Primary cerebral non-Langerhans cell histiocytosis: MRI and differential diagnosis

Neuroimaging in Pediatric Patients with Juvenile Xanthogranuloma of the CNS

BACKGROUND AND PURPOSE

Juvenile xanthogranuloma is a rare clonal, myeloid, neoplastic disorder. Typically, juvenile xanthogranuloma is a self-limited disorder of infancy, often presenting as a solitary red-brown or yellow skin papule/nodule. A small subset of patients present with extracutaneous, systemic juvenile xanthogranuloma, which may include the CNS. The goal of this retrospective study was to evaluate and categorize the neuroimaging findings in a representative cohort of pediatric patients with CNS juvenile xanthogranuloma.

MATERIALS AND METHODS

The brain and/or spine MR imaging data of 14 pediatric patients with pathology-proven juvenile xanthogranuloma were categorized and evaluated for the location; the signal intensity of xanthogranulomas on T1WI, T2WI, DWI, and a matching ADC map for the pattern and degree of contrast enhancement; and the presence of perilesional edema, cysts, or necrosis.

RESULTS

Fourteen pediatric patients (8 girls, 6 boys; mean age, 84 months) were included in the study. Patients presented with a wide variety of different symptoms, including headache, seizure, ataxia, strabismus, hearing loss, facial paresis, and diabetes insipidus. Juvenile xanthogranuloma lesions were identified in a number of different sites, including supra- and infratentorial as well as intracranial and spinal leptomeningeal. Five patients were categorized into the neuroradiologic pattern unifocal CNS juvenile xanthogranuloma; 8, into multifocal CNS juvenile xanthogranuloma; and 1, into multifocal CNS juvenile xanthogranuloma with intracranial and spinal leptomeningeal disease. In most cases, xanthogranulomas were small-to-medium intra-axial masses with isointense signal on T1WI (compared with cortical GM), iso- or hyperintense signal on T2WI, had restricted diffusion and perilesional edema. Almost all xanthogranulomas showed avid contrast enhancement. However, we also identified less common patterns with large lesions, nonenhancing lesions, or leptomeningeal disease. Four cases had an additional CT available. On CT, all xanthogranulomas were homogeneously hyperdense (solid component) without evident calcifications.

CONCLUSIONS

CNS juvenile xanthogranuloma may demonstrate heterogeneous neuroimaging appearances potentially mimicking other diseases, such as primary brain neoplasms, metastatic disease, lymphoma and leukemia, other histiocytic disorders, infections, or granulomatous diseases.

On the knowledge of solitary juvenile xanthogranuloma of the eyelid: a case series and literature review

PURPOSE

Solitary eyelid juvenile xanthogranuloma (JXG) is extremely rare, and there is limited literature on its clinical features and treatment outcomes. Here, we present a case series and comprehensive review of the literature on patients with isolated eyelid JXG.

METHODS

We systematically extracted data from our institution's records of isolated eyelid JXG cases and conducted a search for additional cases from the literature utilising the PubMed, Wanfang, and Chinese National Knowledge Infrastructure (CNKI) databases. Patients with JXG were analysed with respect to age, sex, clinical presentation, therapy, and outcome. Group comparisons were performed.

RESULTS

Thirty-two patients (including 13 at our institution and 19 from prior publications) were identified. The median age at first presentation was higher in current patients than in the patients from the published cases (median 9 years, range 1.2 to 47.0 years; median 2 years, range 0.5 months to 46.0 years, respectively, P = 0.014). Of the patients who had known characteristics, no significant differences were observed between the two groups in terms of sex, affected eye, eyelid site, type of cutaneous involvement, or duration of symptoms (each P > 0.05). Seventeen (54.8%) patients were male. The most common lesion location was the upper eyelid (n = 10, 62.5%). Twenty-four (75.0%) cutaneous lesions had full-thickness skin involvement; 8 (25.0%) subcutaneous masses had a chalazion-like appearance. Histologically, the JXG masses were characterised by Touton giant cells with inflammatory cells. Additionally, there was no significant difference in treatment modalities between the two groups (P = 0.072), and 24 (75.0%) patients underwent surgical excision. The overall recurrence-free survival was 3.6 to 52.8 (median 27.0) months in the current patients. For published cases with available follow-up information, there was no recurrence in 10 cases and improvement in 1 case, with a median follow-up of 9.5 months.

