Nosology and pathology of Langerhans cell histiocytosis

Paediatric Langerhans Cell Histiocytosis Disease: Long-Term Sequelae in the Hypothalamic Endocrine System

Langerhans cell histiocytosis (LCH) is a disorder of the mononuclear phagocyte system that can affect almost any organ and system. The most common central nervous system (CNS) manifestation in LCH is the infiltration of the hypothalamic-pituitary region leading to destruction and neurodegeneration of CNS tissue. The latter causes the most frequent endocrinological manifestation, that is, central diabetes insipidus (CDI), and less often anterior pituitary hormone deficiency (APD). The reported incidence of CDI is estimated between 11.5 and 24% and is considered a risk factor for neurodegenerative disease and APD. Three risk factors for development of CDI are recognized in the majority of the studies: (1) multisystem disease, (2) the occurrence of reactivations or active disease for a prolonged period, and (3) the presence of craniofacial bone lesions. Since CDI may occur as the first manifestation of LCH, differential diagnosis of malignant diseases like germ cell tumours must be made. APD is almost always associated with CDI and can appear several years after the diagnosis of CDI. Growth hormone is the most commonly affected anterior pituitary hormone. Despite significant advances in the knowledge of LCH in recent years, little progress has been made in preventing long-term sequelae such as those affecting the hypothalamic-pituitary system.

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Rare Diseases of the Middle Ear and Lateral Skull Base

Otalgia, otorrhea and hearing loss are the most common ear-related symptoms that lead to the consultation of an otolaryngologist. Furthermore, balance disorders and affections of the cranial nerve function may play a role in the consultation. In large academic centres, but also in primary care, the identification of rare diseases of the middle ear and the lateral skull base is essential, as these diseases often require interdisciplinary approaches to establish the correct diagnosis and to initiate safe and adequate treatments. This review provides an overview of rare bone, neoplastic, haematological, autoimmunological and infectious disorders as well as malformations that may manifest in the middle ear and the lateral skull base. Knowledge of rare disorders is an essential factor ensuring the quality of patient care, in particular surgical procedures. Notably, in untypical, complicated, and prolonged disease courses, rare differential diagnoses need to be considered.

Genetic homogeneity of adult Langerhans cell histiocytosis lesions: Insights from BRAFV600E mutations in adult populations

Langerhans cell histiocytosis (LCH) is a heterologous disease with a recognized disparity in incidence, affected sites and prognosis between adults and children. The recent identification of BRAF^V600E mutations in LCH prompted the investigation of the frequency of these mutations in adult and childhood disease with the involvement of single or multiple sites in the present study. The study analysed the BRAF^V600E status in a cohort of adult LCH patients by DNA sequencing, and performed a broader meta-analysis of BRAF^V600E mutations in LCH in order to investigate any association with disease site and severity. A review of the literature revealed that ~47% of lesions from cases of adult disease (patient age, >18 years) were V600E-positive compared with 53% in those under 18 years. When single and multiple site disease was compared, there was a slight increase in the former (61 vs. 51%, respectively). A greater difference was observed when high- and low-risk organs were compared; for example, 75% of liver biopsies (a high-risk organ) were reported to bear the mutation compared with 47% of lung biopsies. In the adult LCH population, DNA sequencing identified mutations in 38% of 29 individuals, which is slightly lower than the figure identified from the meta-analysis (in which a total of 132 individuals were sampled), although we this value could not be broken down by clinical status. Thus, V600E status at presentation in itself is not predictive of tumour course, but a considerable proportion of LCH patients may respond to targeted V600E therapies.

Pediatric Langerhans cell histiocytosis of the lateral skull base

OBJECTIVE

Describe the presentation, imaging characteristics, management, and outcomes of pediatric patients with Langerhans cell histiocytosis (LCH) of the temporal bone.

METHODS

A retrospective chart review was performed between 2000 and 2014 at a single tertiary care children's hospital. Fourteen patients were identified with a diagnosis of LCH and involvement of the temporal bone.

RESULTS

Ten patients were female and ten were Caucasian. Mean age at diagnosis was 3 years (range 0.3-9.6 years). The most common presenting symptoms were scalp lesions, postauricular lesions, otalgia, and persistent ear infections. Three patients had documented hearing loss. Four cases had otic capsule invasion. Computed tomography demonstrated a lytic temporal bone lesion within the following subsites: mastoid, squamous temporal bone, external auditory canal, middle ear, and petrous apex. Four patients had intracranial disease. Extent and location of disease prompted all patients to be initially managed with chemotherapy. Surgical excision was limited to one case of localized recurrence. After a mean follow-up of 85.2 months (SD 42.4 months) there were no deaths but eight patients had a recurrence. Two patients developed long-term otologic sequelae requiring surgery. One patient developed labyrinthitis ossificans.

