Malignant Peritoneal Mesothelioma Masquerades as Peritoneal Metastasis on (18)F-FDG PET/CT Scans; a Rare Diagnosis...

Area of Science:

• Oncology
• Radiology
• Nuclear Medicine

Background:

• Malignant peritoneal mesothelioma (MPM) is a rare and aggressive malignancy.
• Clinical and imaging features of MPM are often nonspecific, mimicking other abdominal pathologies like peritoneal metastasis.
• Standard diagnostic pathways for MPM can be challenging due to its rarity and varied presentation.

Observation:

• This study presents two biopsy-proven cases of malignant peritoneal mesothelioma (MPM) diagnosed using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT).
• The cases highlight unusual sites of origin, including the visceral peritoneum overlying a polycystic kidney and the parietal peritoneum near an appendectomy scar.
• Diverse metastatic patterns were observed, ranging from localized intra-abdominal disease to extensive multi-organ involvement.

Findings:

• Imaging findings of MPM on (18)F-FDG PET/CT are highly variable and not extensively documented.
• The presented cases demonstrate specific (18)F-FDG PET/CT characteristics associated with MPM in atypical locations and with varied metastatic spread.
• Recognition of these diverse patterns is crucial for accurate interpretation.

Implications:

• Understanding the spectrum of (18)F-FDG PET/CT findings in MPM can improve diagnostic accuracy.
• This knowledge helps clinicians avoid misdiagnosis and facilitates timely and appropriate management of malignant peritoneal mesothelioma.
• Further research into (18)F-FDG PET/CT characteristics may enhance the early detection and characterization of rare peritoneal malignancies.