Solanki, Malvika H

Abstract Cystic breast masses are a common entity encountered by breast radiologists. The imaging features of benign and malignant cystic masses may overlap, causing confusion and miscategorization with the potential to produce diagnostic delay and harm. This article provides a review of key differentiating imaging features that help guide appropriate mass characterization and treatment.

Abstract Adenomyoepithelioma (AME) is a rare, usually benign breast neoplasm with low potential for malignant transformation. Imaging features are nonspecific and overlap with other benign and malignant breast lesions. On mammography, AME most often presents as a mass, usually oval in shape, with variable reported margins. Less commonly, AME can present mammographically as an asymmetry or can be mammographically occult. Associated calcifications are uncommon. On US, AME is usually seen as a hypoechoic oval mass, but it can also manifest as a complex cystic and solid mass. On US, the majority of AME have noncircumscribed margins (indistinct, angular, or microlobulated). Internal vascularity is usually present, and posterior enhancement can be seen. Although there is limited literature on MRI features, the most frequent finding is an irregular mass with washout kinetics; T2 hyperintensity can be observed. These nonspecific and often suspicious imaging features usually merit biopsy. On histologic analysis, AME is characterized by a biphasic proliferation of myoepithelial and epithelial cells. Pathologic diagnosis can be difficult due to the variety of histologic features of AME and heterogeneity in these tumors, especially when sampling is limited, such as in core needle biopsies. Wide local surgical excision of AME is recommended due to potential for recurrence and malignant transformation.

Introduction. Assessment of axillary lymph nodes in breast carcinoma is an important part of staging to guide appropriate clinical management. Lymph node inclusions of different types, including nevoid, squamous, and glandular, are rare but have been reported in multiple different anatomic locations including the axilla. These can result in diagnostic challenges and pose risks of misdiagnoses. Rarely, malignancies may arise intrinsic to otherwise incidental benign nodal inclusions. Case Presentation. We report a case of ductal carcinoma diagnosed within a squamous epithelial inclusion cyst within an axillary lymph node in a patient with pure ductal carcinoma in situ (DCIS) of the ipsilateral right breast. To our knowledge, this is the fifth report in the literature of breast carcinoma confirmed within an axillary inclusion in a patient with pure DCIS. Evaluation of the primary DCIS and lymph node inclusions, by routine and immunohistochemical stains, was performed for assessment. Discussion. The presence of lymph node inclusions can pose a challenge in assessment of benignity and malignancy, on frozen and permanent histologic sections. Pathologists should carefully evaluate lymph node inclusions to ensure that intrinsic malignancies are not missed within rare otherwise benign appearing incidental epithelial rests.

Context.— Progressive independence in medicine is critical to building confidence and decisiveness in trainees. However, this can be difficult to accomplish in the strict regulatory environment of pathology. Objective.— To pilot and adopt a process whereby surgical pathology fellows independently manage a subset of cases and release preliminary reports. Design.— Upon program approval, board-certified surgical pathology fellows were eligible for preliminary report sign-out at their discretion. Eligible cases were sent from outside institutions for confirmatory review. Preliminary reports were viewable in the electronic medical record. Safety measures were used to ensure timely release of final reports by attending pathologists. Results.— Fellows participating in the pilot (n = 4) released 59 preliminary reports out of 101 cases reviewed (58%), with 1 potentially significant discrepancy between preliminary and final report. Turnaround time was not affected. The process was endorsed by all participants and adopted as standard practice. During the first year, eligible fellows (n = 8) released 123 preliminary reports out of 1260 cases reviewed (9.8%). There were no major diagnostic discrepancies and no effects on turnaround time. The number of preliminary reports released by each fellow was variable (range, 2–48; median, 8), likely a reflection of both external factors (number of trainees on service, volume) and trainee-specific factors (confidence, efficiency). Conclusions.— Fellows showed good judgment when independently managing cases, with just 1 potentially significant discrepancy out of 182 cases (<1%). No patients were adversely impacted. Use of this process varied widely among fellows and may require closer monitoring and encouragement for fellows who are tentative about releasing preliminary reports.

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is histologically characterized by anastomosing and slit-like spaces invested by collagenous stroma and lined by flattened, spindle cells. These clear spaces that may mimic microscopic vascular channels do not contain red blood cells. Immunohistochemistry (IHC) studies may also help to confirm a diagnosis of PASH, with the spindled cells marking positively with CD34 and PR while demonstrating no reactivity with more specific endothelial antigens such as CD31 and ERG. In the current case, a 39-year-old female was diagnosed with cellular PASH of the right breast with unique histological patterns showing “tiger-striped” and “zippered” histologies. To our knowledge, this is the first report of these unique variant PASH morphologies.

Adenosquamous carcinoma of the breast is a rare subtype of metaplastic carcinoma, which accounts for <1% of invasive breast malignancy. Metaplastic carcinoma is usually high grade and aggressive with typically reported benign imaging features when compared to invasive ductal carcinoma. However, the adenosquamous variant is a subtype with a more favorable prognosis. Within the literature, there is limited imaging description with case studies focusing on metaplastic carcinoma. Herein, we report seven cases of the adenosquamous subtype describing the imaging findings with correlation to clinical history and pathology. The majority of patients (n = 6) presented with palpable breast masses. One patient was identified through screening mammography. Mammographically (n = 6), tumors appeared as irregular masses. Sonographically (n = 7), tumors appeared as irregular masses ranging from solid to mixed solid/cystic masses. On MRI (n = 1), one tumor appeared as an irregular rim enhancing mass. FDG PET/CT (n = 2) and whole-body bone scan (n = 1) were also available for review. The majority of tumors were low-grade (n = 6) with only one high-grade tumor. This case series of seven patients demonstrated predominantly suspicious imaging features despite the majority being low-grade tumors.

AbstractHidradenoma papilliferum (HP) is a benign adnexal neoplasm of the vulva that typically presents as a unilateral, flesh‐colored papule in the labium majus in middle‐aged Caucasian women. It is considered to be a close counterpart of the intraductal papilloma of the breast. Malignant transformation is rare with few reports in the literature. We present a case of vulvar mammary‐type apocrine hidradenocarcinoma arising in an HP.