Cytologic criteria for fibroadenoma. A step-wise logistic regression analysis

The authors reviewed the fine-needle aspiration biopsy smears from 62 subjects with proven fibroadenoma, 60 subjects with proven ductal carcinoma, and 42 subjects with proven fibrocystic disease. All smears were coded as to the presence or absence of the following variables: epithelial cells, stroma, honeycomb sheets, antler horn clusters, naked nuclei, nucleoli, marked cellularity, foam cells, apocrine cells, anisokaryosis, atypical nuclear hyperchromasia, single cells with cytoplasm, mitotic figures, and nuclei greater than two red blood cell diameters. Step-wise logistic regression analyses were performed to determine the variables predictive of fibroadenoma. The statistical analyses selected stroma, antler horn clusters, and marked cellularity as the key cytologic criteria to differentiate fibroadenomas from fibrocystic disease. The statistical analyses selected stroma, antler horn clusters, and honeycomb sheets as the key cytologic criteria to differentiate fibroadenoma from ductal carcinoma.     

ThinPrep vs. conventional smear cytologic preparations in analyzing fine-needle aspiration specimens from palpable breast masses.

Limited data exist concerning the cellular features of the ThinPrep (Cytyc Corp., Boxborough, MA) technique in the analysis of breast fine-needle aspiration specimens. Therefore, we analyzed a series of 75 surgically excised palpable breast masses and compared ThinPrep and conventional smear fine-needle aspiration preparations. Each mass was aspirated twice. The first sample was used for two alcohol-fixed conventional smears, and the second sample was rinsed into CytoLyt (Cytyc Corp., Boxborough, MA) solution for processing into a ThinPrep slide. The paired slides were separated and independently analyzed for adequacy, overall cellularity, single epithelial cells (absent, rare, moderate, or numerous), epithelial architecture (sheets or three-dimensional clusters), myoepithelial cells and stripped bipolar nuclei (present or absent), and nuclear detail (poor, satisfactory, or excellent). Each sample was classified as negative, negative consistent with fibroadenoma, atypical favoring benign, atypical favoring malignant, or positive for malignant cells. The 75 breast masses included 32 carcinomas and 43 benign lesions. Four conventional smears and one ThinPrep were unsatisfactory. Significantly, more conventional smears were limited by drying artifact (9 vs. 0). ThinPrep aspirates of carcinomas had better nuclear detail (P = 0.03) and greater cellularity (P = 0.05). ThinPrep aspirates of benign masses had greater epithelial cellularity (P = 0.007) and better nuclear detail (P < 0.001), and more specimens had myoepithelial cells (P = 0.007). The ThinPrep interpretation classified 29 of 32 carcinomas (91%) as positive and three as atypical favoring malignant (sensitivity = 100%). The conventional smear interpretation classified 28 of 31 carcinomas (90%) as positive and three as atypical favoring malignant (sensitivity = 100%). The ThinPrep interpretation classified 42 benign lesions as negative (23 cases), negative consistent with fibroadenoma (8 cases), atypical favoring benign (10 cases), and atypical favoring malignant (1 case) (specificity = 74%). The conventional smear interpretation classified 40 benign lesions as negative (25 cases), negative consistent with fibroadenoma (12 cases), and atypical favoring benign (3 cases) (specificity = 93%). ThinPrep was less specific, but the difference was not statistically significant (P = 0.065). In summary, ThinPrep aspirates had greater cellularity and better nuclear detail than conventional smears, and were just as sensitive in identifying the carcinomas. The difference in specificity between the two techniques was not statistically significant (P = 0.065). Diagn. Cytopathol. 1999;21:137-141.     

