Granular cell tumor of the trachea mimicking an infiltrating thyroid cancer. A case report.

Introduction and importance: Granular cell tumor (GCT) is a rare neurogenic neoplasm originating from Schwann cells that predominantly affects women and can involve skin and mucousae. In the respiratory system it most frequently involves bronchi and larynx, while it is rare in the trachea. Case presentation: A 26-year old female smoker was hospitalized for a suspected hypoechoic nodule in the right thyroid lobe closely adherent to the trachea. At preoperative computed tomography tracheal lumen was totally clear. The patient underwent a total thyroidectomy with lymph node dissection and tracheal shaving. The postoperative course was complicated by an extensive subcutaneous bilatreral emphysema associated with respiratory distress appeared on the fifth day. Bronchoscopy revealed a right anterolateral subcentimeter lesion near the second tracheal ring. Histologically, the diagnosis was consistent with a tracheal GCT developing into the thyroid parenchyma. The patient was discharged on the twentieth postoperative day. At the follow-up bronchoscopy the lesion was completely healed and at the last 12 month follow-up the patient is doing well. Clinical discussion: Tracheal tumors are uncommon neoplasms accounting for about 2% of the total respiratory tree tumors. In literature we found <50 papers concerning tracheal GCT and in almost all of the cases patients complained about respiratory symptoms. Conclusion: We report here a rare case of benign GCT of the trachea with extraluminal development, in a young patient who did not complain about preoperative respiratory symptoms, presented on ultrasound as a thyroid nodule with suspected cytology.