Is there Epithelial Tissue in Bone Pate? A Histopathology Study

Objectives: To evaluate the histology of bone pate collected during mastoidectomy in chronic suppurative otitis media (CSOM) patients with or without cholesteatoma. Study Design: Prospective controlled study. Materials and Methods: The study recruited 32 patients (15 males, 17 females; average age 25.3 (range 19-56 years) who underwent mastoidectomy for CSOM: 16 with cholesteatomas (group I) and 16 controls with granulation or polyp tissue (group II). In all patients, bone pate was collected separately from the mastoid cortex (Level 1), subcortical air cells (Level 2), and just before the antrum mastoideum (Level 3). All samples were stained with hematoxylin-eosin (H&E) and immunochemically with a monoclonal antibody against epithelial membrane antigen (EMA). The presence of squamous epithelium in the bone pate was examined under a light microscope. Results: In Group I, we detected epithelial cells in the bone pate samples obtained from the mastoid subcortex (two of 16 patients) and antrum (four of 16 patients) levels. However, no epithelial cells were observed in bone pate from the mastoid cortex. In the controls (group II), no epithelial tissue was observed in any sample from any level. Conclusions: Epithelial cells can inoculate bone pate collected from the subcortical and antral areas of the mastoid bone in patients with cholesteatomatous CSOM. To prevent epithelial cell inoculation, we recommended that bone pate be collected only from the cortical bone of the mastoid.