Transoral Robotic Resection of Pediatric Tongue Base Mucoepidermoid Carcinoma

ABSTRACT

Objective

Mucoepidermoid carcinoma (MEC) of the base of the tongue is exceedingly rare in the pediatric population. While transoral robotic surgery (TORS) has expanded minimally invasive options for oropharyngeal malignancies in adults, its application in pediatric tongue base tumors remains limited. This report aims to highlight the feasibility and oncologic adequacy of TORS in a carefully selected pediatric patient.

Methods

We report the case of a 13‐year‐old girl with low‐grade MEC of the base of the tongue treated with TORS using the da Vinci Xi surgical system (Intuitive Surgical Inc.). Surgical duration, intraoperative findings, histopathologic features, and postoperative course were analyzed. Relevant literature regarding pediatric applications of TORS and alternative surgical approaches was reviewed.

Results

Complete en bloc resection with negative margins (R0) was achieved in 37 min without measurable blood loss. A branch of the right lingual artery was safely clipped under robotic visualization. The postoperative course was uneventful, and nasogastric feeding was maintained until postoperative Day 7. Histopathologic analysis confirmed low‐grade MEC with negative margins and demonstrated MAML2 rearrangement in more than 50% of tumor cells by fluorescence in situ hybridization. No adjuvant therapy was indicated.

Conclusion

Transoral robotic surgery may represent a safe, minimally invasive, and oncologically appropriate surgical option for carefully selected pediatric patients with tongue base mucoepidermoid carcinoma. Further multicenter studies are warranted to better define long‐term oncologic and functional outcomes in this population.

Level of Evidence

N/A.

Transoral robotic surgery (TORS) offers a precise, minimally invasive approach for the management of rare pediatric tongue base malignancies. Intraoperative visualization demonstrates accurate tumor delineation and controlled resection, while postoperative findings confirm effective oncologic clearance with preservation of surrounding structures. This report underscores the emerging role of TORS in expanding surgical options for pediatric oropharyngeal tumors.

1. Introduction

Head and neck malignancies represent a relatively uncommon and heterogeneous group of pediatric cancers, accounting for only a small proportion of all childhood malignancies in population‐based analyses [1, 2]. Within this group, salivary gland tumors form only a small fraction, usually representing under 10% of pediatric head and neck malignancies [3, 4].

Mucoepidermoid carcinoma (MEC) is among the most frequent malignant salivary gland neoplasms in both adults and children, representing approximately 40%–50% of pediatric malignant salivary gland tumors [5, 6]. Despite this, salivary gland carcinomas remain rare in the pediatric population, with an estimated incidence of less than 1.5 cases per million individuals under 20 years of age [3]. Most MECs in children arise from the parotid or minor salivary glands of the palate, whereas tumors originating from the oropharynx—and particularly the tongue base—are exceptionally uncommon, with only sporadic pediatric cases reported to date [7, 8].

In adults, transoral robotic surgery (TORS) is an established minimally invasive approach for the treatment of early stage oropharyngeal tumors, offering three‐dimensional visualization and precise surgical dissection, and has been associated with reduced treatment‐related morbidity compared with traditional open surgical approaches [9, 10]. Nevertheless, its use in pediatric patients remains limited. This is primarily due to the smaller anatomical dimensions of the pediatric upper aerodigestive tract and restricted working space, which often necessitate adapted instrumentation and technique, together with the absence of formal regulatory approval and pediatric‐specific robotic platforms for transoral applications [11, 12, 13].

Although TORS has been described for selected tongue base lesions in pediatric patients, published experience has largely focused on benign pathology, with malignant tumors often being explicitly excluded, and data regarding its oncologic applicability for malignant salivary gland tumors of the tongue base in children remain extremely limited.

