Cytologic differential diagnosis of papillary pattern in breast aspirates: correlation with histology

Papillary neoplasms, fibroadenoma, fibrocystic change, low-grade ductal carcinoma, and apocrine carcinoma are among "gray zone" lesions in breast cytology. They often have cellular smears with a papillary or pseudopapillary pattern. To better define cytologic criteria useful in distinguishing these entities, we correlated them with histology. Papanicolaou and giemsa stained smears from 33 aspirates and their corresponding histology were reviewed. Of these, 28 had an initial cytologic diagnosis or suspicion of papillary neoplasm, while five cases were not diagnosed cytologically as papillary but the histologic diagnosis was a papillary neoplasm. Cytologic features evaluated included cellularity, architecture, apocrine/single/columnar cells, nuclear atypia, intranuclear inclusions, calcifications, background, myoepithelial cells, and bipolar, naked nuclei. Discriminating cytologic features grouped by final histologic diagnosis were as follows: Papillary neoplasm (14 cases): Hemorrhagic/cystic background, 3-dimensional papillary clusters, columnar cells, and fibrovascular cores. Myoepithelial cells within clusters and background naked, bipolar nuclei were inconspicuous. Fibroadenoma (4 cases): Two-dimensional branching clusters often with folding, moderate myoepithelial cells in clusters, moderate to numerous background bipolar nuclei, often forming doublets in smear background, cellular stroma. Ductal carcinoma (11 cases): Papillary ductal carcinoma in situ in 5 of 11 cases, cribriform/tubular architecture in 6 of 11. Absence or paucity of myoepithelial within clusters and background bipolar nuclei was noted. Fibrocystic change (4 cases): Two-dimensional clusters, moderate myoepithelial cells within clusters, and moderate bipolar nuclei in the background. The presence and quantity of myoepithelial cells, bipolar naked nuclei in the background, and ductal cell architecture were the only consistently useful cytologic features in distinguishing breast lesions with a papillary pattern. Ann Diagn Pathol 5:34-42, 2001.     

Adenoid cystic carcinoma of the breast: Diagnosis by fine-needle aspiration

Adenoid cystic carcinoma rarely occurs as a primary breast malignancy. When seen in fine-needle aspiration (FNA) material, it is identical to its counterpart in the salivary glands. We report six cases diagnosed by aspiration in patients aged 32-82 yr. The smears were highly cellular and featured extracellular spheres of metachromatic material. These were surrounded by small, uniform cells with bland nuclei and very little cytoplasm. Numerous similar cells occurred singly in the background. The cytologic differential diagnosis of adenoid cystic carcinoma includes other entities that produce extracellular metachromatic spheres including collagenous spherulosis. We describe and illustrate similar material originating in inspissated secretions or stromal fragments from fibrocystic change and fibroadenoma, as well as infiltrating ductal carcinoma. Diagnostic criteria for adenoid cystic carcinoma and the clinical relevance of distinguishing this rare tumor from typical infiltrating ductal carcinoma are discussed.     

Cytologic features of ductal carcinoma in situ

Fourteen cases of both palpable and non-palpable breast lesions reported as possible ductal carcinoma in situ (DCIS) on fine-needle biopsy (FNB) over a 12-mo period were retrieved from our files and compared to the subsequent histologic diagnosis. Although a definite cytologic pattern of highly cellular smears with high grade nuclei, dissociation, and background necrosis with microcalcifications emerged for comedo DCIS, it was not possible to differentiate these on cytologic grounds from high grade infiltrating carcinoma with necrosis unless mammographic findings were taken into account. Useful criteria for non-comedo low grade DCIS were high cellularity, low grade nuclei, and architectural features of papillary and three dimensional (3D) fragments, palisade arrangements, and monolayer sheets with punched out glandular lumina. We conclude that FNB has a definite role in the diagnosis of these lesions, with the limitation that invasive malignancy can never be excluded on cytologic criteria alone and clinico-radiological correlation is paramount. Diagn Cytopathol 1996;15:367–373. © 1996 Wiley-Liss, Inc.     

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.     

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.     

