2002 CTOS Annual Meeting Oral Presentations — Diagnositc Radiology

PREDICTIVE VALUE OF GADOLINIUM ENHANCEMENT IN DIFFERENTIATING ATYPICAL LIPOMAS (WELL-DIFFERENTIATED LIPOSARCOMAS) FROM BENIGN FATTY TUMORS
[Abstract ID: 27]

Category: Diagnostic Radiology

Presentation: Oral

Authors: Matthew J. Panzarella¹, Timothy A. Damron¹

Author Institutions: ¹SUNY Upstate Medical University at Syracuse, New York, United States

Presenter: Matthew J. Panzarella
panzarem@mail.upstate.edu

Correspondent: Timothy A. Damron
tdamron@twcny.rr.com
Syracuse New York United States 13202
Ph: 315-464-4472
Fax: 315-464-4664

Objectives: To determine the predictive value of gadolinium enhancement on MRI in differentiating atypical lipomas (well-differentiated liposarcomas) from benign fatty tumors.

Methods: Of 129 patients evaluated in the office of the senior author for fatty tumors over the period 1994-2002, the patient population was narrowed to 34 histologically proven fatty tumors with pre-op gadolinium-enhanced MRI, 14 of whom had undergone biopsy after the MRI. Pre-operative gadolinium enhancement was based upon concensus of the musculoskeletal surgeon and radiologists prior to definitive operation. Sensitivity, specificity, positive and negative predictive values for both gadolinium enhancement and biopsy in predicting final atypical lipoma diagnosis (considered equivalent to well-differentiated liposarcoma) were calculated.

Results: As a predictor of atypical lipoma, gadolinium enhancement showed 100% sensitivity , 71% specificity , 59% positive predictive value, and 100% negative predictive value. Needle or incisional biopsy yielded 67% sensitivity, 100% specificity , 100% positive predictive value, and 63% negative predictive value.

Conclusions: Gadolinium enhancement of a homogenous fatty soft tissue tumor, when determined by concensus of an experienced musculoskeletal team, is a sensitive screening tool to determine possible diagnosis of atypical lipoma. Biopsy, on the otherhand, is specific but insensitive. An algorithm is proposed for evaluation of these tumors in which all deep or large tumors undergo screening with gadolinium-enhanced MRI. Only those tumors that enhance would be considered for directed biopsy.