title: Unusual second malignancies following radiation therapy: subcutaneous pleomorphic rhabdomyosarcoma and cutaneous melanoma. Two case reports.
abstract: BACKGROUND
  Among nonepithelial second neoplasms which are known to be induced by irradiation, rhabdomyosarcomas are extremely rare, and melanomas are infrequent. We report a high-grade sarcoma with rhabdomyoblastic differentiation, which appeared 30 years after megavoltage irradiation for an endometrial adenocarcinoma, and a malignant melanoma which arose after 6 years in the irradiation field of a fibrosarcoma.
  
  
  METHODS
  Histology and immunohistochemistry were performed in both cases. In the first case, electron microscopy was also performed. In the second, the previous tumor was re-evaluated.
  
  
  RESULTS
  The first case showed histological, immunohistochemical and ultrastructural features of a rhabdomyosarcoma. In the second case, a lentigoid malignant melanoma was histologically and immunohistochemically demonstrated, whereas the previously resected tumor was a fibrosarcoma negative to melanoma markers.
  
  
  CONCLUSIONS
  Rare cases of rhabdomyosarcomas and melanomas are induced by irradiation, although in some cases other factors (i.e., genetic risk, chemotherapy) may have a prominent etiopathogenetic role in their development. A close follow-up and a careful examination of the irradiated area should facilitate an early diagnosis of these aggressive postradiation second neoplasms.
authors.affiliation: Institute of Pathological Anatomy and Histology, University of Siena, Italy. miracco@unisi.it
authors.forename: C
authors.initials: C
authors.lastname: Miracco
authors.forename: M
authors.initials: M
authors.lastname: Materno
authors.forename: M M
authors.initials: MM
authors.lastname: De Santi
authors.forename: L
authors.initials: L
authors.lastname: Pirtoli
authors.forename: V
authors.initials: V
authors.lastname: Ninfo
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D016889:Endometrial Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D017809:Fatal Outcome; D005260:Female; D005354:Fibrosarcoma / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000737:chemistry / Q000209:etiology* / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis; D009381:Neoplasms, Radiation-Induced / Q000737:chemistry / Q000209:etiology* / Q000473:pathology; D011882:Radiotherapy, High-Energy; D012208:Rhabdomyosarcoma / Q000737:chemistry / Q000209:etiology* / Q000556:secondary; D012878:Skin Neoplasms / Q000737:chemistry / Q000209:etiology* / Q000473:pathology / Q000532:radiotherapy*
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins