Central nervous system-related permanent consequences in patients with Langerhans cell histiocytosis

Langerhans cell histiocytosis: NACHO update on progress, chaos, and opportunity on the path to rational cures

Langerhans cell histiocytosis (LCH) is a myeloid neoplastic disorder characterized by lesions with CD1a-positive/Langerin (CD207)-positive histiocytes and inflammatory infiltrate that can cause local tissue damage and systemic inflammation. Clinical presentations range from single lesions with minimal impact to life-threatening disseminated disease. Therapy for systemic LCH has been established through serial trials empirically testing different chemotherapy agents and durations of therapy. However, fewer than 50% of patients who have disseminated disease are cured with the current standard-of-care vinblastine/prednisone/(mercaptopurine), and treatment failure is associated with long-term morbidity, including the risk of LCH-associated neurodegeneration. Historically, the nature of LCH-whether a reactive condition versus a neoplastic/malignant condition-was uncertain. Over the past 15 years, seminal discoveries have broadly defined LCH pathogenesis; specifically, activating mitogen-activated protein kinase pathway mutations (most frequently, BRAFV600E) in myeloid precursors drive lesion formation. LCH therefore is a clonal neoplastic disorder, although secondary inflammatory features contribute to the disease. These paradigm-changing insights offer a promise of rational cures for patients based on individual mutations, clonal reservoirs, and extent of disease. However, the pace of clinical trial development behind lags the kinetics of translational discovery. In this review, the authors discuss the current understanding of LCH biology, clinical characteristics, therapeutic strategies, and opportunities to improve outcomes for every patient through coordinated agent prioritization and clinical trial efforts.

Craniofacial involvement in Langerhans cell histiocytosis: A review of 44 cases at a single medical center

BACKGROUND

Craniofacial bones are the most commonly involved site of Langerhans cell histiocytosis (LCH). The main purpose of this study was to clarify the relation between subsites of craniofacial bone and clinical presentation, treatment modalities, outcomes, and permanent consequences (PCs) in patients with LCH.

METHODS

Forty-four patients diagnosed with LCH involving the craniofacial region presenting at a single medical center during 2001-2019 were collected and divided into four groups: single system with unifocal bone lesion (SS-LCH, UFB); single system with multifocal bone lesions (SS-LCH, MFB); multisystem without risk organ involvement (MS-LCH, RO-); and multisystem with risk organ involvement (MS-LCH, RO+). Data including demographics, clinical presentation, treatments, outcomes, and the development of PC were retrospectively reviewed.

RESULTS

Temporal bone (66.7% versus 7.7%, p = 0.001), occipital bone (44.4% versus 7.7%, p = 0.022), and sphenoid bone (33.3% versus 3.8%, p = 0.041) involvement were more common in SS-LCH, MFB than they were in SS-LCH, UFB. No difference of reactivation rate was noted among the four groups. The most common PC is diabetes insipidus (DI), reported in 9 of the 16 (56.25%) patients with PC. The single system group was reported with the lowest incidence of DI (7.7%, p = 0.035). The reactivation rate was also higher in patients with PC (33.3% versus 4.0%, p = 0.021) or DI (62.5% versus 3.1%, p < 0.001).

CONCLUSION

An increased risk of multifocal or multisystem lesions was associated with temporal bone, occipital bone, sphenoid bone, maxillary bone, eye, ear, and oral involvement, which may indicate poor outcomes. Longer follow-up may be indicated if there is the presence of PC or DI due to the high risk of reactivation. Therefore, multidisciplinary evaluation and treatment according to risk stratification are vital for patients diagnosed with LCH involving the craniofacial region.

Multifocal Multisystem Langerhans Cell Histiocytosis Involving Pituitary Masquerading as Crohn’s Disease: A Case Report and Review of the Literature

Background/Objective. We present a case of Langerhans cell histiocytosis (LCH) with gastrointestinal involvement masquerading as inflammatory bowel disease (IBD) in a patient who initially had features of central diabetes insipidus (CDI). Case Report. A 19-year-old male presented at 14 years of age with central diabetes insipidus. He subsequently developed panhypopituitarism and sellar-suprasellar mass, the biopsy of which was inconclusive. Secondary causes for hypophysitis were ruled out. Five years later, he developed perianal pus discharging sinuses, positive ASCA, and sacroiliitis. Rectal ulcer biopsy showed nonspecific inflammation and necrosis. Hence, he was managed as inflammatory bowel disease (IBD). Due to nonresponsiveness of symptoms, doubt about diagnosis was invoked and rectal ulcer biopsy was repeated, which then showed infiltration by Langerhans cells. Hence, he was diagnosed with LCH and showed resolution of symptoms on initiating steroids and vinblastine. Discussion. Gastrointestinal involvement by LCH is unusual and only rarely has represented a prominent clinical manifestation. In most cases, such involvement suggests widespread multisystem disease. Its distinctive morphologic and immunohistochemical features allow LCH to be distinguished from other inflammatory infiltrations found in mucosal biopsy specimens. Conclusion. Preceding CDI and hypopituitarism may predict LCH in patients with IBD-like diseases.

Unusual Neurological Manifestation of Langerhans Cell Histiocytosis in an Adult

Langerhans Cell Histiocytosis is a rare disorder characterized by an abnormal proliferation of Langerhans cells in one or multiple organs. It rarely presents with a central vestibular involvement. We report a case of a multisystem Langerhans Cell Histiocytosis with mucosal, hepatic, and neurological involvement, presenting with dizziness and balance disorders. A 39-year-old woman with a histopathologically confirmed mucosal palatal Langerhans Cell Histiocytosis presented with a history of dizziness for a year. Vestibular examination revealed a saccadic eyes pursuit, an up beating spontaneous nystagmus, a bilateral gaze nystagmus and a prolonged positional nystagmus, in the supine roll test. Pure tone audiometry showed a slight left sensorineural hearing loss at the 8000 Hz frequency. Computed tomography (CT) scan showed a bilateral maxillary sinus fullness and a peripheral osteosclerosis of the surrounding bony walls. Hepatic magnetic resonance imaging (MRI) showed a typical hepatic involvement with a hepatomegaly with countless cysts. Temporal bone CT scan and MRI were normal. Cerebral MRI showed an hyperintense nodular signal at T2 FLAIR weighted images lateral to the right pons, at the level of the left middle cerebellar peduncle and at the left mesencephalon. Balance disorders can rarely present a sign of a degenerative neurological cerebellar involvement. Such a rare manifestation can present in different neurological disorders such as Langerhans' cell Histiocytosis.

