Fine needle aspiration cytology of ductal breast carcinoma with neuroendocrine differentiation. Review of eight cases with histologic correlation

OBJECTIVE: To describe the fine needle aspiration cytology findings of ductal breast carcinoma with neuroendocrine differentiation and correlate them with the histologic appearance. STUDY DESIGN: We reviewed the cytologic features of eight cases of ductal carcinoma with neuroendocrine differentiation in the files of Pamela Youde Nethersole Eastern Hospital during the three-year period 1998-2000. Immunohistochemical study for neuroendocrine markers was performed, with ultrastructural correlation. RESULTS: All cases showed similar cytologic features. The smears were of moderate to high cellularity with predominantly dispersed or loosely cohesive tumor cells. The carcinoma cells were mostly of low cytologic grade. They possessed round and relatively uniform, eccentric nuclei; finely stippled chromatin; sometimes small, distinct nucleoli; and discrete cell borders. Abundant eosinophilic and focally granular cytoplasm was a common finding. In some of the cases there was accentuation of staining in the paranuclear region; it correlated with aggregates of dense core neurosecretory granules seen ultrastructurally. Mucoid substance was seen in the background in some of the aspirates. Histologic examination of the tumors showed invasive ductal carcinoma with an organoid growth pattern and sometimes mucinous component. The neuroendocrine differentiation was confirmed immunohistochemically. CONCLUSION: Although this subtype of ductal carcinoma probably carries no significant prognostic value per se, it has distinct cytologic features, rendering preoperative diagnosis possible. Recognition of this entity is important in order to avoid the misdiagnosis of neuroendocrine tumor metastatic to the breast.     

Aspiration biopsy smear pattern as a predictor of biologic behavior in adenocarcinoma of the breast.

Fine needle aspiration cytology (FNAC) is increasingly used for the initial diagnosis of breast carcinoma, yet few studies have investigated the prognostic importance of cytologic features seen in breast FNAC. We studied the relationship between prognosis and smear morphology in 26 patients with breast carcinoma for whom information from long-term follow-up was available. Specifically, we attempted to correlate nuclear grade and smear pattern with hormonal receptor status, lymph node status, breast recurrence and distant metastasis. In an additional five patients (on whom insufficient follow-up information was available), smear pattern and nuclear grade were correlated with hormonal status. Smears were classified into three patterns: typical (sheets and clusters), individual cell predominant and cluster predominant. The individual cell predominant pattern was associated with an increased incidence of distant metastasis when compared with the other two smear patterns (P less than .05). No statistically significant association was observed between smear pattern and the other factors studied. Nuclear grade 2 (of 3) was also associated with an increased incidence of distant metastasis. However, most grade 2 tumors (10/12) were of the individual cell predominant pattern. Smear pattern classification, along with DNA ploidy analysis and hormone receptor analysis of FNAC-derived material, may yield valuable prognostic information.     

Infiltrating micropapillary carcinoma of the breast. Cytologic findings

OBJECTIVE: To examine the cytologic features of infiltrating micropapillary carcinoma (IMPC). METHODS: Using the histopathology files of one of the authors (I.J.B.), we retrospectively identified 20 IMPC cases (pure, 12; partial micropapillary carcinoma differentiation, 8) with corresponding cytology. We evaluated the cases for cellularity, atypia, architecture and background. RESULTS: All cases were diagnostic of malignancy, characterized by atypical cells present predominantly in three-dimensional clusters and single cells, facilitating the diagnosis. The clusters had cell ball and papillarylike arrangements, like the morular growth pattern seen on histopathology. Apocrine cytology was present in 12 cases, focal mucin background in 5 and psamomma bodies in 2. The differential diagnosis includes primary papillary neoplasms of the breast, metastatic ovarian papillary serous carcinoma, apocrine and colloid carcinoma of the breast, and intraductal carcinoma (micropapillary type). CONCLUSION: As in histopathology, the cytologic features of IMPC are unique and should be recognized due to its aggressive behavior.     

