity of FNAC for malignant diagnosis was 78.15% and 94.44%, respectively, and of NCB was 96.5% and 100%, respectively. But NCB had a slightly higher specimen inadequacy rate (8%). NCB improved diagnostic categorization over FNAC by 18%. Tumor grading in cases of IDC showed high concordance rate between NCB and subsequent excision biopsy (94.44%) but low concordance rate between NCB and FNAC (59.1%). NCB is superior to FNAC in the diagnosis of breast lesions in terms of sensitivity, specificity, correct histological categorization of the lesions as well as tumor grading.     

How stereotactic core-needle biopsy affected breast fine-needle aspiration utilization: an 11-year institutional review

To determine the effect of stereotactic core-needle biopsy (SCNB) on the utilization of breast fine-needle aspirate (FNA) biopsy, we retrospectively reviewed 1,568 cases of breast FNAs that were obtained from 1,188 patients between the years 1990 and 2000. There were 378 positive and atypical cases and 497 negative and unsatisfactory cases in the pre-SCNB group (between 1990 and 1996; 7 years); and 225 positive and atypical cases and 468 negative and unsatisfactory cases in the post-SCNB group (between 1997 and 2000; 4 years). The average number of cases per year in the pre- and post-SCNB groups was 125 and 173, respectively. While the average positive/atypical cases per year in both groups remained relatively constant, the average negative/unsatisfactory cases per year were significantly increased in the post-SCNB group (117 in the post-SCNB vs. 71 in the pre-SCNB). The increase in this group was due to a true increase in the negative diagnoses, since unsatisfactory rate decreased in the post-SCNB group (12.6% in the post-SCNB vs. 9.3% in the pre-SCNB). The sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 79%, 92%, and 82% in the pre-SCNB group and 93%, 86%, 91%, and 90% for the post-SCNB group, respectively. In conclusion, the implementation of SCNB did not result in a decrease in the total number of breast FNAs; however, the distribution of cases changed. FNA is increasingly used to complete the triple test in clinically and radiographically negative cases.     

A retrospective study of the diagnostic accuracy of fine-needle aspiration for breast lesions and implications for future use

In recent years, the use of fine-needle aspiration (FNA) in the diagnosis of breast lesions has declined in many institutions. We sought to evaluate the role of FNA for breast lesions and the annual rate of the procedure at our institution over a 4(1/2) year period (May 2002-October 2006). A total of 831 FNAs were performed, with 258 (31%) having histologic follow-up. The number of FNAs obtained was 159 from 5/02 to 4/03, 192 from 5/03 to 4/04, 194 from 5/04 to 4/05, 191 from 5/05 to 4/06, and 95 from 5/06 to 10/06. Each case was placed into one of four categories: nondiagnostic (9%), benign (77.5%), atypical/suspicious (5.5%), or malignant (8%). Surgical tissue was available for 37% of nondiagnostic cases, 22% of benign cases, 80% of atypical/suspicious cases, and 72% of malignant cases. The overall sensitivity and specificity for FNA was 83 and 92% respectively. The overall positive and negative predictive values were 83 and 92% respectively. There were no false-positive cases, indicating a positive predictive value of 100% for a Dx of malignancy. For cases with surgical follow-up, the false-negative rate was 5.4%. Although there is a national trend away from FNAs of breast lesion, this has not been the experience at our institution. Although FNA may not be ideal in the initial evaluation of suspicious lesions, we argue that FNA for clinically benign palpable lesions and recurrent carcinomas has significant value.     

Primary pure squamous cell carcinoma of the breast diagnosed by fine-needle aspiration cytology: a case study using liquid-based cytology

Pure primary squamous cell carcinoma (SCC) is an extremely rare type of breast tumor. We report one of such cases in a 32-year-old woman, diagnosed by fine-needle aspiration cytology (FNAC). Aspiration smears were characterized by squamous cells, both isolated and in aggregates, at various stages of maturation. The tumor was excised, and the histologic sections confirmed the cytologic diagnosis. Pure primary SCC of the breast has a distinctive cytomorphologic appearance, and diagnosis of this tumor by FNAC is possible. For its diagnosis, the exclusion of SCC of local cutaneous structures and metastasis of distant squamous carcinoma are mandatory.     