We herein present a rare case of a 13‐year‐old girl with MEC of the tongue base resected by TORS with negative margins. To our knowledge, this represents one of the few reported pediatric cases of robotic‐assisted resection of a malignant salivary gland tumor arising from the tongue base. This case underscores the potential role of TORS as a minimally invasive yet oncologically sound surgical modality in carefully selected pediatric patients, particularly when anatomical and tumor characteristics are favorable.

2. Methods

A 13‐year‐old girl was referred to our tertiary center following histological confirmation of an intermediate‐grade MEC involving the right side of the tongue base. The lesion had been present for approximately 4 months as a painless swelling and was biopsied under general anesthesia at an outside institution.

Neck MRI demonstrated a right‐sided, contrast‐enhancing mass of the lingual tonsil significantly narrowing the oropharyngeal lumen, without evidence of cervical lymphadenopathy (Figure 1A,B). CT of the neck and chest revealed no signs of locoregional and distant metastases or suspicious lymph nodes.

FIGURE 1.

Imaging studies of a 13‐year‐old girl demonstrating a right‐sided mucoepidermoid carcinoma of the base of the tongue (the lesion is indicated by a red circle). (A) Axial T2‐weighted MRI demonstrating a well‐defined hyperintense lesion at the tongue base, (B) postcontrast sagittal T1‐weighted MRI showing enhancement of the lesion.

Following multidisciplinary tumor board consensus, the tumor was deemed resectable via a transoral approach. Pediatric oncopsychological assessment confirmed emotional stability. Based on the anesthesiological examination, the patient was classified as ASA I.

On April 2025, the patient underwent TORS using the da Vinci Xi surgical system (Intuitive Surgical Inc.). She was placed supine with the head supported in a “drooping head” position. Exposure was achieved using a Morinière mouth‐gag (Integra MicroFrance) with the smaller oropharyyngeal blade (Figure 2). Robotic docking was performed in a three‐arm configuration, with a 30° endoscope mounted on arm 2.

FIGURE 2.

Transoral exposure during transoral robotic surgery in a 13‐year‐old girl using a Mornière retractor (MicroFrance), which allows intraoperative blade repositioning without robot undocking. For tongue base surgery, the tongue was retracted anteriorly to improve exposure of the operative field.

A 1 × 1 cm submucosal tumor was visualized on the right base of tongue. The lesion was excised en bloc with clear macroscopic margins using monopolar cautery and Maryland bipolar forceps in coagulation mode. The right lingual artery branch was encountered intraoperatively, clipped and divided under direct robotic vision (Figure 3). An additional resection from the anterior surgical margin was sent for frozen section, confirming negative tumor infiltration. Hemostasis was achieved with bipolar coagulation and confirmed by Valsalva maneuver. Figure 4 illustrates the surgical field at the time of initial exposure (A) and following tumor resection (B). Video 1 presents a narrated demonstration of the procedure described above.

FIGURE 3.

During resection of the right‐sided tongue base tumor in a 13‐year‐old girl, a dorsal branch of the right lingual artery was clipped. The arrow indicates the branch, with two clips visible on the patient side. The articulated EndoWrist robotic instruments enable optimal manipulation, with a monopolar spatula on the right and a bipolar Maryland dissector on the left.

FIGURE 4.

(A) Intraoperative view during transoral robotic surgery showing a right‐sided mucoepidermoid carcinoma of the tongue base in a 13‐year‐old female patient; the tumor is indicated by a red circle. A nasotracheal tube and a transnasal suction catheter for smoke evacuation are visible in the oropharynx. A monopolar spatula is used on the right and a Maryland dissector on the left. (B) Final surgical field. The right‐sided instrument was removed to improve visualization; a Maryland dissector remains on the left. At the inferior pole of the operative field, the right lateral margin of the epiglottis is seen anteriorly and the right arytenoid posteriorly.

VIDEO 1.

Download video file ^{(275.7MB, mp4)}

Transoral robotic resection of a tongue base mucoepidermoid carcinoma in a 13‐year‐old girl using the da Vinci Xi robotic surgical system. A 30° endoscope is positioned centrally; a Maryland bipolar dissector is mounted on the left arm (Arm 1), and a monopolar spatula on the right arm (Arm 3). Video content can be viewed at https://onlinelibrary.wiley.com/doi/10.1002/lary.70560.

