Pathologic evaluation of cryoprobe-assisted lumpectomy for breast cancer

Cryoprobe-assisted lumpectomy is a relatively new technique that converts nonpalpable carcinomas into well-defined, palpable ones by creating an ice ball under ultrasonographic guidance, thus eliminating the need for preoperative needle localization. We evaluated the effect of cryoprobe-induced freezing on tumor tissue, peritumoral tissue, and margin status in 6 cases of cryoprobe-assisted lumpectomy performed for infiltrating ductal carcinoma. Immunohistochemical stains for estrogen and progesterone receptors and the proliferation marker Ki-67 were performed on 4 cases and results compared with those of the pretreatment biopsy specimens. Although it was possible to recognize the tumor as infiltrating carcinoma in all cases, the alteration in tumor morphology interfered with tumor grading, distinguishing in situ and invasive components, and assessment of mitoses and lymphovascular invasion. The expression of estrogen and progesterone receptors was greatly reduced, whereas the Ki-67 staining was not significantly different when compared with pretreatment biopsy specimens. The "cryoprobe effect" did not interfere with evaluation of the margins and surrounding breast tissue.