A case of myospherulosis in a 67-year-old female is reported. The lesion appeared as a submucosal mass firmly attached to the buccal periosteum of the right molar region of the mandible. Although the records of our case did not specify what medication was placed in the lesion, clinicopathologic features further supported the hypothesis that myospherulosis may be a unique instance of iatrogenic disease caused by petrolatum-based antibiotic ointments.