ESPE Abstracts

Introduction: Pituitary stalk thickening (PST) is a rare condition in pediatric patients. As there are few studies published in pediatric population, the definition has been difficult to establish. The etiologies involved in PST can be divided in neoplastic, congenital, inflammatory/infectious or autoimmune diseases. In children the most frequent causes are neoplastic, followed by congenital lesions. The inflammatory/infectious and autoimmune diseases are rare.

Methods: During the pandemic of COVID-19, we observed an increased incidence in the diagnosis of pediatric patients with PST in Chile, compared with previous years. A multicentric retrospective chart review of clinical, radiological and histological data was conducted on patients with confirmation of PST that presented during COVID-19 pandemic in Chile. The diagnosis of PST was made in patients with neuro-ophthalmic symptoms or pituitary dysfunction, who had a cerebral MRI with a pituitary stalk 3 mm or more at pituitary insertion or 4 mm or more at the optic chiasm, based on consensus guidelines.

Results: A total of 11 patients were diagnosed with PST during the pandemic period, most of them were girls (82%). The mean age at the onset of symptoms was 10.1 years (range 1.1-18). The most common causes were neoplasms. Germinal cell tumors (GCT) were diagnosed in 10 patients and Langerhans cell histiocytosis in 1 patient. Tumor markers for GCT were negative in serum and cerebrospinal fluid in all patients (alpha-fetoprotein and chorionic gonadotropin). All patients presented with central diabetes insipidus and at least one anterior pituitary hormonal deficit. Thirty six percent had an abnormal campimetry. The diagnoses were confirmed by biopsy in all the patients and four patients required a second biopsy to confirm the diagnosis.

Discussion: A surprisingly high frequency of PST presented during the COVID-19 pandemic among Chilean pediatric patients. The most frequent diagnosis was GCT. All had negative tumor markers, with a greater incidence in girls, opposed to data previously reported. The etiological diagnosis still remains challenging, and 36% of the patients required a second biopsy. It is important to establish new markers to assess patients with PST in order to make a prompt diagnosis. Further research is needed to establish if there is a causative relationship between this high frequency of PST and the COVID-19 pandemic, especially among girls.