Diagnostic pitfalls in fine needle aspiration cytology of atypical apocrine metaplasia in a breast lesion. A case report

BACKGROUND: Apocrine metaplastic cells are frequently encountered in fine needle aspirates of breast lesions. Atypical apocrine metaplastic cells with signet ring features can also occur, and their presence may present a diagnostic dilemma in the differentiation of benign versus malignant lesions. CASE: A fine needle aspirate of a 2.5 x 1.0-cm, subareolar mass in a 47-year-old female showed atypical cells with signet ring morphology. Also present were clusters of cells that were enlarged and showed nuclear atypia, prominent nucleoli and cytoplasmic granules. Papillary cohesive clusters of ductal cells were also identified. The fine needle aspiration diagnosis was mucinous carcinoma. The nodule was excised, and the histologic diagnosis was sclerosing ductal papilloma with atypical apocrine metaplasia. CONCLUSION: Atypical apocrine cells can be misinterpreted as mucinous carcinoma or usual duct adenocarcinoma on fine needle aspiration cytology. We present clues that may help in rendering the correct interpretation.     

Fine needle aspiration cytology of lactating adenoma of the breast. A comparative light microscopic and morphometric study

Six cases of lactating adenoma of the female breast diagnosed by fine needle aspiration (FNA) were reviewed. The FNA cytologic diagnostic features included a usually moderately cellular aspirate with an abundant foamy background material, intact epithelial lobules or acini and small groups and solitary epithelial cells that contained uniform nuclei, fine chromatin and prominent nucleoli. When present, the cytoplasm was finely vacuolated or wispy; many nuclei appeared stripped of their cytoplasm. These features were compared light microscopically with the cytopathologic features of six cases of invasive well-differentiated ductal adenocarcinoma, seven cases of invasive lobular carcinoma, one case of granulocytic sarcoma and one case of primary histiocytic lymphoma of the breast. In addition, cytomorphometric analysis demonstrated no statistically significant differences in the nuclear areas of lactating adenoma as compared with those of well-differentiated ductal carcinoma and lobular carcinoma.     

Histiocytoid change in breast carcinoma: a report of 3 cases with an unusual cytomorphologic pattern of apocrine change

BACKGROUND: Breast carcinomas composed predominantly or exclusively of cells with foamy and/or granular cytoplasm have been termed histiocytoid breast carcinoma. CASES: Three cases of HBC had fine needle aspirates that were moderately cellular and composed of cells with abundant foamy and/or granular cytoplasm, arranged in loosely cohesive groups and dispersed singly. The cells showed subtle cytologic atypia, including nuclear hyperchromasia and slightly irregular nuclear outlines. Definitive cytologic diagnosis was not possible in the 3 cases, and they were reported as "suspicious for malignancy." Core biopsies of 2 cases showed a typical Indian file pattern of invasive lobular carcinoma, while the third case was composed of sheets of discohesive histiocytoid cells admixed with a prominent lymphoid infiltrate. All 3 cases were E-cadherin negative, confirming their lobular nature. CONCLUSION: HBC represents an unusual morphologic pattern of apocrine change that may be seen in lobular and ductal breast carcinomas. Recognition of these lesions is vital in that they may be mistaken for a variety of other entities composed of foamy/granular cells; some of those entities have vastly different implications for treatment and prognosis.     

Fine needle aspiration (FNA) appearances of malignant myoepithelioma of the parotid gland

We describe the FNA features of five cases of malignant parotid myoepithelioma, the majority of which were thought clinically to be recurrent pleomorphic adenomas. A major finding was cell shape variation: round-oval, polygonal or spindle-shaped, with basophilic cytoplasm. Many were epithelial and plasmacytoid-like and had nuclear grooves, pseudoinclusions, and multinucleation. the true myoepithelial nature of the neoplastic cells was identified in all cases, but only two showed obvious cytological malignant features, both initially and on re-examination. FNA of malignant myoepithelioma may thus show overt features of malignancy, or may lack atypia and malignancy can only be identified on histology. the correct diagnosis can be predicted in FNA samples in certain cases, both in terms of typing and malignancy, whilst sometimes only the myoepithelial nature of the lesion can be assessed.     

