Langerhans Cell Histiocytosis of Thyroid Gland in a Child: A Case Report and Literature Review

Histiocytic lesion masquerading as papillary carcinoma thyroid-A case report

ABSTRACT

Langerhans cell histiocytosis (LCH) is a rare clonal neoplasm derived from Langerhans-type cells that express CD 1a, langerin, and S 100 on immunohistochemistry. LCH usually involves multiple sites and multiple systems or multiple sites in a single system. Solitary LCH commonly involves the bones (especially the skull), lymph nodes, skin, and lungs. Solitary LCH of the thyroid is an extremely rare disease with a few reported cases in the indexed literature and poses a diagnostic dilemma for both the clinician and pathologist. Histopathology along with ancillary tests forms the gold standard for diagnosis. Surgical resection alone offers a good prognosis once multisystemic involvement has been ruled out. Herein is reported one such case of solitary LCH in a young male patient who remains disease-free after 2 years of follow-up.

Langerhans cell histiocytosis of the thyroid mimicking thyroiditis in a boy: a case report and literature review

BACKGROUND

Langerhans cell histiocytosis affecting the thyroid commonly presents with nonspecific clinical and radiological manifestations. Thyroid Langerhans cell histiocytosis is typically characterized by non-enhancing hypodense lesions with an enlarged thyroid on computed tomography medical images. Thyroid involvement in LCH is uncommon and typically encountered in adults, as is salivary gland involvement. Therefore, we present a unique pediatric case featuring simultaneous salivary and thyroid involvement in LCH.

CASE PRESENTATION

A 3-year-old boy with complaints of an anterior neck mass persisting for 1 to 2 months, accompanied by mild pain, dysphagia, and hoarseness. A physical examination revealed a 2.5 cm firm and tender mass in the left anterior neck. Laboratory examinations revealed normal thyroid function test levels. Ultrasonography revealed multiple heterogeneous hypoechoic nodules with unclear and irregular margins in both lobes of the thyroid. Contrast-enhanced neck computed tomography revealed an enlarged thyroid gland and bilateral submandibular glands with non-enhancing hypointense nodular lesions, and multiple confluent thin-walled small (< 1.5 cm) cysts scattered bilaterally in the lungs. Subsequently, a left thyroid excisional biopsy was performed, leading to a histopathological diagnosis of LCH. Immunohistochemical analysis of the specimen demonstrated diffuse positivity for S-100, CD1a, and Langerin and focal positivity for CD68. The patient received standard therapy with vinblastine and steroid, and showed disease regression during regular follow-up of neck ultrasonography.

CONCLUSIONS

Involvement of the thyroid and submandibular gland as initial diagnosis of Langerhans cell histiocytosis is extremely rare. It is important to investigate the involvement of affected systems. A comprehensive survey and biopsy are required to establish a definitive diagnosis.