A80-4-30 Adenoid Cystic Carcinoma (ACC) as a Primary Lung Malignancy in a Patient Presenting With Diplopia

Introduction Adenoid cystic carcinoma (ACC) is a rare malignancy of salivary gland origin that can occasionally originate in the tracheobronchial tree. We present a case of ACC as a primary lung malignancy with its characteristic radiographic findings on computed tomography (CT) imaging. Case Presentation An 83-year-old male with a past medical history of hypertension, type 2 diabetes mellitus, and known history of adenoid cystic carcinoma presented to the emergency department with blurry vision. On physical exam, patient was noted to have a reactive, but sluggish movement of the left pupil. An MRI of the brain was obtained which demonstrated right temporal and left cerebellar masses concerning for metastases. Steroids were started in the setting of vasogenic edema, and the patient was transferred to the neurosurgery service for resection. A CT chest was obtained which demonstrated a soft tissue mass involving the distal trachea and tracheal bifurcation with encasement and invasion of the left mainstem bronchus (Figure 1). Prior biopsy of the tracheobronchial tree had revealed adenoid cystic carcinoma, and a debulking procedure had been performed with improved aeration of the left lung at an outside hospital. Given the lack of systemic chemotherapy options, patient deferred surgical intervention as well as radiation treatment to the brain mass and was eventually discharged home to pursue hospice on discharge. Discussion Adenoid cystic carcinoma is very rarely found as a primary tumor in the lungs, accounting for less than 0.2% of all primary lung cancers. Among all ACC cases diagnosed, only 10-17% originate in the respiratory tract—including the lung, trachea, and bronchi—with most ACCs arising instead in the head, neck, or salivary glands. ACC tends to present as central airway or endobronchial lesions causing obstruction and can present both centrally and peripherally. Central ACC may present as endobronchial masses that cause airway obstruction, as demonstrated above, and lead to recurrent lung collapse that requires debulking. However, peripheral ACC differs in that it originates from smaller bronchi and may be asymptomatic. Systemic treatment options were limited unfortunately, with medical treatment ultimately deferred in this patient. This abstract is funded by: None