Small cell carcinoma of the bladder. Two cases diagnosed by urinary cytology

BACKGROUND: Primary small cell carcinoma (SCC) of the bladder is a rare but important entity. We report two cases of SCC of the bladder diagnosed by urinary cytology. CASES: A 71-year-old male (case 1) and a 79-year-old female (case 2) presented with asymptomatic gross hematuria. Urinary cytology in case 1 showed the presence of a few undifferentiated malignant small cells and many transitional cell carcinoma (TCC) cells with a bloody and necrotic background. The former cells were small and round, with naked, hyperchromatic nuclei and finely granular chromatin. Pathologic diagnosis after total cystectomy was TCC > SCC > adenocarcinoma, T2M0N0. Urinary cytology of case 2 showed the presence of many undifferentiated malignant small cells and many TCC cells with or without squamous metaplasia. Cytologic features of the former cells were almost the same as those in case 1. Moreover, these cells were neuroendocrine marker positive by immunocytochemistry. Pathologic diagnosis after tumor resection was SCC and TCC > squamous cell carcinoma, T1b. CONCLUSION: The prognosis of primary SCC of the bladder is usually poor. Because our cases were found by urinary cytology at a relatively early stage, both have been well, without any evidence of recurrence, 30 and 25 months after surgery even without adjuvant therapy.     

Granular cell tumor of the parotid gland. A case report

BACKGROUND: Granular cell tumor (GCT) is a relatively uncommon soft tissue tumor of putative Schwann cell origin. This tumor can occur in multiple sites as a small, nontender nodule, but the parotid gland is unusual, and only several cases have been reported. CASE: A 46-year-old woman presented with a slowly growing mass in the left preauricular region for three years. Imaging studies confirmed a nodular lesion in the superficial lobe of the left parotid gland. Fine needle aspiration (FNA) cytology revealed scattered cellular clusters and single cells with abundant granular cytoplasm and indistinct cell borders. Background exhibited eosinophilic, granular, cytoplasmic material, and some scattered naked nuclei were also noted. Histologic examination with supportive immunohistochemical and ultrastructural studies confirmed GCT. CONCLUSION: GCT of the parotid gland is very unusual. Recognition of this tumor is important to make a definitive diagnosis before an operation. FNA is useful procedure in GCT of parotid gland for a preoperative diagnosis and proper treatment.     

Cytology of pleomorphic lobular carcinoma with apocrine cell differentiation of the breast. A case report

BACKGROUND: Pleomorphic lobular carcinoma (PLC) with apocrine differentiation is a rare breast carcinoma, and its cytologic findings have not been reported before. CASE: A 75-year-old woman had a mass in and skin rash on the left breast. Apocrine carcinoma was suggested on aspiration cytology of the mass. The cytologic smears showed a small number of rounded to oval, atypical cells that were poorly cohesive and individually scattered. The cytoplasm was relatively abundant and contained coarse granules and dropletlike, orange granules (Lendrum's granules). The cell border was distinct. Some atypical cells had intracytoplasmic lumina. The nucleoli were round and prominent, and nuclear chromatin was finely granular. The background was clean. Histologically, the tumor cells proliferated mainly in an Indian file pattern and showed a concentric, targetoid pattern around the non-neoplastic ducts. The cytoplasm was abundant, eosinophilic, granular, positive for the periodic acid-Schiff reaction and diastase resistant. Immunohistochemically the tumor cells were positive for gross cystic disease fluid protein-15 (GCDFP-15) and negative for E-cadherin. Lendrum's granules showed positive expression of GCDFP-15 and lysozyme. CONCLUSION: PLC with apocrine differentiation and apocrine carcinoma may be cytologically confused. Poor cellularity, less cohesiveness, finely granular chromatin, a nonpolyhedral cellular outline and clean background indicate the former rather than the latter. It is important to be aware that PLC presents a variety of cytologic configurations.     