Stereotaxic fine needle aspiration cytology of clinically occult malignant and premalignant breast lesions

Stereotaxic fine needle aspiration (FNA) cytology was used to study clinically occult (nonpalpable) breast lesions in 114 consecutive patients with mammographically suspicious findings prior to excisional biopsy. The aspirate contained insufficient material for cytologic evaluation in 15 cases (13.2%), which were histologically diagnosed as benign (7 cases), atypical hyperplasia (7 cases) or carcinoma in situ (1 case). The cytologic findings indicated a benign lesion in 77 cases (67.5%), which were histologically diagnosed as benign (71 cases) or atypical ductal hyperplasia (6 cases). The cytologic sample showed atypia in eight cases (7.0%), which were histologically diagnosed as severe atypical ductal hyperplasia (three cases), carcinoma in situ (one case) or proliferative fibrocystic disease (four cases). In the eight cases (7.0%) cytologically interpreted as probably malignant, histology confirmed six invasive carcinomas, one carcinoma in situ and one fibrocystic disease. Of six cases (4.4%) cytologically reported as malignant, five were histologically diagnosed as invasive carcinoma and one as carcinoma in situ. Overall, stereotaxic FNA cytology reported as malignant or probably malignant 14 of the 15 cases with a histologic confirmation of malignancy, for a sensitivity of 93.3%. Cytology correctly identified 78 of the 83 histologically negative cases, for a specificity of 94.0%. The 16 cases histologically diagnosed as ductal hyperplasia, which carries a high risk for subsequent malignancy, were studied in detail in an effort to define histologic and cytologic criteria for this entity. Using selected histologic criteria, 11 of these cases were graded as showing mild-to-moderate atypical hyperplasia and 5 as showing severe atypical hyperplasia. Three of the latter cases were similarly identified by an analogous cytologic grading; the other two cases had insufficient cytologic samples. The total results in this series of 114 cases support the use of stereotaxic FNA cytology in the diagnosis of these nonpalpable breast lesions, examples of which are illustrated. In particular, it may help to raise the low specificity yielded by mammography alone, which would represent a significant advance for the patient in terms of the accuracy, expediency and reduced cost of diagnosing these lesions.     

Gynecomastia: cytologic features and diagnostic pitfalls in fine needle aspirates.

OBJECTIVE: To illustrate some of the uncommon cytologic findings of gynecomastia, such as apocrine metaplasia, cellular atypia and foamy macrophages, that can be misinterpreted as evidence of malignancy. STUDY DESIGN: The clinical data and fine needle aspiration (FNA) cytologic material from 100 men with the diagnosis of gynecomastia were retrospectively reviewed. The excisional biopsy slides were available for 16 cases. For comparison, FNA smears from five men with breast lesions other than gynecomastia were studied. RESULTS: The patients ranged in age from 23 to 91 years. Cytologic findings were as follows: cohesive sheets of cells containing 20-1,000 cells (98%); scattered, single, bipolar cells (78%); spindle cells (68%); ductal epithelial atypia (26%); apocrine metaplasia (8%); and foamy histiocytes (12%). In nine cases the atypia was marked, and in two of them the possibility of malignancy could not be ruled out. Surgical follow-up on 16 patients, including the cases with marked atypia, showed gynecomastia. In one case, gynecomastia was associated with intraductal papilloma. No correlation between the underlying etiology and atypical cytologic features of gynecomastia was identified. CONCLUSION: Apocrine metaplasia and epithelial atypia are common findings in gynecomastia. Attention to the cell patterns, the presence of sheets of ductal cells and absence of atypical single cells will point to the correct diagnosis.     

Benign mucocele-like lesion of the breast: how to differentiate from mucinous carcinoma before surgery.

