Cytological diagnosis of soft tissue tumours

Cytological diagnosis of soft tissue tumours The aims of this study were to determine the patterns of soft tissue tumours and also to try to assess the utility of fine needle aspiration cytology (FNAC) in diagnosing soft tissue tumours. Of 15 361 patients who visited the cytology diagnostic service of the Pathology Department, Medical Faculty, Addis Ababa University, 623 (4.1%) cases with a diagnosis of soft tissue tumours were retrieved from the department's records for the years 1991-96. Fifty-three soft tissue tumours (25 benign and 28 malignant tumours) with combined FNAC and surgical biopsy results were traced for cyto-histological correlations. Twenty-two out of 25 benign soft tissue tumours were correctly diagnosed, with three false cytologic diagnoses where one mesenchmal neoplasm, one haemangioma, and one haemorragic lesion were identified; and out of 28 malignant soft tissue, 23 were correctly diagnosed however, the five false cytological diagnoses were one soft tissue sarcoma, one dermatofibrosarcoma, one malignant mesenchymal neoplasm, one spindle cell neoplasm and one menechymal neoplasm. Thus, in this study a sensitivity and specificity of 88.5% and 81.5% respectively for the diagnosis of soft tissue tumours were reported. In conclusion, FNAC of soft tissue tumours is a fast, effective and reliable diagnostic tool that may help in categorizing soft tissue tumours into benign and malignant groups for clinical management.     

Stereotactic biopsy and cytological diagnosis of solid and cystic intracranial lesions

Cytological smears from 115 consecutive cases of stereotactic biopsies of intracranial lesions were reviewed. Ninety-five lesions were solid and 20 cystic. Material from 90 solid and 13 cystic lesions was sent both for cytological and histological examination. In 66 of the solid lesions, the cytological diagnosis was confirmed by histology (five were benign lesions and 61 malignant tumours: 56 primary brain tumours, three metastases and two lymphomas). In 24 cases with discrepant cytology and histology, the histology was inconclusive or insufficient in 14 cases, while cytology established the diagnosis of astrocytoma grade II (seven cases), metastases (two cases), gliosis (one case) and benign (four cases). Necrosis of tumour type was observed cytologically in six patients representing glioblastoma (two cases), anaplastic astrocytoma (one case), lymphoma (one case) and normal brain (two cases) histologically. Three cases reported cytologically as benign were primary brain tumour (two cases) and gliosis (one case). One smear of a glioblastoma was insufficient for cytological diagnosis. Cystic lesions were cytologically benign in 17 cases and malignant in three cases. Histology from the cyst wall confirmed the malignant diagnosis in three cases and showed tumour in six more cases, a benign process (two cases), changes induced by radiotherapy for arteriovenous malformation (one case) and insufficient material (one case). In conclusion, cytology from solid brain lesion allows an accurate diagnosis and subtyping of tumours in a majority of cases, and can thus be used to choose type of therapy. In cystic brain tumours, however, examination of the cystic fluid, is often inconclusive and a biopsy from the cyst wall should be performed if there is clinical or radiological suspicion of tumour.     

Fine needle aspiration cytology of the malignant variant of ossifying fibromyxoid tumor of soft parts: a case report

BACKGROUND: Ossifying fibromyxoid tumor (OFMT) of soft parts is a rare, recently defined, fibroosseous neoplasm, generally regarded as clinically benign; however, one-third of cases recur locally, and several malignant examples have been reported. Fine needle aspiration (FNA) cytology of the tumor is rarely described in the literature. We provide the first cytomorphologic study of the malignant variant. CASE: A 70-year-old man presented with an intramuscular mass in the right buttock. Computed tomography revealed ossification within the mass and multiple pulmonary nodules. FNA biopsy showed round and polygonal to spindled tumor cells, arrayed singly, cordlike or in small aggregates, with scattered dense stromal fragments and a slightly myxoid background. The nuclei showed significant pleomorphism accompanied by coarse chromatin with clumping, irregular contours, and one to two distinct nucleoli. The tumor cells were recognizable as sarcoma, with no evidence of high grade malignancy. The tumor was totally excised, histopathologically confirmed as the malignant variant of OFMT of soft parts, and immunohistochemically and ultrastracturally analyzed as of neural origin. CONCLUSION: The FNA specimen revealed that the cytomorphology was consistent with the histologic features of the malignant variant of OFMT, but several characteristic histologic parameters, such as multilobular proliferation and peripherally placed mature, bony trabeculae, were not reflected in the aspirates. Although FNA cytologic findings may be of limited diagnostic utility in OFMT, radiographic evidence of calcification/ossification suggests that OFMT should be subjected to differential diagnosis with fine needle aspiration biopsy of soft tissue tumors. Additional studies will be required for further clarification.     

