Intriguing Cases of Diffuse Large B Cell Lymphoma in Paranasal Sinuses with Review of Literature.

Diffuse Large B-Cell Lymphoma (DLBCL) of the paranasal sinuses (PNS) is an uncommon manifestation of non-Hodgkin lymphoma (NHL), accounting for 0.2-2% of all DLBCL cases. Despite DLBCL being the most frequent subtype of NHL, its occurrence in the PNS is rare, often leading to diagnostic delays due to nonspecific symptoms. The disease primarily affects older adults with a slight male predominance and presents with nasal obstruction, proptosis, and vision loss, among other symptoms. Diagnosis is challenging due to its similarity to more common sinonasal conditions like sinusitis, and timely identification is crucial given DLBCL's aggressive nature. This report presents three cases of DLBCL in the PNS, each characterized by progressive symptoms such as headache, nasal discharge, proptosis, and vision loss. All three patients were treated in a tertiary care center in North India. In each case, diagnostic imaging, histopathological examination, and immunohistochemical staining were utilized to confirm DLBCL. The patients underwent endoscopic biopsy and received chemotherapy, with varying degrees of response. Treatment challenges, particularly in patients with advanced disease, were highlighted, including the potentialfor irreversible vision loss and the high risk of relapse. A literature review further supports that DLBCL of the PNS is a rare but significant diagnosis requiring prompt recognition and treatment. Review of similar cases emphasizes the importance of distinguishing this condition from other sinonasal tumorsand infections to ensure proper management and improved patient outcomes.