• radiotherapy;
  • mucositis;
  • CD68;
  • p53;
  • Ki-67;
  • inflammation

Aims:  The aims of this study were to describe the immunohistopathological and morphometric features of oral mucositis grade I (WHO).

Material and Methods:  Ten samples of oral mucositis were biopsied and submitted to histopathological, morphometric and immunohistochemical analyses (CD68, Ki-67 and p53). The samples were compared with the buccal mucosa of head and neck cancer patients before radiotherapy (NMCP), normal buccal mucosa (NM) and oral dysplasia (OD).

Results:  Epithelial thickness, area and perimeter were decreased in oral mucositis and inflammatory components, increased when compared with NMCP. CD68 immunoreactivity, near to the epithelium, was more evident in oral mucositis than in NMCP (P = 0.01). The Ki-67 counts were higher in oral mucositis than in NM and NMCP (P = 0.001 and P = 0.043, respectively), but without any difference with OD (P = 0.284). The p53 staining was present in all cases of mucositis and oral dysplasia, but negative in NMCP and NM.

Conclusions:  Oral mucositis grade I (WHO) presented epithelial atypia and atrophy, increased inflammatory response, with relevant Ki-67 count and positiveness for p53.