Value of EUS‐FNA cytological preparations compared with cell block sections in the diagnosis of pancreatic solid tumours

Y. Kopelman, S. Marmor, I. Ashkenazi and Z. Fireman
Value of EUS‐FNA cytological preparations compared with cell block sections in the diagnosis of pancreatic solid tumours Objective: Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) is performed in order to achieve a definite tissue diagnosis of pancreatic lesions. This in turn is a guide to the appropriate treatment for the patient. Tissue samples collected by the same needle for cytological preparations and cell block histological sections (often referred to as FNA‐cytology and FNA–biopsy, respectively) are handled differently. The specific contribution of each of these tests was evaluated. Methods: One hundred and two consecutive patients underwent EUS‐FNA while being investigated for pancreatic solid lesions. Diagnosis was made by cytology, cell block sections or both. The diagnosis was confirmed by clinical outcome. Results: Male/female ratio was 61/41. Mean age was 65 ± 12 years (range, 22–94). Mean lesion size was 3.1 ± 1.8 cm (range, 0.6–10 cm); 68% were >2 cm and 75% were located in the pancreatic head. The average number of needle passes was two (range, 1–4 passes). Final tissue diagnosis was malignant in 66 (65%) patients. Sensitivity, specificity and accuracy were 73%, 94% and 81%, respectively, for cytology alone, and 63%, 100% and 78%, for cell blocks alone. Eighty‐two patients (80%) had cytology and cell blocks, which matched in 64 (78%) patients. EUS‐FNA results that relied on both techniques had 84% sensitivity, 94% specificity and 88% accuracy. Cytology revealed 13 malignancies not diagnosed on cell blocks, while cell blocks revealed five malignancies not diagnosed by cytology. Malignant lesions were more common in men; they were larger in size and located in the pancreatic head. Conclusion: EUS‐FNA cytology was more sensitive than cell blocks but less specific for the diagnosis of solid pancreatic lesions. The two methods are complementary and implementing both improves the diagnostic value of EUS‐FNA.     

Ultrasound-guided fine needle aspiration cytology of impalpable breast lesions in a rural setting. Comparison of cytology with imaging and final outcome

OBJECTIVE: To analyze the effectiveness of fine needle aspiration (FNA) cytology in a multidisciplinary setting in rural Australia and to compare the imaging (mammographic and ultrasound) appearances and cytomorphologic findings with the final outcome. STUDY DESIGN: Prospective analysis of ultrasound-guided FNA cytology results from 426 women, aged 40-86 years, with screening-detected mammographic abnormalities. Cases of microcalcification, assessed mainly by stereotactatic core biopsy, were not included in the study. The FNAs were performed at a rural breast screening and assessment program in New South Wales, Australia, over a three-year period between May 1993 and May 1996. RESULTS: Imaging, FNA and combined imaging and FNA results from 426 women were as follows. The imaging diagnoses included 176 (41%) benign, 34 (8%) probably benign, 17 (4%) equivocal, 104 (24%) suspicious and 95 (23%) malignant cases. The FNA findings showed 59 (14%) no epithelial cells seen (nondiagnostic), 175 (41%) benign, 36 (8%) atypical, 41 (10%) suspicious and 115 (27%) malignant. Combined imaging and cytologic results comprised 224 (52.6%) benign, 10 (2.3%) atypical/equivocal, 59 (13.9%) suspicious and 133 (31.2%) malignant cases. All the malignant cases, by combined assessment, had malignant histology, and all the benign cases behaved in a benign fashion. In 80% of the suspicious lesions, the histologic diagnosis was malignant, but only 10% of the atypical/equivocal lesions had malignant histology. The positive predictive value of diagnosis of malignancy by combined imaging and FNA was 100%, and the false negative rate was 0%. CONCLUSION: Despite the recent surge in the popularity of core biopsy, FNA cytology of impalpable, mammographically detected lesions, when practiced in a multidisciplinary setting, is an extremely accurate test with high sensitivity, specificity, predictive values and efficacy. FNA cytology of the breast is a well-tolerated, relatively noninvasive test with a very low risk of complications. The sensitivity and positive predictive values for malignant and suspicious mammographic categories are also very high.     