CONCLUSION

LCH has a varied presentation, age distribution, and treatment algorithm. This series of 14 pediatric patients with temporal bone involvement supports a limited role for surgical resection. Long-term follow-up is critical for detection of local and disseminated disease, and for monitoring of otologic complications.

Feline Progressive Histiocytosis

Histiocytic proliferative diseases include reactive and neoplastic proliferations of dendritic cells (DC) or macrophages. Various forms of DC proliferations have been documented in humans and dogs; their etiology is largely unknown. With the exception of a few case reports, histiocytic proliferations have not been characterized in cats. This study summarizes clinical, morphologic, and immunophenotypic features of a feline progressive histiocytosis (FPH) in 30 cats. There was no breed or age predilection. Females were more often affected than males. Solitary or multiple nonpruritic firm papules, nodules, and plaques had a predilection for feet, legs, and face. Lesions consisted of poorly circumscribed epitheliotropic (13/30) and nonepitheliotropic (17/30) histiocytic infiltrates of the superficial and deep dermis, with variable extension into the subcutis. The histiocytic population was relatively monomorphous early in the clinical course. With disease progression, cellular pleomorphism was more frequently encountered. Histiocytes expressed CD1a, CD1c, CD18, and major histocompatibility complex class II molecules. This immunophenotype suggests a DC origin of these lesions. Coexpression of E-cadherin, a feature of cutaneous Langerhans cells, was only observed in 3 cats. FPH followed a progressive clinical course; the lesions, however, were limited to the skin for an extended period of time. Terminal involvement of internal organs was documented in 7 cases. Treatment with chemotherapeutics or immunosuppressive and immunomodulatory drugs was not successful. The etiology of FPH remains unknown. FPH is best considered an initially indolent cutaneous neoplasm, which is mostly slowly progressive and may spread beyond the skin in the terminal stage.

Activated Conventional T-Cells Are Present in Langerhans Cell Histiocytosis Lesions Despite the Presence of Immune Suppressive Cytokines

Langerhans cell histiocytosis (LCH) lesions are characterized by neoplastic CD1a(+)/Langerin(+) histiocytes (LCH-cells) and display many features of chronic inflammation. Cancer cells can escape immune-surveillance through intra-tumoral secretion of immune-suppressive cytokines. We therefore studied by immunohistochemistry the local cytokine milieu and phenotypic characteristics of T-cells and LCH-cells present in LCH lesions collected from 25 therapy naïve patients. LCH biopsies predominantly expressed interleukin-10 (IL-10) (10/25), transforming growth factor-beta (TGF-β) (9/25), or both cytokines (6/25). The absolute number of CD3(+)T-cells and the CD3(+)FOXP3(-) conventional cell (T-CONV) versus the CD3(+)FOXP3(+) regulatory T-cell (T-REG) was comparable for each suppressive cytokine profile (5:1). IL-10-expressing lesions contained, however, a higher proportion of T-CONV expressing the activation markers CD25 98% (38%-100%) and inducible costimulatory molecule (ICOS) 86% (47%-100%) than lesions wherein solely TGF-β was detected (CD25(+) 20% (6%-54%); ICOS(+) 29% (7%-51%)). Virtually all T-REG expressed CD25 and ICOS in IL-10 lesions, whereas TGF-β(+) lesions contained a lower proportion of ICOS(+) T-REG (P=0.05). IL-10(+) lesions contained more LCH-cells expressing high intensity of ICOS ligand (ICOSL) compared with TGF-β(+) lesions (P=0.03). ICOS expression by lesion-infiltrating T-CONV and T-REG positively correlated to the extent of ICOSL expression by LCH-cells (P=0.004). Our study points out that the combined detection of interlesional IL-10 and ICOSL expression by LCH-cells is associated with the highest prevalence of activated T-CONV. Immune profiling of LCH-affected tissues obtained at the time of diagnosis may set the stage for the development of new types of therapies, which aim at local boosting of immune cells that recognize and eliminate neoplastic LCH-cells.

Isolated Langerhans Cell Histiocytosis Bone Lesion in Pediatric Patients: Systematic Review and Treatment Algorithm

OBJECTIVE

The present study reviewed all cases reported of isolated Langerhans cell histiocytosis bone lesions in the head and neck of pediatric patients. The objective was to create a treatment algorithm to facilitate the diagnosis and management of these lesions.

DATA SOURCES

Eligible articles were identified through a comprehensive search of the following electronic databases: PubMed, Ovid Medline, Embase, and Cochrane Library.