Immunocytochemical evaluation of HER-2/neu on fine-needle aspirates from primary breast carcinomas

Detection of HER-2/neu alterations is increasingly used in breast cancer patients for therapeutic purposes. This study examines the reliability of HER-2/neu immunocytochemical assessment on 66 cytospin smears obtained by fine-needle aspiration biopsy from breast cancer patients. Results were compared with those obtained by both fluorescence in situ hybridization (FISH) on fine-needle aspirate (FNA) and immunohistochemistry (IHC) on matched histologic section. Concordance between immunocytochemistry (ICC) and FISH was 78% and between ICC and IHC was 84%. Discordance mainly concerned seven unamplified cases that resulted positive by ICC and four cases scored negative by IHC but positive by ICC. Simultaneous assessment of HER-2/neu by ICC, IHC, and FISH was available in 24 cases; the concordance was 75%. In this study, the false positivity of immunocytochemical technique represents the major criticism. In our experience, FISH remains the most objective and powerful technique for HER-2/neu assessment on breast cancer FNAs.     

Metaplastic breast carcinoma on fine-needle cytology samples: a report of three cases

Metaplastic breast carcinoma (MBC) may have a varied presentation on fine-needle cytology samples. We herewith describe three cases of MBC found in our series. One of these cases showed a peculiar mixture of malignant ductal, apocrine type, and squamous epithelial cells with fascicles of spindle cells with variable degree of atypia and was diagnosed as metaplastic carcinoma of the carcino-sarcomatous type. The other two lesions were characterized by an abundant chondroid extracellular matrix to which were variably admixed carcinomatous and chondroid-type cells, with variable degree of atypia. Both these latter cases were defined as matrix-producing metaplastic carcinomas. Because of the various presentation of MBC on fine-needle cytology samples and the possible influence of needle "sampling" on the cytological specimen, the spectrum of differential diagnoses to be considered may encompass a number of benign and malignant entities, like keratinous subareolar cysts, malignant fibroepithelial lesions with myxo-chondroid stroma, and true sarcomas of the breast, with cartilaginous metaplasia. It is the Authors' feeling that, with optimal samples, the cytomorphological findings of this rare variant of breast carcinoma permit its accurate pre-operative diagnosis.     

Effectiveness of fine-needle aspiration cytology of breast: analysis of 2,375 cases from northern Thailand

At the Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand, 2,375 cases of breast lesions were sampled by fine-needle aspiration (FNA) from 1994-1999. Cytologic diagnoses were: benign (48%), suspicious for malignancy (5%), malignant (15%), and unsatisfactory (32%). Comparison with histology was possible in 721 cases. The diagnoses obtained by FNA showed a sensitivity of 84.4%, specificity of 99.5%, positive predictive value of 99.8%, negative predictive value of 84.3%, false-negative rate of 16.7%, false-positive rate of 0.5%, and overall diagnostic accuracy of 91.3%. We conclude that, in experienced hands, FNA of breast masses is reliable for diagnosis. Assessment of samples at the time of aspiration can reduce the number of inadequate specimens to near zero. Correlation of FNA results with clinical and radiologic findings can identify false-negatives and false-positives, ensuring optimal patient management. Many centers now recommend needle core biopsy instead of FNA. For regions such as ours, the added cost of this test would make it unavailable to many patients, which could delay a diagnosis of breast cancer. We advocate keeping FNA as a first-line diagnostic procedure, at least in areas under economic restrictions, in order to maximize the availability of health care to women with breast disease.     

