Numb Chin as Signal for Malignancy-Primary Intraosseous Diffuse Large B-Cell Lymphoma of the Mandible

Malignant lymphomas are about 5% of all malignant tumors. Extranodal non-Hodgkin's lymphomas (NHLs) are found in 26% of these cases. Lymphomas of the head-and-neck area occur in 2%–3% of all malignancies, with 28% with an extranodal manifestation. Extranodal NHLs in the oral cavity are usually found in the maxilla, and rarely in the mandible. Their symptoms and clinical manifestation have no pathognomonic features; therefore, the expression of this uncommon entity can be diagnosed with an odontogenic inflammatory process, leading to a misdiagnosis. Delay in the decision for a biopsy, and adequate treatment for the patient directly impairs the prognosis of this neoplasm. This study reports a case of a patient with discomfort in the right mandible and paresthesia of the right lower lip and chin without any dental focus. After performing further diagnostic examinations including a subsequent biopsy, the final diagnosis was a diffuse large B-cell lymphoma (DLBCL). Intraosseous DLBCLs are uncommon in the daily clinical routine, but emphasize the need for careful examination by the clinicians also considering the differential diagnosis of sensory neuropathy. Neurological symptoms with no apparent cause should raise the suspicion of malignancy until the opposite is proven.