Radiation port xanthogranuloma: solitary xanthogranuloma occurring within the irradiated skin of a breast cancer patient‐report and review of cutaneous neoplasms developing at the site of radiotherapy

Xanthogranulomas are benign lesions composed of macrophages in which some of the cells have vacuolated cytoplasm. They commonly occur in children, referred to as juvenile xanthogranulomata, and are histopathologically characterized by the presence of Touton giant cells. Xanthogranuloma can also occur in adults. A woman who developed a solitary xanthogranuloma within the field of radiotherapy following treatment of her breast cancer is reported. In addition to xanthogranuloma, other benign lesions of keratinocytes, mast cells, endothelial cells and lymphatic cells have been observed at the site of radiation treatment. Also, several malignancies, including hematopoietic cancers, sarcomas, metastatic cancers and common skin cancers, have been observed within radiation ports. A causal relationship in the development of our patient's xanthogranuloma is suggested by the temporal association between the treatment with radiotherapy and the subsequent appearance of a xanthogranuloma directly within the radiation field.