Comparative cytology of mucocelelike lesion and mucinous carcinoma of the breast in fine needle aspiration

OBJECTIVE: To study the fine needle aspiration cytology (FNAC) features of mucocelelike lesion (MLL) of the breast and to compare them to those of mucinous carcinoma. STUDY DESIGN: The fine needle aspiration (FNA) smears of 7 cases of histologically proven MLL (2 malignant and 5 benign, including 4 associated with atypical ductal hyperplasia) were reviewed and compared to those of 14 mucinous carcinoma cases. RESULTS: In all cases, grossly visible thick, mucoid material was obtained from FNA. The most important features for distinguishing benign MLL from mucinous carcinoma were: (1) scant cellularity; (2) no or rare single, intact tumor cells; (3) tumor cells arranged in cohesive monolayers; and (4) absence of significant nuclear atypia. In contrast, mucinous carcinoma in general showed higher cellularity; abundant single, intact cells; three-dimensional cellular clusters in most cases; and nuclear atypia ranging from mild to severe. CONCLUSION: Mucinous lesions of the breast should be divided into MLL and frank mucinous carcinoma based on FNAC. However, FNAC diagnosis of malignant MLL has yet to be defined. Excisional biopsy is advised for all hypocellular cases for further separation into benign and malignant MLL and to rule out the possibility of hypocellular mucinous carcinoma.     

O‐6RESPECTIVE ROLES OF FINE NEEDLE ASPIRATION CYTOLOGY AND CORE BIOPSY IN DIAGNOSIS OF SYMPTOMATIC BREAST LESIONS

Introduction: To evaluate and compare the respective roles of fine needle aspiration cytology and core biopsy for diagnosis of symptomatic breast lesions. Methods: Retrospective study on 589 breast fine needle aspiration cytology (FNAC) cases and 88 core biopsies (CB) with no associated FNAC, performed between January and December 2004. A computer database was searched for initial results, subsequent investigations and outcomes. Results: Of the cases that had FNAC performed as an initial investigation, the final diagnosis was reached by FNAC alone in 81.8% of cases. Of these, 59.2% were benign, 6.1% malignant and 2.4% remaining suspicious with 14.1% inadequate samples. There were 31 cases reported as suspicious (C3/C4) on FNAC, of these 14% of C3 and all of C4 were malignant on CB. Of the 86 cases that had both FNAC and CB, CB improved on the FNAC diagnosis of malignancy in 19.8% of cases, half of which were considered inadequate on FNAC. The positive predictive value of malignant cases was 100%, and the negative predictive value 98%. The absolute sensitivity of FNAC in this study was 65% and complete sensitivity 72%. The false negative rate was 8% and false positive rate 0%. The diagnosis of 88 CB without FNAC showed 37.5% to be malignant and 60.2% as benign, with 2.3% as inadequate biopsies. Discussion: FNAC remains the first line investigation in symptomatic breast lesions. Its best use is in the diagnosis of benign disease which constitutes over two thirds of patients in our practice. In suspicious and clinically malignant lesions, it is complemented by CB which may provide additional information relevant to management. In conclusion, the majority benign findings in our patients who had CB without prior FNAC, does not justify the use of CB as a first line investigation. CB is indicated in cases of inadequate or suboptimal FNAC. The continuous use of suspicious categories (C3/C4) in breast cytology is justified by the subsequent outcomes, both benign and malignant.     

The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas

Bonzanini M., Gilioli E., Brancato B., Cristofori A., Bricolo D., Natale N., Valentini A., and Dalla Palma P. (2001)Cytopathology 12, 107-119. The cytopathology of ductal carcinoma in situ of the breast. A detailed analysis of fine needle aspiration cytology of 58 cases compared with 101 invasive ductal carcinomas. The existence of cytological findings that discriminate ductal carcinoma in situ (DCIS) of the breast from invasive ductal carcinoma (IDC) has not been unanimously accepted and the role of fine needle aspiration cytology (FNAC) remains controversial. We report the cytological findings of a large series of FNAC from histologically proven DCIS compared with those of ductal carcinomas having a different extent of the invasive component. The association of high cohesiveness of atypical cells and absence of tubular aggregates showed good sensitivity (SE) and specificity (SP) for the diagnosis of DCIS vs IDC. The simultaneous presence of necrotic background, atypical cells with abundant eosinophilic cytoplasm and a low percentage of single malignant cells resulted in low sensitivity but high specificity and positive predictive value (PPV) for differential cytological diagnosis of DCIS vs IDC.     

