Cytomegalovirus (CMV) reactivation is a known complication in patients with hematological cancers and those who undergo stem cell transplants, often resembling cancer relapse. CMV lymphadenitis, an infection localized to the lymph nodes, can be difficult to distinguish from lymphoma recurrence based on clinical and radiological findings alone. We report a case of a 40-year-old male treated for Hodgkin lymphoma who presented with cervical lymphadenopathy nine months after treatment. PET-CT showed a hypermetabolic lesion, suggesting relapse, but a biopsy confirmed CMV lymphadenitis. Systemic CMV infection was excluded based on negative PCR results and normal thoracic imaging. This report highlights the importance of histopathological confirmation in patients with a history of lymphoma, as CMV lymphadenitis can mimic relapse. Accurate diagnosis prevents unnecessary treatments and avoids misinterpretation of imaging findings. In isolated lymph node cases without systemic symptoms, observation may be sufficient as the condition can resolve spontaneously. This underscores the need for careful evaluation to ensure correct diagnosis and appropriate management.