Technique of Transoral Laser Microsurgery for Carcinoma of the Base of the Tongue

Technique of Transoral Laser Microsurgery for Carcinoma of the Base of the Tongue

Guy J. Petruzzelli


The base of the tongue (BOT) is bounded anteriorly by the circumvallate papillae extending inferiorly to the vallecula and includes the anatomic regions of the lingual tonsils, pharyngoepiglottic folds, glossoepiglottic folds and, laterally, the glossopalatine sulcus. Carcinoma of the tongue represents approximately 25% of all head and neck malignancies with malignancies of the BOT accounting for one-third of all tongue neoplasms. Malignancies of the BOT reflect the histologic and embryologic complexity of this region and include squamous cell carcinoma (SCC), minor salivary gland carcinoma, lymphoma, mesenchymal malignancies, and carcinoma arising in lingual thyroid (Table 7.1).

Optimal treatment of nonlymphoreticular malignancies of the tongue base remains controversial. Traditional open approaches to the BOT included composite jaw-tongue resection, lateral pharyngotomy, suprahyoid pharyngotomy, and either lateral or midline mandibulotomy. Common among these approaches is a breach of the oral-oropharyngeal mucosa with concomitant salivary contamination of the neck, increased surgical morbidity, poorer functional outcomes, and the potential need for microvascular reconstruction of complex oropharyngeal defects.

These technical challenges coupled with the success of concurrent chemoradiation therapy protocols in treating SCC of the larynx lead to the wide acceptance of “organ-sparing” approaches in the treatment of oropharyngeal carcinoma. The concurrent use of platinum-based chemotherapy regimens with external beam radiation as definitive therapy for malignancies of the BOT is not without significant morbidity, including long-term gastrostomy tube dependence and osteoradionecrosis of the mandible.

Advances in laser and optical technologies and the development of specialized instrumentation for transoral exposure and access to tumors of the BOT have contributed to a renewed interest in primary surgical treatment for selected malignancies of the BOT. Benefits of transoral surgical resection include earlier return of speech and deglutition, reduced operative morbidity, and pathologic data obtained from histologic analysis of surgical specimens to more precisely select patients for adjuvant treatment protocols. This approach permits deintensification of adjuvant chemotherapy and radiation to employ its use only when necessary, and is associated with a decrease in the development of late toxicity and improved return of function and overall quality of life.


A careful and comprehensive preoperative physical examination, including a complete assessment of comorbidities with appropriate cardiac and pulmonary risk stratification, should be performed on all patients undergoing transoral laser microsurgery. Carefully listening to the patient’s voice may give an indication as to the degree of extension of the cancer into the BOT. As expected, patients with a normal voice and few local symptoms tend to have smaller, more superficial tumors. Deeply infiltrative cancers can cause fixation of the tongue and paralysis due to hypoglossal nerve involvement resulting in dysarthria, dysphagia, and fasciculation of the tongue. Occasionally the head and neck surgeon will be surprised as to the degree of local infiltration of the tumor and the relative lack of symptoms.

A complete examination of the head and neck, including fiberoptic nasopharyngoscopy and inspection and palpation of the BOT, is also imperative. Aerosolized and topical anesthesia is often necessary to eliminate a bothersome gag reflex in order to achieve a comfortable examination. SCC can present with the typical ulcerating, erythematous, indurated lesion commonly observed in the oral cavity. However, tumors of the BOT are often very difficult to identify visually and separate from the at times exuberant lymphoid tissue of the region. Neoplasms of the BOT, particular minor salivary gland malignancies, are frequently submucosal. Therefore, the examiner must rely upon an asymmetric appearance or irregularity of the contour of the rounded edge of the BOT. Examination of the BOT with a magnified angled Hopkins telescope can be useful in identifying small lesions.

In addition to examining the BOT to assess the dimensions of the primary tumor, a detailed examination of the epiglottis should be performed. Cancer of the BOT may involve the supraglottis either by superficial extension or by deep infiltration. The former can be identified by careful preoperative examination, and the latter requires imaging for confirmation (see below). Superficial SCCs arising in the BOT can extend into the vallecula and migrate superiorly onto the squamous mucosa of the lingual surface of the epiglottis. An epiglottic sparing mucosal resection can be a satisfactory oncologic alternative in this setting. Conversely, deeply infiltrative tumors can involve the preepiglottic space by direct extension through the median thyroepiglottic ligament. The patient may have the classical “hot potato” voice associated with supraglottic carcinoma, and on physical examination the epiglottis will be erythematous, thickened, and firm.

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Jun 15, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Technique of Transoral Laser Microsurgery for Carcinoma of the Base of the Tongue

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