Esophageal Gastrointestinal Stromal Tumors Presenting as Mediastinal Mass
A 73-year-old female presented with vague cough and dyspnea on exertion. She was previously healthy with no pulmonary or heart problems. There was no history of odynophagia, dysphagia or weight loss. Initial chest X-ray showed a mass in the mediastinum (fig. ). A CT scan of the chest with contrast revealed a hypodense, soft tissue mass/lymphadenopathy in the posterior mediastinum measuring 2.0 × 3.0 cm, contiguous with the esophagus (fig. ), suggestive of neoplastic etiology. Further imaging with PET revealed a mediastinal soft tissue mass/lymph node and a standardized uptake value (SUVmax) of 5.1.\nThe patient underwent a bronchoscopy and mediastinoscopy with fine-needle aspiration of the mass. Pathology showed increased cellularity with moderate nuclear atypia and pleomorphism with a mitotic count of 2–3 mitoses/10 high-power fields. Immunohistochemistry was positive for vimentin, SMA, caldesmon and desmin. EMA was focally positive and there were a few positive CD34 cells. It was negative for S100, AE1/AE3 and CD68. The Ki67 index was 3–5% and, finally, the sample was reported as spindle cell well-differentiated leiomyosarcoma (fig. ). The patient was referred to us for further management.\nGiven the possibility of a GIST, CD117 immunostaining was requested and yielded a positive result (fig. ). Then, the patient underwent bronchoscopy with right thoracotomy and esophagoscopy. Esophagoscopy and double lumen bronchoscopy were unremarkable. Thoracotomy findings showed the mass in the posterior mediastinum, which was dissected free from the trachea and inferior aspect of the aorta. The tumor involved muscle layers of the esophagus but not the mucosa. Six weeks after surgery, a repeated PET-CT scan showed no recurrence. On further follow-up, she was free of dyspnea and is currently under surveillance.