Radiation-associated atypical vascular lesions: vascular lesions with endothelial cell atypia presenting in the radiation port of breast cancer patients.

Atypical vascular lesions are an uncommon adverse sequela to the radiotherapy of tumors. Many characteristics are shared between atypical vascular lesions caused by radiation port and well-differentiated radiation-induced angiosarcomas. The authors retrospectively reviewed the medical literature using PubMed, searching the terms acquired, atypical, benign, lymphangioma, lymphangioendothelioma, lymphangiomatous, lesion, papules, progressive, and vascular. Patient reports and previous reviews of the subject were critically assessed and the salient features are presented. Atypical vascular lesions associated with the radiation port present as clinically innocuous flesh-colored to erythematous papules or plaques. The condition presents within the radiation field, approximately 3 years after initial treatment. While the exact me chanism remains to be elucidated, growing evidence supports an association between radiation-associated atypical vascular lesions and radiation-induced angiosarcomas. Atypical vascular lesions within a radiation port are suggested to be in a state of morphologic continuum, which may progress into the more aggressive, malignant angiosarcoma. The authors recommend consideration for biopsy of new skin lesions within or adjacent to radiation. While it is clear that atypical vascular lesions caused by radiation are not equivalent to angiosarcoma, growing evidence supports that radiation-associated atypical vascular lesions may progress to angiosarcoma in some patients; therefore, the authors recommend excision of the lesion with margins depending on clinical judgment and the lesion encountered.