Non-Hodgkin Lymphoma Presenting as Unilateral Hypertrophy Tonsil

Non-Hodgkin lymphoma (NHL) can occasionally present as an extranodal malignancy in the head and neck region. While Waldeyer's ring is the most common site for extranodal NHL in this area, its clinical presentation can mimic benign inflammatory conditions such as tonsillitis or a peritonsillar abscess, leading to diagnostic delays. This case report aims to describe the clinical presentation, diagnostic workup, and histopathological findings of a rare case of diffuse large B-cell lymphoma (DLBCL) presenting as unilateral tonsillar hypertrophy in an elderly patient. We report the case of a 72-year-old female who presented with odynophagia and progressive left-sided neck swelling. The diagnostic process included a thorough physical examination, contrast-enhanced computed tomography (CT) imaging, surgical tonsillectomy, histopathological analysis, and immunohistochemistry (IHC) staining. CT imaging revealed an enhancing mass in the left tonsil. Histopathological examination of the excised tonsil showed a diffuse proliferation of large, atypical lymphoid cells effacing the normal architecture. Immunohistochemical staining was positive for CD20 and BCL-2, and negative for CD3 and CD30, confirming a diagnosis of diffuse large B-cell lymphoma (DLBCL), of the non-germinal center B-cell subtype. This case highlights the critical importance of including lymphoma in the differential diagnosis for unilateral tonsillar enlargement, especially in older patients. A high index of suspicion, followed by timely histopathological and immunohistochemical analysis, is essential for accurate diagnosis and prompt initiation of appropriate therapy.