Immunohistochemical staining of podoplanin is helpful in determining the microinvasion of cervical squamous cell carcinoma.

Cervical squamous cell carcinoma develops through a series of stages, including low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), microinvasive squamous cell carcinoma (MISCC), and invasive squamous cell carcinoma (ISCC). The difference between HSIL and MISCC is the appearance of microinvasion, which determines the treatment for patients. However, sometimes it is difficult to differentiate HSIL from MISCC in morphology, and no effective markers are available to help determine microinvasion. Here, we evaluated the expression patterns of podoplanin in cervical tissues by immunohistochemistry staining. Results showed that podoplanin was specifically expressed in a continuous or discontinuous linear pattern within the basal layer of cells from normal cervical squamous epithelium (NS) (100%, 96/96) and HSIL (81%, 57/70). However, its expression was completely absent in microinvasive lesions (0%, 72/72), and the location of podoplanin expression loss was consistent with that of microinvasive lesions. Thus, for HSIL with positive podoplanin expression, the sudden loss of podoplanin represents the occurrence of early invasion. Furthermore, podoplanin was expressed in 3.4% (4/118) of ISCC, and its expression was not correlated with the age of the patient, tumor size, differentiation, FIGO stage, depth of invasion, lymph node, or distant metastasis. The prognosis of patients with positive podoplanin was slightly better than those without it (p > 0.05). Therefore, we found that podoplanin, as a new specific marker for the basal layer cells of cervical squamous epithelium, could assist the diagnosis of microinvasion in cervical squamous cell carcinoma. The specific staining pattern of podoplanin provides the possibility of clinical application in the future.