Abstract:

Zhu Xiaohong, Zhang Rongrong. Department of Dermatology, Wuxi No. 2 People′s Hospital, Wuxi 214002, Jiangsu, China Corresponding author: Zhang Rongrong, Email: 852718606@qq.com 【Abstract】 Objective To develop an immunohistochemical assay for the diagnosis of cutaneous malignant melanoma （CMM） micrometastasis via blood and lymphatic vessels, and to evaluate its clinical significance. Methods Fifty-three patients （32 males and 21 females） histopathologically diagnosed as CMM were enrolled in this study. The patients were aged （61.2 ± 8.4） years （range, 52 － 72 years）. Tissue specimens were obtained from the central area of tumor in each case, and also from removed lymph nodes in some cases. The average duration of follow-up was （65.00 ± 5.68） months. During the follow-up, 17 patients died of the recurrence or metastasis of CMM, and 6 patients were lost to follow-up. The expressions of D2-40, S100 and CD34 antigens in 53 tissue specimens were examined by immunohistochemical staining with three individual monoclonal antibodies, or by an immunohistochemical method using 2 two-antibody cocktails （D2-40/S100 and CD34/S100） and double-color chromogens in single tissue sections. Results Of the 53 patients, 30.19% （16/53） were positive for hematoxylin-eosin （HE） staining combined with immunohistochemical staining with individual monoclonal antibodies, and 49.06% （26/53） for the immunohistochemical method using two-antibody cocktails and double-color chromogens. Statistical differences were found in the positive rate between the two methods （χ2 = 3.94, P < 0.05）. Compared with patients without blood/lymph vessel tumor emboli, those with blood/lymph vessel tumor emboli showed higher lymph node metastasis rate （80.77% （21/26） vs. 37.04% （10/27）, χ2 = 10.43, P < 0.001）, but lower five-year survival rate （42.31% （11/26） vs. 70.37% （19/27）, χ2 = 4.25, P < 0.05）. Conclusions The immunohistochemical method with two-antibody cocktails is superior to HE staining combined with immunohistochemical staining with individual monoclonal antibodies in the detection of blood/lymph vessel tumor emboli. And blood/lymph vessel tumor emboli may be an important prognostic factor in patients with CMM.