Dearbhail O Driscoll FFR(RCSI), Abstract Co-Author: Nothing to Disclose

Meera Hameed MD, Abstract Co-Author: Nothing to Disclose

Edward Athanasian MD, Abstract Co-Author: Nothing to Disclose

Sinchun Hwang MD, Presenter: Nothing to Disclose

To determine imaging features of hemosiderotic fibrolipomatous tumor (HFLT), which is increasingly recognized as an entity with propensity for local recurrence and the potential to transform into myxoinfammatory fibroblastic sarcoma (MIFS), and to correlate with its clinicopathologic behaviour.

This retrospective study was conducted by searching the electronic medical records from 1990 to 2014. Eight patients (3 males, 5 females; mean age 58, ranging 48-71 years) with histologic diagnosis of HFLT and imaging available on PACS were identified. The review of imaging studies included radiographs (n=2/8), ultrasonograms (n=3/8), and MRI scans (n=16/8). Clinical course of each patient and diagnosis of MIFS were recorded. Imaging features at diagnosis or local recurrence were evaluated including body site, location, calcification, echogenicity at US, and size, border, MR signal characteristics, and contrast enhancement of tumor at MRI.

HFLT was most commonly located in the ankle and foot present in 4/8 (50%) and subcutaneous in 8/8; the mean size was 6.0 cm (range 2-18 cm). Histology at initial diagnosis was HFLT alone in 4 patients and HFLT coexisting with MIFS in 4 patients, and 3/7 after surgical resection recurred as MIFS or HFLT with MIFS. None were calcified on radiograph (2/2), and on US most (2/3) were heterogeneously iso- or hypo echoic to subcutaneous fat with greater than 10 foci of vascular flow on color Doppler. Two of 8 patients had MRI only at local recurrence. The tumor border at initial diagnosis was infiltrative in 4/6 and multinodular in 2/6 patients; it was infiltrative in 2 patients with MRI at recurrence only. Fat interspersed and multiple internal septations in HFLT were present in 7/8 at both initial diagnosis and recurrence. Contrast enhancement was heterogenous in 7/7; blooming in 2/3 cases with GRE sequence suggested intratumoural haemorrhage. None developed distant metastases.

HFLT is a subcutaneous tumor with an infiltrative border, interspersed fat, and septations at MRI. In this series we found high prevalence of concurrent MIFS at initial diagnosis or transformation into MIFS at local recurrence.

HFLT often presents as a subcutaneous mass with an infiltrative border and interspersed fat at MRI; it has a high local recurrence rate and can coexist with MIFS or recur as MIFS.

O Driscoll, D, Hameed, M, Athanasian, E, Hwang, S, Radiologic Imaging Features and Clinicopathologic Correlation of Hemosiderotic Fibrolipomatous Tumor: Experience in a Single Tertiary Cancer Center.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010667.html