Endocrine Abstracts

Introduction: Pilomyxoid astrocytoma (PMA) is a rare entity usually described in the hypothalamic-chiasmatic area. It generally concerns infants and very young children. Clinical presentation is not well-defined. But, the therapists should be aware of diencephalic syndrome as an unconventional cause of failure to thrive during early childhood. We report a case of PMA exhibited by failure to thrive;which is a rare outlined association in the litterature.

Case report: An 11-month-old boy was admitted to our university hospital for further exploration of poor weight gain (<3rd percentile). The physical examination revealed pallid and dry skin besides lack of subcutaneous fat. He had a sunken anterior fontanel, muscle atrophy and left eye’s nystagmus. Brain magnetic resonance imaging (MRI) exhibited a suprasellar mass measuring 59*41*40 mm, isointense on T1-weighted MRI and hyperintense on T2-weighted MRI and homogeneously enhanced upon contrast administration. The lesion extended into retro-sellar region, optic chiasm and right hypothalamus. The lesion compressed mainly temporal lobes, cerebral pedicles and the anterior surface of the pons. The patient underwent a right pterional craniotomy besides a subtotal tumor resection (95%). After the surgery, the child’s clinical course declin ed with blindness of the left eye and left-sided mild hemiparesis besides focal seizures prevented by Levetiracetam twice a day. Hormonal assessment in post op period showed a panhypopituitarism. Therefore, hormonal replacement medications have been immediately introduced. Histological examination revealed monomorphous bipolar cells with a generous myxoid matrix and an angiocentric disposition of the tumor cells. Immunochemistry showed oligo-dendrocyte lineage transcription factor 2(oligo-2)and S-100 positively stained cells while they seemed negative for IDH1 and P53. The proliferation index of Ki 67 was about 8%. During a 6-month follow-up, MRI showed a residual supra-sellar mass with a sellar component compressing optic chiasm, cerebral pedicles, and pons anterior surface, with cystic component extending to third and lateral ventricles.A chemotherapy was suggested instead of surgical reintervention and the patient died after 2 sessions due to medullary anaplasia.

Conclusion: The non specific clinical aspects of diencephalic syndrome and its fluctuating presentation deeply reflects the lack of understanding of its pathogenesis and should keep in mind the necessity of brain MRI within etiological investigations to make diagnosis as early as possible and plan an adequate therapy.