Multiple Atypical Vascular Lesions Following Breast-Conserving Surgery and Radiation

She initially presented to dermatology approximately 3 years after radiotherapy (5 years prior to current presentation) with lesions on the breast that had been present for 6 to 9 months. Physical examination showed 2 firm, painless, 4- to 5-mm papules on the right upper breast. The patient was reassured that the lesions were not suspicious for malignancy; however, 3 years later she presented to surgical oncology with 8 bluish papules or macules (all approximately 4 mm in diameter) on the right breast. These lesions were biopsied and examined by 2 institutions. Pathology of the initial punch biopsy favored a diagnosis of AVLs, though the possibility of RIA could not be ruled out without a complete excisional biopsy. Two excisional biopsies a month later were again consistent with AVLs. In all cases, the lesions were negative for MYC protein. The patient was again reassured but referred to dermatology for a second opinion.

At the current presentation, physical examination showed at least 29 subcutaneous nodules on the right breast ranging in color from pink to deep blue to flesh colored with others more superficially hyperpigmented, possibly secondary to prior biopsy, and measuring 2 to 8 mm in diameter. Histopathologic examination of the biopsy specimens showed a vascular proliferation extending from the dermis into the subcutaneous tissue comprised of dilated and cavernous vascular channels lined by a single layer of endothelial cells with minimal cytologic atypia (Figure 2). There were focal areas of anastomosing slitlike vascular spaces dissecting dermal collagen. No features of malignancy, such as nuclear crowding, multilayering, or increased mitotic activity, were evident. Immunohistochemical studies for MYC protein were negative. The overall morphologic features and immunoprofile were felt to be most consistent with postradiation AVLs.

At the time, surgical oncology felt that the risk of radical mastectomy outweighed the risk of angiosarcoma due to the absence of frank angiosarcoma and the patient’s notable comorbidities, including diabetes mellitus, cerebrovascular disease, peripheral vascular disease, and smoking; however, after reviewing the literature and considering the difficulty of following such a large number of lesions, the dermatology team brought the patient’s case to the multidisciplinary cutaneous tumor board at the University of Massachusetts (Worcester, Massachusetts). In consensus, the tumor board recommended radical mastectomy despite the comorbidities, given her young age and the potential risk for malignant transformation of any one of the numerous AVLs to angiosarcoma.

Postmastectomy pathology showed multiple scattered foci of AVLs ranging from 1.5 to 4 mm in the dermis, similar to those seen on prior biopsies, with no frank evidence of RIA. At 3-year follow-up, the patient has had no recurrence of AVLs or findings suggestive of RIA. There were no reported complications.

Comment

Conservative breast cancer surgery and radiotherapy are becoming more prevalent for breast cancer treatment, thus the number of patients likely to present with AVLs has increased. These patients are at risk for transformation to RIAs.⁶ It is important for clinicians to be aware of the diagnosis of both AVLs and RIAs and their management given their more frequent presentation. In most cases, one or a few AVLs are present, and excision is the treatment of choice. In a retrospective study by Brenn and Fletcher³ examining 16 patients with AVLs and 26 patients with RIA, the majority of cases of AVL had a single lesion and the maximum number of AVLs was 4. One patient in their study had 30 AVLs (each 3–4 mm in diameter), and she was diagnosed with RIA.³ Our patient—with at least 29 identifiable AVL lesions—was felt to be at considerable risk for developing RIA, as the only other case reported with this many AVLs developed RIA.¹ Given the large number of lesions, it was neither feasible to excise each one individually nor monitor all of them for malignant transformation.

Our case demonstrates the important role dermatologists may play in orchestrating care by a multispecialty team including oncology, radiation oncology, surgery, and plastic surgery. In our patient, a close examination of the literature by the dermatology team led to recognition of the potentially elevated risk for malignant transformation. The dermatology team also brought the case for review at the tumor board.

Although future studies are required to determine the relationship between AVL burden and the risk for progression to RIA, it is clear that a multidisciplinary approach and careful consideration of the current literature can prevent unnecessary morbidity and mortality for patients with this increasingly common problem.