FDG-PET-positive ovarian thecoma with GLUT5 expression: Five cases.

Area of Science:

• Oncology
• Nuclear Medicine
• Gynecologic Pathology

Background:

• ¹⁸F-FDG PET-CT is a valuable tool for detecting malignancies.
• Benign lesions can sometimes exhibit false-positive ¹⁸F-FDG uptake, leading to diagnostic challenges.
• Ovarian tumors require accurate differentiation between benign and malignant entities.

Observation:

• Five postmenopausal women with solid ovarian tumors presented with suspicious findings on MRI and ¹⁸F-FDG PET-CT.
• The patients' mean age was 57 years, with average early and delayed ¹⁸F-FDG SUV values of 5.76 and 6.56, respectively.
• Surgical frozen section revealed thecoma in all cases, a benign ovarian tumor.

Findings:

• Immunohistochemistry confirmed glucose transporter 5 (GLUT5) expression in thecoma tissues.
• Thecoma demonstrated positive ¹⁸F-FDG uptake on PET-CT, consistent with malignancy.
• This indicates that thecoma can be a source of false-positive ¹⁸F-FDG uptake.

Implications:

• Clinicians should exercise caution when interpreting ¹⁸F-FDG PET-CT findings in patients with suspected benign solid ovarian tumors.
• The presence of GLUT5 expression may contribute to the observed ¹⁸F-FDG uptake in thecoma.
• This highlights the importance of integrating imaging findings with histopathology for accurate diagnosis and management of ovarian tumors.