The aim of the study was to improve the pre-operative diagnosis of mammary mucinous lesions. All mucinous lesions detected by fine needle aspiration (FNA) and confirmed by histological examination were reviewed by cytological findings, mammographic appearances and sonographic findings. Twenty aspirates had corresponding pathology, including 12 mucinous carcinomas, two mucocele-like lesions (MLL) with atypical ductal hyperplasia, three MLL with ductal hyperplasia and three simple MLL. Simple MLL and mucocele-like with ductal hyperplasia showed scant cellularity, no or rare intact single tumour cells, monolayered arrangement and absence of nuclear atypia. In contrast, most mucinous carcinomas showed higher cellularity, more single tumour cells, three-dimensional clusters, and mild to marked nuclear atypia. However, MLL with atypical ductal hyperplasia showed cytological features overlapping with mucinous carcinoma. MLL had a non-specific mammographic appearance and showed a cystic lesion on sonography. Mucinous carcinoma appeared as a solid mass on sonography and as a distinct nodule on mammography. Based on the combination of FNA cytology and image findings, benign MLL can be correctly distinguished from mucinous carcinoma before surgery.     

Epithelial atypia in gynecomastia induced by chemotherapeutic drugs. A possible pitfall in fine needle aspiration biopsy.

The clinical, cytopathologic and histopathologic features of a case of gynecomastia induced by chemotherapeutic drugs are described. Fine needle aspiration (FNA) smears showed epithelial atypia, and an erroneous cytologic diagnosis of carcinoma was made. Histopathologic study showed gynecomastia with epitheliosis, papillomatosis and atypical ductal hyperplasia. Review of the FNA smears showed the findings to be more typical of a reparative or regenerative process; these findings had been cytologically overinterpreted, partly due to the lack of adequate clinical information submitted with the aspirate. The possible causes of gynecomastia, the induction of epithelial atypia by cytotoxic chemotherapy and the cytologic features whose recognition may prevent false-positive diagnoses in such cases are discussed.     

Fine needle aspiration cytology of mammary duct ectasia: report of a case with novel cytologic and immunocytochemical findings.

BACKGROUND: Mammary duct ectasia (MDE), or periductal mastitis, is a well-defined clinical entity with a characteristic histopathologic appearance on breast biopsy specimens. However, the cytologic features of MDE have been described only recently in the cytopathology literature, and fine needle aspiration (FNA) cytologic findings are based mainly on a small number of case reports in the English-language literature. Therefore, awareness of this entity and recognition of its cytomorphologic features could aid in a more accurate diagnosis. We report the novel cytologic and immunocytochemical findings on a case of MDE that was confirmed by histologic examination on a subsequent biopsy. CASE: We report the findings of breast FNA cytology in a 50-year-old female with a mammographically and clinically suspicious lesion. Cytology displayed a paucicellular aspirate, typified by a few scattered, cohesive clusters of ductal epithelial cells with mild nuclear atypia and distinct, peripherally located myoepithelial cells. Intermingled within the ductal elements were numerous polygonal cells with abundant, finely vacuolated cytoplasm that were immunoreactive for macrophage-specific antibody, CD68. The background consisted of a variable number of foam cells and negligible amount of blood. CONCLUSION: The current case of MDE demonstrates cytomorphologic features that may pose diagnostic problems, particularly as a consequence of variable cytologic atypia this entity may present on FNA cytology. This diagnostic difficulty is compounded because of the abnormal mammographic and suspicious clinical findings that may be associated with MDE. CD68 immunoreactivity is a useful ancillary tool to verify the histiocytic, rather than epithelial and potentially neoplastic, nature of multivacuolated cells. To the best of our knowledge, there has been no prior reported case of MDE in the English-language literature studied utilizing CD68 antibody. This case report emphasizes that MDE is a heterogeneous entity with diverse cytomorphologic features. FNA cytology in conjunction with immunocytochemistry might permit accurate classification in the proper clinical setting.     

