Metachronous cellular angiolipomas of the breast

Abstract

A 67‐year‐old woman presented for routine screening mammogra‐ phy and was found to have an 18 mm oval mass of the right breast (Figure 1). On ultrasound, the mass had circumscribed margins and internal vascularity with posterior acoustic shadowing. Of note, she had a history of a left breast ductal carcinoma with metastases to the contralateral axillary lymph nodes originally diagnosed 7 years prior. At that time, she received neoadjuvant paclitaxel followed by left modified radical mastectomy and contralateral lymph node dissection. The final staging was ypT2 ypN1a. She then received adjuvant left chest wall radiation and anastrozole. She has been in complete remission for the last 5 years. Notably, 2 years after her primary diagnosis of malignancy in the left breast, she was found to have a 5 mm mass within the right ret‐ roareolar region at 11 cm from the nipple. A biopsy revealed a cellular angiolipoma (Figure 2A). The most recent 18 mm oval mass, located at the 2 o’clock position and 3 cm from the nipple, in the same breast, occurred nearly 6 years later. On core needle biopsy, this lesion was also consistent with a cellular angiolipoma (Figure 2B). These two cellular angiolipomas are favored to be metachronous lesions given their aforementioned radiologically distinct locations. Angiolipomas of the breast are benign neoplasms comprised of mature adipocytes admixed with capillary‐sized vascular prolifera‐ tions. They can be grouped into two categories: low vascularity and cellular (high vascularity). The cellular variants, as seen in our pa‐ tient, have vascular proliferations that occupy more than 50% of the lesion. Figure 2B highlights a prominent capillary network lined by flat to oval endothelial cells with bland round nuclei that coalesce to form a cellular stroma. Intraluminal fibrin microthrombi are a classic feature (Figure 2C); however, they may not always be visualized on core needle biopsy due to limited sampling. Necrosis is not present in these lesions; however, apoptotic bodies can rarely be identified (Figure 2C). Mitotic figures may be present in the cellular variant but are usually absent in typical angiolipomas. The cellular variant is likely to be detected by mammography, while the low vascularity variant frequently presents as a palpable mass. This difference is attributed to their respective mean size at presentation (0.7 cm for the former vs 2.0 cm for the latter). Also,