Fine-needle aspiration cytology of mammary adenomyoepithelioma: report of a case with intranuclear cytoplasmic inclusions

Inconclusive or erroneous fine-needle aspirates of breast with adequate and representative material: a cytologic/histologic study

Adequately cellular and representative fine-needle aspirates (FNAs) of breast have a high diagnostic accuracy. There is, however, a recognized category designated as "gray zone" where a definitive diagnosis cannot be reached. We reviewed our experience in this category to identify useful diagnostic parameters. Twenty-four such FNAs with surgical follow-up were retrieved from AUBMC files (2003-2009). Cytology slides were reviewed blindly. All cases were females, 29-73 years. There were three erroneous and 21 inconclusive diagnoses. The majority (15) was invasive adenocarcinomas: two cribriform, four tubular, one lobular, and eight not otherwise specified. The remaining cases were papillary and fibroepithelial tumors (three each), ductal carcinoma in situ, cribriform (two), and one adenomyoepithelioma (AME). Useful diagnostic features included: (1) Biphasic cell population with focal nuclear atypia and intranuclear and cytoplasmic vacuolar inclusions (AME). (2) Complex clusters of epithelial cells with cribriform architecture (cribriform carcinoma). (3) Rigid tubular epithelial structures with abrupt change in diameter, ending in pointed tips with abnormal branching (tubular carcinoma). (4) Cellular stromal fragments (fibroepithelial tumors). (5) Papillary fibrovascular cores, columnar cells, and three-dimensional papillary epithelial fragments (papillary tumors). Myoepithelial cells classically described in benign aspirates were not always a discriminatory factor. The "gray zone" in breast FNA is usually due to overlapping cytologic features of some benign and malignant lesions. Useful distinguishing cytologic features are described.

Indeterminate and erroneous fine-needle aspirates of breast with focus on the 'true gray zone': a review

OBJECTIVE

To review our experience and the literature on inconclusive/erroneous fine-needle aspirates (FNAs) of breast with the focus on the 'true gray zone'. To describe the cytology, differential diagnosis, pitfalls and limitations of common and rare lesions.

STUDY DESIGN

We conducted a literature search focusing on breast FNAs with statistical data of C3 and C4 categories including false-positive and false-negative cases. Similar data from 2003 to 2009 was obtained from our institution.

RESULTS

C3 and C4 categories account for 3-17% of breast FNAs. Contributing factors are technical difficulties, inexperienced pathologists interpreting FNAs of breast and overlap of cytologic features of certain benign and malignant conditions; this last, 'true gray zone' accounts for 2% of cases. Fibroadenoma, proliferative breast lesions, gynecomastia, infiltrating and in situ low-grade adenocarcinomas and tubular, cribriform, lobular and mucinous carcinomas are the most common problematic lesions. Granular cell tumor, adenomyoepithelioma, pregnancy-related lesions, fat necrosis, inflammatory and radiation changes, adenoid cystic carcinoma, spindle-cell lesions and Phyllodes tumor are less common.

CONCLUSION

Inconclusive/erroneous FNAs of breast due to the 'true gray zone' are rare. Most are due to the overlapping cytologic features of some benign and malignant conditions. Practical features that may help arrive at the correct diagnoses are elucidated.

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.

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 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)

Adenomyoepithelioma of the breast: report of two cases with prominent cystic changes and intranuclear inclusions

Adenomyoepithelioma is a rare breast tumor. Histologically it may disclose different patterns of growth, and some additional features may result in diagnostic errors. We describe 2 cases of adenomyoepithelioma of the breast initially examined by fine-needle aspiration biopsy (FNAB). Cytologic features included hypercellularity, clusters of epithelial and myoepithelial cells with occasional intranuclear inclusions, prominent apocrine metaplasia, and foam cells. Histologically, both tumors were diagnosed as adenomyepithelioma tubular-variant, with prominent myoepithelial clear cells, apocrine metaplasia, and foci of squamous metaplasia. Immunohistochemically, the tumors showed strong positivity for keratins CAM 5.2, AE1/AE3, and EMA in the epithelial component, while the myoepithelial cells reacted with muscle-specific actin (A14 and HHF35) and S-100 protein. We point out that FNAB in this rare tumor may exhibit a varied spectrum of cells that may result in confusion with other lesions, and we call attention to the presence of intranuclear inclusions. The latter observation in the present cases by cytologic and histologic assessment provides and additional feature to the morphological characteristics of adenomyoepithelioma of the breast.

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.