Aggressive papillary male breast carcinoma on fine-needle cytology sample

Papillary carcinoma (PC) is a histological variant of breast carcinoma that is more frequently observed in males than in females, showing the same cytological features in both sexes. PC is characterized by a low grade of malignancy and a generally favorable course. We describe a case of male breast PC (MPC) diagnosed by fine-needle cytology (FNC) in which some aggressive morphologically detectable features were associated with bland cytologic features of the tumor. FNC was performed on a 3 cm palpable mass of the left breast of a 55-yr-old male. FNC yielded abundant bloody material. Two smears were Diff-Quik and Papanicolaou stained, others were used for immunocytochemical assessment of estrogen, progesterone, c-erbB-2, and Ki-67; another was Feulgen stained for DNA ploidy. Smears were highly cellular, showing isolated cells and papillary structures. Cells showed tall and well-defined cytoplasm with a columnar aspect, light anisonucleosis, coarse chromatin, and small nucleoli. Immunoperoxidase staining demonstrated positivity for estrogen (50%), negativity for progesterone, intense positivity for c-erbB-2, with specific membrane staining and positivity for Ki-67 in more than 20% of the cells. DNA-ploidy showed an aneuploid histogram with 5c exceeding rate (5cER) of 59% and 2c deviation index (2cDI) of 29%. Subsequent surgical pathology examination confirmed the cytological diagnosis of papillary carcinoma; moreover, it revealed neoplastic endolymphatic thrombi and infiltrative border of the tumor that reached the thoracic wall. Cytological features can suggest diagnosis of MPC on FNC samples. Immunocytochemical evaluation of c-erbB-2 and Ki-67 and DNA ploidy evaluation on cytological smears might reveal a biological aggressiveness of PC despite the bland microscopic features of the tumor and this should influence the therapeutic procedure.     

Fine-needle aspiration cytology of extramammary neoplasms metastatic to the breast

Fine-needle aspiration (FNA) biopsy is the first-line investigation in any breast lump and hence cytomorphological recognition of nonmammary metastatic tumors to the breast and their distinction from primary tumors is important.Metastatic breast neoplasms diagnosed over a 6-yr period from 1997 to 2002 were retrieved from the database of the Department of Cytopathology and the clinical, cytopathological, histochemical, and immunohistochemical findings were correlated with the histopathology of the primary tumor.Fifteen cases of metastatic breast neoplasms were encountered constituting 1.47% of all malignant tumors of the breast diagnosed on FNA. There were 14 female patients and one male patient aged 13-80 yr. The preaspiration clinical diagnosis was either a benign breast lump or a malignancy (primary vs. metastatic). The breast lump was the initial presentation in four cases and the cytodiagnosis of a metastatic malignancy lead to the subsequent detection of the primary malignancy. These included one case each of melanoma, myeloma, rhabdomyosarcoma, and small-cell carcinoma of the lung. There were five pediatric cases that included four cases of rhabdomyosarcoma and one case of leukemic deposit. The adult cases included two cases each of melanoma, small-cell carcinoma, and myeloma; one case of choriocarcinoma; and three cases of soft-tissue sarcomas. These included two cases of malignant fibrous histiocytoma (MFH) and one case of leiomyosarcoma.The presence of unusual cytomorphological patterns on breast FNA should alert the cytopathologist to the possibility of a metastatic breast neoplasm, even if not suspected clinically. A detailed history of the patient, clinical correlation, and immunocytochemistry helps in establishing an accurate diagnosis, which avoids unnecessary surgery and ensures appropriate treatment.     

Interobserver variability in the classification of proliferative breast lesions by fine-needle aspiration: Results of the Papanicolaou Society of Cytopathology study

This study evaluates the applicability of the published cytologic criteria in the categorization of proliferative breast lesions by assessing the diagnostic accuracy and interobserver reproducibility of a panel of experts. Twelve breast fine-needle aspiration (FNA) specimens of biopsy-proven nonproliferative breast lesion (NPL) (1 case), proliferative lesions without atypia (PL) (7 cases), proliferative lesion with atypia (PLA) (1 case), and low-nuclear grade ductal carcinoma in situ (DCIS) (3 cases) were selected. Six FNAs were Papanicolaou (PAP) and 6 were Diff-Quik-stained (DQ). Six expert cytopathologists classified the smears using a summary of published criteria as a guideline. All 6 participants rendered the same cytologic diagnosis in 2/12 (16%) cases. The agreement among the 6 raters was low (Kappa = 0.35). Cytohistologic correlation was achieved in 26/72 (36%) FNA diagnoses. The correlation of the PAP-stained cases was better than the DQ: 17/36 (47%) PAP and 9/36 (25%) DQ correlated. Improving the correlation was achieved by amalgamation of NPL and PL into “low risk” and PLA and DCIS into “high risk” categories: 47/72 (65%) FNA diagnoses then correlated with histology [29/36 (81%) PAP and 18/36 (50%) DQ]. We conclude that the cytologic criteria of proliferative breast lesions need to be further defined and assessed. Consideration should be given to minimizing the number of diagnostic categories and adopting a terminology that has a direct effect on patient management. Diagn. Cytopathol. 1998;18:150–165. © 1998 Wiley-Liss, Inc.     

