P3.N277: When Cushing's Syndrome Reveals A Wilms' Tumor: Impact Of Ectopic ACTH Production.

Introduction: Cushing's Syndrome (CS) is a rare but serious condition in children, characterized by an excess of systemic glucocorticoids due to disrupted feedback in the hypothalamic-pituitary-adrenal axis. Symptoms include central obesity, moon face, and hypertension, among others. Pediatric CS is primarily caused by ACTH overproduction from a pituitary adenoma, with less than 10% resulting from ectopic ACTH production, a rarity in pediatric oncology. This case report presents an exceptional instance of paraneoplastic CS in a pediatric patient, secondary to ectopic ACTH production by a Wilms' tumor, emphasizing the unique oncological and endocrine outcomes observed.

Case Description: We present the case of a 9-year-old girl from an urban area with rapid-onset obesity, acne, and hirsutism. Initially healthy, she exhibited symptoms such as fatigue, muscle weakness, increased appetite, and emotional lability. Physical examination revealed moon face, central obesity, muscle atrophy, and a non-tender abdominal mass. Laboratory tests confirmed hematuria without proteinuria. Cushing's Syndrome diagnosis was established through elevated cortisol levels unresponsive to dexamethasone suppression. MRI excluded a pituitary adenoma. CT scans showed a left renal tumor with suspected metastatic lung nodules, leading to a nephrectomy and histopathological confirmation of Wilms' tumor. Postoperative management included chemotherapy according to the COG protocol and supportive multidisciplinary care, resulting in the favorable resolution of paraneoplastic Cushing's Syndrome. The patient is currently cancer-free under close monitoring.

Discussion: Cushing's Syndrome (CS) poses significant diagnostic and management challenges, particularly in children where it's less common than in adults. CS symptoms, reflecting excessive circulating glucocorticoids, lead to various metabolic, endocrine, and systemic alterations. In our case, the patient exhibited classic CS features, including central obesity and moon face, indicative of cortisol overproduction. Though rare in children, CS should be considered in patients with compatible symptoms. Wilms' tumor (WT), while the most common renal malignancy in children, seldom presents with paraneoplastic symptoms like CS. This case's identification of WT alongside CS is remarkable due to its rarity, with less than 10 cases reported. Treatment involved a multidisciplinary approach including surgery and chemotherapy, following the Children's Oncology Group protocol, leading to a favorable outcome. This case underscores the importance of early diagnosis, timely intervention, and the benefits of a multidisciplinary approach in managing complex conditions like WT associated with CS.

Conclusion: The case underscores the importance of considering rare or infrequent but significant differential diagnoses in pediatric patients with unusual symptoms. Early identification, accurate diagnosis, and timely treatment are crucial for improving the prognosis and quality of life of our patients. With this case, we once again demonstrate the commitment we must have towards our patients and their families. Undoubtedly, teamwork enables our patient to be at home today.