Spindle Cell Squamous Cell Carcinoma of the Larynx with Malignant Osteoid Differentiation: A Case Report and Review of Literature.

Spindle cell squamous cell carcinoma of the larynx is a rare, aggressive variant of squamous cell carcinoma. It comprises 0.6-1.5% of all laryngeal cancers. Heterologous mesenchymal differentiation as bone, cartilage, and muscle is uncommon, especially malignant osteoid differentiation, as a handful of cases reported in the literature. We present the case of a 66-year-old male active smoker who presented with dysphonia and acute stridor. On examination, a 2.0 cm pedunculated, broad-base, glottic mass involving the left true vocal cord and ventricle was noted, with extension to the anterior commissure causing a narrowing of the airway. The patient underwent localized left vocal cordectomy. The histopathologic and immunohistochemical findings were consistent with spindle cell carcinoma with malignant osteoid differentiation. The patient is alive, status-post adjuvant five cycles of cisplatin therapy, with no recurrence at 18 months of follow-up. We discuss a literature review of this rare entity with either malignant osteoid or osteocartilaginous differentiation.