Accuracy of cytologic interpretation of pancreatic neoplasms by fine needle aspiration and pancreatic duct brushings

OBJECTIVE: To investigate the accuracy of fine needle aspiration (FNA) specimens and pancreatic duct brushings in the detection of pancreatic lesions and to compare the results with follow-up biopsy and/or surgical interpretation. STUDY DESIGN: We reviewed a total of 57 specimens (37/20), 37 FNA specimens and 20 pancreatic duct brushings, from 45 patients treated at Froedtert Memorial Lutheran Hospital, affiliated with the Medical College of Wisconsin, Milwaukee, over a 4-year period. The FNA and brushing samples were categorized as follows: positive for malignancy (21/3 = 24), suspicious for malignancy (8/7 = 15) and atypical (8/10 = 18). The results were then correlated with the tissue diagnosis. RESULTS: The 24 cytologic samples positive for malignancy included 23 (20/3) pancreatic ductal carcinoma (CA) and 1 (1/0) neuroendocrine CA; in the suspicious category, 11 (6/5) were pancreatic ductal CA; 2 (0/2) mucinous neoplasms and (2/0) neuroendocrine neoplasms; in the atypical category; 2 (2/0) suggestive of mucinous neoplasia, 1 (1/0) suggestive of serous neoplasia and 9 (2/7) favor reactive; and 6 (3/3) without further categorization. Tissue diagnoses were available in 26 cases: 12 (10/2) cases positive for malignancy, 8 (5/3) suspicious for malignancy and 6 (5/1) atypical. The 12 cytologically positive cases confirmed by histology showed 10 ductal CA, 1 neuroendocrine CA and 1 negative. All 8 cases (100%) suspicious for malignancy revealed positive results, including 5 ductal CA, 1 neuroendocrine neoplasm, 1 mucinous cystic neoplasm and 1 lymphoma. Of the 6 atypical lesions, 1 showed ductal CA, 2 mucinous cystic neoplasm and 3 chronic pancreatitis. CONCLUSION: Pancreatic FNA and duct brushings [table: see text] are accurate methods in identifying pancreatic lesions, particularly ductal CA. Accuracy can be improved in the case of mucinous and other lesions with adequate cellularity of the smear and recognizing the limitations of brush samples in the case of mucinous cystic lesions. False negative results may occur in cases of poor representation of malignant cells or poor sampling.     

Inflammatory myofibroblastic tumor of the breast. A case report

BACKGROUND: Inflammatory myofibroblastic tumor (IMT) of the breast is a very rare tumor like lesion with only 6 previously reported cases. Very little is known about the cytology of IMT. We present the fine needle aspiration (FNA) cytology of a case of recurrent, bilateral IMT of the breast and detail the clinical course, radiologic findings, morphologic appearances and immunohistochemical profile of the lesion. CASE: A 79-year-old female was initially seen in 1991 because of a suspicious mammographic abnormality in her right breast. Ultrasound-guided FNA cytology showed an unusual "inflammatory" lesion with occasional aggregates of cellular connective tissue fragments, sheets of uniform ductal epithelial cells with myoepithelial cells, spindle cells, lymphocytes and histiocytelike cells. The lesion was excised, and histology confirmed a benign process with spindle cells, lymphocytes and histiocytes. No malignant features were noted. During follow-up many new lesions appeared in both breasts, and after several FNA procedures and local excisions, bilateral mastectomy was performed at the patient's urging. She remained disease free. CONCLUSION: Although IMT of the breast has benign cytology and histology, clinically and on imaging, it resembles carcinoma. Awareness of the condition may help prevent a false diagnosis of carcinoma.     

