Methylene blue staining of the endocervix: An intraoperative guide for the excision of glandular tissue during carbon dioxide laser conization

A simple in vivo staining of the endocervical crypts with 1% methylene blue was used as a surgical marker to tailor the resection-line during the laser conization for cervical intraepithelial neoplasia (CIN), and to facilitate the entire removal of the diseased tissue. From June 1986 to December 1988, 60 patients with CIN grade III and 17 with CIN grade II extending to endocervical canal underwent CO2 laser microsurgical resection. Median age of the patients was 34 years (range 20-45). Thirty-nine were nulliparous, 19 uniparous, and 19 had had 2 or more children. Microsurgical laser resection was performed under local anaesthesia, on an outpatient basis. CO2 laser was used in association with the operating microscope under a magnification power of 6-12 X. The surgical specimen approximated a conoid shape in 64 cases, discoid in 8, cylinder in 1, and was combined with peripheral vaporization in 4. The operation was guided by the above mentioned staining in 58/64 conoid resections and in 3 of the remaining 13, with an overall guidance rate of 61/77 (79%). The resections resulted non-guided for intraoperative bleeding in 5 patients, for stenosis in 3, and for non-useful guidance in the 8 discoid resections. Histology of the surgical specimens showed crypt involvement in 15 cases (19.5%) and cleared lateral margins in all 77 cases. The apex resulted cleared in 73 cases (95%) and uncleared in the remaining 4 (5%). One case with all cleared margins showed I b invasive carcinoma. Two of the 4 patients with an uncleared apex had endocervical curettage, 1 had total abdominal hysterectomy, 1 surgical re-conization. The patient with invasive cancer had radical hysterectomy. Further histologic assessment of the 4 uncleared specimens and of the invasive cancer revealed residual disease in 1 case. In a median follow-up period of 42 months (range 24-74) after primary cervical resection, no recurrence was observed in the 67 evaluable cases. Seven patients, lost to follow-up, were free of disease in the first two years. Excluding the one invasive cancer, the resections guided by the described endocervical staining, could be considered adequate in 72 patients (95%) and therapeutic in 75 (99%).