Heterotopic Salivary Gland Tissue in the Larynx

Submucosal laryngeal masses may present with hoarseness, stridor, dysphagia, other symptoms, no symptoms, or an external neck mass. The lesions arise within the vocal folds (VF), pre-epiglottic, paraglottic spaces, or within the laryngeal cartilaginous framework. They may have salivary gland, neurogenic, blood vessel, lymphatic system origin, or systemic causes such as sarcoidosis, amyloidosis, granulomatosis with polyangiitis, and others. Time between onset of symptoms and laryngoscopy, as well as repeated negative biopsies, can delay definitive diagnosis and treatment. Although computed tomography (CT) scan and magnetic resonance imaging (MRI) show the location and extent of the mass and may be helpful in differentiating benign from malignant causes, histopathology is necessary for definitive diagnosis and treatment. ¹

A 56-year-old, nonsmoking male presented with a 4-month history of progressively hoarse, weak voice, and frequent throat clearing. He denied weight loss, fever, chills, cough, dysphagia, and odynophagia. Strobovideolaryngoscopy revealed mild fullness in the left false VF (Figure 1), left VF paresis and bowing, and incomplete glottic closure with no discrete mass lesions. Laryngeal electromyography demonstrated 25% decreased recruitment in the distribution of the left recurrent and superior laryngeal nerves. This weakness did not seem to be severe enough to explain the severity of hypomobility seen on laryngoscopy. A contrast-enhanced CT identified a questionable supraglottic mass originating at the level of the left aryepiglottic fold and extending inferiorly to the false VF. An MRI with gadolinium demonstrated a mass in the left side of the larynx at the glottis, subglottis, and supraglottis (Figure 2). Computed tomography angiogram showed no excess vascularity.

Figure 1.

Preoperative strobovideolaryngoscopy revealed glottic insufficiency and a left bowed, hypomobile vocal fold in the paramedian position.

Figure 2.

Magnetic resonance imaging of the neck shows a left circumscribed submucosal laryngeal mass at the level of glottis (white arrow). It extended superiorly and inferiorly (not shown).

An incisional biopsy anterolateral to the left vocal process was performed and frozen section which was negative for malignancy. Palpation revealed a mild resistance to arytenoid motion. Consequently, the rest of the abnormal tissue was removed. A CO₂ laser (Omniguide - Nurnberg, Germany) was used. After resection, palpation revealed normal passive arytenoid motion. The defect was allowed to heal by secondary intention due to the relatively small amount of epithelial tissue loss. The final pathologic analysis revealed benign heterotopic salivary gland tissue (HSGT). At the 2-week postoperative visit, the patient reported that his voice was substantially improved, and strobovideolaryngoscopy revealed improved left VF movement and glottic closure (Figure 3). He was lost to follow-up 1 month after excision.

Figure 3.

Postoperative strobovideolaryngoscopy revealed improved glottic closure with nearly symmetric abduction of the vocal folds and improved left adduction.

Heterotopic salivary gland tissue is defined as the presence of normal salivary tissue occurring outside of the normal distribution of the major and minor salivary glands ² and is believed to occur secondary to developmental defects. ³ It has been reported in numerous locations in the head and neck including the pituitary gland, middle and external ear, mandible, gingiva, thyroid gland, and cervical lymph nodes. ⁴ Surgical excision has been recommended to avoid infections and neoplastic transformation, ⁴ although there is no evidence to support these recommendations. Our patient also had VF hypomobility caused by mass effect of a benign HSGT as well as mild paresis. The patient’s VF mobility improved surprisingly well after the lesion was removed.