The parapharyngeal space is an anatomically complex region containing the internal carotid artery, internal jugular vein and lower cranial nerves, and is one of the most difficult areas in the head and neck to obtain surgical access to. Herein, we report the case of a large malignant tumor in the parapharyngeal space excised by a microwave energy device-assisted endoscopic procedure.
A 60-year-old man presented with a 5-month history of a gradually enlarging mass in his upper right neck. Physical examination revealed a protuberance of the right posterolateral pharyngeal wall and palpable cervical lymph nodes bilaterally. Computed tomography and magnetic resonance imaging revealed a weakly enhancing mass with granular calcification measuring 50 mm in diameter in the right parapharyngeal space and enlarged bilateral upper cervical lymph nodes. Positron emission tomography revealed intense accumulation in these lesions. The findings of fine-needle aspiration cytology of the lymph node were categorized as class V, indicative of adenocarcinoma. Based on the findings, the patient was diagnosed as having a malignant tumor arising from the deep lobe of the parotid gland, and treated by a microwave energy device-assisted endoscopic resection of the tumor via a transcervical approach, combined with bilateral conservative neck dissection. The tumor was successfully and completely excised under clear visualization of the vessels and nerves, with minimal bleeding. The histopathological diagnosis was salivary duct carcinoma ex pleomorphic adenoma. The postoperative clinical course was uneventful, with no neurological deficit. The patient received postoperative radiotherapy (60 Gy/30 fractions) and has remained free from recurrence of the disease until now, 11 months after the surgery.
We stress that the blind space behind the tumor could be clearly visualized with the endoscope and that the vessels were cut and sealed efficiently and easily with the use of the microwave energy device, without damages to adjacent tissues. We conclude that the present procedure is useful for accurate and safe incision of parapharyngeal lesions.