Institutional ethical approval was obtained from the University of Pécs Medical School Ethics Committee (approval number: 10138‐PTE‐2025). Written informed consent for publication was obtained from the patient's legal guardians.

3. Results

The total operative time was 37 min, with no measurable blood loss. No intraoperative or immediate postoperative complications occurred.

Histopathologic examination confirmed a low‐grade pT1 MEC. Fluorescence in situ hybridization (FISH) for MAML2 demonstrated split signals in > 50% of tumor cells, consistent with the presence of a gene fusion. Surgical resection margins are intact and free of tumor involvement.

A nasogastric tube was placed prophylactically due to anticipated postoperative pain and dysphagia. Because this was our first pediatric TORS case for a tongue base malignancy, and due to the family's geographic distance from the hospital, we opted for cautious postoperative monitoring. Oral intake (liquid–pureed) was initiated on postoperative Day 2 alongside nasogastric feeding. The tube was removed on postoperative Day 7, as the patient reported minimal pain and was able to tolerate solid foods.

To mitigate bleeding risk, the patient remained hospitalized with her father until postoperative Day 14. She was then discharged and referred back to the originating hospital for oncologic follow‐up.

4. Discussion

MEC is among the most frequent malignant salivary gland tumors in both pediatric and adult populations, representing a substantial proportion of salivary gland malignancies [3, 5, 6]. However, localization at the tongue base remains exceedingly rare, especially in children, with only a handful of documented pediatric cases in the literature [7, 8]. In pediatric salivary gland malignancies, MEC represents the most common histologic subtype, with the majority of tumors arising in the parotid gland or from minor salivary glands, particularly the palate [1, 2]. Involvement of the lingual tonsil is exceptionally uncommon, and in pediatric patients only isolated case reports have described MEC arising in this region [4, 7]. To our knowledge, reports on transoral robotic resection of MEC of the tongue base in the pediatric population are exceedingly scarce, underscoring the clinical relevance of the present case.

The base of tongue presents distinct anatomical and technical challenges for surgical access. In pediatric patients, the limited dimensions of the oral cavity and airway may restrict exposure and instrument maneuverability. Alternative surgical approaches are available, but they often impose substantial postoperative burden on pediatric patients. Traditional open approaches such as mandibulotomy provide excellent exposure for large or infiltrative oropharyngeal tumors but are associated with prolonged hospitalization and substantial surgical morbidity, including cosmetic and functional sequelae. Suprahyoid pharyngotomy can provide access for midline lesions without mandibulotomy, though it typically involves neck dissection and may have functional consequences like dysphagia or aspiration [14, 15].

Transoral ultrasonic surgery (TOUSS) represents a nonrobotic, endoscopic alternative for selected tongue base and supraglottic lesions. Early reports have demonstrated the feasibility of this approach using ultrasonic scalpel technology (e.g., Thunderbeat), with effective hemostasis and acceptable complication rates [16, 17]. However, TOUSS lacks the articulation of wristed instruments and the fully immersive three‐dimensional visualization available with robotic platforms.

In adults, TORS has become an established modality for the management of oropharyngeal lesions, offering enhanced visualization and improved access, and has been associated with reduced treatment‐related morbidity compared with traditional open surgical approaches [9, 10] In the pediatric field, adoption remains limited due to anatomical constraints, device size, and the absence of pediatric‐specific regulatory approval and dedicated robotic platforms. Recent reviews have emphasized that bulky instrumentation, limited working space, and cost remain key barriers to widespread pediatric implementation [11, 12, 13]. While most published oncologic TORS series involve adult patients, these reports provide valuable technical and anatomical insights that may cautiously inform pediatric surgical decision‐making.

