endoscopic submucosal dissection of a tumor in the upper esophageal sphincter and piriform sinus We present a 77-year-old male who initially underwent routine EGD for gastroesophageal reflux in June of 2020 that demonstrated mucosal irregularity at the proximal esophagus and upper esophageal sphincter. PET-CT was done that same month, showing no focal uptake or evidence of lymphadenopathy. The patient was brought back for an endoscopic ultrasound for evaluation of the mucosal irregularity with EUS with biopsy in July of 2020 and August of 2020, revealing a raised UT1AN0MX lesion at the cricopharyngeus and upper esophageal sphincter, concerning for a potentially malignant esophageal tumor. Biopsy was done, confirming SCC, and after discussion at tumor board with cardiothoracic and ENT surgery, it was decided that surgery would be both extensive and complicated, involving esophagectomy and laryngectomy. EGD with endoscopic submucosal dissection with concurrent chemoradiation therapy was then chosen to preserve the patient's quality of life while pursuing complete removal of the squamous cell carcinoma and ensure remission with chemoradiation. Prior to the procedure, this mass was visualized by repeating an EUS and using both Lugol's solution and narrowband imaging with similar margins appreciated. These methods allowed for utilization of only MBI during the ESD given that Lugol's solution may inhibit scope mobility given the challenging location of the tumor. On EGD, we once again visualize the 2 cm flat mucosal mass with no bleeding and no stigmata of recent bleeding in the upper esophageal sphincter. This was measured at 18 to 20 cm from the incisors. The mass was partially circumferential. In other words, it involves half of the lumen circumference. General sedation using seboflurane gas was utilized in order to relax smooth muscles. Preparations were then made for endoscopic submucosal dissection. We began the case by carefully marking the borders of the lesion utilizing MBI as to accurately identify the location of the mass and resection area. This was then followed by the injection of 37 milliliters of overized gel, providing adequate lift of the lesion from the muscularis propria, allowing for a submucosal dissection to be carried out. We then began by creating a circumferential incision around the lesion into the submucosa, performing a mucosotomy using a dual knife, careful to avoid damage to any surrounding structures while ensuring the mass was resected in its entirety. Once the mucosotomy was complete, the lesion was then dissected from the underlying submucosal layers, utilizing a triangle knife with spray coagulation at 50 watts in order to prevent bleeding in a highly vascular area. Once the lesion was completely dissected, it was retrieved using a cap. A total of 25 millimeters of area was resected. Visualization of the resected area was then pursued to help ensure total resection of the mass with no bleeding witnessed upon completion of the procedure. This case helps demonstrate the resection of lesions in the cricopharyngeus and the upper esophageal sphincter can be done, ensuring the resection of the esophageal mass. While these cases may be technically difficult given the location of these tumors, this procedure may help avoid complex surgeries that would otherwise involve removal of the larynx and the esophagus. After completion of the procedure, the patient began and completed an adjuvant chemoradiation less than one month later, receiving carbaplatin and Taxol. In December of 2020, the patient began complaining of dysphagia with follow-up CT scans showing no esophageal lesions. A repeat EGD was then done, showing esophageal stenosis requiring dilation. A PET CT in April demonstrated focal metabolic uptake in the proximal right esophagus with a repeat EGD and EOS that month showing no mass or lymphadenopathy and repeat biopsies negative for recurrent disease. Esophageal stenosis was also noted at the prior resection site with dilation done in April, June, and July of 2021. A PET CT scan in July of 2021 showed no evidence of disease recurrence or metastatic disease. Successful endoscopic submucosal resection of the 2cm flat mucosal mass at the piriform sinus in the upper esophageal sphincter was completed with pathology showing a PT1B-SM1 poorly differentiated squamous cell carcinoma with negative deep and lateral margins, R0 resection along with no lymphovascular invasion noted. Adjuvant chemotherapy was recommended due to the tumor invading into the submucosal layer along with the cancer being poorly differentiated. The patient has since completed concurrent chemoradiation with carboflatin and Taxol plus proton radiation therapy. Repeat PET CT scan 10 months post-chemoradiation showed no evidence of cancer or metastasis. The patient is recovering well but has required recurrent dilations at the prior ESD site. Once again, this case helps demonstrate that resection of lesions in the cricopharynges in the upper esophageal sphincter and piriform sinus may help avoid complex surgeries that would otherwise involve removal of the larynx and the esophagus.

endoscopic submucosal dissection

potentially malignant esophageal tumor

upper esophageal sphincter

piriform sinus

squamous cell carcinoma