CLINICOPATHOLOGICAL AND INTERPHASE CYTOGENETIC ANALYSIS OF DESMOID TUMORS

Aims: Recurrence of desmoid tumours is difficult to predict from only histological findings. In this study, immunohistochemistry for countin g stromal blood vessels and proliferative activity, DNA now cytometry, and interphase cytogenetic analysis of chromosome 8 by fluorescence i n-situ hybridization (FISH) were performed to assess the correlation b etween their parameters and the recurrence of desmoid tumours. Methods and results: The cases examined included 16 extra-abdominal desmoid a nd eight abdominal desmoids, comprising 14 recurrent and 10 non-recurr ent cases. Eleven (69%) of the 16 extra-abdominal desmoids and three ( 38%) of the eight abdominal desmoids recurred. Patients with recurrent lesions (mean age, 20 years) were younger than those with non-recurre nt tumours (34 years). Histologically, tumours with hypervascular area s frequently recurred after surgery in comparison with those with hypo vascularity. There was no significant correlation between tumour size, the labelling index of the proliferating cell nuclear antigen (PCNA) and the recurrence. In now cytometric analysis, all the cases examined showed a diploid pattern. The FISH study revealed that the incidence of trisomy 8 was significantly higher in the recurrent (72.7%) than in the non-recurrent cases (12.5%). Conclusions: These results suggest t hat a subgroup of desmoid tumours at risk of recurrence may be hyperva scular lesions associated with trisomy 8.