Benign and malignant neoplasms of myoepithelial cells: cytologic findings

Cytopathology of salivary gland myoepithelial carcinoma: A study of 13 cases and review of the literature

INTRODUCTION

Myoepithelial carcinoma (MECA) is an infrequently recognized salivary gland (SG) neoplasm that commonly develops within a preexisting pleomorphic adenoma (MECA ex PA). Fine-needle aspiration (FNA) biopsy reports of this neoplasm are largely restricted to small series and single case reports.

METHODS

Our cytopathology files were searched for examples of SG MECA/MECA ex PA having confirmatory histopathologic verification. Conventional FNA biopsy smears were performed, and exfoliative specimens processed using standard techniques.

RESULTS

Thirteen cases from 9 patients (M:F = 3.5:1; age range: 36 to 95 years, mean age = 60 years) met inclusion criteria. FNA biopsy sites included parotid gland (4), trunk (2), scalp (2), and neck (2). Exfoliative specimens included pleural fluid (1), bronchial brushing (1), and bronchoalveolar lavage (1). Most cases were metastatic deposits (8; 62%), 4 were primary neoplasms, and 1 a local recurrence. FNA diagnoses were MECA ex PA (6; 46%), myoepithelial neoplasm (2), PA (2), basaloid neoplasm (1), atypical myoepithelial cells (1), and myxoma (1). Ancillary testing in 2 cases showed positive staining for myoepithelial markers. Cytologic features were that of a low-grade neoplasm composed principally of epithelioid/polygonal cells exhibiting minimal if any cytologic atypia. Myxoid and chondromyxoid stroma was often the dominant feature in MECA ex PA aspirates.

CONCLUSION

In the primary setting, a cytologic diagnosis of MECA/MECA ex PA is extremely challenging if at all possible. Due to overwhelming amounts of stroma, the diagnosis may be challenging in some cases of metastatic MECA ex PA.

Synovial sarcoma metastatic to the parotid gland: A possible pitfall in salivary gland fine needle aspiration cytology. Report of a case with immunocytochemical and fluorescence in situ hybridization findings

We report one case of metastatic synovial sarcoma (SS) to the parotid gland in a 93-year-old male. The patient had undergone upper left pulmonary lobectomy with mediastinal lymphadenectomy for SS of the lung 5 years before. The cytopathologic presentation and the immunocytochemical findings on the FNA sample were suggestive of a spindle cell myoepithelioma, while a SYT rearrangement was identified by a FISH performed on a cytological smear of the lesion. The diagnosis was further confirmed also by positive immunocytochemical expression of TLE1 on a section from the obtained cell block. The cytologic and immunophenotypic findings are shortly discussed in view of the reported immunophenotypic inconsistency of SS and of its differential diagnosis with spindle cell myoepithelioma of the salivary glands.The importance of the recently described TLE1 staining and its close correlation to SYT rearrangement is briefly discussed.

Myoepithelial carcinoma of the nasopharynx: Case report of a rare entity

Myoepithelial carcinomas are rare tumors of salivary glands. Most occur in the parotid gland buta few other sites of origin have also been described. Myoepithelial carcinoma of the nasopharynx has only been reported very few times. Because the lesion is so rare in the nasopharynx, there are no specific guidelines for its treatment. We present a rare case of myoepithelial carcinoma in the nasopharynx and discuss its diagnostic and therapeutic aspects.

Adenomyoepithelioma of the breast: a review stressing its propensity for malignant transformation

This review describes the classification, clinical presentation, pathological features and clinical behaviour of adenomyoepithelioma (AME) of the breast. It is based on an extensive review of the literature and study of a collection of cases built up over a 17-year period at the British Columbia Cancer Agency. The diversity of the morphology encountered in both benign and malignant AME is described. The behaviour of malignant AME seems to be related to the grade of the malignant component.

Fine-needle aspiration biopsy of benign adenomyoepithelioma of the breast: radiologic and pathologic correlation in four cases

Benign adenomyoepithelioma of the breast is a rare tumor in which the cytologic findings have been described in only a few cases. While benign, the imaging and pathologic features may be mistaken for malignancy. We report the aspiration biopsy findings in four cases of adenomyoepithelioma with radiologic and histologic correlation. Cytopathologists should familiarize themselves with this entity to avoid a misdiagnosis of carcinoma.