Aspiration biopsy of mammary lesions with abundant extracellular mucinous material. Review of 43 cases with surgical follow-up

We reviewed 43 fine-needle aspiration biopsy (FNAB) smears with abundant extracellular mucinous material to determine whether accurate classification of mucinous lesions is achievable on FNAB: 26 had carcinoma (pure colloid carcinoma [CCA], 23; mixed CCA/invasive ductal carcinoma [IDC], 3); 17 had benign lesions on follow-up (benign MLL, 6; fibrocystic change [FCC], 6; myxoid fibroadenoma [MFA], 5). All carcinomas were identified correctly as malignant on FNAB. The initial cytologic diagnoses in benign cases were benign in 8, atypical in 8, and "suspicious" for carcinoma in 1. CCAs were moderate to markedly cellular with mild to moderate atypia and lacked oval bare nuclei. Marked nuclear atypia was confined predominantly to cases with mixed CCA/IDC. A distinct feature of CCA was thin-walled capillaries. FCCs and benign MLLs had overlapping cytologic features and showed variable cellularity and no or mild atypia. MFAs were markedly cellular with dyscohesion and variable atypia; stromal fragments and oval bare nuclei were present in every case. Mucinous lesions can be divided into 2 categories by FNAB: those that are adenocarcinomas and those that are not. CCAs have distinctive features that allow a definitive diagnosis on FNAB. Unnecessary surgery can be avoided in MFA by careful evaluation of smear characteristics. Cytologic features of FCC and MLL overlap. Owing to the documented association of MLL with carcinoma, we recommend that lesions that cannot be classified definitively as adenocarcinoma or MFA be considered for conservative excision, even in the absence of atypia.     

Cytologic criteria used to diagnose adenocarcinoma in pleural effusions.

A stepwise logistic regression analysis was employed to evaluate the usefulness of the following criteria to distinguish adenocarcinoma in pleural effusion from benign pleural effusion: increased size of nucleus, increased nuclear to cytoplasmic ratio, irregular nuclear borders, sharply defined cytoplasmic boundaries, large nucleoli, aggregates with variable size nuclei, aggregates with nuclear overlap, irregular noncentral vacuoles, aggregates with nuclear molding, multinucleation, three-dimensional aggregates, aggregates with large cytoplasmic vacuoles, atypical mitoses, nuclear vacuoles, homogeneous cytoplasm, aggregates with associated lymphocytes and neutrophils, and uniform size aggregates. A total of 223 patients with benign pleural effusion cases and 221 patients with adenocarcinoma in their pleural effusion were scored as to the presence or absence of the above criteria. The resulting data were subjected to a stepwise logistic regression analysis that chose increased nuclear/cytoplasmic ratio, irregular nuclear borders, large nucleoli, sharply defined cytoplasmic boundaries, and three-dimensional aggregates as the best criteria to differentiate adenocarcinoma in pleural effusion from benign pleural effusion. When used together, these five features had a sensitivity of 94% and a specificity of 93% for predicting adenocarcinoma.     

Cytohistologic features of invasive micropapillary carcinoma in a young female

Invasive micropapillary carcinoma (IMPC) is a recently reported variant of breast carcinoma in women. There has been only a single report describing the cytologic features of IMPC in the literature. We report on the cytohistologic features of IMPC with diffuse involvement of two quadrants of the breast and axillary lymph node metastases in a 32-yr-old female. The cytologic appearance of IMPC was characterized by high cellularity, marked cell discohesion, and epithelial cells forming aggregates, morules, and angular and papillary clusters without fibrovascular cores and showing high nuclear/cytoplasmic ratio, irregular nuclear contours, and finely stippled chromatin. Occasional psammoma bodies were noted. Histologic examination showed a pure IMPC composed of clusters, morules, and aggregates of malignant epithelial cells surrounded by distinctly clear spaces separated by thin fibrovascular septa. The tumor involved both inner quadrants and axillary lymph nodes. A primary tumor elsewhere, particularly in the ovaries, was excluded. The patient has been disease-free 38 mo after the initial diagnosis.     

Male breast lesions: gynecomastia and its distinction from carcinoma by aspiration biopsy cytology

Gynecomastia is a benign proliferative lesion of the male breast. It may present as a diffuse bilateral process or a unilateral, discrete mass, clinically suggestive of carcinoma. We examined the aspiration biopsy cytology of 50 cases of gynecomastia to define the cytologic criteria and to distinguish it from carcinoma. The parameters of cellularity, architecture, single columnar cells, naked nuclei, nuclear and cell size, nuclear and cytoplasmic characteristics, and extraneous cells were accessed. Diagnostic confusion with carcinoma may occur because of cellularity with loose groups and single cells; however, the mixed cell population, composed of cohesive sheets or groups of bland cells, bipolar naked nuclei, and single tall columnar cells, delineates gynecomastia from carcinoma of the male breast.     

