Pitfall of ¹⁸F-FDG PET/CT in Characterization of Relapsed Multisystem Lymphomatoid Granulomatosis

Abstract

We present serial ¹⁸F-FDG PET/CT findings in a case of Epstein-Barr virus positive pulmonary lymphomatoid granulomatosis, grade 3. The patient experienced transient complete response to R-CHOP chemotherapy and subsequent multi-system recurrence, predominately involving the subcutaneous region of the torso on ¹⁸F-FDG PET/CT. Biopsy of the most hypermetabolic subcutaneous lesion demonstrated EBV negative cutaneous lymphomatoid granulomatosis, grade 1. This report highlights the role of ¹⁸F-FDG PET/CT in characterizing and monitoring disease progression and regression, as well as its limitation in accurate grading of multisystem recurrence given the diversity of clinical and histopathological feature of lymphomatoid granulomatosis.