Fine-needle aspiration cytology of mammary adenomyoepithelioma

BACKGROUND

Adenomyoepithelioma (AME) of the breast is a rare neoplasm that is characterized by a biphasic proliferation of epithelial and myoepithelial cells. Incomplete excision of this lesion is associated with a greater risk of recurrence. Although the histology of AME is well characterized, its cytomorphology has not been assessed in a large series.

METHODS

The authors conducted a retrospective evaluation of cytologic findings in fine-needle aspiration biopsy (FNAB) material from 12 patients with histologically proven benign AMEs of the breast.

RESULTS

All aspirates were moderately to highly cellular with large clusters composed of epithelium and myoepithelium. The myoepithelium was admixed with the ductal cells or was present as naked bipolar nuclei in 75% of samples. Small clusters or dispersed myoepithelial cells with epithelioid morphology were also present and showed intranuclear and intractyoplasmic vacuoles in one-third of samples. Mild-to-moderate nuclear atypia was noted in some samples, but no necrosis or mitoses were seen. None of the patients were diagnosed originally with AME: Two tumors were classified as benign and consistent with fibroadenoma, 6 tumors were atypical, 2 tumors were suspicious for carcinoma, and 2 tumors were positive for malignant cells.

CONCLUSIONS

Because of the varied histology of AME, cytologic diagnosis of this neoplasm can be very challenging. Accurate identification of the myoepithelium is crucial to avoid misinterpretation as carcinoma. Conservative diagnosis and further histologic evaluation is recommended for these patients.

Malignant myoepithelioma of the rhinopharynx: case report

Malignant myoepitheliomas are rare tumors of salivary glands. Most occur in the parotid gland; few other sites of origin are described. Malignant myoepithelioma of the rhinopharynx has only been reported twice. Because the lesion is so rare, there are no specific indications for its treatment. We present a third case of malignant myoepithelioma in the rhinopharynx and discuss its diagnostic and therapeutic aspects.

Angiosarcoma after breast-conserving therapy: Fine-needle aspiration biopsy, immunocytochemistry, and clinicopathologic correlates

BACKGROUND

Angiosarcoma that arises after breast-conserving therapy can present clinically as a cutaneous and/or subcutaneous breast lump, which is misinterpreted easily as a recurrence of carcinoma. To the authors' knowledge, the role of fine-needle aspiration (FNA) cytology in the early diagnosis of this life-threatening complication of breast carcinoma therapy has not been established fully.

METHODS

The authors studied three new patients with this type of secondary angiosarcoma diagnosed by FNA biopsy and immunocytochemistry, reviewed the literature on the topic, and examined relevant differential diagnostic issues.

RESULTS

Patients presented with a discrete skin lump that had arisen several years after breast-conservative therapy for early-stage breast carcinoma near the scar from the previous surgery. The lesions were interpreted clinically as recurrent carcinoma. FNA yielded moderately cellular to highly cellular samples with variable patterns of cellular aggregation. Cells were epithelioid and spindle-shaped. Angioformative changes were subtle, and the overall picture suggested an epithelial malignancy, possibly a metaplastic carcinoma. Immunostaining of smears, however, provided conclusive evidence of the endothelial differentiation of tumor cells, and an FNA diagnosis of angiosarcoma was rendered in all patients. The histopathology of all surgically excised tumors confirmed the diagnosis of high-grade angiosarcoma.

CONCLUSIONS

Based on the authors' experience, the FNA cytologic appearance of angiosarcoma that presented as a breast skin nodule in a breast carcinoma survivor easily could have been misinterpreted as carcinoma. A correct diagnosis of this tumor relies on the proper evaluation of clinical findings and, as also shown by a review of the literature, requires immunocytochemical evidence of endothelial differentiation.

Myoepithelial cell-rich neoplasms: cytologic features of benign and malignant lesions

BACKGROUND

Lesions that contain abundant myoepithelial cells may present as a diagnostic challenge in fine-needle aspiration (FNA) specimens. Potential diagnostic problems may arise due to morphologic heterogeneity of myoepithelial cell-rich lesions and difficulty in predicting malignancy in FNA specimens. An accurate diagnosis is important, because malignant myoepithelial cell-rich lesions require a wider local excision and lymph node dissection. The authors characterized the cytologic features of myoepithelial cell-rich lesions in an attempt to define the criteria that facilitate distinction between benign and malignant tumors.

