Well-differentiated Spindle Cell Liposarcoma of the Larynx: A Rare Case Report and Review of Literature

Abstract

Background: Liposarcoma of the larynx is a rare entity. Well-differentiated spindle cell liposarcoma of the larynx has not been yet reported in the literature.

Case report: We report the first case of well-differentiated spindle cell liposarcoma of the larynx on a 59-year-old male who presented with change of voice and phlegmy cough for several months. Laryngoscopy revealed a mucosal covered pedunculated mass on the supraglottis. Computerized tomography (CT) scan showed a low-attenuation mass causing moderate narrowing of the airway. The lesion was excised. Grossly, a 4.2 cm ovoid, solid and soft mass with homogeneously white-gray and rubbery cut surface was identified. Microscopic examination revealed a well-demarcated neoplasm composed of predominantly atypical and pleomorphic spindle cells distributed in collagenous stroma, with admixed adipocytes showing variation in cell size and rare lipoblasts. Immunohistochemical stains showed that the spindle cells were positive for MDM2, CDK4, and CD34. Overall, the histology and immunoprofile are consistent with a well-differentiated liposarcoma, spindle cell type. Due to the positive resection margin, the patient subsequently received endoscopic local re-excision with a carbon dioxide laser. He did well at 4 months after primary excision.

Conclusion: This case illustrates that while well-differentiated spindle cell liposarcoma rarely occurs in the larynx, it should be considered in the differential diagnosis of patients with laryngeal lesions. A panel of immunohistochemistry markers including MDM2, CDK4 and CD34 is helpful to render accurate diagnosis. Wide excision with long-term follow-up is necessary for this rare variant of liposarcoma.

Keywords: CDK4; MDM2; Well-differentiated liposarcoma; larynx; spindle cell.

Figure 1. Radiological finding and gross image of laryngeal WDSCL. (A): CT scan showing a well-defined low-attenuation mass causing moderate narrowing of the airway. (B): Laryngoscopy revealing a pedunculated solid mass extending from the right supraglottis. (C): Gross picture of the mass showing a 4.2 cm ovoid and soft mass with smooth mucosal surface.

Figure 2. Histological features (Hematoxylin and Eosin staining) of laryngeal WDSCL. (A, B): Low- and high-power view of the tumor showing predominantly atypical and focally pleomorphic spindle cells admixed with adipocytes (C) in a fibromyxoid background. (D): High-power magnification showing nuclear pleomorphism and atypical vacuolated lipoblasts. Magnifications: A, ×20; B and C, ×100; D, ×200.

Figure 3. Immunohistochemical stains of laryngeal WDSCL. (A, B): Spindled tumor cells are diffusely positive for CD34. (C, D): Atypical and pleomorphic spindled tumor cells showing a strong nuclear expression of CDK4 (C) and MDM2 (D). Magnification: ×100.