Well-Differentiated Laryngeal/Hypopharyngeal Liposarcoma in the MDM2 Era Report of Three Cases and Literature Review.

Laryngeal/hypopharyngeal liposarcomas are very rare, fewer than 40 cases have been reported. These tumors are polypoid, with a male predisposition, and usually cause hoarseness and difficulty breathing. Their clinical course is characterized by multiple local recurrences. No distant metastasis has been reported, and dedifferentiation is extremely rare. In sum, the prognosis of these tumors is excellent; the 5-year survival rate is essentially 100 %. Pathologic diagnosis of these well-differentiated liposarcomas can be challenging. Many of them were initially diagnosed as benign lipoma, fibrovascular polyp, or "inflammatory polyp". The correct diagnosis is usually made after multiple recurrences. On the other hand, the literature bears out that these incorrect diagnoses do not impact disease-specific survival. Here, we report three patients with laryngeal/hypopharyngeal well-differentiated liposarcomas; this is the first documentation of MDM2 amplification in liposarcomas at this site.