METHODS

FNA biopsies of myoepithelial cell-rich lesions with corresponding histologic specimens were selected. The cytology specimens were evaluated for the following criteria: cellularity, cell morphology, pleomorphism, chromatin pattern, presence of nucleoli, background material, necrotic debris, and presence of mitotic figures. A review of the histologic sections was performed for diagnostic confirmation.

RESULTS

Seventeen specimens from 17 different patients were selected. The histologic diagnoses were myoepithelial carcinoma (n = 6 patients), malignant mixed tumor with predominant myoepithelial carcinoma (n = 2 patients), epithelial-myoepithelial carcinoma (n = 1 patient), and benign mixed tumor (n = 8 patients). The primary sites included the parotid gland (n = 10 patients), submandibular gland (n = 3 patients), minor salivary gland (n = 3 patients), and breast (n = 1 patient). Most specimens, whether they were benign or malignant, were very cellular. Pleomorphism, coarse chromatin, prominent nucleoli, mitotic figures, and necrosis were observed only in malignant specimens. Background material and ductal cells were seen in both benign and malignant specimens.

CONCLUSIONS

The presence of pleomorphism, coarse chromatin, prominent nucleoli, mitotic figures, and/or necrosis should raise the possibility of myoepithelial carcinoma in FNA specimens from myoepithelial cell-rich lesions.

Leiomyosarcoma of the breast: a difficult diagnosis on fine-needle aspiration biopsy

Leiomyosarcoma of the breast is rarely encountered in fine-needle aspiration (FNA) cytologic material. We report a case of primary leiomyosarcoma of the breast in a 52-yr-old female. Aspiration cytology showed large, dissociated round to spindle cells with abundant vacuolated cytoplasm, pleomorphic nuclei, prominent nucleoli, and occasional intranuclear cytoplasmic invaginations. Mitotic figures, osteoclast-like giant cells, and stromal fragments were identified. A diagnosis of malignant neoplasm representing either a sarcoma, a poorly differentiated carcinoma, or a metaplastic carcinoma was made. The patient underwent a wide excision of the lesion after negative work-up. Histologic examination and immunohistochemical studies established the diagnosis of leiomyosarcoma. This case is presented here because we feel that, although FNA cytology with eventual ancillary studies is a valuable diagnostic tool to evaluate any breast mass, malignant spindle cell neoplasms of the breast still represent a diagnostic challenge for the cytopathologist. Recognition of all cytologic features of leiomyosarcoma may help to formulate a correct diagnosis.

Adenomyoepithelioma of the breast: a cytologic dilemma. Report of a case and review of the literature

Adenomyoepithelioma of the breast is a rare benign tumor made up of epithelial and myoepithelial cells. The cytologic features of this lesion are not well defined. This report describes the cytologic features of a case of adenomyoepthelioma characterized by hypercellularity and the presence of many atypical epithelial cells, leading to the erroneous diagnosis of adenocarcinoma. Review of the cytology literature shows that this condition frequently mimics the cytologic features of a number of benign and malignant breast lesions, thus representing not only an important potential pitfall in the diagnosis of carcinoma but also a differential diagnosis to consider in a variety of breast lesions.

Fine-needle aspiration cytology of benign and malignant adenomyoepithelioma: report of two cases

Cytological features of a malignant spindle-cell variant and a benign tubular variant of adenomyoepithelioma were examined to improve diagnosis of this tumor. Fine-needle aspiration cytology, of both a malignant and a benign case, characterized cellular and cohesive cell clusters composed of epithelial and myoepithelial cells. The smears of the malignant case were rich in spindle-shaped myoepithelial cells, admixed with a few epithelial cells. In about a fourth of the clusters, atypical cells with enlarged hyperchromatic nuclei and prominent nucleoli comprised more than 20% of cells. The smears of the benign case were composed of tubular epithelial cells surrounding one to several layers of myoepithelial cells with clear cytoplasm. Mild atypia was occasionally noticed. A review of the literature showed that a cytological diagnosis of malignancy is not warranted, if nuclear atypia is not generally severe. Focal severe atypia is not definitively indicative of benignity or malignancy.

