Ultrasound Dye-Assisted Surgery (USDAS) for Regional Recurrence in Head and Neck Cancer: A Case Report

Abstract

The incidence of regional recurrence in oral squamous cell carcinoma(SCC) after the neck dissection is 32.7%. Regional failure after definite neck treatment not only relates to poor prognosis but also leads to higher complication rate in the salvage neck dissection since the diseased structure is often surrounded by scar tissue and hard to be identified. The adequate and safe neck surgery is crucial for head and neck surgeons. Ultrasound dye-assisted surgery(USDAS) offers a simplified way to localize lesions clearly during the operation. Case report and literature review. We report a 53-year-old male who suffered from the left tongue border ulcer for 2 months. Transoral wide excision was performed for pT1, moderately differentiated SCC with negative p16 staining. 3 months later, the left level I neck mass was palpated. Sono-guided fine needle aspiration was done, and cytology revealed SCC. Bilateral neck dissection of the left level I-IV and the right level I-II was accomplished. Pathology reported ypN2b disease over the left level I and III with remarkable extracapsular spread(ECS) of the former one. However, the adjuvant concurrent chemoradiotherapy(CCRT) was incompletely conducted due to the progressive submental mass 5 weeks later. The sonography delineated one 1.33cm hypoechoic lesion with irregular boundary, incomplete halo and central necrosis over the midline of level IA. Fine needle aspiration was done, and cytology report confirmed SCC. For the adequately and completely wide excision of the malignancy, USDAS was done. Methyl blue in 1ml syringe was injected in the assistance with ultrasound-guided technique into the left periphery, right periphery, upper margin, lower margin and most importantly, the base of the tumor. Wide excision of the submental tumor was consequently executed. Final pathology indicated metastastic squamous cell carcinoma of dermis and subcutis sized 1.2cm. The closest surgical margin was 0.5cm from the peripheral margin. In our case, considering the infiltrative character of dermal pathology ensnared by postoperative fibrosis, USDAS was utilized to mark the surgical boundaries. Final pathology proved adequate margins, and there was no complication. This procedure offers precise localization with avoidance in unnecessary destruction and reduces operative time significantly. Based on the anatomic complexity in head and neck region, the USDAS can be extendedly used in the future. More studies investigating exact decreasing rate of complication and standard procedures regarding injection volume and washing-out time of dye should be achieved.