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.     

Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas

Role of fine needle aspiration cytology in diagnosis of pleomorphic adenomas This retrospective study was carried out to review the cases diagnosed as pleomorphic adenoma in major or minor salivary glands and determine the difficulties encountered on typing this tumour on fine needle aspiration cytology (FNAC). Over a 19‐year period (1982–2000) 488 pleomorphic adenomas were diagnosed on FNAC from different sites (parotid – 372 cases, submandibular – 95 cases; oral cavity – 21 cases). Histology was available in 232 cases. Twenty‐nine cases where a histological diagnosis of pleomorphic adenoma was made but the cytological diagnosis was variable were also reviewed. In 216 of the 232 cases a good cytohistological correlation was available. On review only 4 of the 16 cases initially diagnosed as pleomorphic adenoma on FNAC where the histology revealed a different tumour were categorized as pleomorphic adenoma, while 3 each were classified as adenoid cystic carcinoma and benign tumour ?type, and 2 each were diagnosed to be muco‐epidermoid carcinoma, monomorphic adenoma and acinic cell carcinoma. On review of the FNAC smears from 29 cases where a histological diagnosis of pleomorphic adenoma was available while the cytological diagnosis was variable, only 11 (38%) were categorized as pleomorphic adenoma. In the majority of the remaining cases the cytological diagnosis did not alter markedly, 7 of 10 cases where the tumour could not be typed on cytology initially could not be typed even on review. In conclusion, FNAC is an ideal, fairly accurate preoperative procedure for the diagnosis of pleomorphic adenomas. Certain diagnostic problems occur in differentiating pleomorphic adenomas from adenoid cystic carcinoma, monomorphic adenoma and mucoepidermoid carcinoma. Carcinoma ex‐pleomorphic adenoma is difficult to identify on FNAC and in our series all 4 such cases on histology were considered benign on cytology.     

Primary non-Hodgkin's lymphoma of the breast: a case report

Extranodal non-Hodgkin's lymphoma (NHL) of the breast is a rare entity. It represents 0.04-1.1% of malignant tumors of the breast. 1.7-2.2% of extranodal lymphomas and 0.7% of all NHL. However, primary NHL (PNHL) is the most frequent hematopojetic tumor of the breast. CASE: A 23-year-old woman presented with a mass in the left breast for 3 months followed by enlarged left axillary lymph nodes. Mammography showed a diffuse increase in the density of the left breast. Other investigations were unremarkable. Both fine needle aspiration cytology (FNAC) and histopathology were diagnostic of NHL. Immunohistochemistry was confirmatory of NHL, diffuse large cell type, of B-cell lineage. CONCLUSION: Primary and secondary lymphomas of the breast, though rare, should be considered in the differential diagnosis of breast malignancies. PNHL of the breast is usually right sided, but this patient had left breast involvement. Diagnosis by FNAC was successful as the cytologic picture is similar to that of any other lymphoid or extranodal NHL. When histopathology and immunohistopathology are conclusive, FNAC, supplemented by immunocytochemistry, can be applied as a simple, reliable and cost-effective tool in the early diagnosis of breast lymphomas.     