Fine-needle aspiration of spindle cell and mesenchymal lesions of the salivary glands

Fine-needle aspiration (FNA) biopsy can accurately diagnose epithelial lesions of the salivary gland. Its role in the evaluation of salivary gland lesions containing a significant spindle cell component is less clear. We describe the cytologic features of 25 spindle cell lesions of the salivary gland and discuss the differential diagnosis and potential diagnostic pitfalls. Twenty-five aspiration smears (3.0%) containing a significant spindle cell or mesenchymal component were identified out of 844 salivary gland FNAs performed over a 5-year period. These aspiration smears were from 25 patients. The smears were classified into three categories: 1) reactive or inflammatory conditions, including one granulation tissue and four granulomatous sialoadenitis; 2) benign neoplasms, including one schwannoma, one fibromatosis, four lipomas, and nine pleomorphic adenomas; 3) malignant neoplasms, including one recurrent malignant fibrous histiocytoma (MFH), two metastatic melanomas, and two metastatic osteosarcomas. There was one false-negative biopsy. The metastatic desmoplastic malignant melanoma was initially interpreted as a reactive lymph node with fibrosis. A specific diagnosis was rendered in 21 (84%) cases. The schwannoma was diagnosed cytologically as benign spindle cell lesion, not otherwise specified (NOS), fibromatosis as an atypical cellular proliferation, and MFH as poorly differentiated malignant neoplasm. Salivary gland lesions with a significant spindle cell component are rarely encountered on FNA and constitute a heterogeneous group. A specific diagnosis can be rendered in the majority of cases by correlating clinical and cytologic findings.

Serial transplants of DMBA-induced mammary tumors in fischer rats as model system for human breast cancer: V. Myoepithelial-mesenchymal conversion during passaging as possible cause for modulation of pineal-tumor interaction

An elevation of melatonin secretion parallel to an enhanced production of macrophage-derived biopterin was observed in female F344 Fischer rats bearing passage 2 serial transplants derived from a malignant mammary tumor induced by 7,12-dimethylbenz[a]anthracene (DMBA). As opposed to that both parameters were depressed at passage 12. These results indicate the presence of divergent immunoneuroendocrine interactions during different phases of tumor growth. Since these biochemical events must have their common origin in changes taking place within these tumor transplants the current histopathological study was initiated. The primary tumor used for serial transplantation was a moderately differentiated adenocarcinoma of the mammary gland showing cytokeratin-positive epithelial components located in the inner epithelial tubule layer. In addition, bland-looking round or elongated actin-positive myoepithelial cells were detected which apart from epithelial cells are known to constitute the main cellular components of the mammary ductal system which resemble smooth muscle cells both morphologically and functionally. The tumor of passage 1 showed glandular tubules, lined by an inner epithelial layer, and many nests of clear, bland-looking actin-positive myoepithelial cells lying around tubules as well as in the stroma between actin-negative epithelial elements. The tumor of passage 2 used for transplantation consisted of a chaotic mixture of epithelial carcinomatous cells, forming a few irregular small tubules or solid nests, and, predominantly, of elongated plump or spindle-shaped, "myoid" atypical myoepithelial cells with a strong actin-positive reaction and some of these cells showed a focal vimentin expression. The tumor was characterized as a carcinosarcoma. At passage 12 epithelial cells were not identified. The tumor displayed features of a pleomorphic sarcoma consisting mainly of giant cells with bizarre nuclei being cytokeratin- and desmin-negative, weakly vimentin-positive but strongly actin-positive. These results indicate that DMBA-induced mammary tumor cells in female F344 Fischer rats undergo dramatic morphological changes during serial transplantation characterized by a total loss of malignant epithelial (carcinomatous) cells and the emergence and subsequent predominance of malignant (sarcomatous) mesenchymal cells. It appears that these sarcomatous cells develop out of myoepithelial cells since atypical myoepithelial cells with a strong actin-positive reaction showed a focal vimentin expression at passage 2 indicating myofibroblastic differentiation as part of mesenchymal transition. The loss of epithelial cell elements as well as a parallel transition of myoepithelial to mesenchymal cell elements during passaging could lead to a lack of immunological recognition of these tumor transplants and to depression of melatonin. Possible mechanisms involved in these phenomena as well as the relevance of these findings for a better understanding of the role of melatonin in human mammary cancer are discussed.