Aspiration biopsy of granulosa-cell tumor of the ovary: cytologic findings and differential diagnosis.

Fine-needle aspirates from four histologically confirmed adult granulosa-cell tumors of the ovary revealed irregular sheets, loose aggregates or tight clusters of small tumor cells with round or oval nuclei and scant cytoplasm. Nuclear grooves and indentations were noted in a small number of cells in two cases. Tumor cells arranged in follicular pattern mimicking Call-Exner bodies were not identified in all cases. A cytologic differential diagnosis of "small-cell" tumors of the ovary is briefly discussed.     

Cytologic criteria of hyperplastic lesions in endometrial samples obtained by the endocyte sampler

The present investigation attempted to identify useful parameters for the cytologic diagnosis of endometrial hyperplasias in samples obtained with the Endopap endometrial sampler. A clinical and morphological classification dividing hyperplasia into benign simple hyperplasia (BSH); benign complex hyperplasia (BCH); and endometrial intraepithelial neoplasia (EIN) has been suggested by Meisels, et al. based on five valuable cytologic criteria. To these we added six of our own and applied them to 1.172 cases, 432 of which had a previous histologic diagnosis of normal proliferative endometrium (NPE); 462 were BSH, 210 were BCH, and 14 fit the EIN pattern. The cytologic criteria evaluated were overlapping cells, enlarged nuclei, aniso karyosis, granularity of chromatin, stromal cells, branching glandular structures, and moruloid or papillary-like cellular aggregates, dilated glandular borders in cellular sheets, nuclear clearing, clumped chromatin, and enlarged eosinophilic cytoplasm. Our results are consistent with the following findings: (1) there is no useful parameter for cytologic differentiation between NPE and BSH; (2) BCH is characterized by cellular aggregates, dilated glandular borders in cellular sheets, and branching glandular structures; (3) EIN is characterized by nuclear clearing, clumped chromatin, and anisokaryosis; and (4) enlargement of nucleoli and eosinophilic cytoplasm alone is not sufficient for the diagnosis of EIN.     

Carcinoid tumors of the lung: cytologic differential diagnosis in fine-needle aspirates

Pulmonary carcinoid tumors presenting as peripheral or coin lesions are rare and radiologically may resemble other primary or metastatic neoplasms in the lung. This study consisted of the cytologic evaluation of fine-needle aspirates from five peripheral carcinoid tumors of the lung with particular reference to the differences between the cytologic manifestations of this neoplasm and of small-cell carcinoma and well-differentiated adenocarcinoma. Aspirates of typical carcinoid tumors are characterized by isolated cells and loose aggregates of cells; spindle- and oval-shaped cells of uniform size with scanty, pale eosinophilic cytoplasm; and nuclei with evenly dispersed finely granular chromatin and usually prominent single micronucleoli with occasional macronucleoli. In contrast, the cells of small-cell carcinoma are pleomorphic and arranged in noncohesive loose aggregates, their cytoplasm is scanty, and they show nuclear molding. Their nuclei are hyperchromatic with fine to coarsely granular chromatin. The cells of well-differentiated adenocarcinoma are arranged in three-dimensional clusters or loose aggregates of relatively uniform cells with a columnar configuration. The nuclei are uniformly round and hyperchromatic with finely granular chromatin. Macronucleoli are usually prominent. This study demonstrates that cytologic analysis of fine-needle aspirates can play a significant role in the evaluation and management of peripheral lung tumors.     

Diagnosis of Kaposi's sarcoma by fine-needle aspiration biopsy

Fifteen cases of Kaposi's sarcoma diagnosed by fine-needle aspiration biopsy were reviewed. The diagnosis was confirmed by tissue biopsy in eight of the cases. All of the patients were homosexual males, and 13 had a previous diagnosis of AIDS. The aspirates were obtained from enlarged lymph nodes (five cases), soft-tissue masses (two cases), oral cavity lesions (seven cases), and an abdominal mass. The most characteristic cytologic features were intact tissue fragments composed of overlapping spindle cells with nuclear distortion and ill-defined cytoplasmic borders. Smaller groups of loosely cohesive spindle-shaped cells and individual spindle cells with cytoplasm were also helpful features. In the appropriate clinical setting, these cytologic features on FNAB are felt to be diagnostic of Kaposi's sarcoma.     

