A case of adenoid cystic carcinoma of the larynx: Diagnostic challenges, surgical management, and long-term surveillance

Abstract

Adenoid cystic carcinoma of the larynx is an uncommon malignant neoplasm, accounting for less than 1% of all laryngeal cancers. It arises from minor salivary glands, predominantly located in the subglottic region. ACC is characterized by slow but aggressive growth, with a notable propensity for perineural invasion and distant hematogenous dissemination, particularly to the lungs, which occurs in approximately 35%-50% of cases. Clinical presentation depends on tumor localization and may include dyspnea, dysphonia, dysphagia, and otalgia. Diagnosis is based on clinical and endoscopic examination, supplemented by imaging modalities such as MRI and CT scans, and confirmed by histopathological evaluation, which typically reveals a cribriform growth pattern. Immunohistochemical analysis frequently shows strong positivity for c-kit (CD117) and CK7, with negative expression for thyroid-specific markers (TTF-1, thyroglobulin), excluding a thyroid origin. The standard therapeutic approach involves wide surgical excision, most often via total laryngectomy, with selective neck dissection performed in cases with clinical or radiological evidence of lymph node involvement, although nodal metastases remain uncommon. Postoperative radiotherapy is generally indicated due to the tumor's relative radioresistance and its tendency for perineural spread. Chemotherapy plays a limited role, reserved for advanced or metastatic disease. Given the high risk of late recurrences and distant metastases, long-term follow-up is essential, despite a reported 5-year overall survival rate of approximately 70%. We report the case of a 58-year-old female patient with no history of tobacco or alcohol use, but with a 25-year occupational exposure to irritant vapors in the chemical industry. She presented with progressively worsening dysphonia over approximately 10 months, followed by the onset of laryngeal dyspnea. A comprehensive clinical evaluation, supported by laboratory testing and imaging studies, led to the diagnosis of adenoid cystic carcinoma of the larynx. This exceedingly rare tumor may present with nonspecific symptoms and mimic other head and neck disorders, particularly thyroid-related pathologies. Therefore, a high index of clinical suspicion is essential to avoid diagnostic delays. Early diagnosis and prompt management are critical, and treatment should be based on a multidisciplinary and individualized approach to optimize oncological outcomes while preserving laryngeal function and the patient's quality of life.