Langerhans histiocytosis of temporal bone: role of magnetic resonance imaging

Neuroimaging features of CNS histiocytosis syndromes

Histiocytosis syndromes (HS) are group of heterogeneous disorders characterized by abnormal accumulation and infiltration of histiocytes, cells derived from hematopoietic cells of monocyte/macrophage lineage. Overall these disorders are rare. When they do occur they involve many organ systems including the central nervous system (CNS). While imaging findings can provide important clues, diagnosis of this disorder is challenging and definitive diagnosis often necessitates pathologic examination. In this review, we describe imaging features of HS involving the CNS, with the aim to increase our understanding of these disorders. The entities discussed in this review will include: Langerhans cell histiocytosis (LCH), Rosai-Dorfman Disease (RDD), Erdheim Chester Disease (ECD), hemophagocytic lymphohistiocytosis (HLH), and crystal-storing histiocytosis (CSH).

A systematic approach in the diagnosis of paediatric skull lesions: what radiologists need to know

Paediatric skull lesions are commonly identified on imaging. They can be challenging to image, given their location and size, and often require several imaging modalities to narrow down the differential diagnosis. Accurate diagnosis of these lesions is paramount because the clinical therapy can vary tremendously. In this review, we provide a simple and systematic approach to clinical-radiological features of primary skull lesions. We highlight the imaging characteristics and differentiate pathologies based on imaging appearances. We also accentuate the role of cross-sectional imaging in lesion identification and management implications.

Selected Giant Cell Rich Lesions of the Temporal Bone

Giant cell rich lesions of the temporal bone encompass a wide spectrum of disease that includes infectious, reactive, and neoplastic processes. When dealing with any lesion that can potentially involve bone, it is important to understand both the clinical presentation and to correlate the histologic findings with the radiologic imaging. This review discusses the clinical, the pathologic features including the differential diagnosis, and the treatment of some of the more commonly encountered giant cell rich entities in this region.

Non-odontogenic tumors of the facial bones in children and adolescents: role of multiparametric imaging

Tumors of the pediatric facial skeleton represent a major challenge in clinical practice because they can lead to functional impairment, facial deformation, and long-term disfigurement. Their treatment often requires a multidisciplinary approach, and radiologists play a pivotal role in the diagnosis and management of these lesions. Although rare, pediatric tumors arising in the facial bones comprise a wide spectrum of benign and malignant lesions of osteogenic, fibrogenic, hematopoietic, neurogenic, or epithelial origin. The more common lesions include Langerhans cell histiocytosis and osteoma, while rare lesions include inflammatory myofibroblastic and desmoid tumors; juvenile ossifying fibroma; primary intraosseous lymphoma; Ewing sarcoma; and metastases to the facial bones from neuroblastoma, Ewing sarcoma, or retinoblastoma. This article provides a comprehensive approach for the evaluation of children with non-odontogenic tumors of the facial skeleton. Typical findings are discussed with emphasis on the added value of multimodality multiparametric imaging with computed tomography (CT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI), positron emission tomography CT (PET CT), and PET MRI. Key imaging findings and characteristic histologic features of benign and malignant lesions are reviewed and the respective role of each modality for pretherapeutic assessment and post-treatment follow-up. Pitfalls of image interpretation are addressed and how to avoid them.

Imaging of pediatric head and neck masses

Medical imaging is an important tool in the evaluation and classification of pediatric head and neck masses. Such lesions may include congenital, inflammatory, infectious, vascular, or neoplastic processes. Ultrasound is often the first line modality in the workup of a neck mass in a child, followed by MRI or CT depending on the scenario. This information must be interpreted in the context of the patient's clinical history, physical examination, and demographics. The medical imaging workup of a neck mass in a child must be focused to yield the maximum information possible while minimizing the risks of radiation and sedation.

Head and neck manifestation and prognosis of Langerhans' cell histiocytosis in children

OBJECTIVE

To appreciate the several head and neck manifestations of Langherans' cell histiocytosis (LCH) in children and their multidisciplinary management and outcome.

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

Clinical reports of 42 patients with LCH treated in the Departments of Paediatric Haematology, Paediatric Oncology and Paediatric Otorhinolaryngology of a tertiary care center were analyzed. Only cases where the disease was localized to the head and neck were considered. The age at diagnosis, gender, clinical presentation, extension of disease as well as response to treatment and outcome were recorded from the charts of each of these patients.

