title: Osteosarcoma with rhabdomyosarcomatous component or so-called malignant mesenchymoma of bone.
abstract: BACKGROUND
  Primary malignant mesenchymoma of the bone is a rare neoplasm consisting of two or more unrelated malignant mesenchymal components. The literature reports fewer than 20 cases, most of which were composed of osteosarcoma and liposarcoma.
  
  
  METHODS
  We report an exceedingly rare case of primary malignant mesenchymoma of bone composed of rhabdomyosarcoma, osteosarcoma, and a minor chondrosarcoma component, arising in the right proximal humerus of a 15-year-old girl. The rhabdomyosarcomatous component was present in the initial biopsy and persisted in surgical specimen following chemotherapy.
  
  
  CONCLUSIONS
  Effect of chemotherapy is enigmatic since rhabdomyosarcomatous component could appear, persist or disappear after chemotherapy according to literature.
authors.affiliation: Surgical Pathology Department, Salah Azaiez Institute, 1006 Bab Saadoun, Tunis, Tunisia. karima.mrad@rns.tn
authors.forename: K
authors.initials: K
authors.lastname: Mrad
authors.forename: S
authors.initials: S
authors.lastname: Sassi
authors.forename: M
authors.initials: M
authors.lastname: Smida
authors.forename: F
authors.initials: F
authors.lastname: Oubiche
authors.forename: A
authors.initials: A
authors.lastname: Mekni
authors.forename: K Ben
authors.initials: KB
authors.lastname: Romdhane
mesh_terms: D000293:Adolescent; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D002813:Chondrosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D003131:Combined Modality Therapy; D003893:Desmin / Q000032:analysis; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D005260:Female; D005354:Fibrosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000473:pathology*; D008637:Mesenchymoma / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D008727:Methotrexate / Q000627:therapeutic use; D009363:Neoplasm Proteins / Q000032:analysis; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D010014:Osteolysis / Q000209:etiology; D012516:Osteosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology; D011655:Pulmonary Embolism / Q000209:etiology; D011859:Radiography; D012208:Rhabdomyosarcoma / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D012512:Sarcoma, Ewing / Q000175:diagnosis
chemical_list: D000964:Antimetabolites, Antineoplastic; D003893:Desmin; D009363:Neoplasm Proteins; D008727:Methotrexate