From simple neck pain to the diagnosis of Langerhans cell histiocytosis in the thyroid gland

Abstract

Introduction. Langerhans cell histiocytosis (LCH), as a hematopoietic neoplasm, is a clonal proliferation of Langerhans dendritic cells. A comprehensive clinical examination is sometimes crucial for detecting rare adult diseases, such as LCH with concomitant autoimmune thyroid disease. Case report. A 43-year-old female patient first presented for an endocrinology consultation due to front neck pain and swelling accompanied by fatigue and malaise. The physical examination revealed an enlarged right thyroid gland lobe of extremely firm consistency that was painfully tender on palpation. Echosonographic findings confirmed that the right thyroid gland lobe was enlarged and was not clearly demarcated from the surrounding tissue while exhibiting pronounced parenchyma inhomogeneity characterized by reduced echogenicity of the anterior aspect and pronounced hypoechoicity of the posterior aspect, permeated with fibrous bands and calcifications. The structure of the left thyroid lobe was pseudonodular, with the characteristics of a chronic inflammatory process. Biohumoral findings indicated chronic auto-immune thyroiditis and primary hypothyroidism. Medical history, clinical findings, and personal and family predisposition to malignancy confirmed the need for accelerated additional diagnosis. Fine-needle aspiration biopsy was indicative of atypia of undetermined significance involving Hurthle cells, nuclear overlaps, anisocytosis, anisonucleosis, and the presence of nuclear incisions. Analyses performed after thyroidectomy pointed to the fibrous form of chronic thyroiditis, with suspected monoclonal proliferation of histiocytic and/or lymphoid cells. Immunohistochemical findings confirmed Hashimoto?s thyroiditis and LCH. As the post-operative course was favorable, the patient was prescribed L-thyroxine replacement therapy, along with continuous and systematic monitoring for histiocytosis. Conclusion. Histiocytosis should be suspected more often, given the high incidence of autoimmune thyroid disease in adulthood. A timely LCH diagnosis largely determines the outcome.