A rare case of diffuse large B-cell lymphoma of the frontal sinus and rapid review of literature.

Abstract

Introduction: Primary lymphoma of the paranasal sinuses, especially involving the frontal sinus, is exceedingly rare. Extranodal non-Hodgkin lymphoma (NHL) located in the head and neck frequently poses diagnostic challenges because its nonspecific symptoms can be mistaken for benign issues such as rhinosinusitis.

Aim: This case report seeks to emphasize the challenges in diagnosis, the aggressive characteristics, and the effective treatment of an uncommon manifestation of diffuse large B-cell lymphoma (DLBCL) primarily affecting the frontal and ethmoid sinuses.

Case presentation: We present a case of a 62-year-old male who initially presented with symptoms suggestive of acute rhinosinusitis complicated by periorbital cellulitis. Diagnostic workup included physical examination, laboratory investigations, computed tomography (CT) imaging, magnetic resonance imaging (MRI), histopathological (HP) analysis of biopsy specimens, immunohistochemical staining, and positron emission tomography (PET)-CT. The patient presented with right frontal headache, periorbital edema, palpebral ptosis, and posterior rhinorrhea. Initial CT revealed mucosal thickening, lytic changes, and a mass partially invading the right orbit. Following surgical excision, histopathology confirmed DLBCL with positivity for cluster of differentiation (CD)20, CD79a, B-cell lymphoma (Bcl)-6, and Bcl-2, and a Ki-67 proliferation index of 90%. Subsequent MRI revealed a hypointense mass extending into surrounding structures. Staging CT confirmed stage IVB disease. The patient received six cycles of Rituximab-Cyclophosphamide, Hydroxydaunorubicin (Doxorubicin), Oncovin (Vincristine), Prednisolone (R-CHOP) chemotherapy and radiotherapy for the frontal sinus. At the 6-month and 12-month follow-up CT scans, there was no evidence of metabolically active disease on PET-CT (Deauville score 1). During the 2-year follow-up, the patient remained in complete remission.

Conclusions: This case underscores the importance of considering malignancy in cases of atypical sinusitis and the crucial role of HP examination of biopsy specimens. This case also highlights the importance of considering malignancy in cases of atypical sinusitis.