Long-term outcome, clinical course and treatment approaches of paediatric langerhans cell histiocytosis: A greek reference centre report

AIM

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with diverse clinical behaviour. In this article, we studied the clinical course, management and long-term outcomes of a paediatric cohort treated by our reference centre.

METHODS

We retrospectively studied 66 children with LCH, consecutively diagnosed by a Greek reference centre from 1974 to 2020.

RESULTS

The patients had a median age of 3.9 (range 0.0-15.9) years, 39 and 6 patients were diagnosed with unifocal or multifocal single system disease and 14 and 7 had multisystem disease with or without risk organ involvement. No late occurrence of clinical neurodegenerative disease or diabetes insipidus were observed at a median follow-up period of 4.1 (range 0.5-27.7) years. The 10-year event-free survival and overall survival were 65.0% and 90.3% and improved significantly over a 45-year period. Survival was superior in single system than multisystem cases. BRAF V600E mutation was found in 8/14 tested patients. Reactivation occurred in 12/66 patients (18.2%); 11 achieved remission and one patient died after a second relapse.

CONCLUSION

LCH survival rates significantly increased in our cohort over time. Reactivation occurred in 18.2% patients, but no late neurodegeneration was found. The prognostic value of single system disease status vs. multisystem LCH was confirmed.

Neuroendocrine manifestations of Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia that can affect any organ or system in the human body. It is usually diagnosed during childhood but can also affect adults. Recent studies have demonstrated involvement of the hypothalamo-pituitary axis (HPA) in a significant proportion of patients with deficiencies in both anterior and posterior pituitary function that in the majority of cases are permanent and require specific hormone replacement regimes. Central diabetes insipidus is considered the most frequent abnormality of HPA involvement in LCH and can be encountered either as isolated deficiency or along with other pituitary deficiencies. Complete hormonal evaluation of pituitary hormones and long-term follow-up of LCH patients are strongly recommended, especially when pituitary involvement is established.

Isolated Langerhans cell histiocytosis in the hypothalamic-pituitary region: a case report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease that mainly affects children, but this disease is significantly rarer in patients who are older than 15 years. In this disease, any organ can be involved. The skeleton, skin and lung are commonly affected, and isolated hypothalamic-pituitary (HP) involvement is relatively rare. Here we report a 17-year-old adolescent with isolated HP-LCH of enlarged pituitary stalk presented with central diabetes insipidus (CDI).

CASE PRESENTATION

A 17-year-old male adolescent with polydipsia and polyuria accompanied with elevated serum sodium level and low urine osmolality for 3 weeks was referred to our hospital. After admission, hormonal evaluation showed that his growth hormone (GH) was slightly elevated, and serum osmolality and glucose were normal. The fluid deprivation-vasopressin test demonstrated CDI. Imaging examination showed an obvious thickening of the pituitary stalk. Lymphocytic hypophysitis, sarcoidosis and granulation tissue lesions were suspected. After oral 1-deamino-8-Darginine vasopressin (DDAVP) and prednisone were administered for 2 months, symptoms were relieved, and he discontinued taking the drugs by himself. On reexamination, imaging revealed changes in the size and shape of the pituitary stalk, with thickened nodules. Then, a diagnostic biopsy of the pituitary stalk lesion was performed. Immunohistochemistry confirmed the definitive diagnosis of LCH. The clinical symptoms subsided with oral hormone replacements.

CONCLUSION

CDI is a rare symptom in children and adolescents. Most of the causes are idiopathic, while others are caused by central nervous system (CNS) disorders. Meanwhile, lymphocytic hypophysitis, germinoma, LCH and other CNS disorders can all present as thickening of the pituitary stalk, diffuse enlargement of the pituitary gland, and weakening of high signal intensity in the neurohypophysis on magnetic resonance imaging (MRI). The differential diagnosis among these diseases depends on immunohistochemistry evidence.

PULMONARY AND INTRACRANIAL RADIOGRAPHIC PRESENTATIONS OF LANGERHANS CELL HISTIOCYTOSIS

Background. Langerhans Cell Histiocytosis is a rare disease that affects 1 to 2 adults per million worldwide and often consists of systemic manifestations including pulmonary, intracranial and osteolytic lesions and endocrinologic abnormalities such as Diabetes Insipidus. Objective. The objective of this case report was to expand the medical literature of this rare disease. Methods. A case report of a 51-year-old female patient presenting with systemic symptoms as a result of Langerhans Cell Histiocytosis is presented. Results. A 51-year-old female presented with epistaxis, fatigue, polydipsia, polyuria, headaches and dyspnea. After initial x-rays showed multiple lung and liver nodules and the patient suffered subsequently from a unilateral pneumothorax, an open lung biopsy was recommended. On a pathological basis, the patient was diagnosed with Langerhans Cell Histiocytosis. This report focuses on the radiological presentations of the manifestations of Langerhans Cell Histiocytosis, particularly the presentations in the lung and intracranial regions. Conclusions. Langerhans Cell Histiocytosis is an incredibly rare disease that presents systemically. Recognizing and differentiating radiographic presentation of these patients is important to determine the need for confirmation by biopsy and early chemotherapeutic intervention.

Histiocytic lesions of the orbit: A study of 9 cases

PURPOSE

To describe the clinical presentation, treatment, and outcome of patients with histiocytic lesions of the orbit.

METHODS

Retrospective study of 9 patients treated and followed up between October 2001 and January 2018.

RESULTS

Eight patients in our series were males and one patient was female. The mean age at presentation was 16.8 years (range, 1 to 42 years). All patients had unilateral disease. The most common presenting complaint was upper eyelid swelling in 8 of 9. All patients underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Eight of 9 patients demonstrated orbital bone erosion with adjacent soft tissue mass. Destruction of the orbital roof and contrast enhancement of dura were detected in 3 cases. All cases underwent orbitotomy and subtotal tumor excision with additional bone curettage (4 cases) and intraorbital steroid (40 mg triamcinolone acetonide) injection (3 cases). Adjuvant systemic chemotherapy consisting of vinblastine and prednisone was administered in 3 cases with dural involvement. External radiotherapy (1000 cGy) was applied in one case because of widespread disease. Histopathologic diagnoses were eosinophilic granuloma (7 cases), necrotic xanthogranuloma (1 case), and Langerhans cell sarcoma (1 case). The mean follow-up period after diagnosis was 19.7 months (range, 1-96 months). There was no systemic or multifocal bone involvement in eosinophilic granuloma cases at initial presentation and follow-up. None of these patients developed diabetes insipidus or neurologic symptoms. The patient with Langerhans cell sarcoma died from systemic disease 1 month after diagnosis of the orbital tumor. The patient with necrotic xanthogranuloma did not develop any malignancy at 9 months follow-up.