REVIEW METHODS

Two authors independently reviewed the titles and abstracts retrieved by the electronic search concordant with the criteria for study eligibility. The lists of articles from each author were jointly reviewed and a common list created. All relevant articles were reviewed in hard copies and as full texts to justify inclusion.

RESULTS

A total of 201 patients (67% male, mean age: 8.1 ± 4.3 years) were included from 45 studies. Clinical presentations included swelling (64%), pain (9%), or both (18%). The skull (61%) and the orbit (24%) were the most common location for isolated bone lesions in the head and neck. The most frequently documented management option was resection, followed by observation, chemotherapy, and intralesional steroid injection.

CONCLUSIONS

Due to its rarity and variability in presentation and severity, treatment of these lesions has yet to be standardized. Based on the review, a diagnosis and treatment algorithm was created for head and neck surgeons when encountering these types of lesions.

A review of histiocytic diseases of dogs and cats

Histiocytic proliferative disorders are commonly observed in dogs and less often cats. Histiocytic disorders occur in most of the dendritic cell (DC) lineages. Canine cutaneous histiocytoma originates from Langerhans cells (LCs) indicated by expression of CD1a, CD11c/CD18, and E-cadherin. When histiocytomas occur as multiple lesions in skin with optional metastasis to lymph nodes and internal organs, the disease resembles cutaneous Langerhans cell histiocytosis of humans. Langerhans cell disorders do not occur in feline skin. Feline pulmonary LCH has been recognized as a cause of respiratory failure due to diffuse pulmonary infiltration by histiocytes, which express CD18 and E-cadherin and contain Birbeck's granules. In dogs and cats, histiocytic sarcomas (HS) arise from interstitial DCs that occur in most tissues of the body. Histiocytic sarcomas begin as localized lesions, which rapidly disseminate to many organs. Primary sites include spleen, lung, skin, brain (meninges), lymph node, bone marrow, and synovial tissues of limbs. An indolent form of localized HS, progressive histiocytosis, originates in the skin of cats. Hemophagocytic HS originates in splenic red pulp and bone marrow macrophages in dogs and cats. In dogs, histiocytes in hemophagocytic HS express CD11d/CD18, which is a leuko-integrin highly expressed by macrophages in splenic red pulp and bone marrow. Canine reactive histiocytic diseases, systemic histiocytosis (SH) and cutaneous histiocytosis, are complex inflammatory diseases with underlying immune dysregulation. The lesions are dominated by activated interstitial DCs and lymphocytes, which invade vessel walls and extend as vasocentric infiltrates in skin, lymph nodes, and internal organs (SH).

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.

Polyclonal T-cells express CD1a in Langerhans cell histiocytosis (LCH) lesions

Langerhans cell histiocytosis (LCH) is a complex and poorly understood disorder that has characteristics of both inflammatory and neoplastic disease. By using eight-colour flow cytometry, we have identified a previously unreported population of CD1a(+)/CD3(+) T-cells in LCH lesions. The expression of CD1a is regarded as a hallmark of this disease; however, it has always been presumed that it was only expressed by pathogenic Langerhans cells (LCs). We have now detected CD1a expression by a range of T-cell subsets within all of the LCH lesions that were examined, establishing that CD1a expression in these lesions is no longer restricted to pathogenic LCs. The presence of CD1a(+) T-cells in all of the LCH lesions that we have studied to date warrants further investigation into their biological function to determine whether these cells are important in the pathogenesis of LCH.

Intralesional Injection of Interferon-α2b in Orbital Eosinophilic Granuloma

Considering the immune system dysfunction in unifocal orbital eosinophilic granuloma; possible complications of surgery, intralesional steroid, and radiotherapy; immunomodulatory and cytoreductive effects of interferon-α2b; and its safety profile in treatment of ocular surface neoplasia, intralesional interferon-α2b was first commenced in treatment of 3 cases (8-, 25-, and 43-year-old men) with biopsy proven orbital eosinophilic granuloma (2007-2014). Three intralesional injections of interferon-α2b (1.5 million units/0.5 ml) were given every other day. Cases 1 and 3 showed a rapid response with no recurrence in 86 and 29 months follow up. Case 2, however, required a second course of injection 2 months after the first one due to a partial response to the first injections with no recurrence at last follow up (57 months). Transient flulike symptom was the only side effect that was observed in Cases 2 and 3.