Fine needle aspiration cytology of follicular variant of papillary carcinoma of thyroid

In this retrospective study, we tried to ascertain the fine needle aspiration cytology (FNAC) features of six histopathologically proven cases of the follicular variant of papillary carcinoma of thyroid (FVPCT). These proven cases were diagnosed from 1998-2000. May-Grunwald-Giemsa and haematoxylin & eosin stained FNAC smears were studied independently by two observers (MP and PD) for detailed cytological features. A comparison of the cytological features was undertaken with those reported in the literature. There were six cases of which only one case was diagnosed as FVPCT while the other five cases were diagnosed as follicular neoplasm (four cases) and neoplasm unclassifiable (one case) on FNAC smears. All these cases showed abundant cellularity with a prominent follicular pattern. No papillae were identified in any of the cases. Syncytial clusters (five cases), nuclear grooves (six cases), nuclear inclusions (one case) and chewing gum colloid (three cases) were noted in variable proportions. We suggest that a differential diagnosis of FVPCT should be considered if the cytology smears show abundant cellularity, syncytial clusters and follicular arrangement along with thick colloid.     

Fine needle aspiration cytology of metastatic choriocarcinoma presenting as a breast lump. A case report

BACKGROUND: While choriocarcinoma is a rapidly invasive, widely metastasizing malignancy, it responds well to chemotherapy, so it is important to obtain an early diagnosis. We report the fine needle aspiration cytology (FNAC) of a case of choriocarcinoma metastatic to the breast. CASE: A 48-year-old female presented with a cough, hemoptysis and epistaxis. Chest computed tomography revealed multiple nodules in both lung fields. Also, a firm, slightly tender mass in the lower outer quadrant of the left breast was palpated. The breast mass was clinically suspected to be a metastatic lung cancer. FNAC of the breast showed a malignant tumor that had been misdiagnosed as a metastatic non-small cell carcinoma of the lung. Histologic examination of a nasal biopsy revealed metastatic choriocarcinoma. CONCLUSION: The cytologic features of choriocarcinoma are quite characteristic, with side-by-side, malignant, mononucleated cells and multinucleated giant cells corresponding to cytotrophoblasts and syncytiotrophoblasts, respectively. The disease is possible to diagnose by a careful examination of FNAC samples.     

Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology

U. Handa, S. Chhabra and H. Mohan
Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology Objective: Plasma cell tumours represent autonomous proliferation of plasma cells and can manifest as multiple myeloma, monoclonal gammopathy of undetermined significance, variants of plasma cell myeloma or plasmacytoma. Methods: We report 12 cases of plasma cell tumours, which were initially diagnosed as plasmacytoma on fine needle aspiration cytology (FNAC). The patients were further subjected to bone marrow examination, serum electrophoresis, urine examination for Bence–Jones proteins, and x‐ray examination of the skeleton. Results: The cytological smears from all cases were cellular and showed numerous plasma cells in varying degrees of maturity. Subsequent to investigations, five cases were labelled as multiple myeloma with secondary extramedullary plasmacytoma, three as solitary bone plasmacytoma and two as primary extramedullary plasmacytoma. In the remaining two cases, bone marrow and urine examination findings were not available, so a conclusive diagnosis of multiple myeloma or solitary plasmacytoma could not be made. Conclusion: The study highlights the role of FNAC in the diagnosis of plasma cell tumours. Subsequent work‐up and follow‐up of these patients is important to rule out the presence of multiple myeloma.     

Fine needle aspiration cytology of the thyroid: a comparison of 5469 cytological and final histological diagnoses

OBJECTIVE: We evaluated the efficacy of fine needle aspiration cytology (FNAC) of the thyroid in a series of 5469 lesions with histological control and studied the causes of, and the possibility of reducing the limitations of the method. METHODS: FNAC was always performed by a pathologist under the guidance of a clinician, using a 22-gauge needle. Generally two aspirations were carried out, and usually four slides were obtained for each nodule; they were then stained with May-Grünwald-Giemsa and with Papanicolaou. The cytological diagnoses were classified in four groups: inadequate, benign, suspicious and malignant. RESULTS: We obtained a complete sensitivity of 93.4%, a positive predictive value of malignancy of 98.6%, and a specificity of 74.9%. At histological control, the cytological diagnosis of Hurthle cell neoplasm corresponded to a significantly higher incidence of malignant neoplasms than the diagnosis of non-Hurthle cell follicular neoplasm (32.1% versus 15.5%). There were 66 false-negative findings, the main cause of diagnostic error (24 cases) being failure to recognize the follicular variant of papillary carcinoma. The number of inadequate FNACs was low (4.2%). CONCLUSION: Our study confirmed the great efficacy of thyroid FNAC. A cytological diagnosis of Hurthle cell neoplasm should be considered an indicator of high risk. Awareness that failure to recognize the follicular variant of papillary carcinoma was the main problem in the interpretation of thyroid FNAC should lead to a decrease of false-negative diagnoses. The inadequate rate was very low, as it was the pathologist personally who performed the needle aspiration.     

