[Pituitary hyperplasia due to primary hypothyroidism]. / Hyperplasie hypophysaire secondaire à une hypothyroïdie périphérique.

INTRODUCTION: Pituitary hyperplasia due to primary hypothyroidism is rare and underdiagnosed. CASE REPORT: We report an 18-year-old patient referred for a pituitary mass revealing primary hypothyroidism. Biological parameters confirmed severe primary hypothyroidism and hyperprolactinemia. Outcome was favorable with l-thyroxin supplementation resulting in TSH and prolactin levels normalization and pituitary mass resolution. CONCLUSION: Pituitary hyperplasia due to primary hypothyroidism, although rare, should be recognized to avoid unnecessary surgery leading to irreversible complications.