CONCLUSIONS

Eosinophilic granuloma was the most frequently encountered orbital histiocytic lesion in our series. Eosiophilic granuloma usually responded well to subtotal tumor excision, bone curettage, and intraorbital corticosteroid injections. Systemic chemotherapy was used in cases with full thickness bone destruction and adjacent dural enhancement in an effort to prevent the development of central nervous system disease.

Evaluation and treatment of Langerhans cell histiocytosis patients with central nervous system abnormalities: Current views and new vistas

Central nervous system (CNS) involvement in Langerhans cell histiocytosis (LCH) can include mass lesions of the hypothalamic pituitary axis, choroid plexus, cerebrum, and cerebellum or magnetic resonance imaging (MRI) signal abnormalities of the cerebellum, pons, and basal ganglia. The term neurodegenerative (ND) CNS-LCH has been given to the MRI signal abnormalities and neurologic dysfunction, although initially patients may have no clinical symptoms. Standardized evaluations to better understand the natural history and response to therapy are needed. We propose guidelines for clinical, radiologic, and physiologic tests as a framework for developing the best methods of evaluation, which can then be tested in prospective treatment protocols.

Langerhans Cell Histiocytosis: A Diagnostic Challenge in the Oral Cavity

Background

Langerhans cell histiocytosis (LCH) is a rare disorder of the reticuloendothelial system with unknown etiology. This report aims to present a case of LCH with diffuse involvement of the oral cavity and to raise awareness of the distinguishing features of this diagnostically challenging entity.

Case Report

A 26-year-old male patient presented with complaints of teeth mobility, intense pain, and difficulty in chewing. Intraoral and radiological examinations revealed generalized gingival hyperplasia and severe teeth mobility with widespread alveolar bone loss. Periodontal therapy was performed with no significant improvement. An incisional biopsy revealed Langerhans cells and positive reaction to S-100 and CD1, and the patient was diagnosed with LCH. The patient underwent systemic chemotherapy with vinca alkaloids and corticosteroids. Regression of gingival lesions, as well as significant decrease in mobility of the remaining teeth and severity of pain, was achieved during 12 months of follow-up.

Conclusion

The rarity and variable system involvement of LCH necessitate a multidisciplinary approach be carried out for accurate diagnosis, effective treatment, and an uneventful follow-up. Awareness of oral manifestations of LCH may aid clinicians greatly in reducing morbidity and mortality associated with this debilitating condition.

Langerhans Cell Histiocytosis of the Orbit: Spectrum of Disease and Risk of Central Nervous System Sequelae in Unifocal Cases

PURPOSE

To describe the spectrum of disease extent and clinical response in Langerhans cell histiocytosis (LCH) presenting with orbital involvement and to determine if unifocal orbital disease increases the risk for central nervous system sequelae (CNS-LCH).

METHODS

Retrospective chart review of patients with orbital LCH representing a range of severity treated at the Children's Hospital of Wisconsin from 2003 to 2011; analysis of current international treatment protocols; literature review.

RESULTS

Six patients presenting with orbital LCH are described: 1 with unifocal orbital disease completely responsive to local measures; 1 with multifocal bone disease completely responsive to local intervention; 1 with unifocal orbital disease incompletely responsive to surgical intervention, and requiring systemic chemotherapy; and 3 with multisystem disease at presentation. Literature review identified 806 cases of CNS-LCH. Orbital involvement could be determined in 11 cases. Of these, 6 had multisystem disease and 3 had multifocal bone disease; 1 presented with unifocal orbital disease but progressed to multifocal bone involvement; 1 had insufficient clinical information to distinguish unifocal from multisite presentation. No cases of CNS-LCH directly resulted from isolated unifocal orbital disease.

CONCLUSIONS

Initial treatment of orbital LCH should depend on disease extent at diagnosis. Unifocal cases that completely respond to biopsy, curettage, and/or corticosteroid instillation may be managed with initial oncologic staging and careful long-term observation, with default to chemotherapy for local recurrence or multisite progression. There is currently little evidence that unifocal orbital disease increases the risk for CNS-LCH and therefore warrants prophylactic systemic chemotherapy in all patients.

Diffuse reduction of cerebral grey matter volumes in Erdheim-Chester disease

Background

Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytosis characterized by systemic inflammation and granulomatous infiltration of multiple organs including the central nervous system (CNS), bones, and retroperitoneum. CNS infiltration occurs in one third of patients, but cognitive changes are common in patients without CNS disease. Here we investigate whether there is a neuroanatomic basis to observed cognitive deficits, even in absence of CNS disease.

Methods

We present a volumetric analysis of eleven ECD patients without CNS tumors or prior neurotoxic treatments.

Results

Compared to age-matched controls, ECD patients have diffuse, bihemispheric reduction in cortical thickness and subcortical gray matter.

Conclusions

These findings provide the first corroborating evidence for neurologic disease in ECD patients without direct CNS infiltration.

Early Diagnosis and Monitoring of Neurodegenerative Langerhans Cell Histiocytosis

Background

Neurodegenerative Langerhans Cell Histiocytosis (ND-LCH) is a rare, unpredictable consequence that may devastate the quality of life of patients cured from LCH. We prospectively applied a multidisciplinary diagnostic work-up to early identify and follow-up patients with ND-LCH, with the ultimate goal of better determining the appropriate time for starting therapy.

Methods

We studied 27 children and young adults with either ND-LCH verified by structural magnetic resonance imaging (MRI) (group 1) or specific risk factors for (diabetes insipidus, craniofacial bone lesions), but no evidence of, neurodegenerative MRI changes (group 2). All patients underwent clinical, neurophysiological and MRI studies.

