Clinicopathological and interphase cytogenetic analysis of desmoid tumours

Recurrence of desmoid tumours is difficult to predict from only histological findings. In this study, immunohistochemistry for counting stromal blood vessels and proliferative activity, DNA flow cytometry, and interphase cytogenetic analysis of chromosome 8 by fluorescence in-situ hybridization (FISH) were performed to assess the correlation between their parameters and the recurrence of desmoid tumours.

The cases examined included 16 extra-abdominal desmoid and eight abdominal desmoids, comprising 14 recurrent and 10 non-recurrent 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-recurrent tumours (34 years). Histologically, tumours with hypervascular areas frequently recurred after surgery in comparison with those with hypovascularity. There was no significant correlation between tumour size, the labelling index of the proliferating cell nuclear antigen (PCNA) and the recurrence. In flow 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%).

These results suggest that a subgroup of desmoid tumours at risk of recurrence may be hypervascular lesions associated with trisomy 8.