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

Abstract

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.

Keywords: Head and neck; Larynx; Liposarcoma; Pharynx.

Fig. 1

Top Polypoid well-differentiated liposarcoma in the laryngeal submucosa. Bottom Variable sized adipose lobules with cellular fibrous septae

Fig. 2

a Well-differentiated liposarcoma extends up to intact squamous mucosa. b Interface between fibroblastic and lipomatous components. c, e Atypical fibroblasts with large, pleomorphic nuclei and dark, smudgy chromatin. d, f Atypical lipocytes and rare lipoblasts within the adipose component

Fig. 3

Atypical fibroblasts infiltrate the adjacent skeletal muscle at the deep margin

Fig. 4

MDM2 immunostaining result in one liposarcoma. Diffuse strong nuclear positivity is seen

Fig. 5

MDM2/CEP12 FISH assay in two liposarcomas (a, b one case, c, d another case). The white arrows are examples of normal complement of signals (MDM2-red signals and CEP12-green signals). Cells with yellow arrows are examples of increased FISH signals, corresponding to MDM2 gene amplification

Fig. 6

Regurgitated polypoid well-differentiated laryngeal liposarcoma in a Caucasian male. The tumor grossly is a well-circumscribed polypoid fibrous mass. Courtesy of Dr. Mark Reed, Jackson, Mississippi