Fine Needle Aspiration Cytology of Breast In Invasive Carcinoma of Tubular Type and In Radial Scar/Complex Sclerosing Lesions

Fine needle aspirates (FNA) from 31 invasive carcinomas of tubular type and 22 radial scar/complex sclerosing lesions (RS/CSL), diagnosed in Edinburgh between 1986 and 1991, were reviewed. the lesions in this study varied in size and palpability at presentation, but are of increasing interest in the differential diagnosis of non-palpable areas of increased mammographic density. In agreement with previously published information^1'5'8, it was found that the tubular cancers were usually selected for biopsy following aspiration, but less often definitively diagnosed as malignant. Nearly 50% of the RS/CSL group were correctly reported benign on cytology, but in 40%, biopsy was recommended to exclude malignancy. In addition, cytological features helpful in suggesting malignancy in aspirates from tubular cancers, also raised suspicion in aspirates from the RS/CSL group, with a risk of overdiagnosis of cancer.     

Fine needle aspiration cytology of solitary fibrous tumours of the pleura

OBJECTIVE: To analyse fine needle aspirates from solitary fibrous tumour (SFT) of the pleura and to elucidate the cytological features unique to these tumours and differential diagnostic findings of benign and malignant SFTs. METHODS: Fine needle aspiration (FNA) cytology slides from eight cases of SFT of the pleura, including six benign and two malignant SFTs, were reviewed. The subsequent histological slides were also examined. RESULTS: Cytological diagnoses from six histologically proven cases of benign SFTs were low-grade sarcoma (one), non-small cell carcinoma (one), malignant tumour (1) and benign (three). Two cases of malignant SFTs were cytologically diagnosed as malignancy. The aspirates showed a varying degree of cellularity. Most smears were composed of single, scattered fusiform cells, and irregular loose aggregates of oval to spindle cells intimately admixed with dense collagenous stroma. Two malignant SFTs had a greater number of cells in clusters, and displayed mitotic activity, without significant cytological atypia. CONCLUSIONS: The diagnosis of SFT may be suggested by a combination of cytological and radiological findings. The precise determination of malignancy for SFT, however, is not usually straightforward on the basis of cytological features alone. The findings of highly cellular clusters and mitotic activity in the FNA cytological smear can help differentiate malignant from benign SFTs.     

Fine needle aspiration cytology of soft tissue tumors

OBJECTIVE: To review of the value of fine needle aspiration (FNA) cytology in the diagnosis of soft tissue tumors (STT). STUDY DESIGN: A review of the literature was coupled with the authors' experience with indications, diagnostic specificity and pitfalls; clinical information; and the final cytology report. RESULTS: Over the last few years, FNA has come to be considered a valuable tool in the management of STT in that it affords a specificity of > 90%. FNA is of particular value in any subcutaneous lesion > 5 cm, in all pediatric tumors and whenever direct incision biopsy is particularly contraindicated. Material from aspirates can be used to obtain cytologic smears for conventional staining, special pigment identification, histochemical techniques, cell blocks for paraffin embedding and ancillary techniques (immunocytochemistry, electron microscopy, and densitometric and cytogenetic analyses). The cytologic diagnosis, like its histologic counterpart, should be based on a correct evaluation of clinical data (age, localization, size, effect on bone, nerve and vessel involvement), radiologic information, cytologic findings (architectural pattern, cell and stroma characteristics) and results of special staining techniques. The final cytology report should place the tumor in one of three basic categories: benign, malignant, and inconclusive or undetermined. Wherever possible, a histopathologic diagnosis should also be provided, either based on purely cytologic criteria or aided by ancillary techniques. CONCLUSION: FNA does not present major complications and permits a swift, preliminary diagnosis in a large number of cases. The method is most effective when the aspiration is performed by an experienced pathologist.     

