Subglottic Presentation of a Rare Tumor: Primary or Metastatic?

A 66-year-old white female ex-smoker presented for evaluation of worsening shortness of breath and dysphagia over the course of 1 week. Her medical history was notable for osteoarthritis, hyperlipidemia, and gastroesophageal reflux disease. She had a 30–pack-year history of smoking cigarettes but had quit smoking 20 years prior. Her social history was notable for occasionally drinking wine. On office endoscopic examination, there was a large, leftsided exophytic subglottic mass at the level of the cricoid with approximately 50% to 70% obstruction of the subglottic airway (Figure, A). Therewere no othermasses in the oral cavity, oropharynx, or nasal cavity, or distal trachea. There was no cervical neck lymphadenopathy.Shewasadmittedforairwaymonitoringandthen taken to theoperating roomfordirect laryngoscopy,biopsy, andcarbon dioxide laser debulking of the mass. Examination at direct laryngoscopy revealeda large, left-sidedsubglotticmassat the level of the cricoid with approximately 70% obstruction of the subglottic trachea. Themass extended from the left anterior cricoid to the posterior cricoid just inferior to the left arytenoid cartilage. The hematoxylin-eosin photomicrographs from the biopsy specimen (Figure, B andC) revealeddiffuse sheets andnests of epitheloid cells involving theoverlyingmarkedly attenuated, nonkeratinizing squamous mucosa and extending into the lamina propria. The nuclei were significantly pleomorphic with prominent macronucleoli and mitotic figures present. Nests of tumor cells were present within the squamous mucosa (Figure, C). Focal areas contained finely granular, brown granules (Figure, D). Immunohistochemical staining was positive for the protein S-100 and markers HMB-45 andMART-1. What is your diagnosis? A B