Endocrine Abstracts

Introduction: Thyroid gland involvement by Langerhans Cell Histiocytosis (LCH) is a very rare condition. It occurs by thyroid infiltration that may result in hypothyroidism. LCH may be also related to neoplastic processes such as leukemias or lymphomas. However, the association with papillary thyroid carcinoma (PTC) is exceptional. We introduce a case and review the reported cases of this association.

Case report: We describe a 33 year old patient diagnosed of LCH with lung involvement and diabetes insipidus, which had a primary hypothyroidism by histiocytosis infiltration. During the follow-up, the patient develops a thyroid nodule. The neck ultrasound was suspicious and the fine needle aspiration confirmed PTC. Thyroidectomy was performed. A very invasive CPT mass was encountered, simultaneously with infiltration by the histiocytosis and a lymphocytic thyroiditis. Immunohistochemical studies were performed, revealing CD1a and S100 immunoreactivity in the Langerhans cells and the BRAF oncogen was positive.

Conclusions: There are few cases reported of patients affected by LCH and CPT. Both process could have common pathways in their pathogenesis. The underlying inflammatory process and BRAF mutation, could be the start point for CPT development, in generally more aggressive in this entity. Therefore is essential early diagnosis with routinely thyroid ultrasound.