Plasma cell tumors are lymphoid neoplasms with an uncontrolled proliferation of B cells. These are divided into localized forms (solitary bone plasmocytoma -SBP- and extramedullary plasmocytoma -EP-) and disseminated forms (multiple myeloma-MM-). The SBP is a rare and controversial disease. The aim of this article is the analysis of this entity based on the presentation of a 64-year-old man without previous medical history, with a mass in the left mandibular angle extending to the parotid region on the same side. The panoramic radiography, computed tomography and magnetic resonance imaging showed an osteolytic lesion 6.5 x 5 x 6.7 cm in the mandibular angle with infiltration of the masticator space and left parotid region. The normality of the extension study, and histopathological examination confirmed the diagnosis of SBP. The patient received treatment with radiotherapy with good outcome. © Medicina Oral.