Soft tissue Langerhans cell histiocytosis with secondary bone involvement in extremities: evolution of lesions in two patients

[Bone and soft tissue Langerhans cell histiocytosis with multinucleated giant cells and BRAF V600E mutation]

Langerhans cell histiocytosis (LCH) is a heterogeneous disease characterized by proliferation of Langerhans cells and BRAF mutation in almost half of the cases. Bone involvement is common but large soft tissue disease is uncommon. We report a pediatric patient with a large tumor mass involving the left iliac bone and the adjacent soft tissue. The computed tomography scan showed an osteolytic lesion with soft tissue extension. Surgical curettage of the lesion was performed and the final histopathologic diagnosis was LCH with CD1a immunoreactivity in tumor cells. The molecular analysis revealed a BRAF V600E mutation. We discuss the histopathological and immunohistochemical differential diagnosis with histiocytosis other than LCH.

Unusual sites of bone involvement in Langerhans cell histiocytosis: a systematic review of the literature

Background

Langerhans cell histiocytosis (LCH) is a rare disease that originates from the uncontrolled proliferation and accumulation of bone marrow-derived immature myeloid dendritic cells. Dendritic cells are a type of histiocyte that play an important role in the human immune system and are found in the bone, skin, stomach, eyes, intestines, and lungs.

Objective

This systematic review aimed to collect and report published case reports of rare bone disease caused by LCH to avoid misdiagnoses or delays in diagnosis.

Methods

We systematically searched Scopus, PubMed, Embase, and Web of Sciences from August 1, 2000 to December 31, 2019. Studies reporting cases of LCH with rare bone involvement were included.

Results

We identified 60 articles including 64 cases. Of the identified cases, 31 (48.4%) involved children, and 33 (51.6%) involved adults. Additionally, 46.9% (30 individuals) were from Asian countries. The mean age of the children was 7.6 ± 4.3 years and that of the adults was 36 ± 12 years. The findings indicated that unifocal bone involvements were the most prevalent form of the disease (68.7%), and, overall, the skull and chest wall were the most commonly affected bones in both adults and children. The spine and long bones were the second most commonly affected bones in children, and the spine and jaw were the second most commonly affected bones in adults. Pain and swelling were the most frequent presenting signs among the investigated cases, and loss of consciousness, myelopathy, nerve palsy, visual loss, torticollis and clicking sounds were rare signs. Osteolytic lesions were the most frequent radiologic feature (62.5%), and intracranial hemorrhage, fluid–fluid level, dura and intracranial extension and pathologic fractures were rare radiological features. Total excision, curettage and observation in the unifocal group of patients and systemic chemotherapy in the other groups (i.e., multifocal and multisystem) were the most frequent management approaches. The recovery rates of the unifocal and multifocal groups were 77.3% and 81.8%, respectively, while that of the multisystem group was 55.5%. The rates of recurrence and mortality in the multisystem group were 11% and were higher than those in the other groups.

Conclusions

LCH is a rare disease that can affect any organ in the human body. However, bone is the most commonly involved organ, and rare bone involvements may be the first or only symptom of the disease due to the rarity of such lesions; a lack of familiarity with them may result in misdiagnosis or delayed diagnosis.

Soft tissue tumor diagnosis: A three prong approach utilizing pattern analysis, immunocytochemistry, and molecular diagnostics

Tissue diagnosis of a soft tissue neoplasm is of paramount importance for the development of an appropriate treatment plan. Biopsy technique including approach and biopsy method is important to the success of diagnosis and subsequent treatment. Histologic and cytologic diagnoses are difficult and complicated by the large number of soft tissue lesions described, distinctly different biopotential for morphologically similar lesions, often small biopsy specimen size, and the generally limited experience many pathologists have in the diagnosis of soft tissue neoplasms. While utilized less frequently than core-needle biopsies, fine-needle aspiration is a valuable initial approach for the classification of soft tissue neoplasms. The combination of pattern based morphologic analysis, immunohistochemistry, and molecular diagnostics represents a utilitarian and generally successful approach for the diagnosis of soft tissue lesions.

Langerhans Cell Histiocytosis with Atypical Intervertebral Disc and Sacroiliac Joint Involvement Mimicking Osteoarticular Tuberculosis in an Adult

BACKGROUND

Langerhans cell histiocytosis (LCH), typically found in children, is a rare single or multisystem disorder with a wide range of clinical and radiological manifestations. Unusual presentations of LCH are occasionally encountered and it may be difficult to distinguish LCH from an infection or a benign or malignant tumor.

RESULTS

A 35-year-old female presented with pain in her back and left buttock, malaise, and weight loss, with a duration of several months. Her laboratory test results were within the normal ranges except for the levels of acute phase reactants, which were elevated. Magnetic resonance imaging and computed tomography revealed a unilateral destructive sacroiliac lesion, and multiple vertebral lesions with adjacent discal involvement and extensive soft tissue extensions. She was initially misdiagnosed with multifocal osteoarticular tuberculosis. An open biopsy and joint curettage was performed. Histopathological examination showed that she had LCH.

CONCLUSION

To the best of our knowledge, this is the first case of LCH associated with a destructive unilateral sacroiliac lesion, discal involvement, and involvement of the adjacent vertebrae, in an adult patient; the LCH mimicked osteoarticular tuberculosis. Disease onset in adulthood is rare, and this can potentially delay diagnosis. Familiarity with the imaging features of unusual LCH manifestations is necessary to ensure accurate diagnosis and appropriate treatment.

Whole-body magnetic resonance imaging in children: technique and clinical applications

Whole-body MR imaging is being increasingly used in children to evaluate the extent of various oncologic and non-oncologic entities. The lack of exposure to ionizing radiation, excellent soft-tissue contrast (even without the use of contrast agents), and functional imaging capabilities make it especially suitable for screening and surveillance in the pediatric population. Technical developments such as moving table platforms, multi-channel/multi-element surface coils, and parallel imaging allow imaging of the entire body with multiple sequences in a reasonable 30- to 40-min time frame, which has facilitated its acceptance in routine clinical practice. The initial investigations in whole-body MR imaging were primarily focused on oncologic applications such as tumor screening and staging. The exquisite sensitivity of fluid-sensitive MR sequences to many different types of pathology has led to new applications of whole-body MR imaging in evaluation of multifocal rheumatologic conditions. Availability of blood pool contrast agents has allowed whole-body MR angiographic imaging of vascular malformations, vasculitides and vasculopathies. Whole-body MRI is being applied for delineating the extent and distribution of systemic and multifocal diseases, establishing diagnoses, assessing treatment response, and surveillance imaging. This article reviews the technique and clinical applications of whole-body MR imaging in children.