Spontaneous resolution of isolated thymic Langerhans cell histiocytosis

Langerhans Cell Histiocytosis in an Infant Mimicking a Lymphoma at Presentation

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by proliferation and accumulation of clonal dendritic cells with varied clinical presentation and an unpredictable course. We report a 5-month-old infant with LCH who presented with severe respiratory distress, a large mediastinal mass, significant generalized lymphadenopathy, and hepatosplenomegaly. Lymphoma, especially T cell lymphoblastic lymphoma, can present with superior mediastinal syndrome needing urgent empirical therapy without biopsy. However, lack of response prompted a biopsy which confirmed it to be a case of LCH and that leads to appropriate therapy and survival. There have been reports of LCH presenting with isolated mediastinal mass or with generalized lymphadenopathy, but the combined presentation of generalized lymphadenopathy with large mediastinal mass, hepatosplenomegaly, and fever in an infant has rarely been reported. Conclusion. LCH should also be considered in the differential diagnosis of an infant presenting with generalized lymphadenopathy, mediastinal mass, hepatosplenomegaly, and fever.

Histologic patterns of thymic involvement in Langerhans cell proliferations: a clinicopathologic study and review of the literature

Thymic involvement by Langerhans cell histiocytosis (LCH) has been described mainly in isolated case reports. A description of the histopathologic patterns of LCH proliferations in the thymus, together with therapeutic implications, has not, to our knowledge, been previously addressed. The pathology consultation files at Children's Hospital of Pittsburgh of the University of Pennsylvania Medical Center were reviewed for cases of thymic involvement by LCH. Relevant cases in the literature were also reviewed, and the histopathology and clinical course of those cases were collected. Nine consultation cases of thymic involvement were reviewed, together with 23 cases in the literature, which provided adequate pathologic description and ancillary confirmation (n  =  32), revealing 4 distinct pathologic groups. Group 1 showed microscopic collection of hyperplastic LCH-like cells in incidental thymectomies of patients without LCH disease, requiring no further treatment (n  =  7; 22%). Group 2 showed solitary and/or cystic LCH of the thymus with gland disruption, and at least 3 cases resolved without systemic therapy (n  =  10; 31%). Group 3 showed more variable thymic involvement in multisystemic LCH disease, with either a medullary restricted pattern or more diffuse gland involvement, requiring adjuvant therapy and having a higher mortality rate (n  =  13; 41%). Group 4 showed a mixed histiocytic lesion with a concurrent LCH and juvenile xanthogranuloma-like proliferation (n  =  2; 6%). Thymic involvement in LCH is quite rare. Based on our cases and those in the literature, we propose 4 distinct pathologic groups of thymic involvement in Langerhans cell proliferations with relevance for diagnosis and treatment.

Radiological features of thymic langerhans cell histiocytosis

TI was reported in 18/1,264 (1.4%) LCH patients. All nine patients with TI at initial LCH presentation were below 2 years of age and had multisystem LCH (9/242, 4%). Images (sonography, CT, MRI) for central review were available in 15 cases. Characteristic findings of TI were thymus enlargement (67%), few to many cysts (80%), and few to many calcifications (100%). Sonographic and MRI findings were in excellent agreement. We recommend adding sonography of the thymus to the standard for initial clinical evaluation of LCH patients below the age of 2 years.

Thymus and mediastinal node involvement in childhood Langerhans cell histiocytosis: long-term follow-up from the French national cohort

BACKGROUND

Mediastinal involvement (MI) in Langerhans cell histiocytosis (LCH) has been rarely reported. Here, we describe the clinical, radiological, and biological presentation, and the outcome of childhood LCH with MI.

METHOD

From the French LCH register, which includes 1,423 patients aged less than 18 years, we retrieved the medical charts of patients with mediastinal enlargement detected on chest X-rays.

RESULTS

Thirty-seven patients were retrieved, including 18 males; median age of diagnosis was 0.7 years, and median follow-up time was 6.2 years. The prevalence of MI varied with the age at diagnosis, ranging from 7% below 1 year old to less than 1% at >5 years. Thirteen cases (35%) were diagnosed because of MI-related symptoms, including respiratory distress (N = 4), superior venous cava syndrome (N = 2), and/or cough and polypnea (N = 10). CT scans performed in 32 cases at diagnosis showed tracheal compression (N = 5), cava thrombosis (N = 2), and/or calcification (N = 16). All patients presented multi-system disease at LCH diagnosis, and 35/37 were initially treated with vinblastine and corticosteroids. Death occurred in five cases, due to MI (N = 1) or hematological refractory involvement (N = 4). The overall 5-year survival was 87.1%, and immunodeficiency was not detected as a sequel.