Signet ring cells in fine needle aspiration cytology of breast carcinomas: review of the cytological findings in ten cases identified by histology

Objective:  To establish whether the presence of signet ring cells (SRCs) in histology sections of breast carcinoma cases was reflected by their presence in fine needle aspiration cytology (FNAC) smears, correlating to the histological type of breast carcinoma.
Methods:  We reviewed the FNAC findings of ten cases that had been diagnosed as primary breast carcinoma with SRCs on histological sections between 1998 and 2007. Slides and histological sections were obtained from the archives of Ege University Hospital.
Results:  FNA smears were reviewed for the following cytomorphological features: background, cellularity, architecture, nuclear pleomorphism and the presence of SRCs. The background was bloody in eight cases, necrotic in one, and clean in one. There was no mucinous material in any of the cases. Cellularity was prominent in five cases (hypercellular), moderate in three (cellular) and low in two (hypocellular). Loosely cohesive groups of tumour cells of varying size were observed in all cases. A plasmacytoid appearance to some of the tumour cells was seen in all cases and discohesive tumour cells were present in eight. Nuclear pleomorphism was high in six cases and moderate in four. SRCs were observed in seven of the ten cases. Two of these seven cases also had a tubular pattern and one had tumour giant cells.
Conclusions:  FNAC should be evaluated carefully regarding the presence of SRCs when cells with a plasmacytoid appearance are observed in either hyper- or hypocellular smears. The presence of single SRCs in FNACs with hypercellularity, high nuclear grade and tubular formation or tumour giant cells may be a clue in favour of ductal carcinoma. The presence of single SRCs in FNACs with hypocellularity and mild to moderate nuclear grade may be suggestive of lobular carcinoma. However, larger studies would be needed to establish the predictive value of the presence of SRCs on FNAC.     

False negative cytologic diagnosis of breast carcinoma.

OBJECTIVE: To study the reasons for interpretive errors in false negative diagnosis of breast carcinoma on fine needle aspiration cytology material. STUDY DESIGN: We reviewed only those histologically proved malignant cases where the cytologic material was abnormal and to some extent misinterpreted. RESULTS: There were four lobular carcinomas and one each case of in situ, infiltrating duct, medullary and tubular carcinoma. Smears of lobular carcinomas were hypocellular overall, and the cells showed minimal nuclear pleomorphism. In situ, medullary and tubular carcinoma were associated with fibrocystic changes. The presence of bipolar cells and stromal fragments was misleading in cases of infiltrating duct carcinoma. CONCLUSION: The presence of associated fibrocystic disease may be a misleading factor since it may mask a malignancy. Hypocellularity and relatively nuclear monomorphism were the most common reasons for failure to diagnose malignant breast lesions. Careful attention should be paid to extreme nuclear monomorphism and absence of naked bipolar cells. A cytologically atypical or suspicious diagnosis together with radiologic suspicion should suggest a diagnosis of malignancy.     

Biliary tract brush cytology

OBJECTIVE: To prospectively review brush smears obtained during endoscopic retrograde cholangiopancreatography (ERCP) primarily from the biliary tree. STUDY DESIGN: A total of 175 specimens from 147 patients were included in the study. The smears, prepared directly from the endoscopic brush, were stained by the Papanicolaou technique and analyzed for standard cytologic features. RESULTS: The smears were categorized into benign/reactive, significant atypia and suspicious/positive. The consistent features seen in suspicious or positive smears were tightly cohesive, small, three-dimensional cell clusters that formed cell balls. The cells in the clusters displayed features of malignant cells. CONCLUSION: ERCP-guided brushing is a safe diagnostic procedure for the evaluation of biliary tree lesions. Small, three-dimensional epithelial clusters with marked atypia signify malignancy and warrant the diagnosis of a malignant neoplasm even when only one or two such clusters are seen in the smears. Single cells, cytoplasmic vacuoles and prominent nucleoli are not essential for a diagnosis of malignancy.     

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.     