Results

Seventeen patients had MRI alterations typical for ND-LCH. Nine showed neurological impairment but only three were symptomatic; 11 had abnormal somatosensory evoked potentials (SEPs), and five had abnormal brainstem auditory evoked potentials (BAEPs). MR spectroscopy (MRS) showed reduced cerebellar NAA/Cr ratio in nine patients. SEPs showed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for predicting ND-LCH of 70.6% (95%CI, 44.0%-89.7%), 100% (69.2%-100%), 100% (73.5%-100%), and 66.7% (38.4%-88.2%), respectively. Repeated investigations in group 1 revealed increasingly abnormal EP parameters, or neurological examination, or both, in nine of fifteen patients while MRI remained unchanged in all but one patient.

Conclusion

A targeted MRI study should be performed in all patients with risk factors for ND-LCH for early identification of demyelination. The combined use of SEPs and careful neurological evaluation may represent a valuable, low-cost, well-tolerated and easily available methodology to monitor patients from pre-symptomatic to symptomatic stages. We suggest a multidisciplinary protocol including clinical, MRS, and neurophysiological investigations to identify a population target for future therapeutic trials.

The pituitary gland in patients with Langerhans cell histiocytosis: a clinical and radiological evaluation

Langerhans cell histiocytosis (LCH) is a rare disease in which the most common endocrine manifestation is diabetes insipidus (DI). Data on anterior pituitary function in patients with LCH are limited. Thus, the present study investigated anterior pituitary function in LCH patients with DI via the evaluation of clinical and radiological findings at disease onset and during follow-up. The present study retrospectively evaluated nine patients with LCH (five males and four females). All diagnoses of LCH were made following histological and/or immunophenotypic analyses of tissue biopsies, bronchoalveolar lavage, or cerebrospinal fluid (CSF). Basal and, if necessary, dynamic pituitary function tests were used to assess anterior pituitary function, and magnetic resonance imaging (MRI) scans were used to image the pituitary. The LCH treatment modality was based on organ involvement. The mean age at onset of DI was 27.6 years (range 15-60 years). One patient (11%) exhibited single organ involvement, while eight patients (89%) displayed multisystem organ involvement. On admittance, one patient had hypogonadotropic hypogonadism, one patient exhibited panhypopituitarism [hypogonadotropic hypogonadism, central hypothyroidism, hypocortisolism, and growth hormone (GH) deficiency], and four patients (44%) displayed hyperprolactinemia. The MRI data revealed infundibular enlargement in seven patients (78%), a thalamic mass in one patient (11%), and the absence of the bright spot in all patients. A single patient (11%) showed a mass in the pons that had a partially empty sella. The patients were treated with radiation therapy (RT), chemotherapy (CT), or a combination of both (RT+CT) and were followed up for a median of 91.8 months (range 2-318 months). Seven patients were assessed during the follow-up period, of whom four patients (57.1%) developed anterior pituitary hormone deficiency, three (43%) were diagnosed with GH deficiency, and one (14%) exhibited gonadotropin deficiency. The gonadotropin deficiency in the patient, which was diagnosed on admittance, was resolved during the follow-up period. DI persisted in all patients, and the conditions of the seven patients who have remained on follow-up are stable. In the present study, patients with LCH exhibited altered function in the anterior pituitary as well as the posterior pituitary, which may be due to the natural course of the disease or the effects of treatment. The present findings indicate that anterior pituitary function should be assessed in LCH patients on admittance and during follow-up, especially in LCH patients with multisystem organ involvement.

Association between Pituitary Langerhans Cell Histiocytosis and Papillary Thyroid Carcinoma

Here we report a case of panhypopituitarism caused by pituitary Langerhans cell hystocitosis (LCH) in a 22-year-old woman affected by papillary thyroid carcinoma (PTC). Although several cases of the coexistence of PTC and LCH within thyroid tissue have been described in relative literature, in this case, the patient presented a unique suprasellar retrochiasmatic histocytosis localization which, to the best of our knowledge, had never been described before in association with PTC. Even if this aspect is not addressed in the present case report, it is worth noting that about 50% of the patients affected either by LCH or PTC are characterized by activating mutations of the proto-oncogene BRAF. This, along with other clinical studies, may warrant further biomolecular large-scale case study investigations in order to evaluate a possible connection between the 2 conditions and shed light on the etiology of these diseases, which are still largely unknown.

Optimal therapy for adults with Langerhans cell histiocytosis bone lesions

Background

There is little data on treatment of Langerhans cell histiocytosis (LCH) in adults. Available data is on small numbers of patients with short follow-up times and no comparison of results from different treatment regimens. We analyzed the responses of adult LCH patients with bone lesions to three primary chemotherapy treatments to define the optimal one.

Methods and Findings

Fifty-eight adult patients with bone lesions, either as a solitary site or as a component of multisystem disease, were analyzed for disease location and response to surgery, curettage, steroids, radiation, vinblastine/prednisone, 2-Chlorodeoxyadenosine (2-CdA), or cytosine arabinoside (ARA-C). The mean age of patients was 32 years, with equal gender distribution. Twenty-nine patients had 1 lesion; 16, 2 lesions; 5, 3 lesions; and 8 had 4 or more. Most bone lesions were in the skull, spine, or jaw. Chemotherapy, surgery, curettage, or radiation, but not steroids alone, achieved improvement or resolution of lesions in a majority of patients. Comparison of the three chemotherapy regimens revealed 84% of patients treated with vinblastine/prednisone either did not respond or relapsed within a year, whereas 59% of patients treated with 2-CdA and 21% treated with ARA-C failed. Toxicity was worse with the vinblastine/prednisone group as 75% had grade 3–4 neuropathy. Grade 3–4 cytopenias occurred in 37% of the 2-CdA -treated patients and 20% of the ARA-C-treated patients. The major limitation of this study is it is retrospective and not a clinical trial.

Conclusions

ARA-C is an effective and minimally toxic treatment for LCH bone lesions in adults. In contrast, vinblastine/prednisone results in poor overall responses and excessive toxicity.

Langerhans cell histiocytosis of the optic chiasm: case report

BACKGROUND AND IMPORTANCE

Langerhans cell histiocytosis (LCH) is an uncommon disease, usually affecting the cranium and peripheral bones. We present a rare case of isolated optic chiasm involvement by LCH to highlight the importance of considering LCH in the differential diagnosis of optic chiasm lesions.

