Endocrine Abstracts

A 13- year-old boy presented with a 5-day history of fronto-parietal headaches and low-grade fever. He complained of a 3-month history of polyuria and polydipsia; with a daily oral intake of 4 litres per day, mild weight loss, reduced concentration and reduced exercise tolerance. Examination was unremarkable. Biochemical work-up revealed a picture consistent with Arginine Vasopressin deficiency: Hypernatraemia 150 mmol/l, Serum hyperosmolality 302 mOsm/kg, Urine hypoosmolality 155 mOsm/kg, 24-hour urine output >4 litres/day. MR Pituitary reported a 5 x 4 mm solid mass lesion of the pituitary stalk with an intermediate T1 and T2 signal as well as homogenous and avid enhancement on contrast administration. There was no evidence of optic nerve compression. A skeletal survey reported a 2.5 cm lytic focus in the mid shaft of the left femur with prominent established cortical thickening, implying chronicity. MR Left femur suggested this lesion to be longstanding in nature and consistent with Langerhans’ cell histiocytosis. However, both a CT guided and open biopsy resulted negative for malignancy. This was followed by a negative Bone marrow aspirate and Lumbar puncture. PET CT showed increased uptake in the left femoral lesion. Biochemical surveillance uncovered development of secondary hypothyroidism: TSH 0.018 mU/l and a fT4 15.10 pmol/l. An endoscopic trans-nasal trans-sphenoidal biopsy of the pituitary gland was performed. Post operatively the patient was kept on a hydrocortisone regimen whose need was challenged 6 weeks post-operatively. Due to a poor response to a trial off hydrocortisone and skirting level of cortisol past the 60-minute mark of 536 mmol/l on synacthen test, it was decided to continue the patient on hydrocortisone in view of probably imminent secondary hypocortisolism. The patient moved on to develop secondary hypogonadism with down trending testosterone, FSH and LH levels of <0.69 mmolL, <0.1 U/l and <0.1 U/l respectively. This was then followed by down trending IGF-1 levels and signs suggestive of GH deficiency. 2 years later, an Image guided right parietal craniotomy and biopsy of thickened pituitary stalk was positive for CD1 a positive cells, confirming a diagnosis of multisystem risk organ negative LCH. Primary management involved chemotherapy alongside ensuing obesity and hyperglycaemia. Reactivation of right frontal skull LCH which necessitated an excision biopsy. DDAVP, Levothyroxine, Hydrocortisone, Testosterone undecanoate and Vitamin D supplementation form part of his current treatment regimen with follow-up at a Young Adult Clinic.