Small cell undifferentiated carcinoma of the parotid gland. Cytologic, histologic, immunohistochemical and ultrastructural features of a neuroendocrine variant

A case of primary small cell undifferentiated carcinoma (SCUC) of the parotid gland, diagnosed initially by fine needle aspiration (FNA) cytology and confirmed by histology, immunohistochemistry and transmission electron microscopy (TEM), is presented. The FNA cytologic features that enabled an accurate diagnosis of this rare salivary gland tumor included nuclear granularity and markedly angular nuclear molding of numerous small cells that were usually present as large syncytia in an inflammatory background. Numerous mitotic figures were also present in this vascular lesion. These features were also evident in the surgical specimens. Immunohistochemistry demonstrated neuron-specific enolase positivity while TEM demonstrated intracytoplasmic neurosecretory granules in this case, indicating a neuroendocrine derivation for this neoplasm instead of the more usual origin of salivary gland SCUCs in ductal epithelial or myoepithelial tissue.     

Molecular classification of breast carcinoma in situ

Pleomorphic variant of invasive lobular carcinoma (PILC) is an aggressive variant of invasive lobular carcinoma (ILC). Its in situ counterpart, pleomorphic lobular carcinoma in situ (PLCIS) is a recently described entity. Morphologically it has the typical architectural pattern of LCIS, but the neoplastic cells resemble intermediate grade DCIS. Molecular signatures that distinguish PLCIS from DCIS and LCIS would provide additional tools to aid in the histopathologic classification of PLCIS as a lesion distinct from LCIS and DCIS. CIS lesions, obtained from a study cohort of 38 breast cancer patients, were divided into 18 DCIS, 14 PLCIS and 6 LCIS. DNA from microdissected archival tissue was interrogated for loss or gain of 112 breast-cancer-specific genes using the Multiplex Ligation-dependent Probe Amplification Assay (MLPA). Classification Regression Tree (CART) analysis was employed to develop a gene-based molecular classification to distinguish or separate out PLCIS from DCIS and LCIS. Molecular classification via CART, based on gene copy number, agreed with histopathology in 34/38 CIS cases. Loss of CASP1 was predictive of LCIS (n=4) with one misclassified PLCIS. Gain of RELA predicted only the LCIS classification (n=2 cases). STK15 and TNFRSF1B were predictive only for DCIS with no misclassifications. Gain of EHF and TNFRSF1B and loss of NCOA3 were predictive of PLCIS, but not without misclassification. Molecular reclassification by CART was accomplished in 4 CIS cases: 1 PLCIS was reclassified as LCIS, 1 LCIS reclassified as PLCIS, and 2 DCIS cases as PLCIS. This study provides additional rationale for molecular modeling strategies in the evaluation of CIS lesions. This diagnostic aid may serve to minimize misclassification between PLCIS and DCIS, and PLCIS and LCIS, aiding to increase accuracy in the differential diagnosis of CIS lesions.     

A morphologic and morphometric study of cells from colloid carcinoma of the breast obtained by fine needle aspiration. Distinction from other breast lesions

Morphologic and morphometric studies were carried out on eight cases of pure and mixed colloid carcinoma of the breast initially diagnosed by fine needle aspiration (FNA). Key morphologic features included (1) cellular smears, (2) single cells, loose aggregates and cohesive groups of cells bathed in a mucinous background, (3) single cells displaying nuclear eccentricity and (4) little variation in nuclear size or shape, with bland-to-accentuated chromatin and rare nucleoli. These morphologic features are compared with those observed in pregnancy adenoma, lobular carcinoma, fibroadenoma, ductal carcinoma and medullary carcinoma. A morphometric study employing the major and minor axes of the nucleus, its axis product and axis ratio was also performed. Statistical treatment confirmed that the nuclear axis product (a size factor) distinguished colloid carcinoma from the other breast lesions, except the small-cell type of ductal carcinoma. Furthermore, the nuclear axis ratio (a shape factor) discriminates pregnancy adenoma and small-cell ductal carcinoma from the other breast lesions studied. By combining morphologic and morphometric criteria, one can specifically separate colloid carcinoma from the other breast lesions when examining smears obtained by FNA. Since colloid carcinoma is usually composed of cells with a relatively benign-appearing cytomorphology, the importance of recognizing this entity in fine needle aspirates is emphasized.     

