DNA FLOW CYTOMETRIC ANALYSIS OF CHEST-WALL CHONDROMA AND CHONDROSARCOMA

DNA flow cytometric analysis was performed for prediction of malignanc y potential, and hence of outcome, in 17 patients aged 29-76 (mean 52) years with cartilaginous tumour of the chest wall. Histologically the re were nine chondromas and eight chondrosarcomas. The chondrosarcomas (3 grade I, 4 grade II, 1 grade III) were significantly larger than t he chondromas (13.6 +/- 7.8 vs 4.2 +/- 2.0 cm, p < 0.001). DNA Bow cyt ometry was performed on paraffin-embedded blocks of resected tumour. I n eight of the 17 tumours (6 chondromas, 1 grade I and 1 grade II chon drosarcoma) measurement of DNA content failed because of low cellulari ty and severe calcification. Aneuploid DNA content was detected only i n three chondrosarcomas (2 grade II, 1 grade III). The synthetic phase fraction was less than 15% in all the studied chondromas, but exceede d 25% in four of six chondrosarcomas. This case series though small, m ay indicate a trend towards association between higher histologic grad ing and greater incidence of aneuploidy with higher synthetic phase fr action. Tumour size, histologic grade, DNA ploidy and adequacy of surg ical resection are the main influences on prognosis.