Endocrine Abstracts (2017) 49 EP1025 | DOI: 10.1530/endoabs.49.EP1025

A novel DICER1 gene mutation in a 10-month-old boy presenting with ACTH-secreting pituitary blastoma and lung cystic dysplasia

Alexey Kalinin1, Natalia Strebkova1, Anatoly Tiulpakov1, Eugene Vasiliev1, Vasily Petrov1, Anna Kolodkina1, Maria Kareva1, Nadezhda Mazerkina2 & Valentina Peterkova1

1Endocrinology Research Centre, Moscow, Russia; 2Scientific Research Neurosurgery Institute, Moscow, Russia.

Hypercortisolism due to Cushing disease is an extremely rare condition in children under one year of age. We present a case of a 10-month-old boy with lung cystic dysplasia and pituitary blastoma (ACTH-secreting). The disease manifested with symptoms of hydrothorax due to cystic dysplasia of the right lung’s upper lobe. Surgical resection of the affected area has been carried out. Symptoms of endogenous hypercortisolism appeared soon after lung surgery. Cushing disease due to pituitary macroadenoma has been diagnosed. Pituitary adenoma was surgically removed; pituitary blastoma with isolated ACTH-secretion was revealed by immunohistochemistry. A combination of lung cystic dysplasia and pituitary blastoma was suspicious for a DICER1 gene defect. p.C199X mutation in DICER1 gene was found. He has been followed up for four years after the pituitary surgery. The patient has been receiving replacement therapy with hydrocortisone, levothyroxine and growth hormone. No other DICER1-related conditions were detected during the last follow-up visit. The same mutation was found in the mother, who had a history of euthyroid multinodular goiter.

Conclusion: Combination of lung cystic dysplasia and ACTH- secreting macroadenoma should prompt to DICER1 gene analysis. We have shown the variable clinical phenotype in DICER1 mutation carriers within a family.