Background: Adrenocortical carcinoma (ACC) is one of the most aggressive endocrine malignancies with a dismal prognosis. Typically, the tumor is large and has regional invasion or distant metastasis at initial presentation.
Objective: To describe an unusual case of functioning ACC presenting with superior vena cava (SVC) and upper airway obstruction.
Material and Method: A 23-year-old man with cushingoid appearance was evaluated for a neck mass and SVC syndrome. Hormonal assessment and neck mass biopsy including immunohistochemistry study were performed.
Results: Cushing’s syndrome was confirmed by elevated 24-hr urinary free cortisol and no suppressible cortisol level after standard low dose (2mg/day) of dexamethasone suppression test. Computerized tomography (CT) study revealed a huge left suprarenal mass and multiple mediastinal lymph nodes compressing SVC and trachea. Histopathological findings of the neck mass were compatible with metastatic ACC.
Conclusion: The present report describes a functioning ACC patient with an unusual metastatic site causing SVC and upper airway obstruction. His hospital course was progressively worsened due to peptic perforation and decompensated respiratory failure, which led him to expire.

Keywords: Adrenocortical carcinoma, Superior vena cava obstruction, Cushing’s syndrome