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A 28-year-old woman with multisystem Langerhans cell histiocytosis (LCH) involving the liver and pituitary gland presented with hypothyroidism: thyrotropin, 11.1 μIU/mL (SI: 11.1 mIU/L) (reference range, 0.05-5.00 μIU/mL [SI: 0.05-5.00 mIU/L]); free thyroxine, 0.6 ng/dL (SI: 7.7 pmol/L) (reference range, 0.9-1.7 ng/dL [SI: 11.6-21.9 pmol/L]). Thyroid ultrasonography revealed multiple irregular hypoechoic areas (arrows; A and B, transverse views; C and D, longitudinal views). Color Doppler ultrasonography indicated only scant intralesional vascular flow within the hypoechoic areas (A and B). Fine-needle aspiration cytology revealed cells with clear cytoplasm and indented nuclei (E; ×600). Immunohistochemical staining confirmed LCH involvement of the thyroid, with strong positivity for CD1a (F; ×600) and Langerin (G; ×600), both of which are highly specific for Langerhans cells and have high diagnostic value. This case highlights the classic diagnostic hallmarks of thyroid LCH, namely, irregular hypoechoic lesions, faint vascularity, and an absence of calcification [1, 2]. Given that thyroid involvement can occur in multisystem LCH [2], these features, although not individually pathognomonic, should heighten suspicion of LCH thyroid involvement and guide clinicians toward fine-needle aspiration cytology, which can yield a definitive diagnosis.
Contributor Information
Yui Yamashita, Department of Diabetes and Endocrinology, Osaka City General Hospital, Osaka 534-0021, Japan.
Yumiko Sasai, Department of Diabetes and Endocrinology, Osaka City General Hospital, Osaka 534-0021, Japan.
Keiko Yamagami, Department of Diabetes and Endocrinology, Osaka City General Hospital, Osaka 534-0021, Japan.
Naotetsu Kanamoto, Department of Diabetes and Endocrinology, Osaka City General Hospital, Osaka 534-0021, Japan; Division of Endocrinology and Metabolism, National Hospital Organization Kyoto Medical Center, Kyoto 612-8555, Japan.
Contributors
All authors made individual contributions to authorship. Y.Y., Y.S., K.Y., and N.K. were involved in the diagnosis and management of this patient. Y.Y. was involved in manuscript write-up and submission. All authors reviewed and approved the final draft of the manuscript.
Funding
No public or commercial funding was received in connection with this study.
Disclosures
The authors declare that they have no conflicts of interest.
Informed patient consent for publication
Signed informed consent obtained directly from patient.
References
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