CLINICAL PRESENTATION

A 71-year-old woman presented with a 6-week history of worsening peripheral vision, headaches, weakness, cold sensitivity, and fatigue. She was found to have dense bitemporal hemianopsia. Magnetic resonance imaging revealed a 2-cm lesion, contrast enhancing on T1 and bright on T2 signal, involving the optic chiasm but not the pituitary gland. Preoperative considerations included optic nerve glioma, choristoma of the stalk, sarcoid, hypothalamic glioma, and Langerhans cell histiocytosis. The patient underwent a right subfrontal craniotomy for biopsy of the lesion. The optic chiasm was grossly enlarged with no tissue external to the chiasm. A midline incision was made in the lamina terminalis, and multiple biopsies were taken of firm fibrous material. Histologically, the tumor was characteristic for LCH and included a mixture of histiocytes with features of Langerhans cells, eosinophils, small lymphocytes, macrophages, neutrophils, and plasma cells.

CONCLUSION

LCH is a rare disease, generally affecting bone, skin, lymph nodes, and in more severe cases, visceral organs. LCH involving the optic pathways is a rare condition that should be included in the differential for adults with mass lesions involving the orbit, eye, optic nerve, or chiasm. Future clinical and basic science research is needed to better understand LCH, its molecular origin, and its growth pattern.

A Case of Multisystemic Langerhans Cell Histiocytosis in an Adult

Langerhans cell histiocytosis is a rare disease in adults with a myriad of clinical presentations. A case of multisystemic Langerhans cell histiocytosis with involvement of bone, skin, lungs, and the hypothalamic-pituitary-axis is reported. The possibility of a disseminated disease should be considered in the diagnosis of Langerhans cell histiocytosis, and these patients should undergo a careful evaluation and follow up with early institution of treatment.

Incidence and pattern of radiological central nervous system Langerhans cell histiocytosis in children: a population based study

BACKGROUND

Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and other central nervous system (CNS) dysfunctions revealed by brain magnetic resonance imaging (MRI). We estimated the incidence and pattern of pathological brain MRI findings in a well-defined, population-based cohort of children with LCH.

METHODS

Among children under 15 years of age diagnosed with LCH in the Stockholm County during 1992-2001, brain MRI was performed at a single center in children with clinical and/or laboratory signs of CNS involvement, including endocrine dysfunction.

RESULTS

Out of the 29 children (16 males, 13 females) diagnosed with LCH, brain MRI was performed based on clinical indications in 16 children (55%) with either abnormal endocrine findings (n = 6), such as diabetes insipidus (n = 5), low IGF-1 (n = 1), or panhypopituitarism (n = 1), or clinical CNS symptoms (n = 10). CNS MRI abnormalities were demonstrated in eight children (28%), at a median time of 3.5 years after LCH diagnosis (range 1-11.4 years). Altogether 7 of the 29 children (24%) had MRI findings associated with neurodegeneration, corresponding to a minimal incidence of 2.1/10(6) children per year. Neurodegenerative abnormalities tended to be more frequent in patients with craniofacial involvement (P = 0.12).

CONCLUSIONS

The minimal annual incidence rate of neurodegenerative associated radiographic findings in LCH is estimated at 2.1/10(6) children (24% of all children with LCH). An important question is whether all patients with LCH, or certain forms of LCH, should be recommended for a late follow-up examination including MRI. In patients with CNS-LCH, neurological, neuropsychological, neurophysiological, neurochemical and neuroradiological follow-up assessment is suggested.

Endocrine manifestations of Langerhans cell histiocytosis diagnosed in adults

Langerhans cell histiocytosis (LCH) is a rare granulomatous disease of unknown etiology. We retrospectively reviewed data from four patients (3 males and 1 female), mean age 33.5 years old (range: 21-40), with histopathological diagnosis of LCH. All of them presented with symptoms suggestive of endocrine involvement. The main complaint was goiter in two patients and polyuria and polydipsia in three. Before the LCH diagnosis, two patients had unevaluated symptoms of diabetes insipidus (DI) and hypogonadism. The mean time from symptoms onset to diagnosis was 6.25 years (range: 2-13). Histopathological diagnosis was established by total thyroidectomy (TT) biopsy in two patients, skin lesion biopsy in one, and pituitary stalk biopsy in the other. In the two-first patients, surgery was indicated after the fine-needle aspiration biopsy (FNAB) showed a false positive result of differentiated thyroid carcinoma and immunohistochemistry was used for diagnosis confirmation. Three cases were treated with chemotherapy; one of them had already received radiation therapy on the hypothalamic-pituitary region, developing post-radiation hypopituitarism.

Neurodegenerative central nervous system Langerhans cell histiocytosis and coincident hydrocephalus treated with vincristine/cytosine arabinoside

BACKGROUND

Central nervous system (CNS) complications of Langerhans cell histiocytosis (LCH) include mass lesions and a neurodegenerative (ND) syndrome with ataxia, dysarthria, dysmetria, learning and behavior difficulties and/or characteristic changes on brain MRIs. Hydrocephalus has rarely been reported in LCH. LCH lesions of the orbit, mastoid and temporal bones ("CNS-Risk" lesions) and diabetes insipidus predispose patients to ND-CNS-LCH. Treatment options have been limited and only a case series using trans-retinoic acid (ATRA) and intravenous immunoglobulin (IVIG) have been published.

METHODS

We have used cytosine arabinoside (ARA-C) with or without vincristine to treat eight patients with ND-CNS LCH.

PATIENTS

Seven male children and one young adult male with clinical and radiologic ND-CNS-LCH were treated with a regimen of vincristine 1.5 mg/m(2) on day 1 and ARA-C 100 mg/m(2) daily for 5 days or ARA-C alone monthly for 4-19 months. Seven patients were evaluated with an ataxia rating scale (ARS) and all with serial MRIs of the brain.

RESULTS

Five of seven patients had decreases in their ARS scores and/or decreased T2 hyperintense lesions on MRI images. Grade 2 neutropenia was the most frequent adverse event. Vincristine-associated neuropathy occurred in two patients. Hydrocephalus caused symptoms and signs that confounded the diagnosis and management of ND-CNS-LCH in all four patients affected with both.

CONCLUSIONS

Subtle changes in neurologic function may be complicated by hydrocephalus. Vcr/ARA-C or ARA-C were an effective therapies for some ND-CNS LCH patients. A clinical trial using this and possibly other modalities such as IVIG or ATRA should be done.

