“Stocking Pattern Metabolic Captivity” of Legs on (18) F-FDG PET-CT in Necrotizing Fasciitis: Potential Complimentary Role in Differential Diagnosis and Assessment of Disease Extent in a Life-Threatening Condition

A rare and fatal life-threatening case of necrotizing fasciitis (initially presenting with skin-deep superficial lesions and clinical suspicion of paraneoplastic syndrome) is described, who was finally diagnosed with the help of fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) as more extensive infectious process. A 36-year-old male presented with bilaterally symmetrical cutaneous lesions involving lower limbs that rapidly progressed to ulcerative lesions and pancytopenia. In view of suspicion of paraneoplastic manifestation, the patient underwent (18) F-FDG-PET/CT to rule out any underlying malignancy. The FDG-PET/CT findings confirmed hypermetabolism circumferentially along the fasciae of bilateral lower extremities while sparing muscles and subcutaneous fat from below the knee till toe with diffused hypermetabolic marrow, and no evidence of focal disease suggesting malignancy. Biopsy turned out to be superficial necrolytic fasciitis. The patient's condition deteriorated and, 20 days following the scan, the patient succumbed secondary to severe pancytopenia and hypotension. The case raises the importance of high degree of suspicion and prompt diagnosis of this condition, where FDG-PET/CT imaging can play a valuable complimentary role. Such awareness could be lifesaving due to early optimal treatment in the disease course.