Brown tumors of the oral cavity: presentation of 4 new cases and a systematic literature review

Objective. The aim of this study was to obtain data from a review of cases of brown tumors (BT), which are benign lesions of bone characterized by giant cells that arise during hyperparathyroidism (HPTH). BTs may affect the maxillofacial area and manifest as a brownish, slow-growing swelling causing difficulty in the differential diagnosis. Study Design. We present data from 4 new cases of oral BTs based on a systematic literature review conducted by searching EMBASE, Medline, and CENTRAL databases, according to the PRISMA guidelines. Only articles in English were considered. Individual patient data were analyzed to identify risk factors for multiple or extraoral maxillofacial BTs. Results. In total, 167 cases (163 from 136 articles and 4 new cases; mean age 36.6 years; male-to-female ratio 1:2) were retrieved. The onset of extraoral maxillofacial BTs (odds ratio [OR] 176.3; 95% confidence interval [CI] 18.7<1657.8; P <.05) and maxillary BTs (OR 17.5; 95% CI 6.0<50.8; P <.05) were the risk factors for multiple oral BTs, whereas the presence of a BT in the mandible (OR 0.01; 95% CI 0.001< 0.1; P <.05) was a negative predictor for the presence of other extraoral maxillofacial BTs. Conclusions. The results of this systematic review suggested that the mandible is the most frequent oral location of BTs. Whenever a BT is detected in the maxilla or when multiple oral BTs are diagnosed, more BTs in the maxillofacial area should be suspected.