Cytologic features of small-cell carcinoma on ThinPrep

The use of ThinPrep (TP) technology for fine-needle aspiration (FNA) cytology has become widely accepted. However, some literature suggests that small-cell carcinoma may present a diagnostic pitfall due to morphologic alterations. In this study, we retrospectively compared 14 FNA of small-cell carcinoma prepared using TP with corresponding conventional smears (CS). We also examined the TP appearance of 23 other small round-cell lesions in order to determine if differential diagnostic features were preserved. TP and CS were evaluated semiquantitatively for background, architecture, chromatin quality, nuclear molding, nuclear smearing, nucleolar prominence, amount of cytoplasm, nuclear size, and single-cell necrosis. The data were analyzed using the McNemar chi(2) test. TP slides of small-cell carcinoma showed a cleaner background than CS (P < 0.005). Although some degree of nuclear molding was preserved, it was decreased in amount (P < 0.025) and subtler in quality. Similarly, nuclear smearing was present but decreased in amount (P < 0.05), and less prominent qualitatively. The amount of discernible cytoplasm was greater on TP (P < 0.005). No significant differences were found for any of the other parameters studied. The presence of nuclear molding was the single most useful feature in differentiating small-cell carcinoma from other small round-cell tumors on TP. Small-cell carcinoma may be diagnosed with confidence by FNA using TP. However, pathologists should be aware of certain morphologic alterations in order to avoid diagnostic pitfalls.     

Current utilization of breast FNA in a cytology practice

Over the past decade, core biopsy rapidly replaced fine needle aspiration (FNA) in evaluation of diseases of the female breast in many centers in the USA. The inability to diagnose invasive cancer by FNA, and the general feeling of unease in interpretation of cytologic specimens among pathologists who are not trained in cytopathology are among factors leading to decline in the use of FNA. At our institution, we continue to rely heavily on FNA for evaluation of breast masses. In this article, we discuss our multidisciplinary team approach which is essential in sustaining a successful breast cancer screening program. We also review the general utility of breast FNA and core biopsy in a comparative fashion. In the second part of this article which will appear in an upcoming issue, we will review the use of FNA and core biopsy in challenging breast lesions focusing on the pitfalls and limitations of both modalities in selected specific lesions. Diagn. Cytopathol. 2009. © 2008 Wiley‐Liss, Inc.     

Diagnosis of melanoma aspirates on ThinPrep: the University of Michigan experience

The purpose of this study was to compare the cytologic features of melanoma fine-needle aspirates (FNAs) prepared by ThinPrep (TP) with those in conventional smears (CS) and to identify any diagnostic pitfalls. Fifty-one aspirates diagnosed as melanoma were obtained, 36 of which were prepared by both TP and CS. The preparations were evaluated for cellularity, cell aggregates, cellular appearance, melanin pigment, cytoplasmic, and nuclear features. Categorical data were analyzed by the chi-square test and continuous data by the Wilcoxin-signed rank test. Correlation was determined by Spearman's test for bivariate correlations (rho). Good correlation between the two methods was identified for the following features: cellularity, cell type, bi/multinucleated cells, cytoplasmic features, NC ratio, and presence of macronucleoli. TP exhibits coarser chromatin compared to CS (P = 0.005). Six of 36 CS contained large cellular groups; none of the TP contained them (P = 0.018). Twenty-five of 36 CS contained intranuclear inclusions as opposed to 12/36 TP (P < 0.001). The number of inclusions was significantly reduced on TP. The amount of intracellular melanin was the same with both techniques. Background melanin was markedly reduced on TP except when either trapped by fibrin or attached to cellular clusters (P = 0.006). Background blood was also markedly reduced on TP (P < 0.005). In summary, the cytological features of TP and CS for FNA evaluation of melanoma correlate well; however, one needs to be aware of the cytologic alterations introduced by TP. TP is a sufficient preparation method in the diagnosis of melanoma FNA aspirates when performed by clinicians. It is also a useful adjunct in bloody or low-cellular aspirates, where it tends to reduce the background blood and concentrate the cells.