Concomitant Langerhans cell histiocytosis of cervical lymph nodes in adult patients with papillary thyroid carcinoma: A report of two cases and review of the literature

Abstract

Objective: Langerhans cell histiocytosis (LCH) is an uncommon entity of unknown etiology. It contains a wide range of clinical presentations. The discovery of oncogenic BRAF V600E mutation in LCH has provided additional evidence that LCH is a neoplasm. Papillary thyroid carcinoma is the most common cancer of the thyroid characterized by a high incidence of BRAF V600E mutations. LCH with concomitant PTC is rare, with few cases reported in the literature. Cases summary: We identified two cases of LCH with concomitant papillary thyroid carcinoma in adult patients. The first was a 49-year-old female with a thyroid nodule diagnosed with papillary thyroid carcinoma. Later, the patient had a left neck mass; Ultrasound-guided lymph node FNA was diagnosed with Langerhans histiocytosis. Subsequently, a chest CT scan revealed signs of Langerhans cell histiocytosis in the lung. The second case refers to a 69-year-old male who presented with a left thyroid nodule diagnosed on FNA cytology as papillary thyroid carcinoma. The patient was found to have multiple bone lytic lesions. Biopsies revealed Langerhans cell histiocytosis. Later, the patient experienced LCH involvement of the bone marrow with associated secondary myelofibrosis. Conclusions: LCH is rare in adults; the association with papillary thyroid carcinoma is reported and should be considered in the presence of Langerhans cell groups along with PTC, whether in the thyroid gland or cervical lymph nodes. Once LCH has been diagnosed, pulmonary involvement should also be investigated. This will direct treatment plans for patients with pulmonary or systemic disease involvement.

Thyroid Langerhans cell histiocytosis concurrent with papillary thyroid carcinoma: A case report and literature review

“…Primary thyroid LCH in adults is rare ( 4 , 21 , 23 ). PTC is the most common thyroid cancer, accounting for 80–90%, and is more common in women ( 14 , 24 ).…”

Co‐existence of BRAF V600E‐mutated malignant melanoma and BRAF V600E‐mutated Langerhans cell histiocytosis: A case report

“…The reported secondary tumors include lymphoma and leukemia without BRAF mutations [4][5][6]8,13,14 ; however, histiocytic sarcoma, Erdheim-Chester disease, acute lymphoblastic leukemia, and monocytic leukemia, all of which are BRAFmutated, have also been reported as secondary tumors. 5,7,9,12,13,15,19 In addition, papillary thyroid carcinoma can be accompanied by LCH 11,16,17,[19][20][21][22][23][24][25][26] and occurs with the oncogenic driver mutation V600E in BRAF, [31][32][33][34][35][36] on average, in 45% of cases. 37 Recently, a patient with multiple neoplastic conditions, which harbored the BRAF V600E mutation, was reported.…”

“…Although it can follow a mild clinical course and resolve spontaneously, it can also involve multiple organ systems with fatal consequences in about 20% of disseminated cases 1‐3 . This hematological condition can be associated with other hematological tumors, including Hodgkin lymphomas, non‐Hodgkin lymphomas, myeloid leukemias, histiocytic sarcoma, and Erdheim‐Chester disease, or carcinomas 4‐26 . Genetically, BRAF V600E mutation is found in approximately 50% of LCH cases 3,27‐30 …”