Case 2

A 50-year-old male presented with a huge mass in his distal thigh. He had first noticed it at age 16 when he described it as being the size of a grapefruit. The mass remained asymptomatic and without increase insize until 3-years prior to presentation when it began to enlarge.
    A: Appearance of the mass at presentation.
    B: AP radiograph of the thighs.
    C: Total body isotope scan.
    D: Axial CT image cut through the midportion of the mass.
    E: A representative field from the biopsy of the margin of the mass. The field contains the margin of the lesion, a well-defined connective tissue capsule, and a more peripheral zone of reactive tissue. The lesion has a moderately high cell to matrix ratio, moderate cellular atypia, and an occasional double-nucleated chondrocytes admixed with mature chondroid matrix.

Stage I-B chondrosarcoma secondary to an exostosis in view of the clinical history, radiographic findings and microscopic appearance.

A wide above-knee amputation was done.

There has been no recurrence or metastasis in the 18 mos since the amputation.