Primary tracheal hyalinizing clear cell carcinoma.

Area of Science:

• Oncology
• Pulmonology
• Genetics

Background:

• Clear cell carcinoma (CCC), previously known as hyalinizing clear cell carcinoma (HCCC), is a rare tumor type.
• These tumors most commonly originate in the salivary glands of the head and neck region.
• Primary CCC of the airway is exceptionally rare, with initial reports in the lung emerging in 2015.

Observation:

• A 66-year-old female patient presented with progressive dyspnea.
• Computed chest tomography identified a polypoid mass on the posterior-lateral wall of the trachea.
• The mass caused malignant airway obstruction, necessitating mechanical ventilation.

Findings:

• Bronchoscopic examination confirmed the obstructive tracheal mass.
• Pathological analysis revealed nests of clear cells within a hyalinized stroma.
• Fluorescence in situ hybridization (FISH) testing identified a recurrent EWSR1 gene translocation, confirming the CCC diagnosis.

Implications:

• This case represents the first documented instance of clear cell carcinoma arising primarily from the trachea.
• The findings expand the known anatomical sites for primary CCC.
• This report highlights the importance of considering rare tumor types in the differential diagnosis of airway obstructions.