Granulomatous inflammation: The overlap of immune deficiency and inflammation

Pediatric granulomatous diseases constitute a heterogenous group of conditions in terms of clinical phenotypes, pathogenic mechanisms, and outcomes. The common link is the presence of multinucleated giant cells in the inflammatory infiltrate. The clinical scenario in which a tissue biopsy shows granulomatous inflammation is not an uncommon one for practicing adult and pediatric rheumatologists. Our role as rheumatologists is to develop a diagnostic plan based on a rational differential diagnostic exercise tailored to the individual patient and based mainly on a detailed clinical assessment. This chapter presents a comprehensive differential diagnosis associated with a classification developed by the authors. We describe with some detail extrapulmonary sarcoidosis, Blau syndrome, and immunodeficiency associated granulomatous inflammation, which in our view are the paradigmatic primary forms of granulomatous diseases in childhood. The other entities are presented only as differential diagnoses listing their most relevant clinical features. This chapter shows that almost all granulomatous diseases seen in adults can be found in children and that there are some entities that are essentially pediatric at onset, namely Blau syndrome and most forms of immunodeficiency associated granulomatous diseases.

Clinical characteristics and treatment outcome of Langerhans cell histiocytosis: 22 years' experience of 154 patients at a single center

Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology. Large studies by single institutions have been infrequent because of the rarity of the disease and the diversity of clinical manifestations. In this study, the clinical characteristics, prognostic factors, and treatment outcomes were analyzed. Medical records were analyzed retrospectively for the 154 patients diagnosed and treated with LCH at Seoul National University Children's Hospital from January 1986 to December 2007. A total of 154 patients were evaluated. One hundred and six patients (68.8%) had single system disease, 48 patients (31.2%) had multisystem disease. Twenty-nine patients (18.8%) had risk organ involvement. Twenty-nine patients (18.8%) relapsed and the overall survival (OS) of the total study population was 97.1% with a median follow-up period of 7.0 years. Patients less than 4 years old, with involvement more than 2 organs and with risk organ involvement showed lower progression free survival (PFS) (P = .001, <.001, and <.001, respectively). Estimated 10-year PFS of patients with and without risk organ involvement were 52.6% and 83.8%, respectively. Patients with single system LCH had excellent prognosis showing 89.6% of PFS and 100% of OS. Patients with multisystem LCH also had a high survival rate, although the incidences of relapse remain to be solved. A new strategy to decrease the incidence of relapse is needed.

Collagen remodeling and peripheral immune cell recruitment characterizes the cutaneous Langerhans cell histiocytosis microenvironment

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare and potentially fatal disorder of unknown etiology arising from the accumulation of epidermal Langerhans-like cells in bone, skin, or other tissues. Tissue damage and morbidity results from lesional cytokine release, and we sought to investigate the LCH microenvironment using a combination of histological stains and immunohistochemistry.

METHODS

CD1a immunoreactivity was used to identify lesional cells in archival paraffin-embedded samples of cutaneous LCH. A combined Orcein and Giemsa stain identified immune cells in general (particularly granulocytes and mast cells) and extracellular matrix (particularly elastic fibers), while CD3 and CD68 staining identified T cells and macrophages, respectively. Collagen synthesis was investigated with Herovici staining, which discriminates newly synthesized from mature collagen, while cross-polar microscopy of picrosirius-stained sections identified changes in matrix organization.

RESULTS

Immune cells were consistently identified at the periphery of cutaneous LCH lesions. We quantified an increased number of thickened and disorganized elastic fibers surrounding lesions and an absence of elastic fibers within lesions. Furthermore, lesions exhibited a decrease in mature collagen fibers and a loss of supporting collagen matrix within lesions and compromised collagen integrity in adjacent tissue.

CONCLUSIONS

Cutaneous LCH lesions are associated with the peripheral recruitment of a variety of immune cells and are consistently characterized by localized elastosis, collagen damage, and remodeling.

Langerhans cell histiocytosis of the orbit: five clinicopathologic cases and review of the literature

Langerhans cell histiocytosis (LCH) is a proliferation of Langerhans cells intermixed with inflammatory cells, in particular eosinophils, that may manifest as unisystem (unifocal or multifocal) or multisystem disease. Orbital involvement typically manifests as a solitary lesion that carries a favorable prognosis. We describe the clinical and histologic spectrum of LCH of the orbit in our five cases. One patient exhibited multifocal unisystem disease; the other four had a localized process. Typical histologic features included numerous histiocytes with varying degrees of giant cell formation and scattered eosinophilic granulocytes. The presence of Langerhans cells was confirmed by CD1a and S100 immunohistochemistry. Transmission electron microscopy demonstrated characteristic intracytoplasmic Birbeck granules. We review the different ophthalmic manifestations of LCH and treatment strategies. As LCH may solely involve the orbit, treatment is based on the degree of organ involvement. LCH should included in the differential diagnosis in tumors of the ocular adnexae, especially in young children.