Comparative cytologic findings of in situ and invasive adenocarcinoma of the uterine cervix

The cytologic findings in 13 cases of cervical adenocarcinoma in situ (mean age 33.9 yr) were compared with those in 9 cases of cervical invasive adenocarcinoma (mean age 45.7 yr). All diagnoses were confirmed by biopsy. the major differences found were that a necrotic background (66% invasive vs. 0% in situ) and macronucleoli (77% invasive vs. 0% in situ) were more common in invasive cases, whereas associated squamous-cell dysplasia (69% in situ vs. 0% invasive) was more common in in situ cases. Other differences included syncytial tissue fragments with irregular cell borders, frequent cell drop-off, and markedly atypical single columnar cells (or markedly atypical naked nuclei) seen more commonly in invasive cases, whereas monolayer sheets and/or syncytial tissue fragments with smooth borders and rare cell drop-off were more common in in situ cases. Although none of these features is diagnostic individually, in combination they are helpful in distinguishing between in situ and invasive adenocarcinoma. Nine of 13 of the in situ cases showed associated squamous-cell dysplasia. in all nine of these cases, the glandular dysplasia was overlooked or underestimated in severity on original cytologic diagnosis. This suggests that the presence of a squamous lesion may lead to decreased detection of glandular lesions, perhaps because the features of squamous lesions are more well known; thus they are more easily recognized, at the expense of glandular lesions. All invasive adenocarcinomas were identified as carcinoma in the original diagnosis with seven specified as invasive adenocarcinomas. © 1995 Wiley- Liss, Inc.     

Cytologic features of tubular adenocarcinoma of the breast by aspiration biopsy.

Tubular adenocarcinoma is an invasive mammary adenocarcinoma associated with an excellent prognosis and a low incidence of axillary metastases. However, identification of tubular adenocarcinoma by fine-needle aspiration (FNA) biopsy has proven difficult. One hundred five patients with documented "pure" tubular adenocarcinoma were diagnosed at Tisch Hospital from August of 1992 to December of 1998. Twenty-one of these patients had an FNA before excision. We reviewed the smears of these cases and compared them with cases of fibroadenoma and fibrocystic change to identify criteria for diagnosis. Moderately to highly cellular smears with angular cellular clusters with sharp borders and oval cells outlining these clusters, dispersed single cells with minimal atypia, and the absence or paucity of dispersed bare oval nuclei in the background were features that suggest a diagnosis of tubular adenocarcinoma in our study. Attention to these features in combination with appropriate mammographic findings should preclude a false-negative diagnosis in the majority of cases of tubular adenocarcinoma diagnosed by aspiration biopsy. We point to the presence of the peripheral perpendicular cells in the characteristic tubular arrays as an important clue to the diagnosis of tubular adenocarcinoma.     

Diagnostic significance of signet ring cells in fine-needle aspirates of the breast

Fine-needle aspiration (FNA) is a reliable and cost-effective procedure in the evaluation and management of breast lesions. One diagnostic dilemma that may sometimes arise is the finding of signet ring cells. The isolated finding of such cells in aspirate smears may be particularly problematic in cases of low cellularity or those with otherwise benign features. Although it is generally held that such cells are almost exclusively associated with carcinoma (particularly the lobular subtype), their significance in FNA smears has never been systematically evaluated. To establish their diagnostic utility, we evaluated aspirate smears from 150 cases of histologically proven benign (77) and malignant (73) breast lesions for the presence of signet ring cells, defined as those containing a prominent intracytoplasmic vacuole with nuclear displacement. Signet ring cells were identified in 71% of malignant cases (75% of ductal carcinomas and 71% of lobular carcinomas), mostly as single cells or within small, loosely cohesive tissue fragments. Such cells were also present in 6% of histologically proven benign lesions, most commonly within large tissue fragments. Many of these cells were proven to be vacuolated myoepithelial cells, based on histologic correlation and immunostaining results using anti-muscle-specific actin. On the basis of these findings, we conclude that (1) the presence of signet ring cells within small loose tissue fragments or as single cells in FNA smears should prompt close clinical follow-up (including repeat FNA and perhaps surgical biopsy), regardless of smear cellularity, (2) the presence of signet ring cells in cases of adenocarcinoma does not predict a particular tumor subtype, and (3) rare benign breast lesions may contain signet ring cells, particularly within large tissue fragments, and do not, in isolation, warrant surgical biopsy to exclude malignancy. Diagn. Cytopathol. 16:117–121, 1997. © 1997 Wiley-Liss, Inc.     