Fine-needle aspiration cytology of spindle cell lesions of the breast

BACKGROUND

Fine-needle aspiration biopsy (FNA) has been successful in diagnosing epithelial lesions of the breast. Its role in the evaluation of spindle cell and mesenchymal lesions of the breast, which include a variety of benign and malignant conditions, is less clear. This article discusses the cytologic features and differential diagnosis of these lesions, as well as the potential diagnostic pitfalls associated with them.

METHODS

FNAs of the breast, in which a spindle cell or mesenchymal component was a key or dominant feature, were retrieved. Fibroadenomas without cellular stroma and typical lipomas were excluded.

RESULTS

Forty-six aspirates (0.87%) in a series of 5306 breast FNAs contained a significant spindle cell or mesenchymal component. The aspirates were classified into 4 categories: 1) reactive conditions, including 2 diabetic mastopathies, 3 granulation tissue specimens, and 7 granulomatous lesions; 2) benign neoplastic conditions, including 1 mammary hamartoma, 1 dermatofibroma, 1 fibromatosis, 2 granular cell tumors, 2 angiolipomas, and 7 cellular fibroadenomas; 3) low grade malignant neoplastic lesions, including 10 low grade phyllodes tumors; and 4) high grade malignant neoplastic lesions, including 1 metaplastic carcinoma with chondroid stroma, 1 pleomorphic liposarcoma, 2 malignant fibrous histiocytomas, 2 osteosarcomas, and 4 metastatic melanomas. A specific diagnosis was rendered in 38 cases (82.6%). The mammary hamartoma was diagnosed as fibrocystic changes; the dermatofibroma as benign spindle cell lesion, not otherwise specified (NOS); and the primary osteosarcoma as an atypical spindle cell proliferation, NOS. The reactive ductal epithelial cells in one of the granulomatous mastitis specimens, as well as the hyperplastic ductal epithelial cells in one of the phyllodes tumors, were interpreted as atypical ductal proliferation. The marked cytologic atypia displayed by one granular cell tumor was interpreted as low grade adenocarcinoma and the primary liposarcoma as poorly differentiated carcinoma.

CONCLUSIONS

Breast lesions with a significant spindle cell or mesenchymal component are rarely encountered in FNA and constitute a heterogeneous group that may pose a diagnostic dilemma. FNA should be the initial diagnostic procedure for investigating these lesions, as a specific diagnosis was rendered in the majority of cases. Cancer (Cancer Cytopathol)

Malignant myoepithelioma of the vulva resembling a rhabdoid tumour

AIMS

We report an example of malignant myoepithelioma of the vulva, which has not been hitherto described. We discuss the differential diagnosis and briefly review the literature.

METHODS AND RESULTS

The lesion was found in an 81-year-old woman as an indolent 40 mm tumour. The neoplastic cells showed a myoid, spindled, epithelioid and plasmacytoid phenotype. Hyalinization of extracellular material and myxoid changes were present. There was a partly solid and microcystic pattern and a tight cohesiveness of cells was lacking. The circumscribed multinodular tumour somewhat resembled an extrarenal rhabdoid tumour, having large tumour cells with prominent nucleoli and large amounts of acidophilic cytoplasm. Immunohistochemically, the tumour cells were immunoreactive for cytokeratin, vimentin, muscle-specific actin, alpha-smooth muscle actin, and S100 protein, but not for desmin, epithelial membrane antigen, factor VIII-related antigen, CD34 and CD31.

CONCLUSIONS

The histological and cytomorphological appearance of the tumour well as the immunohistochemical findings suggest the diagnosis of malignant myoepithelioma, possibly derived from minor vestibulary glands or ectopic breast tissue. Differential diagnoses are, in particular, extrarenal rhabdoid tumour and 'proximal type' epithelioid sarcoma. Differentiation is important, because the tumours show a different behaviour and prognosis.