Role of morphometry in evaluation of cytologically borderline breast lesions: a study of 70 cases

Fine needle aspiration, an accepted minimally invasive diagnostic procedure for breast masses, leads to an indeterminate (borderline) diagnosis in a significant proportion of cases. This study was aimed at evaluation of the utility of image analysis and morphometry in the cytologic assessment of borderline breast cases. A 'study' group of 45 cases (including fibroadenoma, fibrocystic change and ductal carcinoma) and a 'test' group of 25 cytologically borderline cases were included. Nuclei from each of the groups (nuclei of monolayer sheet of fibroadenoma, naked nuclei of fibroadenoma, ductal cells nuclei of fibrocystic change and nuclei of carcinoma) were manually traced and analyzed using self-written image analysis software. Discriminant analysis was done on the 'study' group and the resultant discriminant functions were applied to the 'test' group. The percentage of nuclei correctly classified of the study as well as test group was noted. On step-wise discriminant analysis, various morphometric, textural parameters and color information parameters were selected. Of the original 'study' group, 98.49% of nuclei could be correctly classified. No overlapping of benign and malignant nuclei was observed in the 'study' group. When the resulting functions were tested on the 'test' group, all the cases were correctly classified as benign or malignant (compared with the final histologic diagnosis). This study suggests that application of computerized image analysis to cytologically borderline breast cases can help in the classification of these cases as benign or malignant. This may prevent unnecessary surgery in many of these cases.     

Fine‐needle aspiration of gray zone lesions of the breast: Fibroadenoma versus ductal carcinoma

While breast lesions have characteristic cytological features, some lesions, particularly adenocarcinoma and fibroadenoma, may present with overlapping features causing erroneous diagnoses. The current study aimed to define significant cytomorphologic features predictive of fibroadenoma and adenocarcinoma, respectively. Further, we intended to evaluate the predictive characteristics for differentiation between gray zone lesions and to identify root causes contributing to misdiagnoses. First, direct smears prepared from 14 histology‐confirmed fibroadenomas and 14 adenocarcinomas were reviewed and characteristics of commonly encountered morphologic features were assessed. We then retrospectively and blindly reviewed nine cytohistologic discrepant cases using the significant characteristic as a guideline, in order to assess whether these discrepant cases could be correctly categorized. Morphologic characteristics predictive of fibroadenoma included moderate cellularity, large, folded cellular sheets/aggregates, staghorn projections, smooth and round borders, monolayers, honeycomb arrangement, smaller nuclear size, and background bipolar cells. Predictive characteristics of adenocarcinoma included high cellularity, loose cohesive sheets/aggregates, pointed projections, irregular borders, larger nuclear size, irregular nuclear membrane, prominent nucleoli, and single atypical epithelial cells. Retrospective, blind review correctly re‐classified seven out of nine cytohistologic discrepant cases, including five false negative cases and two false positive cases. Root causes contributing to the misdiagnoses were large branching sheets of carcinoma mimicking folded sheets of fibroadenoma; fibroblasts mimicking myoepithelial cells; apocrine cells mimicking carcinoma cells; and not recognizing the loose myxoid matrix presenting as soap bubbles in fibroadenoma. In conclusion, this study identified significant characteristics that can assist in achieving accurate diagnosis in a subpopulation of breast aspirates that present with overlapping features. Diagn. Cytopathol. 2013;41:806–811. © 2012 Wiley Periodicals, Inc.     

Ductal adenoma of the breast: The cytological features of six cases

Ductal adenoma of the breast may simulate malignancy by both clinical, histological, and cytological examination. Fine-needle aspirations from breast lesions are now daily routine and preoperative recognition of this benign lesion is desirable. This study describes the cytologic features of six additional cases of ductal adenoma. The smears from all the lesions were highly cellular with epithelial cells in sheets. Numerous large fragments of purple stroma in tight connection with epithelial cells often making finger-like hyaline structures or globules between cells were seen. Naked oval nuclei in the background were observed in all cases indicating benignancy. We find the cytologic picture in fine-needle aspirations from ductal adenomas sufficiently characteristic for preoperative diagnosis. The differential diagnoses toward other benign and malignant conditions are discussed. © 1994 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.     

Tubular carcinoma of the breast: Cytologic features in fine-needle aspirations and application of monoclonal anti-α-smooth muscle actin in diagnosis

Twenty fine-needle aspirations (FNAs) of histologically proven tubular carcinoma of the breast (TCB) were reviewed, and the staining distribution of α-smooth muscle actin (SMA) was evaluated to see if this improved FNA sensitivity. In 18 cases, the aspirates were cellular, consisting predominantly of epithelial cells arranged in cohesive tubular structures that appeared angular or twisted. Single epithelial cells were present in varying numbers in 14 cases (70%). Cribriform fragments corresponding to in situ ductal carcinoma were noted in 9 cases (45%). Individual, bare nuclei were present in seven cases (35%). The initial cytologic diagnoses were 10 carcinomas, eight suspicious for carcinoma, and two cases were misinterpreted as fibroadenoma. In 8 of 14 cases, the epithelial fragments stained negatively for SMA, whereas in six cases some fragments (<10%) stained positively. These findings were in contrast to a reticulated staining pattern noted in almost all of the epithelial fragments in nine fibroadenomas and three fibrocystic changes. Eighteen well-differentiated invasive ductal carcinomas stained negatively, whereas four had occasional positively staining fragments. We conclude that TCB displays distinct cytomorphologic features that can be recognized or at least suggested by FNA. Awareness of the cytologic characteristics—angulated tubular structures with or without single epithelial cells—coupled with mammographic/ultrasound findings, is necessary to avoid a misdiagnosis. Alpha-smooth muscle actin staining may help in selected cases. © 1994 Wiley-Liss, Inc.     

