Endocrine Abstracts

Introduction: Histiocytosis X is a rare disease involving clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes. Its manifestations range from isolated bone lesions to multisystem disease. Seen mostly in children, multifocal histiocytosis may involve in 50% of cases the pituitary stalk, leading to diabetes insipidus and usually permanent pituitary deficiencies. We present an adult patient with a complex hypothalamic–pituitary disorder after histiocytosis X in childhood.

Case presentation: A 28 years old female has been diagnosed at the age of 4 with histiocytosis X and treated for 1 year with prednisone. She has had since diabetes insipidus treated with desmopressine and hypothyroidism treated with 50 μg thyroxine. She had grown until the age of 10 when she achieved the current height of 151 cm, her parents’ heights being 170 and 180 cm. She had normal menarche with menstrual cycles of 40 days. Clinical examination revealed only slight overweight and polyuria after desmopressin withdrawal.

Hormonal evaluation (after 6 weeks thyroxine withdrawal) showed hypothyroidism FT₄ 0.61 ng/dl (0.7–1.4), TSH 5.2 mUI/l (0.35–4.94), ATPO 0.45 UI/ml (<5.61), normal FSH 5.06 mUI/ml, LH 2.97 mUI/ml, PRL 19.69 ng/ml (5–26), low day-21 progesterone 0.1 ng/ml (2–24) suggesting chronic anovulation, normal basal and stimulated cortisol (16.4 and 22.9 μg/dl), severe GH deficiency IGF1 29.2 ng/ml (117–329), peak GH in insulin-induced hypoglicemia=0.1 ng/ml. The dehydration test confirmed central diabetes insipidus. Thyroid sonography was normal. CT scan showed empty sella and pituitary hypoplasia.

Discussion: A peculiarity of this patient is the continuous linear growth for another 6 years after diagnosing histiocytosis, suggesting a late and perhaps progressive GH deficiency. In the absence of thyroid autoimmunity, the slightly increased TSH has probably low bioactivity, as described in central hypothyroidism.

Conclusion: Histiocytosis X in children may lead to a complex hypothalamic disorder persistent into adult life, including diabetes insipidus, severe (sometimes progressive) GH deficiency, hypothyroidism and chronic anovulation.