Inter- and intraobserver reproducibility of thyroid fine needle aspiration cytology: an analysis of discrepant cases

OBJECTIVE: To determine the inter- and intraobserver reproducibility and analyse the discrepant cases of fine needle aspiration cytology (FNAC) of the thyroid. METHODS: Cases of thyroid FNAC with a corresponding histological diagnosis were reviewed regarding the original cytological diagnoses by two observers. The final cytological diagnoses (FCD) included both concordant and consensus diagnoses. The inter- and intraobserver reproducibility and efficacy of thyroid FNAC were calculated based on the FCD. RESULTS: A total of 97 FNAC cases with corresponding histopathological specimens were analysed. Although inter- and intraobserver disagreement in the cytological diagnoses occurred in about one-quarter of the cases analysed (24.7% and 23.7%, respectively), a substantial level of diagnostic interobserver (kappa = 0.71) and intraobserver (kappa = 0.66) reproducibility was observed. The efficacy of the method was 94.4%. Disagreement in the diagnosis was detected in 24 cases (24.7%), most of them (41.7%) for follicular lesions. Discordant cytological diagnoses between the two observers were represented by six (16.2%) of the 37 cases with an FCD of colloid nodule, five (41.7%) of the 12 cases of cellular follicular lesion, all three cases of follicular neoplasm, in two (6.3%) of the 32 cases of PTC, one (16.7%) of six cases of follicular neoplasm with a predominance of Hürthle cells and in one case of poorly differentiated neoplasia. Similarly, major disagreement in intraobserver cytological diagnoses was observed for the diagnosis of follicular lesions: 18 (78.3%) of a total of 23 discordant cases. CONCLUSION: As discrepancies in the cytopathological diagnosis can have repercussions in the management of patients, all cases with a cytological diagnosis of follicular lesions/neoplams should be reviewed in multidisciplinary meetings thus minimizing interobserver variability.     

Cytomorphological changes after ultrasound-guided percutaneous ethanol injection in benign thyroid nodules

Objective:  To characterize the cytomorphological changes after percutaneous ethanol injection (PEI) in benign thyroid nodules, we compared the cytological features of fine needle aspiration cytology (FNAC) samples before and after PEI.
Methods:  Fifty-five cases diagnosed with adenomatous goitre (group 1, 35 cases) or cystic changes only (group 2, 20 cases) were included. In all cases, FNACs were performed by the pathologists before and after PEI. PEI was performed in all cases by a diagnostic radiologist according to the ultrasound guidelines. The following cytological features were evaluated by two pathologists: cellularity of follicular epithelial cells, background, cellular pleomorphism, nuclear/cytoplasmic (N/C) ratio, chromatin pattern, presence of nucleoli, macrophages, multinucleated giant cells, and mitosis.
Results:  In group 1, 19 cases (54%) showed changes in cellularity after PEI, with reduced cellularity in 13 cases (37%) and increased cellularity in six cases (17%). No necrotic background was observed before PEI; however, 14 cases (40%) developed necrotic background after PEI ( P  < 0.0001). Multinucleated giant cells were observed in 18 cases (51%) after PEI, which is in contrast to four cases (11%) before PEI ( P  = 0.001). In group 2, necrotic background was seen in 11 cases (55%, P  < 0.0001) and multinucleated giant cells were observed in four cases (20%) after PEI.
Conclusions:  Necrotic background and presence of multinucleated giant cells are indicative of tissue damage caused by PEI in the FNAC specimens of benign thyroid nodules. In contrast to other modalities including chemotherapy or radiation treatment for malignant tumour, no unusual cytological change is observed after PEI.     