Primary malignant lymphoma of the uterine corpus diagnosed by endometrial cytology. A case report

BACKGROUND: A relatively small number of cases of primary malignant lymphoma of the uterine corpus have been reported, and it is rare for cases to be preoperatively diagnosed by cytology. CASE: A 59-year-old female experienced abnormal uterine bleeding of two months' duration. Preoperative evaluation of endometrial cytology revealed malignant cells. These cells demonstrated a rather round or oval configuration, with a markedly increased nuclear/cytoplasmic ratio, and were isolated and scattered in an inflammatory background. The nuclei were round or oval, and macronucleoli were marked. The cytologic diagnosis was malignant lymphoma. Postoperative histologic evaluation verified the presence of a primary malignant lymphoma in the uterine corpus, with a B-cell phenotype. CONCLUSION: Preoperative endometrial cytology correctly demonstrated malignant lymphoma of the uterine corpus.     

Fine needle aspiration cytology of hepatoblastoma. Recognition of subtypes on cytomorphology

OBJECTIVE: To delineate the cytomorphologic appearances of hepatoblastoma (HBL) in the largest series to date and to evaluate the feasibility of subtyping on fine needle aspiration cytology (FNAC). STUDY DESIGN: Papanicolaou- and May-Grünwald-Giemsa-stained smears of aspirates from 26 cases of HBL were analyzed by 2 observers. Histologic material, available in 15 cases, was correlated. A cytology grouping system was proposed on the basis of which all cases were classified. RESULTS: The ages of the patients ranged from 4 months to 9 years. Twenty-five cases were categorized as epithelial HBL, with epithelial fragments showing a trabecular arrangement and acinar formation in all, and extramedullary hemopoiesis in 20 cases. It was possible to differentiate fetal and embryonal areas on FNAC. Six cases showed only fetal elements (cytology group F), characterized by cells with abundant cytoplasm and a small, rounded nucleus resembling a normal fetal hepatocyte. The chromatin was finely granular, with a single, central nucleolus. Pleomorphism and mitoses were not seen, and the nuclear/cytoplasmic ratio was < or = 1/3. Fourteen cases showed, in addition to fetal elements, an embryonal component characterized by cells with scant cytoplasm, a pleomorphic nucleus, N/C ratio of > or = 3/1, coarsely granular chromatin and 2-4 angulated nucleoli. Mitoses were seen in these cells (1-4/1,000 cells). Of these 14 cases, 6 showed predominantly fetal and scant embryonal cells, while 8 cases showed fetal and embryonal components in equal amounts (cytology groups Fe and FE, respectively). Four cases showed predominantly embryonal cells (cytology group E). One case was unclassifiable (U). On histology, 8 of 14 cases were of mixed epithelial and mesenchymal type, but mesenchymal tissue was not seen on the corresponding cytology. The cytology grouping system correlated well with histology. One case was small cell undifferentiated HBL and resembled a round cell tumor without differentiation. Macrotrabecular arrangement was not seen on cytology but was seen on histology in 1 case. CONCLUSION: Epithelial HBL can be easily diagnosed in aspirates further classified into fetal and embryonal subtypes, which may be of prognostic relevance. The proposed cytology grouping system is effective in semiquantification of the observed subtypes.     

Fine needle aspiration cytology of neuroendocrine tumors of the pancreas. A cytologic, immunocytochemical and electron microscopic study.

We report the fine needle aspiration cytology findings in six cases of neuroendocrine tumor of the pancreas. Three cases were from the pancreas, two from hepatic metastases and one from a peripancreatic lymph node metastasis. The cytologic features that permitted a preoperative diagnosis of pancreatic neuroendocrine tumor were: a cellular aspirate; numerous isolated cells and irregular, loose, dyshesive cellular aggregates; minimal nuclear pleomorphism; infrequent mitoses; fine, evenly dispersed nuclear chromatin with occasional inconspicuous nucleoli; a scant-moderate amount of granular, amphophilic, well-defined cytoplasm; clustering of tumor cells around segments of capillaries; and rosette formation. The differential diagnosis includes cells derived from normal pancreatic acini, islet cell hyperplasia, acinic cell carcinoma, well-differentiated pancreatic adenocarcinoma, metastatic small cell undifferentiated carcinoma of the lung, pancreatic small cell anaplastic carcinoma and malignant lymphoma. The application of immunocytochemistry to cytologic smears can be easily and reliably performed to confirm the neuroendocrine nature of the tumor and identify the specific type of polypeptide hormone or hormones produced by these tumors. Four aspirates showed immunoreactivity for chromogranin, and one was positive for gastrin. Cells of a lipid-rich neuroendocrine tumor were negative for chromogranin; however, the tissue section contained neuron specific enolase, and neurosecretory granules were demonstrated by electron microscopy.     

