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

Abstract

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 adenomyoepithelioma 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 an additional feature to the morphological characteristics of adenomyoepithelioma of the breast.

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

“…AME is a rare neoplasm of the breast with a biphasic proliferation of epithelial and ME cells. The FNA cytologic features of such lesions are described in a few case reports, [8][9][10][11][12][13][14][15][16][17][18][19] the largest and most recent of which describes 12 such aspirates. 9 In none of the cases was a correct diagnosis of AME made.…”

Fine needle aspiration cytology of nodular fasciitis of the breast

“…[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] The smears are moderately to highly cellular. As a biphasic tumor, epithelial elements are present in the slides [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] though epithelial cells may be fewer in case of malignant AME. 37 The epithelial cells sometimes harbor apocrine features.…”

“…37 The epithelial cells sometimes harbor apocrine features. 38,42,43 The myoepithelial cells are abundantly present in the background as naked bipolar nuclei, and they show variable look such as spindle, epithelioid, clear cell, and plasmatoid appearance. The myoepithelial cells often have intranuclear inclusion, [35][36][37][38]46,48 and its vacuolated cytoplasm may exhibit a "soap-bubble" appearance.…”

“…38,42,43 The myoepithelial cells are abundantly present in the background as naked bipolar nuclei, and they show variable look such as spindle, epithelioid, clear cell, and plasmatoid appearance. The myoepithelial cells often have intranuclear inclusion, [35][36][37][38]46,48 and its vacuolated cytoplasm may exhibit a "soap-bubble" appearance. 36,43 The presence of epithelial cells, especially associated with apocrine metaplasia, and myoepithelial cells with fascicular arrangement, intranuclear cytoplasmic inclusions, and vacuolated cytoplasm are useful in the discrimination of NF from myoepithelial lesions.…”

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

“…2 Knowledge of this entity is important as the cytologic and radiologic features may mimic malignancy. While the histologic features of adenomyopithelioma are well documented, there are few reports in the literature describing the cytologic findings [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and even fewer describing the imaging findings. 3,4,18 The purpose of this study was to report the fine-needle aspiration biopsy findings in four cases of benign adenomyoepithelioma of the breast and correlate them with the radiographic and histologic findings.…”