Orbital involvement in langerhans cell histiocytosis

PURPOSE

The authors studied a series of patients with Langerhans cell histiocytosis in an attempt to better define the incidence and significance of orbital involvement within the vast spectrum of the disease.

METHODS

Retrospective chart review of consecutive patients with a recorded diagnosis of Langerhans cell histiocytosis treated at St. Jude Children's Research Hospital between 1992 and 2007. Pertinent information included age, gender, clinical features, radiological features, treatment, disease progression, orbital involvement, and development of diabetes insipidus.

RESULTS

The authors found and evaluated 24 patients (16 male). The median age at diagnosis was 24 months (range, 4-179 months), and median follow-up was 75 months (range, 6-186 months). Nine (37.5%) patients had orbital involvement (6 on presentation, 3 on subsequent follow-up). The 2 patients with unifocal orbital lesions developed progressive disease. All patients with orbital lesions received systemic chemotherapy either at the time of diagnosis (n = 8) or on documented disease progression (n = 1). Six patients (25%), 2 of whom had orbital involvement, developed diabetes insipidus in the setting of either multibone (n = 1) or multisystem (n = 5) disease.

CONCLUSIONS

In this study, orbital involvement occurred in one third of patients with Langerhans cell histiocytosis, usually in the context of multifocal bone or multisystem disease. Thus, the authors believe a comprehensive workup and follow-up in the context of a multidisciplinary approach is necessary. The authors found that the response to local curretage or steroid injection for small lesions, and to systemic chemotherapy for extensive lesions, is usually excellent and that aggressive local control measures, such as surgical resection or radiation, are not indicated in most cases.

Biomarkers in the cerebrospinal fluid and neurodegeneration in Langerhans cell histiocytosis

BACKGROUND

Progressive neurodegeneration may result in potentially severe cognitive and motor dysfunctions as a complication of Langerhans cell histiocytosis (LCH), a suggested IL-17A-associated inflammatory condition. To detect this complication (CNS-LCH) early and to evaluate the potential efficacy of therapeutic interventions, biomarkers detecting and measuring ongoing neurodegeneration would be valuable. We evaluated cerebrospinal fluid (CSF) biomarkers of ongoing neurodegeneration in CNS-LCH patients.

PROCEDURE

Nine patients with endocrine, neuromotor, cognitive or/and behavioral abnormalities as well as neuroradiological evidence of CNS-LCH were evaluated 4-12 years after LCH diagnosis for CSF levels of neurofilament protein light chain (NF-L), glial fibrillary acid protein (GFAp), and total tau protein (TAU). Two patients were analyzed longitudinally. One hundred ten children with newly diagnosed acute lymphoblastic leukemia (ALL) served as controls.

RESULTS

NF-L, TAU, and GFAp levels were elevated in four, six, and eight of nine patients studied, respectively. NF-L (P < 0.001) and GFAp (P < 0.001) were higher in patients than in controls (TAU not analyzed in controls). The patient with most severe clinical and neuroradiological CNS-LCH displayed the highest levels of NF-L and GFAp whereas three patients without signs of systemic disease had low TAU levels and normal/slightly elevated NF-L. NF-L tended to be higher at radiological progression of neurodegeneration than at status quo (P = 0.07). Notably, we experienced frequent lumbar puncture complications in these patients.

CONCLUSIONS

CSF levels of NF-L, TAU, and GFAp appear to be elevated in CNS-LCH. It would be valuable if these markers were validated in order to serve as markers for early CNS-LCH, to monitor disease progression and to evaluate various treatment attempts for CNS-LCH.

Pituitary tumours: inflammatory and granulomatous expansive lesions of the pituitary

Inflammatory and granulomatous diseases of the pituitary are rare causes of sellar masses. Lymphocytic hypophysitis is the most relevant of these disorders, and it is characterised by autoimmune pathogenesis with focal or diffuse inflammatory infiltration and varying degrees of pituitary gland destruction. Endocrine symptoms may include partial or total hypopituitarism, with adrenocorticotropic hormone (ACTH) deficiency being the earliest and most frequent alteration. Pituitary abscess is a rare but potentially life-threatening disease and, in 30-50% of patients, anterior pituitary hormone deficiencies or central diabetes insipidus (DI) at onset may be observed: the earliest manifestation being growth hormone deficiency (GHD), followed by follicle-stimulating hormone (FSH)/luteinising hormone (LH), thyroid-stimulating hormone (TSH) and ACTH deficiencies. Fungal infections of the pituitary are also very rare and include aspergillosis and coccidioidomycosis. Concerning pituitary involvement in systemic diseases, in sarcoidosis endocrine complications are rare, but the hypothalamus and pituitary are the glands most commonly affected. DI is reported in approximately 25-33 % of all neurosarcoidosis cases and is the most frequently observed endocrine disorder. Hyperprolactinaemia and anterior pituitary deficiencies may also occur. Rarely, partial or global anterior pituitary dysfunction may be present also in Wegener's granulomatosis, either at onset or in the course of the disease, resulting in deficiency of one or more of the pituitary axes. Other forms of granulomatous pituitary lesions include idiopathic giant cell granulomatous hypophysitis, Takayasu's disease, Cogan's syndrome and Crohn's disease. The hypotalamic-pituitary system is involved mainly in children with Langerhans' cells histiocytosis who develop DI, which is the most common endocrine manifestation. Anterior pituitary dysfunction is found more rarely and is almost invariably associated with DI. Pituitary involvement may also be observed in another form of systemic hystiocitosis, that is, Erdheim-Chester disease. Tuberculosis is a rare cause of hypophysitis, which may present with features of anterior pituitary dysfunction, such as hypopituitarism with hyperprolactinaemia. In conclusion, in patients with a sellar mass and unusual clinical presentation (DI, neurological symptoms), aggressiveness and onset and in the presence of systemic diseases, inflammatory and granulomatous pituitary lesions should be carefully considered in differential diagnosis.

Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a poorly understood proliferative disease, with different patterns of clinical presentation. Currently it is classified according to the number and type of system involved and the degree of organ dysfunction. The aetiology of the disease remains uncertain, and in some cases the disease is polyclonal, suggesting a reactive condition. Many cytokines have been implicated in the pathogenesis of LCH. Different therapeutic approaches can be considered depending on the affected organ, including surgery, radiotherapy and chemotherapy. Long-term organ dysfunction may remain, despite disease control and/or eradication, making indefinite supportive treatment mandatory. Here we present a literature review on all of the aspects of the disease, treatment approaches and existing protocols, and finally an adult clinical case.

