Jacob's disease: Report of a case.

PURPOSE: Jacob's disease (JD) is an uncommon disorder that presents as pseudojoint formation between the enlarged mandibular coronoid process and the zygoma, resulting in mouth opening limitation (MOL). Intraosseous lipoma (IOL) usually presents in the long bone, but it is very rare in the mandible. The authors present a rare case of JD and coexisting IOL in the same anatomical area and discuss diagnosis and surgical intervention.

CLINICAL PRESENTATION AND INTERVENTION: The patient was a 39-year-old Korean female with MOL. Magnetic resonance imaging showed a large lobulated mass with fat-specific signal intensity. A combined extraoral and intraoral approach was used to resect the large mass. Histopathologic examination revealed a degenerated lipomatous tumor replacing the marrow cavity, with cartilaginous cap formation on the articular surface.

CONCLUSION

Postoperatively, the patient showed uneventful healing and resolution of MOL.