Severe Cholestatic Jaundice (Stauffer Syndrome) as a Rare Paraneoplastic Manifestation in Adrenocortical Carcinoma

Background: Adrenocortical carcinoma (ACC) is a rare malignancy arising from the adrenal cortex. While ACC can be associated with adrenal hormone excess syndromes, classic paraneoplastic syndromes are rarely seen. Stauffer syndrome, a paraneoplastic phenomenon characterized by reversible cholestasis in the absence of liver metastases, has been described with renal carcinoma and other malignancies but has not been previously reported in ACC. Case Presentation: A 38-year-old man presented with emesis, painless jaundice, pruritus, and weight loss. Laboratory evaluation demonstrated elevated total bilirubin of 8.7 mg/dL (N < 1.3 mg/dL). Computed tomography revealed a 20.4-cm left adrenal mass without evidence of liver metastases. The patient's condition deteriorated rapidly with progressive renal failure and worsening hyperbilirubinemia. The patient underwent left adrenalectomy, nephrectomy, ureterolysis, and wedge liver biopsy. Histopathology showed necrotic ACC with tumor invasion into the adrenal capsule, no lymphovascular invasion, uninvolved margins, and Ki-67 of 40%. Kidney parenchyma exhibited diffuse pigment casts. The liver specimen contained diffuse bile deposits and minimal chronic inflammation in the portal tracts. He tested positive for the pathogenic variant of folliculin (FLCN) gene consistent with Birt-Hogg-Dube syndrome. Renal function recovered after surgery, and bilirubin level normalized after several weeks. Based on clinical presentation and absence of other etiologies, reversible cholestatic jaundice was attributed to Stauffer syndrome. Conclusion: This is the first report of a unique presentation of paraneoplastic-related hyperbilirubinemia in the setting of ACC. While extremely rare, Stauffer syndrome should still be considered in differential diagnosis in patients with ACC with liver dysfunction and jaundice without evidence of liver metastases.