DEFINITION AND PATHOGENESIS

  • Formed of at least two unrelated types of tumor, not including fibrosarcoma and MFH

IMPORTANCE

  • Rare, with only 8 reported cases in the literature as of 1983

CLINICAL FEATURES

  • Most pts reported in the mid-teen years
  • Fibular location accounting for a third of all cases

RADIOLOGIC FEATURES

  • ? spiculated periosteal reaction, Codman triangle
  • MRI may demonstrate an associated soft tissue mass
  • Metaphyseal

GROSS PATHOLOGY

  • Grayish yellow lobulated mass

HISTOLOGIC FEATURES

  • Liposarcoma and osteosarcoma are the two most common malignant tissues of mesenchymal origin encoun-tered
  • Sampling error may give initial dx of liposarcoma

DIFFERENTIAL CLINICOPATHOLOGIC DIAGNOSIS

  • Osteosarcoma
  • Liposarcoma

DISEASE COURSE AND TREATMENT

  • High rate of LR
  • Wide resection

REFERENCES

Bulychova IV, Unni KK, Bertoni F, Beabout JW: Fibrocartilagenous mesenchymoma of bone. Am J Surg Pathol 17:830-6,1993.


Reijnierse M, Kroon HM, Van Der Heul RO, Mulder JD: Mesenchymoma of bone. A case report. J Bone Joint Surg 75A:112-5,1993.


Scheele PM Jr, Von Kuster LC, Krivchenia G 2nd: Primary malignant nesenchymoma of bone. Arch Pathol Lab Med 14:614-7,1990.


Sumner TE, Ward WG, Kilpatrick SE, Opatowsky MJ: Fibrocartilaginous mesenchymoma of bone: case report and review of the literature. Pediatr Radiol 30:315-7,2000.