Ultrasonographically and stereotactically guided fine-needle aspiration cytology of non-palpable breast lesions: cyto-histological correlation

Objective:  To determine the diagnostic accuracy of ultrasonographically (US) and stereotactically guided fine needle aspiration cytology (FNAC) for the diagnosis of non-palpable breast lesions.
Patients and methods:  From January 2002 to December 2004, 470 women with 478 mammographically detected non-palpable breast lesions had US or stereotactically guided FNAC of the breast lesion. Subsequent histological evaluation of the same lesion was performed at the Institute of Oncology Ljubljana, Slovenia. The correlation between the original cytological and histological diagnosis was assessed and the sensitivity, specificity, positive predictive value and negative predictive value were calculated.
Results:  Among US-guided FNACs, 144 (53.5%) were histologically verified benign lesions and 125 (46.5%) were carcinomas. Cytological diagnoses were: true positive (TP) in 63 cases (50.4%), suspicious in 35 (28%), false negative (FN) in eight (6.4%), and in 19 (15.2%) cases, the material was inadequate for diagnosis. In the stereotactically guided FNAC group, there were 209 women with 209 lesions, with 95 (45%) histologically proven carcinomas and 114 (55%) benign lesions. Cytological diagnoses were TP in 49 (51.6%) cases, true suspicious in 21 (22.1%), FN in nine (9.5%), and in 16 (16.8%) cases, the material was not adequate for the diagnosis.
Conclusion:  The sensitivity of 88.7% and specificity of 98.6% for US-guided FNAC and 84.5% and 100% for stereotactically guided FNAC, respectively, suggest that clinicians can rely upon cytological diagnosis for planning further management of women with non-palpable breast lesions.     

The diagnostic value of fine needle aspiration cytology (FNAC) in the assessment of palpable supraclavicular lymph nodes: a study of 218 cases

The aim of this study was to evaluate the diagnostic value of fine needle aspiration cytology (FNAC) in the assessment of palpable supraclavicular lymph nodes. The material was analysed in 218 cases with enlarged supraclavicular lymph nodes in which FNAC was performed by the conventional method. In all cases cytological examination was performed on-site after staining the smears by the Papanicolaou method. In addition, air-dried smears, fixed smears, filter preparations from needle washings and cell blocks were studied. The FNAC diagnosis was supported by examining cell blocks which added the reliability of histological architecture; further support was obtained by tissue biopsy and/or comparison with the primary tumour in some of the cases. Eleven cases were diagnosed as inflammatory lesions and 41 cases were unsatisfactory because of scanty/acellular samples (despite two to three repeat samplings). However, in five of these, malignant tumours were later found on biopsy, which was done for persistent enlargement of the supraclavicular lymph node(s). Fifty-three cases were diagnosed as negative for malignancy (normal cellular elements, n=15; reactive elements, n=38) and 12 cases were suspicious of malignancy. In 11 cases a diagnosis of lymphoma was made on histology and in 90 cases metastatic tumours were diagnosed. The overall sensitivity was 92.7%, specificity 98.5%, positive predictive value 97.3% and the negative predictive value was 94.8%. Based on our study we feel that FNAC of palpable supraclavicular lymph nodes as a first line of investigation is a cost-effective procedure and is not only useful in the diagnosis of various lesions but can also help in deciding on appropriate management. Furthermore, the histological architecture from cell blocks can be correlated with cytology, and such material can be used for appropriate histochemical and immunomarker studies, which can be useful in enhancing the diagnosis.     

