Well-differentiated liposarcoma (WDL) is a common adult sarcoma, mainly occurring in the retroperitoneum as well as deep soft tissues of proximal lower extremities and trunk. Lesser known is that WDL can rarely present in deep head and neck sites as a clinically distinctive entity — a so-called “giant fibrovascular polyp (GFVP)”. GFVPs were previously thought to be benign reactive lesions, but recent literature suggests that the majority of GFVPs in the oesophagus and upper airways are WDLs, as confirmed by fluorescence in-situ hybridisation (FISH) demonstrating MDM2 amplification. Histological features of WDL may be subtle in GFVPs. We report a case of a woman in her forties who presented with obstructive upper aerodigestive tract symptoms, found to have a large pedunculated pharyngeal polyp. Histological examination of the polyp was complicated by extensive torsion effect, demonstrating a fibroepithelial polyp-like lesion with minimal fat and only mildly atypical stromal cells. WDL was diagnosed by FISH showing MDM2 amplification. We present this case to illustrate the importance of considering liposarcoma in all GFVP-type lesions of the upper aerodigestive tract, with MDM2 FISH being a crucial adjunct test in morphologically challenging cases.
Uemura et al. (Sun,) studied this question.