This report describes a case of adult temporal bone Langerhans cell histiocytosis（LCH） that presented as posterior canal dehiscence syndrome（PCDS）. The patient initially presented with vertigo, tinnitus, and hearing loss. Computed tomography（CT） revealed erosive changes in the mastoid and posterior semicircular canal. After the operation, the patient's hearing and vestibular symptoms disappeared and postoperative recovery was favorable. Adult LCH is relatively rare, and this case serves as an example to discuss the clinical features and treatment options of this disease, followed by a literature review.
Humans ; Histiocytosis, Langerhans-Cell/complications* ; Semicircular Canal Dehiscence/etiology* ; Temporal Bone/pathology*

Humans ; Anaplastic Lymphoma Kinase ; Histiocytosis, Langerhans-Cell ; Receptor Protein-Tyrosine Kinases ; Lymphoma, Large-Cell, Anaplastic/pathology*

OBJECTIVES: Pulmonary Langerhans cell histiocytosis (PLCH) is a clonal disease, characterized by proliferation of Langerhans cells that derived from bone marrow infiltrating the lungs and other organs. Due to the rarity of the disease, the current understanding of the disease is insufficient, often misdiagnosed or missed diagnosis. This study aims to raise clinicians' awareness for this disease via summarizing the clinical characteristics, imaging features, and treatment of PLCH. METHODS: We retrospectively analyzed clinical and follow-up data of 15 hospitalized cases of PLCH from September 2012 to June 2021 in the Second Xiangya Hospital of Central South University. RESULTS: The age of 15 patients (9 men and 6 women, with a sex ratio of 3 to 2) was 21-52 (median 33) years. Among them, 8 had a history of smoking and 5 suffered spontaneous pneumothorax during disease course. There were 3 patients with single system PLCH and 12 patients with multi-system PLCH, including 7 patients with pituitary involvement, 7 patients with lymph node involvement, 6 patients with bone involvement, 5 patients with liver involvement, 2 patients with skin involvement, 2 patients with thyroid involvement, and 1 patients with thymus involvement. The clinical manifestations were varied but non-specific. Respiratory symptoms mainly included dry cough, sputum expectoration, chest pain, etc. Constitutional symptoms included fever and weight loss. Patients with multi-system involvement experienced symptoms such as polyuria-polydipsia, bone pain, and skin rash. All patients were confirmed by pathology, including 6 by lung biopsy, 3 by bone biopsy, 2 by lymph node biopsy, and 4 by liver, skin, suprasternal fossa tumor, or pituitary stalk biopsy. The most common CT findings from this cohort of patients were nodules and/or cysts and nodular and cystic shadows were found in 7 patients. Three patients presented simple multiple cystic shadows, 3 patients presented multiple nodules, and 2 patients presented with single nodules and mass shadows. Pulmonary function tests were performed in 4 patients, ventilation dysfunction was showed in 2 patients at the first visit. Pulmonary diffusion function tests were performed in 4 patients and showed a decrease in 3 patients. Smoking cessation was recommended to PLCH patients with smoking history. Ten patients received chemotherapy while 2 patients received oral glucocorticoid therapy. Among the 11 patients with the long-term follow-up, 9 were in stable condition. CONCLUSIONS PLCH is a neoplastic disease closely related to smoking. The clinical manifestations and laboratory examination are not specific. Pneumothorax could be the first symptom which is very suggestive of the disease. Definitive diagnosis relies on histology. There is no unified treatment plan for PLCH, and individualized treatment should be carried out according to organ involvement. Early smoking cessation is essential. Chemotherapy is the main treatment for rapidly progressing PLCH involved multiple organs. All diagnosed patients can be considered for the detection of BRAF^V600E gene and relevant targeted therapies have been implemented recently.
Adult ; Cysts ; Female ; Histiocytosis, Langerhans-Cell/therapy* ; Humans ; Lung/pathology* ; Male ; Retrospective Studies ; Smoking/adverse effects* ; Smoking Cessation

Langerhans cell histiocytosis (LCH) is a rare proliferative disease dominated by the proliferation of Langerhans cells, which is inflammatory myeloid neoplasms. Its clinical manifestations are variable, occurring at any age and at any site, and it is rarer in adults than in children. The gold standard for diagnosis is histopathological biopsy. Due to the rarity of adult LCH and the heterogeneity of this disease, treatment of adult LCH should be developed according to the extent of the disease and risk stratification. With the discovery of MAPK, PI3K and c-KIT signaling pathway activation, especially BRAF V600E and MAP2K1 mutations, targeted therapy has become a hot spot for therapeutic research. Meanwhile, the discovery of high expression of M2-polarized macrophages and Foxp3⁺ regulatory T cells (Treg) in LCH has provided an important basis for the immunotherapy. In this article, we will focus on reviewing the latest research progress in the treatment of adult LCH in recent years, and provide a reference for clinical research on the treatment of adult LCH patients.
Adult ; Child ; Histiocytosis, Langerhans-Cell/therapy* ; Humans ; Mutation ; Proto-Oncogene Proteins B-raf/metabolism* ; Signal Transduction ; T-Lymphocytes, Regulatory/pathology*