Multifocal intraparenchymal Langerhans' cell histiocytosis concomitant with an arachnoid cyst in a child: case report and review of the literature

Langerhans' cell histiocytosis is a disease usually found in children and characterized by idiopathic proliferation of histiocytes in the reticuloendothelial system. Intracranial Langerhans' cell histiocytosis presenting as multifocal intraparenchymal lesions is very rare. In this article, the authors report on a 4-year-old boy diagnosed with multifocal intraparenchymal Langerhans' cell histiocytosis concomitant with an arachnoid cyst. After a series of laboratory examinations, the right frontal mass was surgically excised. Histological examinations confirmed the diagnosis of intracranial Langerhans' cell histiocytosis. The patient's intracranial hypertension symptoms were alleviated, and the remaining foci were treated by Langerhans' cell histiocytosis-directed standard chemotherapy. At the 8-month follow-up visit, no recurrence of the excised lesion was found, and no change in the size of other lesions was seen. Supratentorial intracerebral lesions with mass effect and enhancement have rarely been described; in this report, the histological features of and therapeutic options for such a case are discussed.

Lymphoproliferative conditions of the serosa

CONTEXT

A diverse and complex variety of lymphoproliferative diseases may involve the serosa, with widely differing clinical outcomes encompassing a spectrum of benign and malignant conditions.

OBJECTIVE

To review lymphoproliferative disease involving the serosa and to provide a practical approach to the evaluation of lymphoid and plasma cell infiltrates in the serosa, together with a review of various tumors and tumorlike conditions that may mimic lymphoproliferative disease.

DATA SOURCES

Analysis of published literature.

CONCLUSIONS

All forms of hematologic malignancy may involve the various serosal sites, although this is usually observed as secondary involvement in persons with known lymph nodal, marrow-based, or extranodal disease. Primary pericardial, pleural, and peritoneal lymphomas are rare; many nonneoplastic conditions may mimic lymphoma and a variety of nonhematolymphoid tumors may simulate hematologic malignancies. An understanding of the role of ancillary tests, together with an appreciation of their limitations, will prevent misdiagnosis.

Recent advances in the understanding of Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a proliferative disease of cells that share phenotypic characteristics with the primary antigen presenting cells of the epidermis. Its clinical manifestations are highly variable, extending from very benign forms to a disseminated, aggressive disease that causes significant mortality. Although many of the fundamental pathogenetic features of LCH have been enigmatic, recent advances have led to a much clearer understanding of the disease. In particular, careful molecular analyses of mouse models and human LCH samples suggest that LCH's cell of origin may not be the epidermal LC itself but a myeloid-derived precursor. Advanced genomic technologies have revealed the presence of activating, somatic BRAF mutations in the majority of patient specimens. Together, these observations have produced a new picture of LCH as a myeloid neoplasm. These advances are likely to have profound implications for the use of targeted therapeutics in LCH.

Langerhans cell histiocytosis in endoscopic biopsy: marked pinching artifacts by endoscopy

Various diseases should be considered when evaluating a suprasellar mass. Diabetes insipidus has been reported as the primary manifestation in a patient with Langerhans cell histiocytosis involving the hypothalamopituitary axis (HPA) and can be helpful for the diagnosis. The use of endoscopic biopsy for suprasellar masses has increased. However, as it is difficult to make a diagnosis with endoscopic biopsy because of the many artifacts, pathologists must be careful. Langerhans cell histiocytosis involving the HPA as solitary lesions is rare. We report the eighth case that provides neurologists, radiologists, and pathologists with various implications.

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.

Langerhan's cell histiocytosis: A single institutional experience

Background:

Langerhans cell histiocytosis (LCH) is a disease that primarily affects bone but can be associated with a clinical spectrum that ranges from a solitary bone lesion with a favorable natural history to a multisystem, life-threatening disease process.

Aim:

We analyzed our single institutional experience of managing children with LCH.

Settings and Design:

A total of 40 children of LCH, managed in tertiary cancer center in South India in the period from 2001 to 2005, were evaluated retrospectively.

Materials and Methods:

Clinicopathological features, laboratory findings, treatment modalities and long-term outcome were analyzed.

Results:

Children were aged between 2 months and 12 years, with a mean of 3 years. Majority of the children were below 5 years of age. Group B constituted a bulk of children. Disseminated cases were less (five patients). Liver function dysfunction was seen in four (10%) children. Pulmonary interstitial infiltrates were seen in two (5%) cases. Diabetes insipidus manifested in three patients. There was one death.

