Laryngeal Alveolar Rhabdomyosarcoma: An Exceedingly Rare Entity.

Alveolar rhabdomyosarcoma (ARMS) of the larynx is an exceedingly rare malignancy with only 3 cases previously documented. This fourth case was a 54-year-old female patient who presented with progressive dyspnea, dysphonia, dysphagia, and otalgia. Positron emission tomography/computed tomography imaging revealed a 2.8 × 2.3 × 1.9 cm fluorodeoxyglucose-avid supraglottic mass centered in the left aryepiglottic fold with mild regional lymph node uptake. Histopathologic examination demonstrated nests of small round tumor cells with alveolar-like spaces, staining positive for myogenin, desmin, smooth muscle actin, and CD56. Molecular analysis confirmed a FOXO1 rearrangement, consistent with ARMS. Treatment with ARST 1431 protocol resulted in partial response with tumor reduction and no evidence of fluorodeoxyglucose-avid metastatic disease on follow-up positron emission tomography/computed tomography. This case highlighted the diagnostic challenge of laryngeal ARMS due to its rarity, nonspecific presentation, and resemblance to more common laryngeal lesions such as squamous cell carcinoma. Accurate diagnosis and treatment require multidisciplinary integration of histopathology, immunochemistry, molecular testing, chemotherapy, and surgical assessment. Recognition is critical, as early identification and multimodal treatment may improve outcomes and help preserve laryngeal function. This fourth reported case of laryngeal ARMS, which has thus far resulted in a favorable patient outcome, contributed invaluable insight into this disease's presenting features and response to therapy.