Expression of cytokeratin 20 in urine cytology smears: a potential marker for the detection of urothelial carcinoma

BACKGROUND: Urine cytomorphology is one of the oldest methods for screening and monitoring patients with transitional cell carcinoma (TCC). Sensitivity of urine cytology is relatively low. Ancillary techniques on urine sample may increase the sensitivity. AIM: To explore the utility of cytokeratin 20 (CK20) immunostaining in identifying malignant cells in urine cytology smears. MATERIALS AND METHODS: Fourteen cases each of confirmed TCC and benign urinary cytology along with five cases of atypical cells in urine were immunostained with a monoclonal CK20 antibody. Of 14 cases of TCC, 12 showed strong positive staining with the antibody. All benign cases were negative except for a few cases in which the umbrella cells were weakly to moderately positive. In all five cases of atypical urine cytology the atypical cells stained positive with the antibody. These cases were later confirmed as TCC on histopathology of bladder wall biopsy. CONCLUSION: CK20 is an important biomarker that can be used to identify TCC in urine cytology smears. It is particularly useful in those cases where malignancy cannot be confirmed by morphology alone.     

Paranuclear blue inclusions of small cell carcinoma of the stomach: report of a case with cytologic presentation in peritoneal washings

BACKGROUND: Primary gastric small cell carcinoma is a rare but important entity. We describe a case that we diagnosed by peritoneal washing cytology. CASE: A 70-year-old male presented with upper abdominal discomfort and underwent endoscopic evaluation. Gastric endoscopy revealed a diffuse, infiltrating tumor from the body to the antrum. Total gastrectomy with lymph node dissection and intraoperative peritoneal washing cytology were carried out. Peritoneal washing cytology showed the presence of many undifferentiated malignant small cells with a necrotic background. The tumor cells were small and round, with naked, hyperchromatic nuclei and finely granular chromatin. Some tumor cells contained paranuclear blue inclusions (PBls) in the cytoplasm. The tumor cells were positive for neuron-specific enolase and synaptophysin on immunocyto-chemistry. Carcinoembryonic antigen, alpha-fetoprotein (AFP) and leukocyte common antigen were negative. Pathologic diagnosis after the operation was moderately to poorly differentiated adenocarcinoma and small cell carcinoma containing AFP-positive cells. CONCLUSION: The prognosis of primary gastric small cell carcinoma is usually poor. Our patient died of multiple liver metastases and peritonitis carcinomatosa 69 days after surgery. When a gastric small cell carcinoma is suspected in peritoneal washings, immunocytochemical demonstration of neuroendocrine differentiation is required to arrive at the final diagnosis.     

Independent prognostic value of hormone receptor expression and S-phase fraction in advanced breast cancer

OBJECTIVE: TO assess the prognostic value of immunocytochemically assessed hormone receptor expression and DNA flow cytometry data in advanced breast cancer. STUDY DESIGN: This prospective study with long-term follow-up evaluated the above parameters in relation to overall survival in 392 patients with advanced breast cancer (stages IIB, n = 106; IIIA, n = 66; IIIB, n = 174; and IV, n = 46) using fine needle aspiration cytology. RESULTS: Estrogen and progesterone receptor positivity was detected in 65.1% and 46.1% of the tumors, respectively. DNA aneuploidy was present in 70.9% of the cases, and the median S-phase fraction (SPF) was 9.4%. There was a significant correlation of aneuploidy and high SPF with lack of hormone receptors. The median SPF and SPF tertiles (cutoff values, 6.5% and 12%), applied in the whole series, showed a significant correlation with survival, whereas if SPF was used according to ploidy status, no prognostic significance was found. No differences in relation to survival among different DNA aneuploidy subclasses were verified. In univariate analysis, clinical staging, hormone receptors, DNA ploidy and SPF showed a statistically significant correlation with the overall survival. In multivariate analysis only DNA ploidy did not maintain independent prognostic significance. CONCLUSION: Hormone receptor expression and flow cytometric SPF are independent prognostic factors in advanced breast cancer.     