Renal fine needle aspiration cytology

OBJECTIVE: To audit and evaluate the pitfalls in renal fine needle aspiration (FNA) cytology. STUDY DESIGN: A retrospective analysis of 180 renal FNAs from 163 patients, encountered at Canberra Hospital, Australian Capital Territory, between June 1989 and July 1997 was undertaken. The FNA procedures had been performed by radiologists under computed tomography (CT) or ultrasound (US) guidance. The study correlated the FNA results with biopsy findings and clinical outcome. RESULTS: The initial cytologic diagnoses included 84 (47%) benign, 6 (3%) atypical, 7 (4%) suspicious, 70 (39%) malignant and 13 (7%) inadequate. Six of the 13 cytologically inadequate group, on further investigation, had malignant histology. The benign cytologic categories contained 79 benign conditions and 5 cases with a malignant outcome. The atypical cytologic group contained 5 benign and 1 malignant case. All nine cytologically suspicious cases had malignant histology. The cytologically malignant group contained 62 malignant, 7 benign and 1 patient lost to follow-up. The sensitivity was 92.5%, specificity was 91.9%, positive predictive value was 89.9%, negative predictive value was 94.0%, and efficacy of the test was 92.2%. CONCLUSION: Renal FNA can provide an accurate diagnosis in most instances; however, aspiration cytology of the kidney has limitations and pitfalls. Low grade renal cell carcinoma has to be differentiated from oncocytoma, angiomyolipoma, renal infarct and reactive conditions. Renal FNA has a high negative predictive value, which is useful in reassuring patients with radiologically and cytologically benign lesions. Negative FNA does not exclude malignancy in the presence of a radiologic suspicion.     

Role of fine needle aspiration cytology in the diagnosis of soft tissue tumours and tumour-like lesions

In this study, we evaluated the usefulness of fine needle aspiration cytology (FNAC) in the diagnosis of soft tissue tumours. We have also assessed the various pitfalls of FNAC of soft tissue tumours. This was a retrospective study and here we analysed only 82 histopathology proven cases of FNAC of soft tissue tumours diagnosed in a five and half year period. On histopathological examination, 55 of these cases were malignant and 27 were benign. There was a total of 15 recurrences and histopathology was available prior to FNAC in only eight of these cases. Therefore, excluding these eight cases, malignant tumours were primarily diagnosed by FNAC in 47 cases. The sensitivity, specificity and positive predictive value of FNAC in diagnosis of soft tissue tumours were 91.5%, 92.5% and 95.5%, respectively. Only 22 of 47 cases (46.8%) were correctly categorized. There were two false-positive and four false-negative cases. One case each of fibromatosis and schwannoma were reported as sarcoma. False-negative cases were fibrosarcoma (1), malignant nerve sheath tumour (2) and haemangiopericytoma (1). FNAC was very useful in distinguishing benign from malignant soft tissue tumours. However, it was not so effective in exact categorization of tumours.     

Diagnostic utility of fine needle aspiration (FNA) cytology in HIV-infected patients with lymphadenopathy

reid a. j. c., miller r. f. and kocjan g. i. (1998) Cytopathology 9, 230–239
Diagnostic utility of fine needle aspiration (FNA) cytology in HIV-infected patients with lymphadenopathy
Sixty-five FNA cytology procedures were performed on lymph nodes in 52 HIV⁺ patients. Cervical lymph nodes were the commonest site of FNA cytology investigation (54%). The diagnoses were persistent generalized lymphadenopathy (38%), infection (17%), and malignancy (11%). Diagnosis could not be rendered in 25% of FNA cytology due to inadequate sampling. Of those with infection, mycobacterial disease was the commonest cause (91%), the diagnosis of which was enhanced by concurrent microbiological examination. Non-Hodgkin's lymphoma was the commonest malignancy. Sixteen lymph node FNA cytologies had subsequent tissue biopsy. There were two false-positive and four false-negative FNA cytologies. FNA cytology in HIV⁺ patients is most useful in the diagnosis of infection, obviating the need for tissue biopsy and allowing prompt initiation of treatment.     