Health-related quality of life, cognitive functioning and behaviour problems in children with Langerhans cell histiocytosis

BACKGROUND

This study was designed to evaluate generic and disease-specific health-related quality of life (HRQoL), cognitive functioning and behaviour problems of children with Langerhans Cell Histiocytosis (LCH). Furthermore, we investigated which medical determinants and social demographic factors were predictive for HRQoL, cognitive functioning and behavioural problems.

PROCEDURE

In this cross-sectional case-control study 24 children ranging from 7 to 17 years of age were administered a HRQoL questionnaire, cognitive tests and behaviour ratings. In addition, a disease-specific HRQoL measure was developed and tested. Results were compared to a reference group consisting of healthy peers and to proxy-ratings by parents and teachers.

RESULTS

Children with LCH reported a lower physical HRQoL than the reference group (P <or= 0.05). Children older than 12 reported lower HRQoL scores. Scores on the disease-specific HRQoL questionnaire were lower than on the generic measure used. Performances on cognitive tests varied widely, short term visual memory was most affected. Twenty-five percent of the children follow special education. According to parents and teachers, children with LCH had more internalising behaviour problems (i.e., anxiety and depression), compared to the instrument norms. Children with Diabetes Insipidus, other CNS involvement and children who have had chemotherapy had more cognitive and behaviour problems than the other children with LCH.

CONCLUSIONS

HRQoL is affected in children with LCH, especially in older children. Children with LCH show more internalising problem behaviour than their peers. Teachers are important additional informants about behaviour problems.

Neuropsychological sequelae in patients with neurodegenerative Langerhans cell histiocytosis

BACKGROUND

Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and significant CNS sequelae, affecting a significant proportion of the patients. We here aimed to investigate the neuropsychological consequences in more detail.

METHODS

Using an extensive neuropsychological test battery, we evaluated nine LCH patients, 6-20 years old, with radiological signs indicative of neurodegeneration.

RESULTS

Altogether 3/9 patients performed below 1 SD of normal for age on full IQ. Detailed analysis revealed that 4/9 had deficient performance IQ, whereas 1/9 had subnormal verbal IQ (defined as below 1 SD). Furthermore, 3/8 patients showed slow speed of performance for age. Notably, 8/9 (89%) had deficient verbal working memory and 7/8 (88%) performed below normal on visual-spatial working memory.

CONCLUSIONS

The results indicate a specific, uneven neuropsychological profile in patients affected by CNS-LCH, with a decline particularly on perceptual tasks whereas the verbal performance was not as negatively influenced. Furthermore, verbal and visual-spatial working memory functions were below normal for age in all but one patient studied. LCH may easily be misdiagnosed, but it is important that individuals affected by CNS-LCH are diagnosed to provide advice and support. It remains a challenge to find a treatment reducing this unfortunate neurodegeneration.

Failure to treat obstructive hydrocephalus with endoscopic third ventriculostomy in a patient with neurodegenerative Langerhans cell histiocytosis

The second most frequent central nervous system involvement pattern in Langerhans cell histiocytosis (LCH) is a rare condition documented in a number of reports called "neurodegenerative LCH" (ND-LCH). Magnetic resonance images confirming the presence of the disease usually demonstrate striking symmetric bilateral hyperintensities predominantly in the cerebellum, basal ganglia, pons, and/or cerebral white matter. The authors here describe for the first time in the literature a patient with ND-LCH and concomitant hydrocephalus initially treated using endoscopic third ventriculostomy (ETV). This 9-year-old boy, who had undergone chemotherapy for skin and lung LCH without central nervous system involvement at the age of 10 months, presented with acute ataxia, headaches, and paraparesis and a 1-year history of gradually increasing clumsiness. Magnetic resonance images showed obstructive hydrocephalus at the level of the aqueduct of Sylvius and signs of ND-LCH. After registering high intracranial pressure (ICP) spikes with an intraparenchymal pressure monitor, an ETV was performed. A second ETV was required months later because of ostomy occlusion, and finally a ventriculoperitoneal shunt was placed because of ostomy reocclusion. Endoscopic third ventriculostomy was initially considered the treatment of choice to divert cerebrospinal fluid without leaving a ventriculoperitoneal shunt and to obtain biopsy specimens from the periinfundibular recess area. The third ventriculostomy occluded twice, and an endoscopic aqueduct fenestration was unsuccessful. The authors hypothesized that an inflammatory process related to late ND disease was responsible for the occlusions. Biopsy specimens from the infundibular recess and fornix column did not show histopathogical abnormalities. Increased ICP symptoms resolved with cerebrospinal fluid diversion. This case is the first instance of ND-LCH with hydrocephalus reported in the literature to date. Shunt placement rather than ETV seems to be the favorable choice in relieving elevated ICP.

Pattern and course of neurodegeneration in Langerhans cell histiocytosis

OBJECTIVE

To explore the frequency and course of neurodegenerative central nervous system (CNS) disease in Langerhans cell histiocytosis (ND-LCH).

STUDY DESIGN

We studied 83 patients with LCH in whom magnetic resonance imaging (MRI) of the brain was performed at least twice for various clinical indications. We defined radiologic ND-LCH as an MRI pattern comprising bilateral symmetric lesions in the dentate nucleus of the cerebellum or basal ganglia.

RESULTS

Forty-seven of 83 patients (57%) had radiologic ND-LCH, at a median of 34 months (range 0-16 years) from the diagnosis of LCH. The MRI findings deteriorated in 31/47 (66%) patients over a median of 3 years (range 2 months to 12 years 6 months) and did not reverse in any patient. In 12 patients with radiologic ND-LCH (25%), clinical ND-LCH with overt symptoms were found 3 to 15 years (median 6 years) after initial LCH diagnosis. These symptoms included intention tremor, cerebellar ataxia, dysarthria, dysdiadochokinesis, concentration deficits, psychomotor retardation, severe headaches, and psychosis.

CONCLUSION

We conclude that radiologic ND-LCH is serious, not uncommon in patients studied by MRI, irreversible, and may be followed by severe clinical ND-LCH many years after the initial diagnosis of LCH.

