A case of Langerhans cell histiocytosis with thyroid involvement.

Thyroid involvement with Langerhans cell histiocytosis (LCH) is very rare. We report here the case of a 15-year-old female patient with LCH affecting the thyroid gland. She was referred to the department of pediatric endocrinology for secondary amenorrhea. Prior to the diagnosis of LCH, the patient had symptoms of diabetes insipidus (DI) and amenorrhea. The mean time from symptom onset to diagnosis was 2 years. On physical examination the patient had grade 2 goiter, and ultrasound showed bilateral multiple hypoechoic nodules and thyroid heterogeneity. Biochemical analysis indicated central diabetes insipidus and panhypopituitarism. Magnetic resonance imaging (MRI) demonstrated a mass lesion involving the hypothalamus, which appeared iso- to hypo-intense on T2-weighted images and had an intense postcontrast enhancement on T1-weighted images. Nodular goiter coinciding with a hypothalamic mass suggested LCH, and an excisional biopsy was performed. Histological evaluation of the thyroid gland revealed extensive involvement by LCH, and this was confirmed by immunohistochemical analysis showing S-100 protein and CD1a positive Langerhans cells that were weakly positive for CD68. LCH should be considered in the differential diagnosis of a diffusely enlarged firm and irregular thyroid gland and posterior or anterior pituitary dysfunction.

Histiocytosis X in an elderly patient. Ultrastructure and immunocytochemistry after PUVA photochemotherapy.

The clinical features of a 76-year-old man with histiocytosis X of the Letterer-Siwe type, with extensive skin involvement, are described. The patient's lesions responded dramatically to PUVA-photochemotherapy. Light microscopic, immunocytochemical and immunoelectron microscopic findings, before and after PUVA, are reported. Birbeck granules in phagolysosomes of dermal macrophages indicated uptake of destroyed HX cells. Residual HX cells in the skin and HX cells in a recurring lesion expressed the same membrane antigens as in the primary lesions.

Autoimmune cranial diabetes insipidus: its association with other endocrine diseases and with histiocytosis X.

Thirty-nine patients with idiopathic cranial diabetes insipidus (DI) and 81 secondary to hypothalamic lesions were investigated for the presence both of associated autoimmune diseases and autoantibodies. Eleven (28%) of the idiopathic but none of the secondary DI cases had an overt autoimmune disease. A further two patients with idiopathic DI had associated organ-specific autoantibodies. Autoantibodies to vasopressin (AVP)-secreting hypothalamic cells were detected in 12 patients with idiopathic DI (31%). Seven out of 13 cases of DI secondary to histiocytosis X (HX) were also positive (54%), whereas only two (3%) of the other 68 sera from patients with secondary DI reacted with AVP cels. Of the 13 patients with DI associated with frank organ-specific autoimmune diseases or autoantibodies alone, eight (62%) were positive for AVP-cell antibodies. The finding of associated autoimmune diseases in a patient with idiopathic DI is therefore suggestive of an autoimmune origin of DI, and this can be supported by the detection in the serum of AVP cell antibodies. In cases of HX, the new finding of the presence of AVP-cell antibodies reflects hypothalamic infiltration by HX cells, and suggests that DR + 'Langerhans-like' cells play more than a passive role in the hypothalamic lesion.