Differential diagnosis of malignant intrahepatic tumors by ultrasonically guided fine needle aspiration biopsy and by laparoscopic/intraoperative biopsy. A comparative study

Thirty-six cases of ultrasonographically detected liver tumors (28 malignant and 8 benign lesions) were investigated by both fine needle aspiration (FNA) biopsy and laparoscopic or intraoperative tissue biopsy. The sensitivity of FNA biopsy in detecting a neoplasm was 85.7% while that of tissue biopsy was 82.1%. Specificity was 100% in both methods. A correct histologic diagnosis of the neoplasm could be made on the cytologic smear in only 14 cases (50.0%) due to technical and methodologic difficulties. Endoscopic and intraoperative tissue biopsy yielded sufficient material to make a definite histologic tumor diagnosis in 23 of 28 cases. Additional information on tumor spread and sequelae of liver infiltration was obtained by macroscopic tissue observations in nine cases. These results indicate that FNA biopsy is less sensitive in the classification of primary or secondary liver tumors and that tissue biopsies obtained during laparoscopy or laparotomy are required if a suspected hepatic neoplasm needs to be classified exactly to plan therapy and to establish a prognosis.     

Fine needle aspiration outcomes of masses detected by positron emission tomography: correlation with standard uptake value

OBJECTIVES: To characterize the cytopathologic outcome of lesions detected on positron emission tomography (PET) scan. STUDY DESIGN: Cases with fine needle aspiration (FNA) performed because of a PET-positive lesion over an 18-month period were reviewed. Correlation with the standard uptake value (SUV) (using 2.5 as a cutoff value) was carried out. RESULTS: A total of 112 FNAs were found, of which 83 had adequate tissue for evaluation and available corresponding SUVs to be included in the final study. Fisher's exact test was carried out for correlation between FNA diagnosis and SUV Sixty-one (73.5%) lesions had an SUV > or = 2.5, 53 (87%) ofwhich were malignant and 8 (13%) benign on cytology. Twenty-two (26.5%) lesions had an SUV < 2.5, of which 12 (54.5%) showed benign and 10 (45.5%) showed malignant cytology. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of SUV were 84%, 60%, 87%, 56% and 78%, respectively. CONCLUSION: Our data show that FNA procedures performed for PET-positive lesions have high PPV, but low NPV. Therefore interpretation of PET SUV values < 2.5 as benign should be made with extreme caution.     

Fine needle aspiration cytology in the management of palpable benign and malignant breast disease. Correlation with clinical and mammographic findings

Two surgeons in a health maintenance organization group practice performed 280 fine needle aspirations (FNAs) on 257 palpable breast lesions in 200 patients. The cytology was interpreted by four pathologists at a community hospital. FNA cytology had a sensitivity of 96% and a specificity of 94% in these cases; there were no false-positive diagnoses of cancer. FNA cytology improved the identification of benign disease and decreased the risk of missing cancers. FNA cytology also improved the predictive value of mammographic information and was more helpful than mammography in demonstrating the need for biopsy of small palpable lesions that turned out to be "minimal" breast cancers.     

Serial fine needle cytology in the diagnosis of esophageal cancer

OBJECTIVE: To describe a method of registering local spread of cancer in the esophageal wall through serial endoscopic fine needle aspiration (FNA), to evaluate FNA as a diagnostic tool as compared to histologic biopsies and brush cytology, and to investigate cytologic appearances of aspirates and correlate them with survival STUDY DESIGN: Fifty-two patients with esophageal cancer were investigated with serial FNA every second centimeter from the upper esophageal sphincter aborally down to the level of macroscopic tumor. Histologic biopsies and brush cytologies were then performed. RESULTS: Of investigated cases, 33% showed malignant or suspect malignant cells from macroscopic tumor, at > or = 4 cm orally, as did 3 of 12 patients at 14 cm. FNA was more sensitive than brush cytology in establishing the diagnosis. A high ratio between the numbers of benign and malignant cells in aspirates from gross tumor tissue correlated with shorter survival (P < .03). CONCLUSION: Serial FNA can demonstrate local microscopic tumor spread in the wall of the esophagus in vivo in esophageal cancer patients. FNA is also a useful adjunct in establishing the diagnosis. Finally, evaluations of tumor cytology may have prognostic value.     

