ESPE Abstracts

Background: Non functioning pituitary macro adenoma is rare during childhood. Therapeutic options are reduced to surgery and radiotherapy. Proton therapy is a particle therapy that uses a beam of protons to irradiate the tissue with the chief advantage that as a charged particle the dose is deposited over a narrow range and there is minimal exit dose.

Objective and hypotheses: Proton therapy is largely used in France for paediatric craniopharyngiomas irradiation and more recently for some adult pituitary adenomas. Proton therapy could be a good therapeutic option for benign tumor as pituitary adenoma in a young child to reduce side effects observed usually with conventional radiotherapy.

Method: We report a 10 years old boy with invasive and aggressive non-functioning pituitary adenoma treated by surgery and proton therapy with more 24 months follow up.

Clinical case: No significant familial or personal history. He was referred for a sudden lost of visual acuity and bilateral hemianopsia, but normal clinical examination (P1G1). Brain MRI showed a voluminous (3.5 cm) intra and supra sellar tumor with right cavernous sinus invasion and chiasma compression. GH and TSH deficiency were documented by endocrine testing while blood prolactin, FSH, αsubunit levels were normal. The search for gene mutations were negative for AIP, NEM1 and GNAS genes. Neurosurgeon performed partial resection twice, first and 9 months later for progression and visual defect recurrence. Histopathology studies confirmed aggressive pituitary adenoma with focal immunolabelling for FSH and αsubunit (40%), PRL<3%; P53: 3% and MIB1: 6%. Radiotherapy was then decided with proton therapy 54 Gy proposed because of the young age. From the end of treatment, as long as 24 months, we didn’t observe progression on tumor size on MRI with complete visual rescue and no additional endocrine deficit. GH treatment was initiated after 1 year following with excellent catch-up growth.

Conclusion: Non-functioning pituitary adenoma is a rare paediatric disease. Proton therapy seems a good option in replacement to conventional radiotherapy to treat it. However long-term outcome is necessary.