Inflammatory cell accumulation in traumatic neuromas of the human lingual nerve

ObjectiveTo quantify the accumulation of inflammatory cells in traumatic neuromas of the human lingual nerve, and to establish any correlation with the patients’ reported symptoms of dysaesthesia.DesignUsing fluorescence immunohistochemistry, the extent of any chronic inflammatory infiltrate was quantified in human lingual neuroma specimens removed from 24 patients at the time of microsurgical nerve repair. A pan-leucocyte marker (CD45) and a specific macrophage marker (CD68) were used, and comparisons made between neuromas-in-continuity (NICs) and nerve-end neuromas (NENs) in patients with or without symptoms of dysaesthesia.ResultsCD68 and CD45 labelling was significantly associated with areas of viable nerve tissue in neuromas and the CD68 labelling was significantly higher in NICs than NENs. CD68 labelling density tended to decrease with increasing time after the initial nerve injury, but this correlation was only significant for labelling associated with viable nerve tissue in NENs. No significant difference was found between the level of CD68 or CD45 labelling in patients with or without symptoms of dysaesthesia.ConclusionThis study has demonstrated the presence of inflammatory cells within traumatic neuromas of the human lingual nerve. These cells were found to be closely associated with regions of viable nerve tissue, but there was no correlation with the patients’ clinical symptoms.