Expression of podoplanin in primary and metastatic poorly differentiated and undifferentiated carcinomas of the head and neck.

UNLABELLED The invasive growth properties of head and neck carcinoma can be determined by proteins associated with cellular motility. Podoplanin is a recently identified protein associated with motility of cells. MATERIALS AND METHODS Sixty-five tumour specimens of 51 patients with poorly and undifferentiated carcinomas were investigated for podoplanin expression. All tissues were fixed in buffered formalin and embedded in paraffin. RESULTS Podoplanin expression showed a tendency towards a more intense staining in carcinomas with a squamous epithelia differentiation compared to tumours without any remnants of cellular layers. Podoplanin expression was very rarely seen in lymph node metastases and the staining was weak in these specimens. The differences of podoplanin expression between primary and metastatic carcinoma were highly significant (p<0.005). CONCLUSION Podoplanin is expressed in primary undifferentiated carcinoma, both inside and outside of Waldeyer's ring. This study shows that podoplanin can be used as a marker of tumour invasion in poorly or undifferentiated head and neck carcinoma.