TORS has previously been reported for the management of tongue base lesions in pediatric patients, predominantly in the context of benign pathology. In the largest available pediatric series to date, Kayhan et al. described the feasibility of TORS for various tongue base masses, including a single case of pleomorphic adenoma in an infant [18]. However, these reports predominantly addressed benign disease, and experience with malignant salivary gland tumors of the tongue base treated by TORS in children remains exceedingly limited, raising important considerations regarding oncologic adequacy and margin control.

To contextualize the rarity of pediatric tongue base MEC managed with TORS, we performed a comprehensive literature search in PubMed/MEDLINE, Embase, Scopus, Google Scholar, and the Cochrane Library using combinations of the terms “mucoepidermoid carcinoma,” “pediatric/adolescent,” “tongue base/base of tongue,” and “transoral robotic surgery/TORS.” No peer‐reviewed reports meeting all criteria were identified.

Nonetheless, accumulating evidence supports the feasibility of pediatric TORS. In a systematic review, Vianini et al. analyzed 73 pediatric TORS procedures—predominantly performed for nononcologic indications—and reported minimal intraoperative hemorrhage, low complication rates, and infrequent need for tracheostomy [12]. Similarly, Kayhan et al. reported a series of eight pediatric base of tongue lesions treated with TORS, including one minor salivary gland tumor, without specific focus on malignant salivary gland pathology. The authors described a mean robotic setup time of approximately 13 min and minimal intraoperative blood loss, generally below 50 mL [18].

Our case aligns with these findings, demonstrating safe and efficient application of TORS in a 13‐year‐old with a 1 cm MEC of the tongue base. The procedure was completed in 37 min with no measurable blood loss. A branch of the right lingual artery was encountered, clipped, and divided safely under robotic vision. Postoperative recovery was uneventful, without complications. Histopathologic examination confirmed a low‐grade MEC with negative margins (R0), and > 50% of tumor cells exhibited MAML2 rearrangement, a molecular alteration associated with favorable prognosis and diagnostic specificity in MEC [19, 20].

While surgery remains the cornerstone of treatment for MEC, the role of adjuvant therapy in pediatric patients is highly selective. According to international expert consensus recommendations from the EXPeRT/PARTNER group, adjuvant radiotherapy should be considered only in the presence of high‐risk histopathologic features, such as positive surgical margins, perineural invasion, or high‐grade histology; however, its use in pediatric patients must be approached with caution due to the risk of long‐term toxicities, including growth restriction, xerostomia, dysphagia, and secondary malignancies [21, 22]. MEC is generally considered moderately radiosensitive, particularly in low‐grade subtypes; however, pediatric‐specific data remain limited [22, 23]. Chemotherapy is not routinely indicated in pediatric MEC and is generally reserved for advanced, recurrent, or metastatic disease. Large pediatric series and registry‐based analyses have demonstrated excellent outcomes for low‐grade, completely resected tumors treated with surgery alone, supporting the avoidance of adjuvant therapy in low‐risk cases such as the present one [3, 5, 22].

The present case supports the feasibility of TORS as a precise, minimally invasive surgical approach that may be oncologically appropriate for selected pediatric tongue base malignancies. However, further collaborative, multicenter investigations are required to clarify long‐term oncologic and functional outcomes and to inform the development of standardized pediatric robotic surgery guidelines [11, 12].

5. Conclusion

This case demonstrates that TORS can represent a safe and minimally invasive surgical option that is oncologically appropriate for carefully selected pediatric patients with MEC of the base of tongue. The procedure combines the advantages of minimal invasiveness, enhanced three‐dimensional visualization, and functional preservation, offering a viable alternative to traditional open approaches in selected cases. These observations are consistent with recent reports highlighting the feasibility and safety of pediatric TORS across benign and malignant head and neck lesions [11, 12, 22]. Further prospective studies and multicenter collaborations are warranted to establish standardized protocols, refine patient selection criteria, and better define long‐term oncologic and functional outcomes in pediatric head and neck oncology [22].

Funding

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.