Unplanned excision of soft tissue sarcoma: does it impact the accuracy of intra-operative pathologic assessment at time of re-excision?

PURPOSE: An "unplanned excision" refers to soft tissue sarcomas excised without planning imaging studies and a diagnostic biopsy, resulting in the presence of residual disease and usually necessitating a re-excision procedure. We aimed to assess the impact of previous unplanned excisions on the intra-operative pathologic assessment at the time of re-excision, in terms of need to perform repeat assessments and the accuracy to predict margin status of the final pathologic specimen.

METHODS

Data was collected for all patients with extremity soft tissue sarcoma who had undergone wide local excision limb salvage surgery or amputation between 2012 and 2017. Intra-operative pathologic assessment with frozen sections was performed in all cases and was classified as negative, negative but close (< 1 mm), and positive.

RESULTS

A total of 173 patients with extremity soft tissue sarcoma were included, 54 in the unplanned excision group and 119 in the planned excision group. The accuracy of intra-operative pathologic assessment to predict the margin status on final pathology was similar between groups (87% unplanned vs. 90.7% planned excisions). However, the need for repeat intra-operative pathologic assessment and subsequent resection due to microscopically positive margins was found to be higher within the unplanned excision group ((p = 0.04), OR = 3.2 (95% CI: 1.1-9.1, p = 0.048)).

CONCLUSIONS

Intra-operative pathologic assessment of resection margins had a similar accuracy in planned and unplanned excisions; however, unplanned excisions showed a higher risk of re-resection during the same surgical setting.