The significance of the diagnosis of atypia in breast fine-needle aspiration

The diagnosis of atypia in breast fine-needle aspiration (FNA) continues to be an area of debate in cytology practice. The aim of this study was to assess the clinical significance of this term and to evaluate potential morphological criteria, which would determine the patient's outcome. A computer-based search was carried out to retrieve breast FNAs performed between 1990 and 2000 that were diagnosed as atypical. Cases followed by surgical resection were reexamined for the presence of morphological features potentially differentiating benign and malignant lesions. Out of 1,568 breast FNAs, there were 64 cases (4%) with a diagnosis of atypia. Thirty-eight cases had surgical follow-up material that revealed malignancy in 14 cases (37%) and benign lesions in 24 cases (63%). The benign diagnostic categories included fibrocystic change (12/24), fibroadenoma (3/24), tubular adenoma (2/24), and nonspecific findings (7/24). The malignant diagnoses included ductal carcinoma (9/14), lobular carcinoma (3/14), ductal carcinoma in situ (DCIS; 1/14), and tubular carcinoma (1/14). The evaluation of cytological criteria used to differentiate benign from malignant lesions (i.e., cellularity, loss of cohesion, myoepithelial cells, nuclear enlargement, nuclear overlap, prominent nucleoli) revealed significant overlap between benign and malignant cases, particularly in cases of fibroadenoma, tubular adenoma, and proliferative breast disease. The surgical follow-up of four hypocellular cases revealed lobular carcinoma in two cases and ductal carcinoma in the remaining two cases. Our study confirmed that the diagnosis of atypia is clinically significant because it is associated with a high probability of malignancy. No morphological criterion is able to reliably differentiate benign and malignant lesions in cases diagnosed with atypia. Diagnosis of atypia is particularly significant in hypocellular cases. We recommended that breast FNAs with a diagnosis of atypia be evaluated further histologically.     

Fine-needle aspiration cytology of sclerosing adenosis of the breast: a retrospective review of cytologic features in conjunction with corresponding histologic features and radiologic findings

We retrospectively reviewed 25 fine-needle aspiration cases of sclerosing adenosis of the breast in conjunction with histologic features of the paired core-needle biopsy and radiologic findings. The original cytologic diagnoses were benign (n = 19), focally atypical (n = 3), and suspicious for carcinoma (n = 3). The frequent features, although not specific, were low-to-moderate cellularity, bland epithelial cells that focally formed cohesive groups/tubules or occasionally discohesive clusters or individual cells, and fragments of dense fibrous stroma. Some tubules had an angulated configuration. Myoepithelial cells were present in all cases but were scant or absent in small epithelial groups. These cytologic features closely reflected the histologic appearances (ie, compressed and attenuated tubules and sclerotic stroma), but may cause overinterpretation on cytologic smears, especially when angulated tubules, discohesive or individual epithelial cells, scanty myoepithelial cells, and nuclear atypia are noted concurrently. Familiarity with its cytologic features may prevent false-positive diagnosis. Histologic confirmation is recommended for difficult cases.     

Fine needle aspiration cytology of insular carcinoma of thyroid

Poorly differentiated (insular) thyroid carcinoma is defined as a thyroglobulin-producing non-follicular non-papillary thyroid carcinoma, having an intermediate behavior between well-differentiated and anaplastic carcinomas. FNAC is widely used as aid for workup of thyroid gland lesion. However, scant information is available in the literature about cytologic findings of this rare entity. Ten cases of surgically resected insular carcinoma with a corresponding cytology were selected. The cytologic smears and histological sections were reviewed for presence of cytomorphologic features including cellularity, predominant cytoarchitectural pattern, additional cytologic co-patters pattern, cell size, cell shape, nuclear pleomorphism, nuclear/cytoplasmic (N/C) ratio, chromatin pattern, amount of cytoplasm, mitotic figures, colloid, background debris, nuclear grooves, and intranuclear pseudoinclusions. In all the cases, the cells were arranged predominantly in solid clusters. Focal microfollicular pattern was identified in five cases of which three cases showed presence of inspissated colloid within the follicles. Singly scattered malignant cells and bare nuclei were seen in all cases. Cells were monomorphic, round with high N/C ratio, finely granular chromatin and inconspicuous nucleoli. Background showed presence of cellular debris in two cases. Mitotic figures were obvious and atypical mitosis was also identified. Cellular smears composed of monomorphic population of small cells arranged in large clusters and sheets with high N/C ratio and high mitosis suggest the possibility of insular carcinoma. Background cellular debris/necrosis also supports the diagnosis. Cell block preparation in these cases may be of additional help in accurate 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.     

