Case Study from the year 2025 in the subject Medicine - Otolaryngology, grade: Case Presentation, University of Miami (Miami Family ENT), language: English, abstract: This case study of a 75-year-old female patient who presented with a suspicious neck mass. Extensive diagnostic efforts, including histopathology, PET-CT imaging, and hematopathology consultation, revealed a complex presentation in which the first biopsy was positive for actinomycosis without tumor cells, while a second more profound biopsy revealed and confirmed the coexistence of diffuse large B - cell lymphoma. This case emphasizes the importance of a multidisciplinary approach to diagnosis and treatment.