Characteristic cytological features of histological grade one (G1) breast carcinomas in fine needle aspirates

Objective:  To analyse the spectrum of nuclear features as well as dissociation pattern found in fine needle aspirates (FNAC) from histological grade 1 breast carcinomas and evaluate the critical cytological features of these lesions.
Material and methods:  The material consisted of FNAC smears from 494 histologically confirmed grade 1 breast carcinomas. All smears were revaluated for cell dissociation pattern, nuclear size, cell uniformity, nucleoli, nuclear margin and chromatin pattern. All features were compared with the histological subtype and cytological grading.
Results:  73.9% of the cases were cytological grade 1, 24.3% were grade 2 and 1.8% were grade 3. The majority of the cases had a cell dissociation pattern showing both a population of single carcinoma cells and cell clusters (65.9%). Practically all tumours had a granular chromatin pattern (94.7%) and a slightly irregular nuclear margin with folds and grooves (94%) irrespective of histological subtype and cytological grading. Nucleoli were mostly indistinct or small (74%), whereas 24.3% were noticeable and 1.7% abnormal. Practically all cases revealed some degree of pleomorphism with 74.3% showing mild and 22.4% a distinct pleomorphism. A small subgroup of IDC was classified as monomorphic (3.3%). Almost all tumours had nuclear sizes in the range of 2–4 × RBC (96.9%).
Conclusion:  Not all histological grade 1 carcinomas are cytological grade 1. About 25% were grade 2, and a small subpopulation reached grade 3. The typical/average findings in FNAC from grade 1 breast carcinomas were a population of both groups and single cells showing mild pleomorphism, granular chromatin, slightly irregular nuclear margin, indistinct nucleolus and nuclear size 2–4 × RBC.     

Cell cycle-dependent AgNOR analysis in invasive breast cancer

OBJECTIVE: To investigate to what extent analysis of silver-stained nucleolar organizer regions (AgNORs) is cell cycle dependent in breast cancer and to assess the prognostic value of an AgNOR analysis that takes into consideration the cell cycle status of tumor cells. STUDY DESIGN: In 97 cases of invasive breast carcinoma, morphometric AgNOR analysis was performed in tumor cells with immunohistochemical MIB-1 reactivity (NORcyc analysis) and in MIB-1-negative tumor cells (NORnon analysis). Additionally, conventional (NORconv) analysis without preceding MIB-1 staining was done. Findings were compared with the Nottingham prognostic index (NPI). RESULTS: In comparison to noncycling tumor cells, cycling ones exhibited significantly higher AgNOR numbers (mean values, 3.84 +/- 1.09 vs. 2.40 +/- 0.78 per nucleus), higher total AgNOR areas (5.95 +/- 3.17 vs. 5.62 +/- 3.05 micron 2, NS) and significantly lower mean AgNOR areas (2.08 +/- 1.14 vs. 2.93 +/- 1.69 micron 2). When related to NPI, correlation coefficients of NORnon analysis were higher than those of NORcyc analysis but lower than those of NORconv analysis. Among the different AgNOR parameters, total AgNOR area correlated best with NPI. CONCLUSION: Cell cycle status has a high impact on AgNOR analysis. However, the best prognostic information in breast cancer is derived from an AgNOR analysis that considers both cycling and noncycling tumor cells.     