Papillary neoplasms of the breast: Fine-needle aspiration findings in cystic and solid cases

Papillary neoplasms of the breast are uncommon; at the time of needle aspiration, the diagnostic yield from such lesions can be initially classified as cystic or solid. We describe the fine-needle aspiration findings in four cystic papillary neoplasms (three intracystic papillary carcinomas and one intracystic papilloma) and three solid masses (two sclerosing ductal lesions and one infiltrating ductal carcinoma with prominent papillary component). The smears were examined with respect to the following features: cellularity, architectural pattern in cell groups, cytologic pleomorphism, degree of cohesiveness, morphology and size of individual cells, anisonucleosis, nuclear-cytoplasmic ratio, irregularity of nuclear contour, chromatin texture, macronucleoli, the presence of bipolar nuclei, apocrine cells, and multinucleated giant cells. A combination of cytologic and clinical characteristics may be helpful in distinguishing benign from malignant papillary lesions. © 1994 Wiley-Liss, Inc.     

Are epithelial cells in fat or connective tissue a reliable indicator of tumor invasion in fine-needle aspiration of the breast?

The diagnosis of breast carcinoma tumor invasion by fine-needle aspiration (FNA) cytology continues to be controversial. To assess the reliability of predicting tumor invasion by FNA, we examined the cytologic smears of 183 FNAs of benign and malignant solid epithelial lesions of the breast for which histologic follow-up was available. The study group consisted of 94 invasive carcinomas, eight pure ductal carcinomas in situ (DCIS), and 81 benign lesions (fibroadenoma, fibrocystic changes, papilloma, adenosis). Epithelial cellularity, presence of epithelial cells in dispersed fat droplets and presence of epithelium within intact fragments of fibrofatty connective tissue were tabulated. Epithelial cellularity in dispersed fat was semiquantitatively scored. The cytologic diagnosis of the epithelial cells in all cases was recorded as benign, malignant, or indeterminant for malignancy. Findings showed that 95.5% of invasive carcinomas, 100% of DCIS, and 68.1% of benign lesions contained epithelial cells in dispersed fat; 80.8% of invasive carcinomas, 66.7% of DCIS, and 60.7% of benign lesions contained epithelial cells in intact fibrofatty connective tissue. Corrected score of epithelium within fat was 0.781 for invasive carcinoma, 0.727 for DCIS, and 0.562 for benign lesions. The difference in values for all parameters was not statistically significant between invasive carcinoma and DCIS, but reached significance between invasive carcinoma and benign lesions. Eighteen cases (7/94 invasive carcinoma, 5/8 DCIS, 6/81 benign lesions) contained atypical epithelial cells indeterminant for malignancy, all of which had epithelial cells present in dispersed fat when dispersed fat was present on the slides, indicating that this criterion was not helpful in discriminating between a benign and malignant diagnosis. We conclude that the presence of epithelial cells either admixed within dispersed fatty droplets or seemingly within fragments of fibrofatty connective tissue is not a reliable indicator of tumor invasion in FNA of the breast, and is frequently found in both benign and malignant breast lesions. The presence of epithelial cells in intact or dispersed fat is most likely a mechanical artifact of aspiration and/or smear preparation. Diagn. Cytopathol. 16:137–142, 1997. © 1997 Wiley-Liss, Inc.     

Fine-needle aspiration cytology of medullary breast carcinoma: report of two cases and review of the literature with emphasis on differential diagnosis

Medullary carcinoma is a rare variant of breast carcinoma with a relatively good clinical prognosis as strictly defined. Characteristic features on fine-needle aspiration cytology (FNAC) allow medullary carcinoma to be considered in the cytologic differential diagnosis. We present two FNAC cases with such features, including high cellularity with clusters and single intact malignant cells, bizarre stripped nuclei with prominent nucleoli in a lymphoplasmacytic background, and illustrate one case in liquid-based preparation. Surgical excision revealed that one patient had medullary carcinoma, while the second patient had high-grade infiltrating ductal carcinoma. Breast FNAC samples with syncytial fragments, bizarre nuclei with prominent nucleoli, and a chronic inflammatory infiltrate should raise the possibility of medullary carcinoma. However, the differential diagnosis also includes high-grade ductal carcinoma, lymphoma, or metastasis to breast or intramammary lymph nodes; thus, histopathologic analysis is required for definitive diagnosis.     

