Atypical vascular lesion

Benign vascular neoplasms that occur in radiation fields of various malignancies (most frequently after radiation of breast carcinomas, also ovarian carcinomas). They are of great diagnostic importance, as this group may also include precursor stages of early radiation-induced angiosarcoma.

Red or skin-coloured, even translucent, nodules limited to the former irradiation field, mostly grouped, up to 0.4 cm in size. The latency period between the clinical manifestations and the first skin symptoms is several (up to 10) years.

In the upper and middle corium located, regular but irregularly dilated and branched lymphatic vessel spaces with flat endothelials without significant nuclear atypia. Freely floating endothelia (accumulations are more likely to indicate malignancy) or protruding hobail endothelia are rarely found. Mitoses are rare. The proliferative index (Ki-67 positivity) = <10%. The vessels mark podoplanin. Cytogenetically(FISH analysis), MYK amplification (important DD for radiation-induced angiosarcoma) is missing.

The prognosis is different, as the clinical findings may be benign radiation-induced vascular ectasia or the precursor stage of radiation-induced angiosarcoma. In this respect, regular histological check-ups are mandatory.

1. Anzalone CL et al (2014) Radiation-associated atypical vascular lesions: vascular lesions with endothelial cell atypia presenting in the radiation port of breast cancer patients. Skinmed 12:344-348.
2. Baum S et al (2013) A vascular growth following radiation therapy for breast carcinoma treatment. Atypical vascular lesion (AVL) (lymphatic type). JAMA Dermatol 149:1341-1342.
3. Cornejo KM et al (2015) The utility of MYC and FLT4 in the diagnosis and treatment of postradiation atypical vascular lesion and angiosarcoma of the breast. Hum Pathol 46:868-875.
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5. Fraga-Guedes C et al (2014) Clinicopathological and immunohistochemical study of 30 cases of post-radiation atypical vascular lesions of the breast. Breast Cancer Res Treatment 146:347-354.
6. Ginter PS et al (2014) Diagnostic utility of MYC amplification and anti-MYC immunohistochemistry in atypical vascular lesions, primary or radiation-induced mammary angiosarcomas, and primary angiosarcomas of other sites. Hum Pathol 45:709-716.
7. Neal L et al (2014) Diagnosis and management of benign, atypical, and indeterminate breast lesions detected on core needle biopsy. Mayo Clin Proc 89:536-547.
8. Sinclair W et al (2013) Widespread atypical vascular lesions of the skin after whole-body electron beam therapy: expanding the clinical spectrum. At J Dermatopathol 35:e11-15.