Modified Alcian blue enhances the intraoperative diagnosis of sentinel lymph node metastasis in invasive lobular carcinoma: a prospective study.

CONTEXT: The sensitivity of an intraoperative diagnosis of sentinel lymph node metastasis of invasive lobular carcinoma using conventional staining is low.

OBJECTIVE: To develop a fast, modified, Alcian blue stain to decrease the intraoperative false-negative results in testing for metastatic invasive lobular carcinoma.

DESIGN: Modified Alcian blue was optimized. Patients who had invasive lobular carcinoma on needle biopsy were candidates for this study. Touch preparations from every sentinel lymph node were prospectively prepared in the same manner, one stained with modified Alcian blue and one with conventional staining. These slides were independently interpreted.

RESULTS: A total of 121 sentinel lymph nodes from 31 patients with invasive lobular carcinoma were studied. There were 11 patients (35.5%) who had at least one positive lymph node test result. There were a total of 18 positive lymph node results (14.9%). Although 10 sentinel lymph nodes with abnormalities were detected in 7 patients with conventional staining, modified Alcian blue detected 15 sentinel lymph node abnormalities in 10 patients. Modified Alcian blue increased the sensitivity compared with conventional staining from 63.6% to 90.9% (calculated based on the number of patients) and from 55.6% to 83.3% (calculated based on number of sentinel lymph nodes). The staining process takes approximately 11 minutes.

CONCLUSIONS: Modified Alcian blue stain is a relatively rapid, cheap, highly sensitive, and specific method of detecting metastatic invasive lobular carcinoma. This method can be used in conjunction with conventional staining methods used intraoperatively.