Non-Hodgkin's lymphoma of the frontal sinus presenting as osteomyelitis

Abstract

Objectives The aim of the study was to present a case of non-Hodgkin's lymphoma (NHL) originating in the frontal sinus that presented as osteomyelitis of the frontal bone. Methods A review of a single case including radiographic, intraoperative, and pathologic findings was done, followed by a discussion highlighting relevant literature. Results A 55-year-old man presented with pain and swelling of the forehead with 8 weeks duration. He had a history of chronic rhinosinusitis and underwent endoscopic maxillary antrostomies 4 years prior. A presumptive diagnosis of frontal sinusitis with osteomyelitis was made and prolonged oral antibiotic therapy started. The patient was referred to our center after symptoms and objective findings failed to improve. Computed tomography revealed a destructive process of the frontal bone with near total opacification of the frontal sinuses. An exploratory external frontal sinusotomy was performed revealing an infiltrative soft tissue mass filling most of the frontal sinus. Dehiscence of the posterior table was noted without dural involvement. Pathology of this mass revealed diffuse large B-cell lymphoma of intermediate grade. The patient underwent 6 cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone; radiotherapy to the frontal bone; and central nervous system prophylaxis via intrathecal methotrexate. Clinically, he fell into the Ann Arbor Stage II EA NHL category because of an isolated axillary lymph node. Now, 18 months after completion of therapy he is without evidence of disease based on serial positron emission tomography and computed tomography scanning. Conclusions We describe a case of NHL of the frontal sinus, which presented as osteomyelitis. We highlight important features of this patient's clinical presentation that can help differentiate an inflammatory process from a neoplastic process in the frontal bone. Timely diagnosis is critical, and neoplasms of the frontal sinus can be easily misdiagnosed as inflammatory.