Cytodiagnosis of hepatocellular carcinoma in fine-needle aspirates of the liver: its differentiation from reactive hepatocytes and metastatic adenocarcinoma

Fine-needle aspiration (FNA) cytology is a useful tool for diagnosis of primary malignancies and metastatic lesions of the liver. However, well-differentiated hepatocellular carcinoma (HCC) may resemble benign/reactive hepatocytes, and less differentiated HCC may simulate poorly differentiated adenocarcinoma, leading to difficulties in interpretation of aspirates from liver. To determine the subtle cytomorphological features which can differentiate these lesions, ultrasound-guided FNA smears from 86 cases of liver malignancy were subjected to detailed cytologic assessment. These included 20 cases of HCC, 38 cases of metastatic adenocarcinoma, and 28 cases of benign/reactive hepatocytes. The important features for separating HCC or well-differentiated HCC from benign/reactive hepatocytes were excessive cellularity, trabecular pattern vs. thin cords of hepatocytes, nuclear pleomorphism, atypical stripped nuclei, and macronucleoli (P < 0.001 to < 0.0001). The most significant features for differentiating HCC from metastatic adenocarcinoma were trabecular growth pattern, hepatocytic cells vs. columnar/cuboidal cells, eosinophilic granular cytoplasm, lipid vacuoles, bile pigments, and atypical stripped nuclei (P < 0.001 to < 0.0001). The cytomorphological features which may distinguish poorly differentiated HCC from poorly differentiated adenocarcinoma were polygonal (hepatocytic) cells, eosinophilic granular cytoplasm and lipid vacuoles in HCC, and columnar/cuboidal cells and acinar/glandular formation in adenocarcinoma (P < 0.05 to < 0.001). Diagn. Cytopathol. 1999;21:370-377.     

Cytology of polypoid adenomyomas: a report of two cases

Uterine polypoid adenomyomas, both typical and atypical variants, often arise in the lower uterine segment or endocervical canal as pedunculated polypoid masses that may be accessible for cytologic sampling. However, their cytologic findings have rarely been described in the literature. Two women in their reproductive age presented with abnormal vaginal bleeding. The cervicovaginal smear of the first patient contained sheets and strips of reactive endocervical cells in an inflammatory background. In addition, loose aggregates of spindle-shaped smooth muscle cells were also noted. The findings were consistent with those of a typical polypoid adenomyoma. The cervicovaginal smears of the second patient consisted of tightly packed, crowded clusters of glandular cells which were initially interpreted as atypical glandular cells, suspicious of adenocarcinoma. In retrospect, loose aggregates of smooth muscle stromal cells were noted. Subsequent curettage revealed an atypical polypoid adenomyoma. The cytologic findings of typical polypoid adenomyoma were nonspecific except for the presence of loose aggregates of smooth muscle cells. The cytologic features of an atypical polypoid adenomyoma may mimic that of a neoplastic glandular process. The findings of tightly packed clusters of glandular cells and loose aggregate of bland-appearing smooth muscle cells in premenopausal patients may suggest the diagnosis of atypical polypoid adenomyoma. Diagn. Cytopathol. 2000;22:176-180.     

