Endocrine Abstracts

Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with diverse manifestations. Patients with NF1 are particularly prone to developing tumors of the central nervous system (CNS) and endocrine disorders. Herein we report a case of pituitary hyperplasia in a woman with NF1.

Observation: A 55-year-old woman was referred to our department for the exploration of recurrent hypoglycemia. Her past medical history included NF1, asthma treated with inhaled glucocorticoids, and ischemic stroke. On physical examination she had a body weight of 46 Kg, a body height of 1m40, corresponding to a body mass index of 23.5 kg/m² blood pressure of 120/80 mmHg, a heart rate of 90 bpm, a normal thyroid gland, multiple cutaneous neurofibromas, mainly in the chest and abdomen, café-au-lait spots, and thoracic scoliosis. No dysmorphic syndrome was observed. Biological investigations revealed a morning cortisol level of 11 ng/ml (nr: 40-200), an ACTH level of 4.9 pg/ml (nr: 10-48), a TSH level of 0.68 mUI/l, a FT4 level of 1.13 ng/dl, a prolactin level of 25 ng/ml, a FSH level of 68.7U/l, and a LH level of 18.5 U/l. The diagnosis of isolated corticotroph deficiency was established. A steroid-induced adrenal insufficiency was evoked. The first pituitary magnetic resonance imaging (MRI) scan showed an enlarged sella measuring 7.8 mm in height with superior convexity and homogeneous contrast enhancement. No focal lesion was detected. The patient was treated with hydrocortisone. A follow-up pituitary MRI scan performed at seven months showed the same aspect.

Conclusion: NF1 is a tumor predisposition syndrome, frequently associated with CNS tumors, especially optic gliomas. Few cases of pituitary adenomas have also been reported. To the best of our knowledge, this is the first report of pituitary hyperplasia with no evidence of prolactin and GH hypersecretion diagnosed in the context of NF1. The mechanisms inducing pituitary abnormalities remain misunderstood.