V. Satyananda1, C. Dauphine1, D. Hari1, K. Chen1, J. Ozao-Choy1 1Harbor UCLA Medical Center,General Surgery,Los Angeles, CALIFORNIA, USA
Introduction:
Lipomatous masses are the most frequent non-cutaneous soft tissue masses encountered in clinical practice. Benign Lipomas comprise the majority,however,it is necessary to differentiate these from malignant lesions for which adequate surgical margins are important. In the abscence of suspicious clinical features, such as overlying skin changes,rapid growth,pain and firmness on examination, radiographic features have traditionally been to determine which patients should undergo core needle biopsy (CNB) prior to excision. We sought to examine whether CNB should be routinely performed in all lipomatous masses that demonstrate high -risk radiographic features
Methods:
A retrospective chart review of all patients who underwent excision of extremity or truncal lipomatous masses at a single institution between October 2014 to July 2017. Patients were divided into three groups-those who did not undergo pre-operative imaging or CNB(Group 1), those who underwent imaging (ultraosund, CT or MRI)without CNB (Group 2) and those who underwent both imaging and CNB(Group 3). High risk radiographic features were defined as size > 5 cm , intramuscular location, presence of septationa (either < 2mm or > 2mm) and presence of areas of non -fat nodularity within the lesion. the number of high risk features present, pathologic results of surgical excision were evaluated to determine the subset of patients most likely to benefit from CNB.
Results:
In the 58 month study period, 182 patients underwent excision of lipomatous mass. Of these, 57 patients (Group1) had no preoperative imaging or CNB, and all were found to have benign lipotamous masses. In the remianing 125, 70 had imaging only(Group 2) and 55 had both imaging and CNB performed (Group 3). Overall, 2 patients (1.1%) were found to have atypical or malignant lipomatous lesions. Both had > 3 high risk features (thick/thin septations, intramuscular location, size >5cm)and both had undergone CNB( Table 1).
Conclusions:
Few recommendations exist regarding management of lipomatous masses; current guideline suggest imaging and CNB should be performed on large (> 5cm ) and /or high risk radiological features. Nonetheless, the rate of malignancy in these lesions appears to be low. Only 1% of our patients had an atypical or malignant final pathology. Our data suggests that patients who have small lipomatous masses (< 5 cm) may undergo excisional biopsy without further imaging or CNB. in additiona, our study suggests that routine performance of CNB based upon size alone is not warranted , but presence of 3 or more high-risk radiographic features should indicate pre operative CNB to ensure proper surgical approach at the time of excision.