Prostatic adenocarcinoma metastases mimicking small cell carcinoma on fine-needle aspiration

Prostate adenocarcinoma (PA) is known to metastasize widely to bone, lung, lymph nodes, and other sites. We have observed a rare, although distinctive, neuroendocrine (NE) cytomorphology of metastatic PA on fine-needle aspiration (FNA) that mimics small cell carcinoma (SCC). From a total of 117 cases, eight cases of metastatic PA diagnosed on FNA showed cytomorphologic features indistinguishable from SCC. All specimens were reviewed, along with immunoperoxidase (IPOX) studies using prostate specific (PSA, PSAP) and NE markers (synaptophysin, chromogranin, etc.). The patients ranged in age from 51-68 (mean age = 63). The PSA levels at the time of FNA ranged from <0.1 to 2,892 ng/ml (normal postprostatectomy <0.2 ng/ml). Sites of FNA included liver (two), soft tissue (five), and lymph node (one). FNA was performed from 11 mo to 6 yr after the initial diagnosis of the primary tumor. All primary PA were of high Gleason grade ranging from 7-9. None of the primary PA showed neuroendocrine morphology. Cytomorphologic characteristics observed on FNA included predominantly single cells with occasional sheets or loose cell aggregates. A predominant NE nuclear morphology was evident (i.e., hyperchromasia, fine dusty chromatin, inconspicuous nucleoli, nuclear molding, chromatinic crush artifact, karyorrhexis, mitoses, etc.), with none of the tumors displaying glandular formation. Taken together, these features gave these metastases a cytomorphology indistinguishable from SCC. IPOX studies revealed PSA-positivity (5/7), PSAP-positivity (4/7), and only focal NE markers positivity (3/6). Metastatic prostate carcinoma may rarely mimic a SCC (6.8% in this study). This often necessitates further patient workup to identify the primary source for the patient's metastasis, particularly if the patient has multiple lesions. An accurate diagnosis of these lesions as PA metastases is essential for effective, timely treatment and therapeutic design.     

Duodenal carcinoid tumor: report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy with immunocytochemical correlation

Fine-needle aspiration biopsy is a reliable and accurate method for the endoscopic diagnosis of gastrointestinal malignancies and it is particularly well suited for evaluation of submucosal lesions. We report the cytopathologic findings of a case of malignant carcinoid tumor of a 44-year-old male who presented with melena and a nonhealing duodenal ulcer. Endoscopic ultrasound examination revealed a submucosal lesion in the pyloric region. Fine-needle aspiration revealed abundant cellularity with tumor cells arranged in sheets and loose groups and dispersed single cells in a clean background. Papillary fragments, capillaries cuffed by tumor cells, and rosette formation were also noted. The cells were moderate in size, round to oval, with a small subpopulation of spindle-shaped cells. The nuclei were uniform, round to oval, with smooth nuclear borders. The chromatin pattern was finely granular with a salt-and-pepper appearance. The cytoplasm of the cells was small to moderate in amount, pale, and showed fine granularity. The differential diagnosis included a neuroendocrine neoplasm vs. an epithelioid gastrointestinal stromal tumor. The tumor cells were focally positive for chromogranin and negative for CD34, supporting the diagnosis of a neuroendocrine neoplasm. The differential diagnosis of primary gastrointestinal carcinoid tumors from gastrointestinal stromal tumors can be very difficult in cytologic material. In cases when diagnostic material is scant, or only present on one smear, the use of smear division and cell transfer in order to perform immunocytochemical stains may be of considerable value to confirm the neuroendocrine nature of the neoplasms.     

Use of the ThinPrep method in bile duct brushings: analysis of morphologic parameters associated with malignancy and determination of interobserver reliability

