Rhabdomyosarcoma of the Supraglottis in an Adult

A 50-year-old morbidly obese black man presented with a 6-month history of progressive dyspnea. He denied dysphagia and unexpected weight loss. He was breathing comfortably but with audible inspiratory breath sounds. He was tolerating his secretions, but he could speak in spurts of only 4 or 5 words.

Flexible laryngoscopy demonstrated a large, right supraglottic mass (figure 1). Visibility of the left vocal fold was limited, and the right vocal fold was not at all visible. Magnetic resonance imaging (MRI) demonstrated a 4 × 3.7-cm lesion of the right supraglottis; the lesion extended posteriorly into the retropharyngeal area (figure 2). Destruction of the thyroid cartilage was noted, as well as narrowing of the airway. A surgical biopsy was performed, and findings on histopathology were consistent with rhabdomyosarcoma. The patient underwent a tracheotomy and tumor excision, followed by chemotherapy. He was subsequently scheduled for radiation therapy to decrease the risk of recurrence.

Figure 1

The large, right-sided supraglottic mass (arrow) is seen on laryngoscopy.

Figure 2

The mass (arrow) is seen on MRI.

Primary laryngeal rhabdomyosarcoma is an extremely uncommon malignant neoplasm in adults. It accounts for relatively few documented cases compared with squamous cell carcinoma, which represents 95% of all laryngeal tumors.^1–3 In children, however, rhabdomyosarcoma is the most common soft-tissue sarcoma and the third most common extracranial solid tumor.^1–4

Rhabdomyosarcoma is derived from skeletal muscle progenitors, and it is thought to arise from cells associated with skeletal muscle embryogenesis. ⁴ Various classifications of histologic subtypes exist, each with its own prognostic, clinical, and treatment specificities.

Adult rhabdomyosarcoma of the larynx is usually diagnosed at an advanced stage because of its comparatively hidden location of origin and its uncharacteristic clinical symptomatology. ² While research on pediatric cases has led to the development of treatment guidelines, recommendations for management of the adult form have been lacking because of its rarity. Further complicating the interpretation of the limited available data is the different behaviors of the various histologic subtypes.

Prognostic criteria in the pediatric population depend on the primary site, lesion size, histologic subtype, and tumor staging. ³ The results of studies aimed at determining long-term outcomes have been conflicting.^2,3