Fine needle aspiration cytology diagnosis of a cutaneous granular cell tumor in a 7-year-old child. A case report

BACKGROUND: Granular cell tumors are neoplasms of uncertain histogenesis, although a neural origin is favored. Most reports on the cytologic features of granular cell tumors have been on lesions from the breast or respiratory tract. However, there are only a few reports on fine needle aspiration (FNA) cytologic diagnosis of cutaneous or soft tissue granular cell tumors. CASE: A 7-year-old girl presented with a skin lesion on her right forearm of one year's duration. The FNA smears showed sheets and clusters of oval to polygonal cells with an abundant amount of granular cytoplasm. Many single, scattered cells with similar morphology were seen in the background. Immunostaining for S-100 protein showed granular cytoplasmic positivity. The tumor was diagnosed as a benign granular cell tumor. The histopathology report on the excised lesion confirmed the FNA diagnosis. CONCLUSION: The cytopathologic features of granular cell tumors presenting as skin lesions are distinctive enough to allow a correct diagnosis on FNA cytology.     

Fine needle aspiration cytology of sclerosing adenosis of the breast

OBJECTIVE: To analyze the cytologic findings of sclerosing adenosis of the breast. STUDY DESIGN: We reviewed the fine needle aspiration (FNA) cytologic slides of 7 cases of sclerosing adenosis of the breast and compared the cytologic findings with those of 10 cases of fibroadenoma and 7 cases of fibrocystic change. RESULTS: The smears of sclerosing adenosis were moderately to markedly cellular, consisting of small to large groups of benign epithelial cells arranged with variable architecture. Acinar sheets, scattered individual epithelial cells and small, dense, hyalinized stroma were found in all cases of sclerosing adenosis. Epithelial cells in sclerosing adenosis appeared more frequently as acinar sheets and discohesive individual cells than did those of fibroadenoma (P < .05). However, the branching pattern of epithelial sheets, large sheets and bipolar, naked nuclei were commonly found in fibroadenoma (P < .05). Fibroadenoma had large, hypocellular, fibromyxoid stroma, whereas sclerosing adenosis had small, dense, hyalinized stroma occasionally attached to the epithelial sheets. As compared with fibrocystic change, sclerosing adenosis had similar findings but showed more abundant cellularity, acinar sheets and individual epithelial cells, and the presence of stroma (P < .05). CONCLUSION: Findings of frequent acinar sheets and small, dense, hyalinized stroma attached to epithelial sheets can aid the FNA cytologic diagnosis of sclerosing adenosis. Awareness of the presence of scattered individual epithelial cells in cytologic smears of sclerosing adenosis can help prevent a misdiagnosis of malignancy.     

Cytologic appearances in invasive lobular carcinoma of the breast. A study of 21 cases

OBJECTIVE: To examine the fine needle aspiration cytologic features of invasive lobular carcinoma of breast and to discuss problems that may occur in cytodiagnosis. STUDY DESIGN: Fine needle aspiration cytologic smears from 21 cases of invasive lobular carcinoma (ILC) of breast were subjected to detailed cytomorphologic analysis. Features studied included pattern of cells, size of cells, nuclear placement, pleomorphism, presence of intracytoplasmic lumina (ICL) and signet ring cells. RESULTS: Cellularity was generally moderate or high, and the pattern was predominantly or partly dissociated in 86% of cases. Rosettelike pattern was discerned in alveolar-type ILC. Cell size was usually small or intermediate, with nuclei placed eccentrically in most cases. ICLs with or without signet ring cells were present in 12 cases (57%). CONCLUSION: A cytologic picture consisting of predominantly dissociated small or intermediate-sized tumor cells with eccentric nuclei, with some of the cells showing ICLs, is highly suggestive of ILC. Indian file pattern, another characteristic feature of ILC, is, however, focal and inconsistent. Variant patterns of ILC may show other cytologic features, such as rosettelike pattern (alveolar variant of ILC) or large cell pattern (pleomorphic variant of ILC) and may consequently be difficult to categorize on cytologic smears.     

