<prompt> Which of the following type of tumor may occur in the residual breast or overlying skin following wide local excision and radiotherapy for mammary carcinoma?AngiosarcomaLeiomyosarcomaBasal cell carcinomaSquamous cell carcinoma  <response>: Angiosarcoma has an unknown etiology but it may be associated with radical mastectomy, radiotherapy for cancer breast, ovary, cervix, endometrium, introduction of foreign materials into the body dacron, steel, environmental carcinogens dioxin, vinyl chloride, AIDS or with pre-existing benign lesions bone infarct, osteomyelitis. Ref: Pathologic Basis of Disease, Robbins, 7th Edition, Page 1151; The MD Anderson Manual of Medical Oncology, 2nd Edition, Chapter 40. 