CT of primary retroperitoneal soft tissue masses

Area of Science:

• Radiology
• Oncology
• Pathology

Background:

• Primary peritoneal soft tissue masses are rare.
• Accurate diagnosis is crucial for treatment planning.

Purpose of the Study:

• To evaluate the diagnostic performance of computed tomography (CT) in differentiating benign from malignant primary peritoneal soft tissue masses.
• To identify specific CT features indicative of malignancy.

Main Methods:

• Retrospective analysis of CT scans from 54 patients with untreated primary peritoneal soft tissue masses.
• Evaluation of imaging criteria including lesion size, number, delineation, border definition, and internal structure.
• Histological confirmation of all lesions.

Main Results:

• CT demonstrated lesions in all patients with detailed anatomical information.
• Gas and attenuation values below -30 HU were specific for abscesses and lipomatous tumors, respectively.
• No other CT criteria could reliably differentiate between sarcomas and benign masses.
• CT morphology alone predicted benign or malignant nature in 43% of cases.
• With clinical information, 54% of lesions were correctly classified into etiological subgroups (soft tissue sarcoma, abscess).

Conclusions:

• CT has limited ability to distinguish between benign and malignant peritoneal soft tissue masses.
• Specific CT findings are useful for identifying abscesses and lipomas.
• Clinical information improves etiological classification but overall diagnostic accuracy remains suboptimal.