Pleomorphic lobular carcinoma of the breast. A case report

BACKGROUND: Pleomorphic lobular carcinoma of the breast is associated with aggressive behavior. CASE: Fine needle aspiration cytology was performed on a breast lump in a 55-year-old woman. The aspirates showed highly pleomorphic, large cells in a dyscohesive pattern, with a tendency of few cells to aggregate in small groups. A diagnosis of ductal carcinoma was made on cytology. On histology, the paraffin sections showed features of pleomorphic lobular carcinoma of the breast. CONCLUSION: The cytologic features of pleomorphic lobular carcinoma overlap with those of infiltrating ductal carcinoma. It is very difficult to make a diagnosis of pleomorphic lobular carcinoma prospectively on cytology. However, if Indian file arrangement and cytoplasmic vacuolation are present, pleomorphic lobular carcinoma must at least be suggested for the differential diagnosis as it has different clinical implications.     

Papillary breast lesions diagnosed on cytology. Profile of 65 cases

OBJECTIVE: To analyze the cytologic features of nipple discharge and fine needle aspiration (FNA) cytologic smears from breast lesions reported as showing papillary features and to correlate them with histopathologic features. STUDY DESIGN: The study group consisted of FNA smears and/or nipple discharge smears from 65 breast lesions diagnosed on cytology as duct papilloma, papillary lesion, fibrocystic condition, fibroadenoma, papillary neoplasm or papillary carcinoma. Cytomorphologic features assessed included cellularity, cell pattern (clusters, papillary, 3-dimensionality, etc.) and cell characteristics (monomorphism, pleomorphism, apocrine change, plasmacytoid features). Histological material was available for review and cytohistologic correlation in all cases. RESULTS: Forty-six specimens were FNA smears, and 16 were nipple discharge smears; in 3 cases FNA and nipple discharge cytologic smears were available for review. Cytologic study could predict the presence of a papillary pattern in all neoplasms with pure or focal papillary differentiation. There was an overlap in cytomorphologic features between papillary and nonpapillary benign lesions as well as between benign and malignant papillary neoplasms. Frank blood in the aspirate, cell dissociation and atypia, however, were more frequent in the last. CONCLUSION: Overlap of cytologic features in nonneoplastic and neoplastic benign papillary lesions and between benign and malignant papillary neoplasms necessitates histologic evaluation in all cases diagnosed as papillary on cytology. Since 49.2% of lesions showing papillary features on cytology prove to be malignant, all cases reported as papillary on cytology should be excised urgently for histologic assessment.     

Significance of squamous cells in fine needle aspiration cytology of the breast. A review of cases in a seven-year period

OBJECTIVE: To delineate the significance of detecting squamous cells in fine needle aspiration biopsy of breast lesions. STUDY DESIGN: The authors reviewed 15 cases of fine needle aspiration cytology of the breast with a discernible number of squamous cells from the files of Pamela Youde Nethersole Eastern Hospital, Hong Kong, during a seven-year period from the start of 1994 to the end of 2001. The cytologic features were correlated with clinical, radiologic and histologic findings, if any. RESULTS: Among the 15 fine needle aspirates of the breast with a discernible number of squamous cells, 5 of them represented metaplastic carcinoma. The remaining consisted of 3 cases of fibroepithelial tumors, 1 case of duct ectasia, 3 cases of subareolar abscess, 2 cases of sclerosed intraduct papilloma and 1 case of benign breast cyst. In general, benign squamous cells were bland looking and often associated with anucleated squames. They were mitotically inactive and could show a good maturation pattern. Tumor cell cannibalism was rare. The presence of abundant, foamy macrophages in the background suggested a benign lesion. The primary diagnosis could be deduced by recognition of other features, such as the presence of myxoid stromal tissue and papillary structures. In contrast, malignant squamous cells in metaplastic carcinoma were more pleomorphic and mitotically active. Dyskeratosis and tumor cell cannibalism were obvious. Tumor diathesis and bizarre-shaped cells were sometimes found. CONCLUSION: Squamous cells occur in fine needle aspirates from a number of benign and malignant breast lesions. Benign conditions with abundant squamous cells may sometimes mimic malignant squamous lesions and vice versa. Careful assessment of the cytologic features of squamous cells and background appearance is crucial for achieving a correct diagnosis.