Increased content of Type V Collagen in desmoplasia of human breast carcinoma.

Type V (AB) collagen is present in increased amounts in desmoplasia of human breast carcinoma. Type V collagen occurs as linear deposits in the interstitium (desmoplastic stroma surrounding the tumor), as demonstrated by immunofluorescence and immunoperoxidase techniques utilizing antibodies to Type V collagen. In contrast, no demonstratable Type V occurs in the interstitium of fibroadenoma, fibrocystic disease, or normal breast tissue. As identified and quantitated by pepsin extraction, salt fractionation, and polyacrylamide gel electrophoresis, Type V constitutes 10% +/- 5% of all interstitial collagens (Types I, III, and V) in desmoplasia, compared with 1.5% +/- 0.5% in fibroadenoma and less than 0.1% in all types of fibrocystic disease, including sclerosing adenosis, and less than 0.1% in normal breast tissue. For infiltrating ductal carcinoma, Type V collagen is not secreted by the invasive carcinoma cells, nor is it present in an extracellular basement membrane location. By immunohistologic methods, Type V collagen can be seen exclusively in the desmoplastic stroma. The authors propose that desmoplasia of human breast carcinoma manifests a characteristic collagen profile and that the increased Type V may be produced by specialized cells such as myofibroblasts in the interstitium, which are recruited in response to invasive carcinoma.     

Cytopathologic differential diagnosis of low‐grade urothelial carcinoma and reactive urothelial proliferation in bladder washings: a logistic regression analysis

Conventional cytomorphologic assessment is the first step to establish an accurate diagnosis in urinary cytology. In cytologic preparations, the separation of low‐grade urothelial carcinoma (LGUC) from reactive urothelial proliferation (RUP) can be exceedingly difficult. The bladder washing cytologies of 32 LGUC and 29 RUP were reviewed. The cytologic slides were examined for the presence or absence of the 28 cytologic features. The cytologic criteria showing statistical significance in LGUC were increased numbers of monotonous single (non‐umbrella) cells, three‐dimensional cellular papillary clusters without fibrovascular cores, irregular bordered clusters, atypical single cells, irregular nuclear overlap, cytoplasmic homogeneity, increased N/C ratio, pleomorphism, nuclear border irregularity, nuclear eccentricity, elongated nuclei, and hyperchromasia (p ? 0.05), and the cytologic criteria showing statistical significance in RUP were inflammatory background, mixture of small and large urothelial cells, loose monolayer aggregates, and vacuolated cytoplasm (p ? 0.05). When these variables were subjected to a stepwise logistic regression analysis, four features were selected to distinguish LGUC from RUP: increased numbers of monotonous single (non‐umbrella) cells, increased nuclear cytoplasmic ratio, hyperchromasia, and presence of small and large urothelial cells (p = 0.0001). By this logistic model of the 32 cases with proven LGUC, the stepwise logistic regression analysis correctly predicted 31 (96.9%) patients with this diagnosis, and of the 29 patients with RUP, the logistic model correctly predicted 26 (89.7%) patients as having this disease. There are several cytologic features to separate LGUC from RUP. Stepwise logistic regression analysis is a valuable tool for determining the most useful cytologic criteria to distinguish these entities.     

Superficial endometriosis of the cervix: A source of abnormal glandular cells on cervicovaginal smears

Superficial endometriosis of the cervix, a benign process which may be associated with atypical glandular cells of undetermined significance (AGUS) on cervicovaginal (CV) smears, is becoming increasingly recognized on colposcopic examination. This study details the clinical, cytologic, and histology features of six cases of superficial cervical endometriosis. All CV smears featured atypical endocervical-like columnar cells in sheets and strips as well as cells with endometrial characteristics including solid cohesive, crowded, overlapping glandular groups, loss of cellular polarity, and a frequent ragged "feathered" edge appearance with protruding nuclei, occasional rosette formations, and endometrial stroma. Recognition of endometrial stroma in continuity with groups of cells with these features on CV smears may suggest the diagnosis of this benign condition. However, the cytologic features of endometriosis show sufficient overlap with those of precancerous and cancerous glandular lesions that many of these cases will continue to be diagnosed as "atypical glandular cells."