Conclusion:

A better understanding of the etiology and pathogenesis of LCH will result in more directed and efficacious treatment regimens.

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.

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.

Postchemotherapy histiocyte-rich pseudotumor involving the spleen

We report 2 cases of splenic postchemotherapy histiocyte-rich pseudotumor. Each patient had a history of diffuse large B-cell lymphoma, treated with multiagent chemotherapy. Computed tomography scans performed on both patients showed splenic masses. A positron emission tomography scan performed on 1 patient showed increased metabolic activity. The preoperative diagnosis in both patients was recurrent lymphoma, prompting splenectomy. The splenectomy specimens showed multiple, tan-white, firm nodules, up to 3.5 cm in diameter, that were histologically composed of central necrotic B cells (CD20+/CD3-), consistent with necrotic lymphoma, surrounded by numerous lipid-laden (xanthomatous) histiocytes. Clinical staging studies at the time of splenectomy showed no other sites of disease. We conclude that these histologic and immunophenotypic findings represent chemotherapy-induced tumor necrosis with a florid histiocytic reaction mimicking residual viable lymphoma. Others have used descriptive terminology or the term xanthomatous pseudotumor for these lesions that have been only rarely reported in the spleen previously.

Alopecia areata and multifocal bone involvement in a young adult with Hodgkin's disease

A 17-year-old girl presented with a 3 month history of alopecia areata, a generalized scaling skin, enlargement of the inguinal lymph nodes and severe back pain. Staging procedures revealed multifocal bone disease and generalized lymphadenopathy. The diagnosis of nodular sclerosing Hodgkin's disease was established by biopsies of the os ileum and a left inguinal lymph node. Complete clinical remission was achieved after 2 OPPA (vincristine, prednisone, procarbazine, and doxorubicin) and 4 COPP (cyclophosphamide, vincristine, prednisone, and procarbazine) cycles and treatment completed with involved-field irradiation. After the completion of therapy, skeletal lesions had mostly resolved or become sclerotic and the patient had normal hair regrowth and skin appearance. Conclusively, this case illustrates that alopecia areata may occur as a paraneoplastic phenomenon or an autoimmune process related to the deranged cellular immune system in children and adolescents with Hodgkin's disease.

Epidemiology, pathology, and genetics of histiocytic sarcoma in the Bernese mountain dog breed

Histiocytic sarcoma (HS) refers to a highly aggressive and frequently disseminated neoplastic disease belonging to the class of canine histiocytic proliferative disorders. Disseminated HS (previously called malignant histiocytosis) is highly breed specific, with Bernese mountain dogs (BMDs), rottweilers, and retrievers having a high prevalence with a frequency of approximately 25% in the BMD breed. We collected DNA samples and clinical information from 800 BMDs, of which 200 are affected by HS. To better characterize the physiopathology and epidemiology, an in-depth analysis of 89 BMD cases has been performed. The mean age of onset was 6.5 years, males and females being equally affected. The clinical features, biochemical parameters, and pathological features have been determined. The life span after diagnosis has been estimated to be 49 days. A large BMD pedigree of 327 dogs, 121 of which are affected, was assembled. Using a subset of 160 BMDs, encompassing 21 complete sibships, we now propose an oligogenic transmission mode of the disease. Whole-genome linkage scans as well as association studies using a case/control analysis, in parallel with expression profiling of neoplastic versus normal histiocytes, are all underway. Altogether, these complementary approaches are expected to localize the genes for HS in the BMD, leading to advances in our knowledge of histiocyte diseases in dogs and humans.

Langerhans' cell histiocytosis mimicking metastatic carcinoma of the lung

Langerhans' cell histiocytosis (LCH), previously known as Histiocytosis X, is characterized by abnormal accumulations of large mononuclear cells forming granulomas in various organs, mainly bone, skin and lung. This case report describes a 50-year-old man with a history of left pneumonectomy due to squamous cell carcinoma (SCC). During routine follow up, a CXR showed new parenchymal nodules in the right lung 57 months post treatment. Chest CT scan confirmed the presence of multiple parenchymal nodules. Open lung biopsy from the right upper lobe was performed and LCH was diagnosed. Re-analysis of the initial pneumonectomy specimen revealed no evidence of LCH in the surrounding lung tissue. On diagnosis, the patient stopped smoking and was treated with vinblastine and prednisolone for LCH. The nodules disappeared and have not returned in a further 18 months of follow up. In this patient LCH was diagnosed after SCC, which highlights that smoking-related diseases can be seen concomitantly or sequentially in the same patient.