RESULTS

Of the 42 patient charts reviewed, 31 (73.8%) presented with head and neck localization. 10 of these had an exclusive head and neck presentation. Multisystem LCH was mostly found in infants under 3-year-old (mean age: 2-year-old), and bony manifestations in older. All treatments delivered to patients were well-tolerated and the evolution good.

DISCUSSION AND CONCLUSION

Head and neck involvement is known to be very frequent in LCH. There is no consensus about treatment but authors highlight that all teams in charge of patients presenting with LCH agree to remain as conservative as possible. For solitary large lesions looking like a tumor which resection could result in functional or cosmetic morbidity, it would be important to get first a biopsy. For multisystemic LHC, therapeutic trials with chemotherapy agents still in process should increase the rate of success.

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.

Central diabetes insipidus: Is it Langerhans cell histiocytosis of the pituitary stalk? A diagnostic pitfall

Central diabetes insipidus (CDI) is a rare disorder that may be caused by a variety of diseases. In pediatric and adolescent patients the most common causes for CDI are Langerhans cell histiocytosis (LCH) and germinoma. To avoid a potentially hazardous biopsy of the hypothalamic pituitary region it is recommended to evaluate patients with CDI carefully to identify potential extracranial lesions. Since LCH is the most common systemic disease that may cause CDI, special focus is paid to the identification of LCH lesions. We report on a 9(1/2) year old girl who presented with central diabetes insipidus and a thickening of the pituitary stalk on magnetic resonance imaging. Diagnostic workup revealed a history of recurrent ear infections and a compressed 6th thoracic vertebral body on radiographs. Based on these findings LCH was anticipated. Upon growth of the pituitary stalk lesion the patient was treated with LCH standard chemotherapy. After an initial shrinkage of the lesion, a further growth of the pituitary stalk lesion was observed and the tumor was resected. Histopathology revealed germinoma. This case underscores the importance of a istopathologically proven diagnosis in patients with HPR tumors before the initiation of a specific therapy, even if the clinical findings are highly suggestive.

Lumps and Bumps on the Head in Children: Use of CT and MR Imaging in Solving the Clinical Diagnostic Dilemma

Lumps and bumps of the scalp are a common presenting complaint in children and often pose a diagnostic dilemma. These lesions can be difficult to image, with evaluation confounded by their small size. However, accuracy in diagnosis is critical because the diagnostic and therapeutic implications can vary significantly. The clinical examination can be helpful in developing the differential diagnosis and the imaging strategy. Often, however, a single imaging study is insufficient, and the radiologist finds it necessary to image with more than one modality to correctly diagnose a lesion and provide adequate information for the surgeon. Radiography and ultrasonography are often the initial screening diagnostic tests, followed by magnetic resonance (MR) imaging or computed tomography (CT) for more detail. Multidetector thin-section CT and thin-section MR imaging with surface coils are beneficial in the work-up of these small lesions of the head and neck. The use of newer MR imaging sequences such as heavily T2-weighted single-shot turbo spin-echo imaging and diffusion-weighted imaging can improve the characterization of difficult lesions. Familiarity with the variety of new imaging tools and techniques that are available can help characterize pediatric head and neck lesions and guide clinical management.

Langerhans' Cell Histiocytosis of the Labyrinth in Adults

OBJECTIVE

To describe and analyze three unusual cases of Langerhans' cell histiocytosis of the temporal bone in adults.

STUDY DESIGN

Retrospective case review.

SETTING

A tertiary referral center.

PATIENTS

Three adult patients with progressive sensorineural or mixed hearing loss, vertigo, and tinnitus as presenting symptoms of Langerhans' cell histiocytosis of the temporal bone.

INTERVENTION

Patients were evaluated by means of computed tomography and magnetic resonance imaging. All patients underwent complete surgical excision of the lesion via a transmastoid approach, extended to a translabyrinthine approach in one case. One patient with a multifocal disease underwent excision of a mandibular lesion 1 year later, followed-up by chemotherapy.

RESULTS

The Langerhans' cell histiocytosis was located adjacent to or within the area of the endolymphatic sac region in all cases. The middle ear was spared. Hearing function was preserved in the two patients who had serviceable hearing preoperatively. No complication occurred.

CONCLUSION

Langerhans' cell histiocytosis of the temporal bone is centered on or adjacent to the endolymphatic sac. The fact that the endolymphatic sac plays an immunologic role in the inner ear suggests that the infiltration of the Langerhans' cell may derive from it.