Endocrine Abstracts

Langerhans cell histiocytosis (histiocytosis X) is a rare, proliferative monoclonal histiocytic disease of unknown cause that can involve many systems. Intermediate forms of the disease are characterized by a chronic course of a multi-organ involvement, including skin, bone lesions, interstitial lung disease, diabetes insipidus and rarely can involve primarily the thyroid gland.

A 23-year-old gentleman presented with weight gain, lethargy and headaches. Investigations showed raised baseline plasma osmolality at 298 mOsm/kg with hypotonic paired urine at 121 mOsm/kg. Water deprivation test confirmed the presence of cranial diabetes insipidus. Anterior pituitary hormone testing showed:

ITT confirmed low cortisol reserve. Panhypopituitarism was diagnosed and he was started on hormone replacement. MRI pituitary showed large patchily-enhancing suprasellar mass close to optic chiasm superiorly and compressing the pituitary gland itself is normal. Appearance consistent with deposit of histiocytosis. His disease involved pituitary, hypothalamus and thyroid. On follow-up, goitre developed: further imaging of thyroid and FNA showed papillary carcinoma thyroid with metastasis to cervical lymph nodes. He underwent total thyroidectomy with bilateral neck dissections, a difficult procedure because of deep infiltration of the disease. He also received 3 doses of ablative dose of radioiodine. Interestingly, his brother is also affected with langerhans histiocytosis involving pituitary gland.

We suggest that patients with histiocytosis X, with involvement of thyroid, should undergo thyroidectomy if there is goitre of sufficient size to cause obstructive symptoms. We also consider whether patients with thyroid and systemic disease may be treated with combination therapy including thyroid surgery, glucocorticoid therapy, radiotherapy and chemotherapy, though there have been no clinical trials for this disorder, because of its rarity.