Diffuse B-Cell Lymphoma of the Mandible Disguised as Acute Osteomyelitis.

Background: Primary bone lymphoma (PBL) is a rare form of extra nodal non-Hodgkin's lymphoma (NHL). Case description: We describe a 39-year-old-male with no medical history who presented with unilateral facial swelling following a tooth extraction. Initial diagnoses after various presentations over the course of three weeks, based on inflammatory and infectious aetiologies. However, the patient was ultimately diagnosed with diffuse large B-cell lymphoma. Discussion: Symptoms of PBL are very similar to inflammatory and infectious diseases of the bone, such as osteomyelitis or osteonecrosis. Clinical features of PBL involving the head and neck include persistent jaw pain, tooth mobility secondary to extensive destruction of bone, and in advanced cases, lip numbness and swelling. On examination it may present as an exposed necrotic bone with surrounding soft tissue oedema. Misdiagnosis of these lesions as an infectious or inflammatory aetiology may lead to an unnecessary delay in lymphoma treatment, and subsequently worsen the prognosis if caught at a later stage. Therefore, any concerning lesion, especially in the oral cavity, must be subjected to early histopathological evaluation to differentiate PBL from osteomyelitis and/or osteonecrosis. Conclusion: This case report highlights the importance of an early histopathological evaluation to prevent delay in the diagnosis of primary bone lymphomas. LEARNING POINTS: Resemblance in symptoms: Primary bone lymphoma (PBL) symptoms overlap with bone infections, necessitating careful consideration and differential diagnosis to prevent misjudgment.Head and neck manifestations: recognising PBL's signs in the head and neck region, such as jaw pain and bone destruction, aids in timely identification and treatment.Timely biopsy significance: swift histopathological assessment for suspicious lesions is critical to avoid delays in diagnosing primary bone lymphomas.