A 45-year-old woman presents with progressive dysphonia and is found to have a firm submucosal mass at the right vocal cord. Biopsy reveals a neoplasm with spindle cells arranged in fascicles, with focal cartilage formation. Immunohistochemistry is positive for desmin and negative for cytokeratin. The most likely diagnosis is:
- A Verrucous carcinoma
- B Chondrosarcoma of the larynx ✓
- C Rhabdomyosarcoma
- D Squamous cell carcinoma with sarcomatoid differentiation
Correct answer: B. Chondrosarcoma of the larynx
Explanation
Chondrosarcoma of the larynx is the most common laryngeal sarcoma and typically arises from the cricoid cartilage (60-70%), presenting as a firm submucosal mass with cartilaginous differentiation histologically. It is a low-grade malignancy with spindle cell morphology and focal cartilage/chondroid matrix, and is positive for S100 protein and cartilage markers but negative for cytokeratin (ruling out SCC) and desmin (ruling out rhabdomyosarcoma). Verrucous carcinoma has a warty, exophytic papillary pattern of squamous epithelium.
Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.