Assessment of excision margins following wide local excision for breast carcinoma using specimen scrape cytology and tumour bed biopsy.

Specimen scrape cytology (SSC) and tumour bed biopsy (TBB) were used to assess adequacy of wide local excision of breast cancer. Thirty-nine (49%) of 80 cases were SSC positive and 18 (23%) TBB positive. When the main specimen contained ductal carcinoma in situ (DCIS) 21 (66%) of 32 cases were SSC positive compared to 18 (38%) of 48 when DCIS was absent (chi 2 = 9.17, P < 0.01). TBB results were not affected by the presence of DCIS. These findings may reflect the multifocal nature of breast cancer and especially DCIS. It is postulated that positive specimen cytology could be a better indicator of inadequate local surgical treatment than involved tumour bed biopsies or positive margins judged by conventional histology.