Langerhans cell histiocytosis: update for the pediatrician

PURPOSE OF REVIEW

Langerhans cell histiocytosis is the commonest of the histiocytic disorders. Owing to the relative rarity of the condition, it remains a disease in which the diagnosis is often delayed or missed and in which many questions remain unanswered, ranging from etiology and pathogenesis to therapy. The management is often frustrating for care-givers and parents/patients. The purpose of the review is therefore to raise awareness of the disease and to highlight the clinical findings that should make the pediatrician or primary care-giver suspect the diagnosis, as well as current thinking regarding management of the various and diverse manifestations of this disease.

RECENT FINDINGS

We discuss new and interesting insights into the biology of Langerhans cell histiocytosis that raise the possibility of future targeted therapy. Important points in the diagnosis, investigation and management of the various forms of the disease are also discussed.

SUMMARY

We present a review of childhood Langerhans cell histiocytosis, highlighting new insights into pathogenesis and management of the various forms of this complex disease.

Analysis of outcome for patients with mass lesions of the central nervous system due to Langerhans cell histiocytosis treated with 2-chlorodeoxyadenosine

PURPOSE

To assess the activity and tolerability of 2-chlorodeoxyadenosine (2-CDA) in treating mass lesions of the central nervous system (CNS) due to Langerhans cell histiocytosis (LCH).

PATIENTS AND METHODS

The records of eight children and four adults with CNS LCH who were treated with 2-CDA were reviewed. The pattern of CNS disease included involvement of the hypothalamic-pituitary axis, gadolinium enhancing parenchymal as well as dural and choroid plexus based mass lesions, and atrophy. 2-CDA (5-13 mg/m(2)/day) was given on 3-5 consecutive days and repeated every 2-8 weeks for a period ranging from 3 to 12 months.

RESULTS

Eight patients demonstrated a complete radiographic response to 2-CDA with resolution of all enhancing mass lesions and four patients showed a sustained, partial radiographic response. One patient died from a non-treatment related cause without evidence of LCH on autopsy. With a follow-up ranging from 2 to 10 years after completion of therapy, the 11 surviving patients remain in continuous remission or are progression free. Prolonged bone marrow suppression was the most common toxicity (four patients). Permanent sequelae of CNS LCH, such as panhypopituitarism, diabetes insipidus (DI) and neurocognitive dysfunction, were not found to be reversible with 2-CDA therapy.

CONCLUSIONS

2-CDA is an active agent in patients with CNS LCH, with the possible exception of neurodegenerative disease, and should be further evaluated in a prospective multi-center clinical trial for LCH patients with enhancing mass lesions of the CNS.

Systemic and endocrine manifestations of Langerhans' cell histiocytosis: current concepts in diagnosis and management

Langerhans' cell histiocytosis (LCH) is a rare disease of unknown etiology and variable biologic behavior and course. Almost every organ can be affected; however, it frequently involves the bones, lungs, skin and lymph nodes. LCH exhibits a particular predilection for involvement of the hypothalamo-pituitary axis resulting in diabetes insipidus and/or other anterior pituitary deficiencies. Although LCH can sometimes resolve spontaneously, it usually follows a chronic course and systemic treatment is mandatory for the management of multisystem disease. However, a significant number of patients will develop at least one permanent sequela as a consequence of the disease, with diabetes insipidus being the most common. A multidisciplinary approach is always needed in diagnosis, treatment and follow-up of all patients with LCH.

Histiocytose langerhansienne encéphalique isolée à forme pseudotumorale: une observation et revue de la littérature

INTRODUCTION

Langerhans cell histiocytosis is a multivisceral pathology. Neurological manifestations are rare.

EXEGESIS

We report the case of a 31 year old man hospitalized for left partial motor seizure revealing a right frontal tumor with criteria for histiocytosis X. The histological and biological examination found criteria for Langerhans cell histiocytosis (CD1a and S100 reactivity). The check-up for extracerebral localisations of the disease was negative. The outcome was favourable after a total surgical resection. The review of the literature and a discussion on neurological manifestations of this disease were carried out.

CONCLUSION

A neurological manifestation can be the first and only symptom of a Langerhans cell histiocytosis.

Long-term MR imaging course of neurodegenerative Langerhans cell histiocytosis

BACKGROUND AND PURPOSE

MR imaging signal intensity abnormalities in the cerebellum, the pons, and the basal ganglia, compatible with a neurodegenerative process (ND) were reported in up to 10% of patients with Langerhans cell histiocytosis (LCH). Although the imaging features of ND-LCH have been extensively described, the temporal course of ND-LCH has not been assessed as of yet. The purpose of this study was to describe the long-term course of MR imaging signal intensity abnormalities in ND-LCH on T1- and T2-weighted images.

MATERIALS AND METHODS

In this retrospective study, 9 patients with ND-LCH with an observation time of at least 5 years were included. Three or more MR imaging studies per patient, performed in 3-year intervals (+/-11 months), were reviewed. Signal intensity abnormalities on T1- and T2-weighted images in the cerebellum, the pons, and basal ganglia were scored for their signal intensity quality and their extension. In addition, the severity of cerebellar atrophy was scored.

RESULTS

The signal intensity alterations were not resolved in any of the patients. Instead, a progression of the signal intensity alterations either in the cerebellum or basal ganglia was observed in all of the patients but did not correlate with a clinical deterioration. Overt and severe neurologic symptoms were reported in only 2 patients in whom some form of atrophy was noted.

CONCLUSIONS

ND-LCH appears to be a slowly progressive process. The increase of signal intensity abnormalities in the cerebellum and basal ganglia does not correlate with neurologic deterioration. MR imaging appears to be a sensitive technique to detect and monitor radiologic ND-LCH.

Endocrine manifestations in Langerhans cell histiocytosis

Langerhans cell histiocytosis is a rare, multisystem disease that shows a particular predilection for hypothalamo-pituitary axis involvement. Diabetes insipidus is the most frequent permanent consequence of Langerhans cell histiocytosis, developing in around a quarter of patients. Although the exact prevalence of anterior pituitary hormone deficiencies is not known, it is probably high and is almost always associated with diabetes insipidus. Established pituitary hormone deficiencies are mostly permanent and require prompt diagnosis and treatment, whereas continuous follow-up is needed to detect deficiencies that might evolve later during the course of the disease. Involvement of endocrine tissues other than the pituitary has also been described but is relatively rare. Further studies are needed to evaluate the effect that endocrine deficiencies exert on the overall prognosis of patients with Langerhans cell histiocytosis.