CONCLUSIONS

MI in LCH mainly occurs in young children, and diagnosis was based on CT showing thymus enlargement and calcifications.

An infant with self-healing cutaneous Langerhans cell histiocytosis followed by isolated thymic relapse

Thymic involvement with Langerhans cell histiocytosis (LCH) typically occurs in children as part of multi-system (M-S) LCH. Patients who develop skin-only LCH during infancy may either follow a self-healing course with spontaneous regression or may progress to M-S involvement. We describe a male infant who developed isolated thymic LCH after spontaneous complete regression of isolated cutaneous lesions. His erythrocyte sedimentation rate and C-reactive protein increased temporarily during the skin-only stage of LCH, and increased again considerably during the thymic relapse. Even for patients with skin-only LCH, these laboratory data might indicate possible relapse or late progression of the disease.

Thymic Langerhans cell histiocytosis mimicking lymphoma

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by clonal expansion of antigen presenting Langerhans cells. Different clinical features can be seen according to the involved organs and systems. Multisystem disease with organ dysfunction is more common in infants, whereas single system disease is usually observed in older children. The disease can affect any system or organ throughout the body. Thymus is a rarely involvement site reported in LCH and usually is accompanied by skin, bone or lung disease. Here we report a 12-year-old male with thymic involvement by LCH clinically mimicking lymphoma.

Extraosseous langerhans cell histiocytosis in children

Langerhans cell histiocytosis, a rare disease that occurs mainly in children, may produce a broad range of manifestations, from a single osseous lesion to multiple lesions involving more than one organ or system. The clinical course varies widely in relation to the patient's age. Multisystem disease may demonstrate especially aggressive behavior in very young children, with the outcome depending largely on the stage of disease and the degree of related organ dysfunction at the time of diagnosis. Extraosseous manifestations are less commonly seen than osseous ones and may be more difficult to identify. To accurately detect extraosseous Langerhans cell histiocytosis at an early stage, radiologists must recognize the significance of individual clinical and laboratory findings as well as the relevance of imaging features for the differential diagnosis. The pattern and severity of pulmonary, thymic, hepatobiliary, splenic, gastrointestinal, neurologic, mucocutaneous, soft-tissue (head and neck), and salivary involvement in Langerhans cell histiocytosis generally are well depicted with conventional radiography, ultrasonography, computed tomography, and magnetic resonance imaging. However, the imaging features are not pathognomonic, and a biopsy usually is necessary to establish a definitive diagnosis.

Langerhans cell histiocytosis: retrospective analysis of 217 cases in a single center

Langerhans cell histiocytosis (LCH) is a disorder with unclear etiology and pathogenesis, which is characterized by abnormal clonal proliferation and accumulation of langerhans cells at various tissue and organs. A total of 217 patients with LCH were evaluated retrospectively for clinicopathological features, laboratory findings, treatment modalities, long-term outcome, and factors affecting the outcome. Median age at the time of diagnosis was 3.5 years and male/female ratio was 1.8. The most common complaint at presentation was a bone lesion-related symptom. Fifty percent of the patients younger than 2 years had organ dysfunction (OD). Treatment consisted of surgery, chemotherapy, and radiotherapy alone or in combination. Vinblastine with or without prednisolone was the most common used chemotherapy regimen. Overall (OS) and event-free survival (EFS) rates were 84% and 51.5%, respectively, at an 8-year median follow-up time. Overall survival was significantly lower in patients younger than 2 years of age and patients with OD. The age at diagnosis, pulmonary, liver, or hematological involvement, and elevated acute-phase reactants were found to have a statistically significant effect on the OS or EFS rates.

Langerhans cell histiocytosis of mediastinal node

The predominant clinical and radiological features of Langerhans Cell Histiocytosis (LCH) in children are due to osseous involvement. Extra-osseous disease is far less common, occurring in association with bone disease or in isolation. In the present study, LCH was presumptively diagnosed on Ultrasound guided Fine needle aspiration cytology (FNAC) of the mediastinal lymph node in a 18 month-old child. The diagnosis was confirmed by histological examination of the biopsy material.S-100 protein localization in the LCH cells is often positive on immunohistochemistry.