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.     

Computed tomography-guided fine needle aspiration of peripheral lung opacities. An initial diagnostic procedure?

OBJECTIVE: To evaluate the results of computed tomography (CT)-guided fine needle aspiration (FNA) cytology following negative fiberoptic bronchoscopy and sputum cytology. STUDY DESIGN: Retrospective study of 64 patients who underwent CT-guided needle aspiration of lung opacities over one year. Following a review of the CT studies, patients were selected according to image characteristics of a primary neoplasm and pleural effusion in cases with pleural lesions. The lesions were classified into three categories--intrapulmonary and peripheral pulmonary, pleuropulmonary and pleural--and were localized and aspirated under CT using a fine needle (22-23 gauge) for obtaining cellular material. Lesions diagnosed as benign on FNA cytology were followed by serial CT scans for a period of two years at six-month intervals. RESULTS: Thirty-nine of 64 (61%) lesions were diagnosed as malignant on FNA cytology and 25 of 64 (39%) as benign. There was one false negative case. There were no serious complications from the procedure. CONCLUSION: FNA under CT guidance may be applied as the initial procedure in the diagnosis of peripheral malignant pulmonary lesions, rendering a high diagnostic yield.     

Analysis of fine needle aspiration cytology of the breast: a review of 1,297 cases and correlation with histologic diagnoses

OBJECTIVE: To evaluate the accuracy of fine needle aspiration (FNA) cytology of the breast and to ascertain its usefulness. STUDY DESIGN: The authors reviewed 1,297 cases of FNA cytology of the breast which were performed at Chonnam National University Hospital from 1999 to 2002. Cytologic diagnoses were compared with histologic diagnoses in 457 cases that underwent both cytologic and histologic examination. RESULTS: Of 1,297 cases, 1,201 (92.6%) were satisfactory and 96 (7.4%) unsatisfactory. Subsequent histologic examination was performed on 291 cases (29.7%) out of 981 "benign" lesions, 28 (73.7%) of 38 "suspicious," 124 (68.1%) of 182 "malignant" and 14 (14.6%) of 96 "unsatisfactory." FNA cytology revealed 77.7% sensitivity, 99.2% specificity, 98.4% positive predictive value and 88.0% negative predictive value. Diagnostic accuracy was 91.1%. Of the 291 benign cases on cytology, 35 cases were malignancy on histology. Of the 124 cases reported as malignant, 2 were benign. Interpretive error was the leading cause of false positive diagnoses. CONCLUSION: Although FNA cytology is a useful diagnostic procedure for the evaluation of breast lesions, it should be combined with other diagnostic modalities, such as physical examination, ultrasonography and mammography.     

Metaplastic carcinomas of the breast—fine needle aspiration (FNA) cytology findings

nogueira m., andré s. and mendonça e. . (1998) Cytopathology 9, 291–300
Metaplastic carcinomas of the breast—fine needle aspiration (FNA) cytology findings
Metaplastic carcinomas of the breast are defined by mesenchymal and/or squamous cell components associated with ductal carcinoma and may raise diagnostic problems in FNA cytology. We reviewed FNA smears of a series of nine cases; seven were compared with histological sections and two with cell-block sections. The cytological pattern was diagnostic of carcinoma in six cases; in two cases a diagnosis of sarcoma/phyllodes tumour was considered, as cells were predominantly spindle-shaped. One case had a pleomorphic adenoma type pattern. The cytological findings suggesting a diagnosis of metaplastic carcinoma include a liquid aspirate, a proteinaceous or chondromyxoid background and a poorly differentiated tumour with multinucleated giant cells, neoplastic or histiocytic. A definite diagnosis requires the presence of both carcinomatous and metaplastic (squamous/mesenchymal) components.