Clear cell carcinoma of salivary gland type presenting as an endotracheal polypoid tumor

A 66-year-old woman presented with a 2-year history of asthma has progression of dyspnea within a week, and a computed tomography (CT) revealed an endotracheal tumor at level of aortic arch. The resected tumor, measured by 18 × 12 × 10 mm, has histologically malignant features including frank invasion with desmoplastic stroma and foci of necrosis. Presence of glycogen and mucin was confirmed by periodic acid-Schiff (PAS) and diastase PAS staining. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin (CK) 7 and AE1/3, focally positive for CK5/6 and CK14, but negative for CK20. Thyroid transcription factor-1 (TTF1), Napsin A, and SP-A, indicating lung parenchymal origin were all negative. Other muscular markers, neuroendocrine markers, renal cell carcinoma markers, and markers related to perivascular epithelioid cell tumors were all negative. Postoperative systemic examination suggests no primary tumor outside the lung. The follow up was excellent being recurrence free for 14 months in spite of the positive surgical margin by the tumor cells. This is a first report of rare neoplasm, clear cell carcinoma of salivary gland type, presenting as an endotracheal mass.