Mental foramen in panoramic radiography can be a reference for discrimination of punched-out lesions in the mandible in patients with symptomatic multiple myeloma: A cross-sectional study.

Multiple myeloma (MM) is a hematopoietic malignancy characterized by monoclonal proliferation of plasma cells. MM features bony radiolucencies called punched-out lesions (POLs), which require appropriate diagnosis due to increased risk of surgically-related adverse events. Although dental surgeons can identify dental focal infections (DFIs) in MM patients, the prevalence and characteristics of POLs in the jawbone of MM patients have not been investigated. We examined the prevalence of POLs in the mandible of MM patients, evaluated its relationship with MM International Staging System progression, and examined panoramic radiographs as a diagnostic reference for POLs in a single center in Japan. We identified 98 patients (55 men, 43 women) with a median age of 63 (range, 34 to 91) years. Of these, 18 patients (18.4%) had POLs in the mandible, including two patients in stage I (2/37; 5.4%), six in stage II (6/43; 14.0%), and ten in stage III (10/18; 55.6%). The prevalence of POLs significantly increased with MM stage progression ( < 0.0001). POLs confirmed on computed tomography (CT) were also detected on panoramic radiographs. The Hounsfield unit value at the site of POLs was nearly the same or lower than that of the mental foramen. Although the prevalence of POLs in the mandible is low, dental surgeons need to differentiate POLs as radiological findings when examining DFIs in MM patients. Confirmation of POLs in the mandible is possible by CT and panoramic radiography, and the mental foramen is likely to be a reference for discrimination.