Atypical plasmacytoid monomorphic adenoma of salivary glands of the tongue: cytologic, histologic, immunohistochemical, and ultrastructural findings

We describe the case of an 11-yr-old boy with a 2.5-cm-diameter soft tumor superficially located at the dorsal aspect of the tongue. Fine-needle aspiration cytology smears showed plump epithelioid cells with round to mildly oval nuclei and open chromatin. One or two nucleoli of intermediate size were noticed in each nucleus. These cells appeared singly or in small groups. The findings were interpreted as containing plasmacytoid cells coming from an adenoma of salivary gland origin. The histologic examination of the surgical specimen revealed noncohesive, pleomorphic polygonal cells combining plasmacytoid/rhabdoid cytoplasmic features, with mild to moderate nuclear pleomorphism. One mitotic figure was observed per 10 high-power fields. Immunoreactivity was strongly positive for vimentin and S-100 protein, less intense for the cytokeratins, and negative for smooth muscle actin, muscle-specific actin, myoglobin, and GFAP. No ultrastructural evidences of myogenous differentiation were found. We propose that this case represents an unusual atypical variant of plasmacytoid monomorphic adenoma.

Malignant plasmacytoid myoepithelioma of the palate: histological observations compared to benign predominant plasmacytoid myoepithelial cells in pleomorphic adenoma of the palate

Predominant benign plasmacytoid myoepithelial cells in pleomorphic adenoma and malignant plasmacytoid myoepithelioma cells were investigated morphologically. The cells of both tumors were plasmacytoid in appearance and sheet-like. Immunohistochemically, they were positive for keratin, vimentin, and S-100 protein, and negative for alpha-smooth muscle actin. In the malignant cells, large nuclei with irregular nuclear membranes and distinct nucleoi and occasional intranuclear inclusions and nuclear grooves were seen. Ultrastructural findings showed that the benign cells were richer in intermediate filaments and had fewer mitochondria. The intranuclear inclusions and nuclear grooves of the malignant cells were caused by invagination of the irregular nuclear membranes. Taken in their entirety, the above light microscopical nuclear findings may be useful as an adjunct for distinguishing malignant from benign plasmacytoid neoplastic myoepithelial cells of the salivary gland.

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.

Fine-needle aspiration cytology of spindle-cell argyrophilic mucin-producing carcinoma of the breast

An unusual breast carcinoma with prominent spindle cells, intracytoplasmic mucin, and argyrophilia in an 82-yr-old woman was sampled preoperatively by fine-needle aspiration (FNA). The smears contained highly cellular sheets and fragments of uniform spindle cells with abundant vacuolated cytoplasm. The cells were mucicarmine positive and contained many cytoplasmic argyrophilic granules. The findings were confirmed by histologic examination of the excised tumor, which was also studied with a panel of immunohistochemical stains. A review of the literature indicated that spindle-cell argyrophilic mucin-producing carcinoma (SCAMPC) of the breast is a very rare neoplasm presenting primarily in elderly patients. The FNA cytologic features seem to be unique and should allow distinction from other primary breast lesions.

Adenomyoepithelioma of the Breast: A Case Reprot and a Review of Literature

A 74-year-old woman complained of a small nodule in the outer lower quadrant of her left breast. On physical examination, a 0.9 x 0.8 cm, round-shaped and firmly elastic nodule was palpated. Excisional biopsy was performed. Histologically, the tumor was separated into, with a bicellular pattern, containing both numerous glandular structures and numerous spindle-shaped cells. Immunohistochemical staining for EMA and cytokeratin showed strongly positive immunoreactivity for epithelial cells. Staining for &aipha;-SMA showed strongly positive immunoreactivity for myoepithelial components. Staining for keratin and S-100 protein showed weakly positive immunoreactivity for myoepithelial cells. Microscopically, the tumor was diagnosed as adenomyoepithelioma of the breast. Immunohistochemical examination is needed to distinguish epithelial cell proliferation from myoepithelial cell proliferation. Immunohistochemical examination using antibodies against EMA, alpha-SMA, Keratin, cytokeratin and S-100 protein, is indispensable.

Pitfalls in the cytologic diagnosis of angiosarcoma of the breast by fine-needle aspiration: a case report

This paper describes a case of angiosarcoma of the breast in a 26-yr-old female. The tumor, originally thought to be granulation tissue on fine-needle aspiration biopsy, was correctly identified as a malignant neoplasm of probable mesenchymal origin on a repeat FNA biopsy 4 mo later. A diagnosis of angiosarcoma was made on a subsequent excisional biopsy. Review of the cytologic features revealed findings that should suggest angiosarcoma, especially when correlated with the clinical history. The authors describe the cytological features seen in this case, and discuss an important pitfall in the diagnosis of angiosarcoma of the breast on FNA.