Thyroid Bethesda reporting category, ‘suspicious for papillary thyroid carcinoma’, pitfalls and clues to optimize the use of this category

A. Mahajan, X. Lin and R. Nayar Thyroid Bethesda reporting category, ‘suspicious for papillary thyroid carcinoma’, pitfalls and clues to optimize the use of this category Objective: The Bethesda System of Reporting Thyroid Cytopathology classifies the indeterminate categories based on their differing risks of malignancy, as atypia of undetermined significance (AUS), follicular neoplasm/suspicious for follicular neoplasm (FLUS) and suspicious for malignancy. The vast majority of cases of the last category are suspicious for papillary thyroid carcinoma (PTC). The aim of the present study was to identify the pitfalls and clues to improve the usage of the suspicious category as well as improve its outcome of malignancy. Methods: We reviewed the cytological features on air dried Diff‐Quik® and alcohol‐fixed Papanicolaou smears from 54 thyroid fine needle aspirates (FNAs) with surgical follow‐up that were originally diagnosed as suspicious. Procedure data/specimen adequacy was correlated and follow‐up histology reports were reviewed after our cytological review was completed. Incidental PTC that was not the target of the FNA was excluded from the calculations for correlation. Results: In our cytological review, we retained a diagnosis of suspicious in 18 of the 54 cases and the remaining 36 were re‐categorized as follows: 6 malignant, 10 neoplasm (which is used in our centre instead of FLUS) and 20 AUS. The reasons for overcall of suspicious cases included pseudopapillae, syncytial sheets, nuclear grooves and pinpoint nucleoli in chronic lymphocytic thyroiditis and Hürthle cell neoplasms, and intranuclear inclusions in parathyroid adenoma, hyalinizing trabecular adenoma and mesenchymal repair. The primary reasons for undercall of PTC as suspicious included cystic aspirates with minor features of PTC such as histiocytoid cells, bubblegum colloid, syncytial sheets and cellular swirls. Cases with cytoplasm similar to Hürthle cells were also noted to cause difficulty in accurate classification. Conclusions: Recognition of these pitfalls and clues can help improve diagnosis, patient treatment and consequently reduce the number of unnecessary thyroidectomies.     

Cytomorphologic and morphometric limitations of the assessment of atypia in fibroadenoma of the breast

OBJECTIVE: To investigate the relevance of nuclear morphometry in separating the categories of "fibroadenoma" and "fibroadenoma with atypia." STUDY DESIGN: Thirty consecutive breast lumps, on which a fine needle aspiration (FNA) diagnosis of fibroadenoma was followed by excision and histopathologic confirmation of the diagnosis, were included. Atypia on cytology was based on cell overlap, nuclear enlargement and cell dyscohesion. Nuclear morphometric comparison was carried out between the categories of fibroadenoma, fibroadenoma with atypia and grade 1 ductal carcinoma cases that formed part of an earlier study. The parameters employed were area, roundness, diameter, perimeter and grey level. RESULTS: Among the 30 cases of fibroadenoma reported on FNA, an additional component of atypia was noted in 5. On subsequent histopathology, atypia was not confirmed in any of the cases. On morphometric analysis, a significant difference was noted between fibroadenoma and fibroadenoma with atypia categories, as between fibroadenoma and grade 1 ductal carcinoma cases. However, no significant difference was noted between fibroadenoma with atypia and grade 1 ductal carcinoma cases. CONCLUSION: FNA assessment of atypia in cases of fibroadenoma is difficult. Even conventional nuclear morphometry, though supporting the initial impression of atypia, does not help with this assessment. Also, based on morphometry alone, there may be difficulty separating fibroadenomas with atypia and grade 1 ductal carcinomas. Larger studies, employing other morphometric parameters, such as chromatin texture and fractal dimension, may shed further light on the subject.