Sonography of Invasive Apocrine Carcinoma of the Breast in Five Cases

Abstract

ObjectiveTo evaluate the sonographic features of invasive apocrine carcinoma (IAC) of the breast.Materials and MethodsThis study included five pathologically proven cases of IAC, and their sonographic features were retrospectively analyzed according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon.ResultsAll five lesions involved the left breast and were seen as irregularly shaped masses. All lesions, except one, had a parallel orientation to the chest wall. All five lesions showed noncircumscribed margins and heterogeneous echotexture; however, they showed various posterior features. One lesion had edema as an associated feature. Sonographic assessments were classified as BI-RADS category 4 in all five cases.ConclusionInvasive apocrine carcinoma sonographic findings are difficult to differentiate from those of invasive ductal carcinoma of no special type.

A Rare Case of Invasive Apocrine Carcinoma of the Breast with Unusual Radiologic Findings

“…IAC was initially described by Krompecher in 1916, and is now defined as more than 90% of apocrine differentiated neoplastic cells (1, 9). The incidence of IAC is reportedly variable from less than 1% to 4% (8). However, the definite incidence of IAC remains unknown currently, because there is no standardized consensus on the standard diagnostic criteria for IAC, despite the diagnostic criteria of Japaze et al in 2005 (3).…”

“…Microscopically, IAC presents almost the same architectural growth pattern as IDC of NOS, but it shows difference only in its cytological appearance (8). The cells are characterized by typical apocrine features such as abundant, eosinophilic granular cytoplasms, and prominent or multiple nucleoli (3).…”

“…Likewise, our case showed the same immunohistochemical stain result (1). Several reports suggest that apocrine carcinomas show a unique response to androgen (such as fluoxymesterone) administration as a part of treatment, but there is no standardized treatment option for IAC (8). …”

“…Gokalp et al showed an irregular shaped IAC with microcalcification (5). Seo et al presented five case reports with mammographic findings in three cases (8). One case showed an irregular, partly indistinct hyperdense nodule and the other presented as an asymmetry (8).…”

“…In addition, IAC has a similar clinical presentation and overall patient survival rate similar to IDC of NOS (3). There are few case reports on radiologic findings of IAC, but all cases show comparable malignant appearance to IDC (5-8). Herein, we present a rare case of IAC with its multiple radiologic modality findings that suggests a benign rather than malignant feature on initial ultrasonography (USG) and mammography and the pathologic correlation.…”