Oral focal mucinosis: report of 15 cases and review of the literature.

AIMS: To describe 15 cases of oral focal mucinosis (OFM) and compare these to previously reported cases.

METHODS

Cases diagnosed as OFM in the period 1981-2003-were reviewed. Clinical information provided at the time of submission of each specimen was retrieved and supplemented by additional clinical details provided by the respective clinician at the time of compilation of this paper. The literature was reviewed.

RESULTS

OFM presented as an innocuous soft tissue swelling that may be either pedunculated or sessile. The gingiva was confirmed as the most common site for OFM, with a predominance of females affected. Microscopically, OFM is characterised by an area of myxoid tissue which is usually well-defined. The lesion is periodic acid-Schiff (PAS)-negative and alcian blue-positive, with pre-digestion with hyaluronidase preventing the alcian blue staining. As the differential diagnosis includes myxoid neural lesions, S100 staining is important in establishing the diagnosis, with cases of OFM being negative.

CONCLUSIONS

The cause of OFM remains unknown. The cases presented in this paper bring OFM to the attention of anatomical pathologists when considering the differential diagnosis of myxoid lesions of the oral cavity.