Feline Pulmonary Langerhans Cell Histiocytosis with Multiorgan Involvement

Histiocytic proliferative diseases are uncommon in cats, although recently a progressive histiocytosis of the skin with terminal involvement of internal organs has been described in cats. Here we describe 3 cats (2 males and 1 female) with pulmonary Langerhans cell histiocytosis (PLCH). The cats were euthanized due to progressive respiratory clinical symptoms and deterioration. Macroscopically, extensive, multifocal to confluent, pulmonary masses were evident. Infiltration of pancreas (2 cats), kidneys (1 cat), liver (1 cat), as well as tracheobronchial, hepatosplenic, or mesenteric lymph nodes (2 cats) was observed by gross or microscopic examination. The infiltrating cells had histiocytic morphology with cytologic atypia characterized by anisokaryosis and hyperchromasia regionally within infiltrated tissues. Lesional histiocytes expressed vimentin, CD18, and E-cadherin. Expression of E-cadherin was usually markedly reduced in extra-pulmonary lesions, which is consistent with possible down-regulation of E-cadherin associated with distant migration from the lung. Transmission electron microscopy demonstrated intracytoplasmic organelles consistent with Birbeck's granules of Langerhans cells in the lesional histiocytes in all cats, except in the pancreas of one cat. These findings were compatible with PLCH with limited organ involvement of humans. It remains unproven whether feline PLCH represents a reactive or neoplastic cell proliferation.

Pulmonary Langerhans cell histiocytosis and other pulmonary histiocytic diseases: a review

CONTEXT

Pulmonary Langerhans cell histiocytosis is the most common and best known pulmonary histiocytic lesion; however, the realm of pulmonary histiocytic lesions also includes an assortment of uncommon diseases that may exhibit pulmonary involvement.

OBJECTIVE

To review pulmonary Langerhans cell histiocytosis and other pulmonary histiocytoses to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the author's institution.

CONCLUSIONS

This review discusses the most common pulmonary histiocytosis, pulmonary Langerhans cell histiocytosis, and also reviews the uncommon pulmonary histiocytic lesions, which are distinct from pulmonary Langerhans cell histiocytosis.

Langerhans cell histiocytosis

The clinical manifestations of Langerhans cell histiocytosis have been recognized for more than a century. For most of that time, physicians have viewed the disease from different perspectives, interpreting portions of its clinical spectrum as if they were distinct and unrelated entities. More recently, Langerhans cell histiocytosis has been unified into a single concept, though the disease continues to defy traditional classification. By most accounts, Langerhans cell histiocytosis appears to be a morphologically benign proliferation of inflammatory cells that escapes regulatory control mechanisms. Studies from patients with all stages of the disease, however, document clonal proliferation of immune processing cells (i.e., Langerhans cells), suggesting a malignant disease process. The most common ophthalmic manifestation of Langerhans cell histiocytosis is a solitary lesion of orbital bone, which typically responds to minimally invasive therapy. The best management of solitary orbital Langerhans cell histiocytosis is debatable and has been complicated by its recent designation as a risk factor for central nervous system disease. This article summarizes recent developments in understanding the biology of Langerhans cell histiocytosis, reviews its ophthalmic manifestations, prognosis, and the controversy surrounding treatment of isolated orbital disease.

IL-1 beta and PGE2 levels are increased in the saliva of children with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disorder mainly of children, whose pathogenesis is still unknown. Some studies have demonstrated that LCH lesions produce different cytokines abnormally that may be relevant to the pathogenesis of the disease. The purpose of this study was to investigate interleukin-1 beta (IL-1 beta) and prostaglandin E2 (PGE(2)) levels in saliva from children with different clinical subtypes of LCH. We studied 29 children with LCH: seven unifocal (Group I), seven multifocal (Group II), 15 multisystemic (Group III) and 12 healthy volunteers (Group IV). Salivary IL-1 beta and PGE(2) levels were significantly higher in LCH than in normal children. A multi-comparison test showed significantly (P < 0.001) higher levels of both IL-1 beta and PGE(2) in saliva from Group III compared with Groups II and I. A significant correlation (r = 0.05) between IL-1 beta and PGE(2) concentrations in saliva from each group was determined. Our findings demonstrated an association between high concentrations of salivary IL-1 beta and PGE(2) and advanced stages of the disease. This allows us to suggest that the abnormal amount of these factors in saliva may serve as a risk marker for disease progression.

