Increased Prostate-Specific Membrane Antigen Uptake in Neurofibromatosis

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• Neurofibromatosis is a genetic disorder characterized by the growth of tumors on nerve sheaths.
• Prostate-specific membrane antigen (PSMA) is a transmembrane protein that is highly expressed in prostate cancer.
• Gallium-68 PSMA PET/CT is a sensitive imaging modality for detecting prostate cancer.

Observation:

• A 51-year-old man with a history of neurofibromatosis presented with elevated prostate-specific antigen and back pain.
• Ga-PSMA PET/CT revealed no abnormal uptake in the prostate gland.
• Unexpected PSMA uptake was observed in lung, thorax, ilium (later confirmed as squamous cell carcinoma), and notably, in benign neurofibromatosis skin lesions.

Findings:

• The study identified PSMA uptake in benign neurofibromatosis lesions, which is not a typical finding.
• This uptake occurred alongside confirmed metastatic lung squamous cell carcinoma, highlighting a potential diagnostic challenge.

Implications:

• Benign neurofibromatosis lesions can exhibit PSMA uptake, potentially leading to false positives in prostate cancer imaging.
• Clinicians should consider benign conditions like neurofibromatosis when interpreting Ga-PSMA PET/CT scans.
• Further research is needed to understand the mechanisms behind PSMA uptake in neurofibromatosis.