Recent work suggests the ThinPrep method can improve diagnostic sensitivity and accuracy in bile duct brushings. However, the proportion of atypical and suspicious diagnoses remains high. The aim of this study was to identify the most useful morphologic features in ThinPrep bile duct cytology and evaluate interobserver reliability. We evaluated 100 bile duct brushings prepared by ThinPrep, all with either histology or long term clinical follow-up (55 malignant, 45 benign). Morphologic features were evaluated by four experienced cytopathologists blind to clinical information and follow-up diagnoses. These features included cellularity, blood or diathesis, mitoses, inflammation, three-dimensional groups, discohesive atypical cells, macronucleoli, well-defined cytoplasmic borders, and nuclear features of malignancy (nuclear membrance irregularity, chromatin clumping). The data were analyzed by intraclass correlation (ICC) and stepwise multiple logistic regression. Reviewers showed unanimous agreement in 29% of cases, one degree of disagreement in 58% of cases, and full disagreement in 13% of cases. Of benign cases, 38% were thought to be diagnostic of malignancy by at least one of the four reviewers. Sensitivity for the morphologic parameters varied from 18 to 67%; the highest sensitivity was for discohesive atypical cells, well-defined cytoplasmic borders, nuclear features of malignancy, and cellularity (67, 62, 51 and 46%, respectively). Specificity of parameters varied from 16 to 100%; the highest specificity was for mitoses, three-dimensional groups, nuclear features of malignancy, and macronucleoli (100, 98, 93, and 93%, respectively). Interobserver reliability (ICC) was very good for specimen cellularity (0.72) and nuclear features of malignancy (0.60). In logistic regression analysis, only nuclear features of malignancy and increasing patient age separated benign from malignant. On ThinPrep bile duct brushings, nuclear features of malignancy are most useful in distinguishing benign from malignant, and interobserver reliability for this parameter is very good. Discohesive atypical cells show moderate sensitivity and specificity, while three dimensional clusters and macronucleoli are specific but not sensitive for malignancy, and are not significant in multivariate logistic regression models. The relatively high proportion of benign cases thought to be diagnostic of malignancy by at least one reviewer argues for a consensus approach to this diagnosis.     

Fine-needle aspiration cytology of columnar-cell carcinoma of the thyroid: Report of two cases with cytohistologic correlation

The columnar-cell variant of papillary carcinoma is a rare tumor of the thyroid, associated with aggressive behavior, early visceral metastasis, and a rapidly fatal course. In this report we present the fine-needle aspiration cytologic findings of two examples of this variant of papillary carcinoma with cytohistologic correlation. In the smears, clusters, monolayered sheets, and scattered papillary fronds of tumor cells were present. The tumor cells were columnar and exhibited overlapping and stratification of the nuclei. In the first case the tumoral cells showed round nuclei with finely granular chromatin pattern, small nucleoli and vacuolated-appearing cytoplasm. The malignant cells in the second case presented oval to elongated nuclei with stippled chromatin, inconspicuous nucleoli and indistinct cytoplasmic borders. It is important to distinguish this tumor from the common thyroid papillary carcinoma because of its much more aggressive behavior. Diagn. Cytopathol. 1998;18:352–356. © 1998 Wiley-Liss, Inc.     

Adenocarcinoma in colonic brushing cytology: High-grade dysplasia as a diagnostic pitfall

Cytologic evaluation of brushing specimens obtained from the colon may be useful in the diagnosis of neoplastic and inflammatory lesions, as previous studies have reported favorable sensitivity and specificity figures for this procedure. In this study, we report our experience with 80 colonic brushings examined over a 5-yr period. Thirty cases received an atypical or malignant cytologic diagnosis. Nineteen of 20 cases diagnosed cytologically as adenocarcinoma revealed adenocarcinoma on biopsy; one case showed only adenomatous epithelium on biopsy and subsequent resection. Cases diagnosed cytologically as "atypical" or "adenomatous" showed adenocarcinoma, adenoma, and inflammatory conditions upon biopsy. Slides from 30 atypical/malignant cases were retrospectively reviewed for a number of cytomorphologic features and were correlated with the histologic diagnosis. Cases from histologically confirmed adenocarcinoma tended to show greater degrees of altered nuclear polarity, nuclear pleomorphism, membrane irregularities, and chromatin pattern alterations than those from histologically proven adenomatous or inflammatory lesions. The most likely cause of a false-positive diagnosis in this setting is sampling of an adenoma with high-grade dysplasia which fails to meet histologic criteria for adenocarcinoma (invasion of the underlying muscularis mucosae). Thus, in the second part of the study, we examined histologic sections from surgically excised adenomas to determine the frequency with which profound nuclear atypia is at least focally present, potentially resulting in a false-positive cytology diagnosis upon brushing. Slides from 51 cases were reviewed; cytologic atypia beyond that typically observed in adenomas was not observed in 43% of cases. However, profound nuclear atypia was present in 6% of cases; cytologic evaluation of a brushing specimen from these lesions may have resulted in a false-positive diagnosis of adenocarcinoma, despite the histologic diagnosis of adenoma with severe dysplasia. The remaining cases demonstrated intermediate degrees of atypia. These findings serve to quantitate the frequency with which cytohistologic discrepancies might be expected for mass lesions of the colon.