Herpes Zoster on FDG PET/CT: Dermatomal Uptake With Diffuse Splenic Activation

Area of Science:

• Oncology
• Nuclear Medicine
• Infectious Disease

Background:

• 18F-FDG PET/CT is crucial for evaluating cancer treatment response.
• Metabolic changes in the spleen and skin can indicate various conditions.
• Differentiating infection from cancer recurrence is vital for patient management.

Purpose of the Study:

• To report an unusual case of 18F-FDG PET/CT findings.
• To highlight the potential for infection to mimic malignancy on PET/CT.
• To emphasize the importance of correlating imaging findings with clinical presentation.

Main Methods:

• A 78-year-old woman with endometrial cancer was evaluated using 18F-FDG PET/CT.
• Imaging analysis focused on metabolic activity in the skin, lymph nodes, and spleen.
• Clinical correlation with symptoms and physical examination was performed.

Main Results:

• Diffuse linear hypermetabolic skin thickening along the right thoracic wall was observed.
• Hypermetabolic right axillary lymph nodes and diffuse splenic uptake were noted.
• The skin uptake pattern followed a dermatomal distribution, correlating with pain and vesicular eruptions.

Conclusions:

• 18F-FDG PET/CT can show findings suggestive of infection that mimic metastatic disease.
• Herpes zoster infection can present with FDG uptake in the skin, lymph nodes, and spleen.
• Clinical correlation is essential to correctly interpret unexpected FDG-avid findings on PET/CT.