Langerhans cell histiocytosis of the orbit 10 years after involvement at other sites

Langerhans cell histiocytosis within the orbit generally occurs in children and is marked by periorbital pain and swelling. Although these lesions respond well to minimal local curettage and concomitant corticosteroid injection, this disorder can be extremely aggressive and destructive. Recurrences usually occur within 12 months to 18 months after diagnosis. Herein, we discuss a patient who initially had mastoid and maxillary lesions and developed unilateral orbital involvement with periorbital pain and edema after a 10-year disease-free interval, and review other cases of late recurrence. The patient's symptoms resolved after curettage and injection of intralesional steroids. Clinicians should be aware that Langerhans cell histiocytosis may reappear at other sites, including the orbit, even after several years of quiescence.

Langerhans cell histiocytosis: a review of the current recommendations of the Histiocyte Society

Langerhans cell histiocytosis is a rare proliferative disorder where pathologic Langerhans cells accumulate in a variety of organs. Historically, the nomenclature regarding this entity has been confusing because the disease had been subcategorized simply based upon the different clinical manifestations. In the following article, we summarize the current recommendation of the Histiocyte Society regarding the classification, evaluation, prognosis, and treatment of Langerhans cell histiocytosis.

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.

Langerhans cell histiocytosis infiltration into pancreas and kidney

An 18-month-old male presented with a swelling of the neck for 2 months. A presumptive diagnosis of Langerhans cell histiocytosis (LCH) was made on fine needle aspiration cytology from the lymph node. The child received chemotherapy. He remained well for around 10 months, when he represented with loose stools, cough, and respiratory distress. His condition deteriorated over a few hours culminating in death. A partial autopsy revealed LCH infiltration in liver, pancreas, and kidneys along with bronchopneumonia. The pancreatic and renal infiltration by LCH is extremely rare.

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.

High serum values of soluble CD154, IL-2 receptor, RANKL and osteoprotegerin in Langerhans cell histiocytosis

BACKGROUND

To determine useful biochemical markers in Langerhans cell histiocytosis (LCH), we analyzed the serum levels of soluble CD154 (sCD154), IL2 receptor (sIL2-R), receptor activator of NF-kappaB ligand (sRANKL), and osteoprotegerin (OPG).

PROCEDURE

Our study included 46 newly diagnosed LCH patients (single-system multi-site (SM type): n = 20, and multi-system multi-site (MM type): n = 26) who were treated with the JLSG-02 protocol between 2002 and 2004. The median age of the patients was 3.8 years old (range 0-18). sCD154, sIL2-R, sRANKL, and OPG were measured by ELISA at diagnosis (n = 46) and after 6-weeks of induction therapy (n = 14).

RESULTS

The values of sCD154, sIL-2R, sRANKL, and OPG, and the sRANKL/OPG ratio in sera were significantly higher in patients with LCH compared with controls (1.83 +/- 1.38 vs. 0.22 +/- 0.16 ng/ml, P < 0.001; 1,600 +/- 1,060 vs. 420 +/- 160 pg/ml, P < 0.001; 1.72 +/- 1.20 vs. 1.04 +/- 1.09 pmol/L, P = 0.019; 6.34 +/- 2.94 vs. 3.71 +/- 2.03 pmol/L, P < 0.001; and 0.40 +/- 0.45 vs. 0.16 +/- 0.17, P = 0.023, respectively). Serum levels of sIL-2R were significantly elevated in the MM type compared with the SM type (2,050 +/- 1,060 vs. 870 +/- 340 pg/ml, P < 0.001). Serum OPG levels were also significantly elevated in the MM type compared with the SM type (7.58 +/- 2.72 vs. 5.13 +/- 2.69 pmol/L, P = 0.008) and negatively correlated with the number of bone lesions (r = -0.56, P = 0.007). In contrast, the sRANKL/OPG ratios were significantly higher in the SM type than the MM type (0.57 +/- 0.54 vs. 0.19 +/- 0.14, P = 0.002) and positively correlated with the number of bone lesions (r = 0.34, P = 0.040). In patients who responded to the induction therapy, serum levels of sIL-2R, sRANKL, and OPG, and the sRANKL/OPG ratio decreased significantly after the therapy (1,170 +/- 600 vs. 730 +/- 290 pg/ml, P = 0.029; 2.19 +/- 1.06 vs. 1.24 +/- 0.66 pmol/L, P < 0.001; 6.13 +/- 2.40 vs. 4.72 +/- 2.03 pmol/L, P = 0.040; and 0.57 +/- 0.52 vs. 0.41 +/- 0.37, P = 0.02, respectively). In the three patients who did not respond to the induction therapy, the serum levels of sCD154 increased significantly after the therapy (1.3 +/- 1.1 vs. 2.7 +/- 1.2, P = 0.004).

CONCLUSIONS

Serum levels of sIL-2R and sCD154 could be useful as indicators of inflammation and sRANKL/OPG ratios as markers of osteolytic activity in LCH patients.