DNA flow cytometric analysis was performed for prediction of
malignancy potential, and hence of outcome, in 17 patients aged 29-76 (mean 52) years with cartilaginous tumour of the chest wall. Histologically there were nine
chondromas and eight
chondrosarcomas. The
chondrosarcomas (3 grade I, 4 grade II, 1 grade III) were significantly larger than the
chondromas (13.6 +/- 7.8 vs 4.2 +/- 2.0 cm, p < 0.001).
DNA flow cytometry was performed on
paraffin-embedded blocks of resected tumour. In eight of the 17 tumours (6
chondromas, 1 grade I and 1 grade II
chondrosarcoma) measurement of
DNA content failed because of low cellularity and severe calcification.
Aneuploid DNA content was detected only in three
chondrosarcomas (2 grade II, 1 grade III). The synthetic phase fraction was less than 15% in all the studied
chondromas, but exceeded 25% in four of six
chondrosarcomas. This case series though small, may indicate a trend towards association between higher histologic grading and greater incidence of
aneuploidy with higher synthetic phase fraction. Tumour size, histologic grade,
DNA ploidy and adequacy of surgical resection are the main influences on prognosis.