Cytopathological diagnosis of alveolar soft part sarcoma,a rare soft tissue neoplasm

S. Agarwal, R. Gupta, V. K. Iyer, S. R. Mathur and R. Ray Cytopathological diagnosis of alveolar soft part sarcoma, a rare soft tissue neoplasm Objective: Alveolar soft part sarcoma (ASPS) is a rare soft tissue neoplasm, having various morphological mimics, especially on fine needle aspiration cytology (FNAC). Because no definite immunohistochemical markers are available to aid a correct diagnosis, knowledge of the cytomorphological features is essential for correct patient management. Cytological features of five cases of ASPS are discussed, along with the ultrastructural findings available in one of them. Methods: Cytology records from 1997 to 2009 were reviewed for cases with a diagnosis of ASPS on cytology. The histology slides of the cases were also assessed for confirmation of the diagnosis. All the slides were reviewed by three pathologists. Results: There were five cases of ASPS diagnosed on FNAC. Their cytological features were noted in detail. The diagnoses in all the cases were confirmed on histology, and ultrastructural findings available in one of them were also assessed. Conclusions: The knowledge of cytological features may aid in diagnosing this rare tumour correctly on FNA smears, thus enabling correct patient management.     

Fine needle aspiration cytology of primary non-Hodgkin's lymphoma of the tongue. A case report.

BACKGROUND: Fine needle aspiration cytology (FNAC) of extranodal non-Hodgkin's lymphoma of the tongue has rarely been described. CASE: A 47-year-old male was referred to the cytology laboratory for FNAC of a 3-cm-diameter swelling on the dorsum of the tongue, with a primary clinical diagnosis of soft tissue tumor. FNAC smears showed discrete, monomorphic, round to oval cells with scanty, deep blue cytoplasm. The nuclear margin was regular, with occasional prominent nucleoli and fine nuclear chromatin. The background showed many lymphoglandular bodies. The cells were strongly positive for leukocyte common antigen. A cytologic diagnosis of high grade non-Hodgkin's (NHL) was offered and subsequently confirmed by histopathology. CONCLUSION: Primary NHL of the tongue is relatively rare. As there are no characteristic clinical features of extranodal NHL of the tongue, FNAC may be useful for rapid diagnosis and management of such cases.     

Fine needle aspiration cytology of mammary carcinoma with choriocarcinomatous features: a report of 2 cases

BACKGROUND: Neoplasms of the breast containing multinucleated giant cells (MGCs) include both benign and malignant entities, such as benign soft tissue giant cell tumors, atypical fibrous histiocytoma, sarcomas, metaplastic carcinomas and the uncommon carcinomas containing osteoclast-like giant cells (OGC). Breast carcinoma with choriocarcinomatous features (BCCF) is a distinct variant of breast cancer. CASES: We report the cytologic features, pathologic findings and immunohistochemical profile in 2 cases of this unusual variant of breast carcinoma. Two women aged 53 and 50 years women presented with a history of left and right breast lump but no local lymphadenopathy, respectively. Fine needle aspiration cytology (FNAC) of both cases revealed abundant MGC with highly pleomorphic tumor cells in the hemorrhagic necrotic background. Both of the cases were histopathologically diagnosed as BCCF. CONCLUSION: Choriocarcinomatous differentiation with multinucleated syncytiotrophoblast-like giant cells is extremely rare in breast tumors. Although rare, FNAC of breast cancer with pleomorphic MGC requires careful search for differential diagnosis; breast carcinoma with giant cell features (choriocarcinomatous features, OGC features) must be differentiated from metastatic tumors and other breast lesions containing giant cells.     

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.     

The gray zone in breast fine needle aspiration cytology. How to report on it?

OBJECTIVE: To study the "gray zone" in breast fine needle aspiration cytology in which an unequivocal diagnosis cannot be reached with fine needle aspiration cytology findings. STUDY DESIGN: This study compared cytology and histopathology of 72 breast lesions in which an initial cytologic diagnosis of atypia was given. RESULTS: There were 36 benign (50%) and 36 malignant (50%) histologic biopsy cases in the cytologic atypia group. Anisonucleosis, chromatin and nuclear membrane irregularity, and presence of myoepithelial cells were significantly different in benign and malignant cases. CONCLUSION: The gray zone in breast fine needle aspiration cytology is a broad spectrum that changes from proliferative fibrocystic disease to sclerosing adenosis to malignancy. Diagnosing gray zone pathology as atypical in fine needle aspiration cytology causes no delay in treatment as excisional biopsy is recommended for all equivocal cases.