A rare case of radiation-induced breast angiosarcoma: a case report

Figure 1.. Gross examination shows a small purple skin lesion with irregular margins in periareolar region in breast left inner quadrant transition and no evidence of skin ulceration.

Figure 2.. Gross examination shows purple plaque with hemorrhagic cut surface extending in superficial dermis. At the cut surface the lesion comes close to the epidermis with no evidence of epidermal invasion.

Figure 3.. H&E stain (40x), histological findings tipically shows dermal basal proliferation of irregular staghorn branched blood vessel with atypical epithelioid cells with large pleomorphic vescicular eosinophilic nuclei and small micro papillary proliferations.

Figure 4.. Ki-67 immunostain (40x), this picture shows strong nuclear positivity of neoplastic cells >20%. antigen KI-67 is a nuclear protein that is associated with cellular proliferation and ribosomal RNA transcription. The Ki-67 percentage score is defined as the percentage of positively stained tumor cells among the total number of malignant cells assessed.

Figure 5.. ERG immunostain (40x): strong nuclear expression of neoplastic cells. Transcritional regulator factor (ERG) is a protein encoded by ERG (ETS family transcription factor). ERG is a highly sensitive immunohistochemical marker for vascular differentiation.