"Breast within a breast" sign: Mammary hamartoma

I saw the "breast within a breast" sign

The "breast within a breast" sign is used to describe the appearance of a breast hamartoma, also known as a fibroadenolipoma. A breast hamartoma is a benign mass made up of the same tissues that are found in a normal breast, giving the appearance of a breast within a breast on mammography. The "breast within a breast" sign is pathognomonic for a breast hamartoma and can help confidently diagnose these masses as benign without the need for further imaging or biopsy.

MRI of the Lactating Breast

The breasts undergo marked physiologic changes during lactation that can make conventional imaging evaluation with mammography and US challenging. MRI can be a valuable diagnostic aid to differentiate physiologic and benign processes from malignancy in patients who are lactating. In addition, MRI may allow more accurate delineation of disease involvement than does conventional imaging and assists in locoregional staging, screening of the contralateral breast, assessment of response to neoadjuvant chemotherapy, and surgical planning. Although the American College of Radiology recommends against patients undergoing contrast-enhanced MRI during pregnancy because of fetal safety concerns, contrast-enhanced MRI is safe during lactation. As more women delay childbearing, the incidence of pregnancy-associated breast cancer (PABC) and breast cancer in lactating women beyond the 1st year after pregnancy is increasing. Thus, MRI is increasingly being performed in lactating women for diagnostic evaluation and screening of patients at high risk. PABC is associated with a worse prognosis than that of non-PABCs, with delays in diagnosis contributing to an increased likelihood of advanced-stage disease at diagnosis. Familiarity with the MRI features of the lactating breast and the appearance of various pathologic conditions is essential to avoid diagnostic pitfalls and prevent delays in cancer diagnosis and treatment. The authors review clinical indications for breast MRI during lactation, describe characteristic features of the lactating breast at MRI, and compare MRI features of a spectrum of benign and malignant breast abnormalities. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Chikarmane in this issue.

Multimodality imaging features of primary breast lymphoma - A rare entity

Primary lymphoma of breast is very rare which has no tell-tale imaging characteristics. Multimodality imaging helps not only in suggesting the possibility of lymphoma but also in its management. We present here one such case which was extensively worked up with various imaging modalities and was histologically proven as primary breast lymphoma.

Hyperechoic Lesions on Breast Ultrasound: All Things Bright and Beautiful?

Ultrasound (US) lexicon of the Breast Imaging Reporting and Data System (BI-RADS) defines an echogenic breast mass as a lesion that is hyperechoic in comparison with subcutaneous adipose tissue. However, at sonography, only 0.6 to 5.6% of breast masses are echogenic and the majority of these lesions are benign. approximately, 0.5% of malignant breast lesions appear hyperechoic. The various benign pathologic entities that appear echogenic on US are lipoma, hematoma, seroma, fat necrosis, abscess, pseudoangiomatous stromal hyperplasia, galactocele, etc. The malignant diagnoses that may present as hyperechoic lesions on breast US are invasive ductal carcinoma, invasive lobular carcinoma, metastasis, lymphoma, and angiosarcoma. Echogenic breast masses need to be correlated with mammographic findings and clinical history. Lesions with worrisome features such as a spiculated margin, interval enlargement, interval vascularity, or association with suspicious microcalcifications on mammography require biopsy. In this article, we would like to present a pictorial review of patients who presented to our department with echogenic breast masses and were subsequently found to have various malignant as well as benign etiologies on histopathology.

Imaging Findings of Mammary Myofibroblastoma: A Rare Fat-Containing Entity

ABSTRACT

Mammary myofibroblastoma (MFB) is a rare benign stromal neoplasm; its imaging features are rarely reported and nonspecific. We retrospectively analyzed a case of pathologically proved breast MFB that revealed indistinct high-density mass in mammography and hypoechoic ill-defined breast tumor in ultrasonography. Meanwhile, hypointense appearance on T2-weighted imaging of magnetic resonance imaging and containing fat tissue might be very valuable characteristics in the differential diagnosis of breast MFB.

The First Case of HER2+ Invasive Ductal Carcinoma Arising From a Breast Hamartoma and Literature Review

Carcinomas arising from breast hamartomas are exceedingly rare. We present the first reported case of an African-American female presenting with a right breast lump and a subsequent mammogram suggestive of a hamartoma. She later underwent lumpectomy and was found to have HER2+ invasive ductal carcinoma (IDC) arising from a hamartoma. She was amenable to HER2-targeted trastuzumab, hormone therapy and adjuvant radiation but declined chemotherapy. In a review of the literature, IDC is the predominant neoplastic type found in hamartomas. The average hamartoma size at time of neoplasm diagnosis is 6.0 cm. Patients with hamartomas greater than 6.0 cm, with changes in calcification pattern; new nodules or asymmetry should be considered for additional evaluation with ultrasound, MRI and/or biopsy. HER2 status is under-reported among cases and should be evaluated in any malignancy found within hamartomas as HER-2 therapy has improved overall survival and recurrence free survival in HER2+breast cancer patients.