A Rare 18F-FDG PET/CT Finding Mimicking Leukemia Cutis in Acute Myeloid Leukemia: Palisaded Neutrophilic Granulomatous Dermatitis

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a rare benign dermatosis typically associated with connective tissue diseases. Its occurrence as a paraneoplastic or reactive phenomenon in hematologic malignancies, particularly acute myeloid leukemia, is exceedingly rare. We present the case of a 65-year-old woman with acute myeloid leukemia who exhibited widespread, intensely hypermetabolic subcutaneous nodules on 18 F-FDG PET/CT, strongly mimicking leukemia cutis. Histopathologic examination confirmed PNGD, averting a false-positive interpretation. This case highlights PNGD as a critical diagnostic pitfall in oncologic PET/CT imaging, emphasizing the necessity of histopathologic correlation for hypermetabolic cutaneous lesions to prevent inaccurate upstaging.