Objective To investigate the clinical and magnetic resonance imaging(MRI) manifestations of Rosai-Dorfman disease(RDD) in central nervous system. Method The clinical and MRI data of 5 cases of RDD in central nervous system confirmed by pathology in the PLA General Hospital were analyzed retrospectively. Results The 5 cases included 4 males and 1 female,aged(39.8±21.7) years on average.Among them,4 cases were located in the intracranial area and 1 case in the thoracic spinal canal.The lesion showed isointense signal on T₁ weighted image and iso,slight-hypo,and slight-hyperintense signals on T₂ weighted image,and it presented intensively homogeneous enhancement in contrast-enhanced MRI.Two cases showed compressed brain area with edema around the left parietal and left frontotemporal dura,thickening and enhancement in the adjacent dura,and dural tail sign.Three cases presented bone destruction in adjacent diploe and thoracic vertebrae.One case showcased slight-hypo perfusion of the left parietal dura in arterial spin labeling. Conclusions RDD lesion usually appears as iso,slight hypo and slight hyper-intense signals on T₂ weighted image and presents intensively homogeneous enhancement in contrast-enhanced MRI.The disease may involve the adjacent bone and the lesion shows slight hypo-perfusion on perfusion images.The MRI manifestations of RDD are characteristic,which are helpful for preoperative diagnosis and evaluation of RDD.
Central Nervous System/pathology* ; Female ; Head ; Histiocytosis, Sinus/pathology* ; Humans ; Magnetic Resonance Imaging/methods* ; Male ; Retrospective Studies

Langerhans cell histiocytosis (LCH) is a rare disorder histologically characterized by the proliferation of Langerhans cells. Here we present the case of a 13-year-old girl with LCH wherein CT and MRI results led us to an initially incorrect diagnosis of meningioma. The diagnosis was corrected to LCH based on pathology findings. An intracranial mass was found mainly in the dura mater, with thickening of the surrounding dura. It appeared to be growing downward from the calvaria, pressing on underlying brain tissue, and had infiltrated the inner skull, causing a bone defect. The lesion was calcified with the typical dural tail sign. The dural origin of the lesion was verified upon surgical dissection. There are no previous reports in the literature describing LCH of dural origin presenting in young patients with typical dural tail signs and meningioma-like imaging findings. The current case report underscores the need for thorough histological and immunocytochemical examinations in LCH differential diagnosis.
Adolescent ; Brain ; Diagnosis ; Diagnosis, Differential ; Dura Mater ; Female ; Histiocytosis, Langerhans-Cell* ; Humans ; Langerhans Cells ; Magnetic Resonance Imaging* ; Meningioma* ; Pathology ; Skull ; Tail

Brain Diseases ; pathology ; Histiocytosis, Sinus ; pathology ; Humans ; Skull ; pathology

Carcinoma ; pathology ; Carcinoma, Papillary ; Histiocytosis, Langerhans-Cell ; pathology ; Humans ; Thyroid Neoplasms ; pathology

OBJECTIVETo study the prevalence of IgG4-positive plasma cells in Rosai-Dorfman disease and to assess the association between Rosai-Dorfman disease and IgG4-related sclerosing disease (IgG4-SD).

METHODSThe clinicopathologic features of 12 tissue samples of Rosai-Dorfman disease (11 extranodal and one nodal) from nine patients were reviewed. The degree of fibrosis and occlusive phlebitis was studied by HE staining. The expression of IgG4 and IgG in plasma cells were studied by immunohistochemistry (EnVision) and quantitatively analyzed by medical image analysis system.

RESULTSNine tissue samples showed different degree of fibrosis (four tissue samples were mild, one tissue sample was moderate and four tissue samples were severe) and two tissue samples showed occlusive phlebitis in the lesional tissue. Immunohistochemical study showed marked infiltration by IgG4-positive plasma cells (> 50 per high-power field) in four tissue samples, moderate infiltration (30 to 50 per high-power field) in two tissue samples, mild (10 to 29 per high-power field) in three cases and negative infiltration (< 10 per high-power field) in three tissue samples (P < 0.01). Three tissue samples fulfilled the diagnostic criteria of IgG4-SD (> 50 IgG4-positive plasma cells per high-power field and IgG4-to-IgG ratio > 40%), including one tissue sample each of Rosai-Dorfman disease in the left facial skin, above the left eye socket, and in the right parotid.

CONCLUSIONSSome cases of Rosai-Dorfman disease fulfill the diagnostic criteria and show the histologic features of IgG4-SD. They may represent members of the IgG4-SD spectrum. The detection of IgG4-positive plasma cells in the lesional tissues of Rosai-Dorfman disease may have clinical pathological significance.

Fibrosis ; Histiocytosis, Sinus ; diagnosis ; immunology ; Humans ; Immunoglobulin G ; chemistry ; Immunohistochemistry ; Phlebitis ; pathology ; Plasma Cells ; chemistry

Female ; Histiocytosis, Langerhans-Cell ; pathology ; Humans ; Infant, Newborn