PET scan and PET/CT scans are being widely used for staging of diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma. They are sensitive and specific imaging techniques available for lymphoma. However, practicing hematologists must be aware of false-positive tests, which can upgrade the stage of the lymphoma significantly and may alter the treatment paradigm for an individual patient. This report describes a case of DLBCL that was upgraded with PET/CT scan to stage IVA from stage IA. Pursuit of tissue biopsy with minimally invasive surgery eventually confirmed it to be stage IA DLBCL and paraesophageal leiomyoma. This case highlights the potential pitfalls of modern imaging techniques and the need for histologic diagnosis.