CONCLUSION

Solitary eyelid JXG is a rare clinical entity and should be included in the differential diagnosis of eyelid mass lesions in patients of all age groups. Surgical excision is often selected for efficient treatment and to obtain an excisional biopsy.

Fatal Disseminated Multiple Intracranial Juvenile Xanthogranuloma without Cutaneous and Other Organ Involvement: A Rare Case Report

INTRODUCTION

Juvenile xanthogranuloma (JXG) is a disorder of histiocytic proliferation that affects young children and usually presents as spontaneously regressing cutaneous lesions. JXG with systemic involvement is a rare entity associated with significant morbidity and mortality. Intracranial solitary lesions are uncommon, and when comorbid with multiple lesions of the central nervous system in young children, it has an extremely worse prognosis.

CASE PRESENTATION

We have reported here an unusual case of a 6-year-old boy who initially presented with the complaints of headache, vomiting, seizure, and speech disorder without cutaneous and other organ involvement and a neurological tendency to sleep. Acute hydrocephalus was detected in his brain CT. As an emergency intervention, ventriculo-peritoneal shunt operation was performed on the patient. His postoperative MRI revealed a disseminated intracranial disease involving the extensive dural, sellar-suprasellar region, the orbit, and the brain parenchyma. The patient accordingly underwent a pterional approach for open biopsy and for the mass tissue diagnosis. Histopathology reports were consistent with JXG. Unfortunately, the patient succumbed to the disseminated disease within 2 months of the JXG diagnosis.

CONCLUSION

JXG is a disorder that usually affects the skin. Intracranial lesion can be simple or have multiple involvement. This is a rare case of fatal disseminated multiple intracranial JXG without cutaneous and other organ manifestations. The presentation as a sellar-suprasellar, extensive dural, orbit, and parenchymal involvement at the time of diagnosis is unusual and rarely described in the literature.

A Subcutaneous Juvenile Xanthogranuloma in a 4-Year-Old Girl Who Presented with a Lower Eyelid Mass

Juvenile xanthogranuloma (JXG) is a relatively uncommon, benign, histiocytic proliferative cutaneous disorder that typically affects children, with the head and neck being the most common sites. The present case report describes an isolated subcutaneous JXG in a 4-year-old girl who presented with a circumscribed oval mass located in the lower eyelid of the right eye. This lesion was histologically diagnosed as JXG after a surgical resection of the mass.

BRAF V600E mutation in Juvenile Xanthogranuloma family neoplasms of the central nervous system (CNS-JXG): a revised diagnostic algorithm to include pediatric Erdheim-Chester disease

The family of juvenile xanthogranuloma family neoplasms (JXG) with ERK-pathway mutations are now classified within the "L" (Langerhans) group, which includes Langerhans cell histiocytosis (LCH) and Erdheim Chester disease (ECD). Although the BRAF V600E mutation constitutes the majority of molecular alterations in ECD and LCH, only three reported JXG neoplasms, all in male pediatric patients with localized central nervous system (CNS) involvement, are known to harbor the BRAF mutation. This retrospective case series seeks to redefine the clinicopathologic spectrum of pediatric CNS-JXG family neoplasms in the post-BRAF era, with a revised diagnostic algorithm to include pediatric ECD. Twenty-two CNS-JXG family lesions were retrieved from consult files with 64% (n = 14) having informative BRAF V600E mutational testing (molecular and/or VE1 immunohistochemistry). Of these, 71% (n = 10) were pediatric cases (≤18 years) and half (n = 5) harbored the BRAF V600E mutation. As compared to the BRAF wild-type cohort (WT), the BRAF V600E cohort had a similar mean age at diagnosis [BRAF V600E: 7 years (3-12 y), vs. WT: 7.6 years (1-18 y)] but demonstrated a stronger male/female ratio (BRAF V600E: 4 vs WT: 0.67), and had both more multifocal CNS disease ( BRAFV600E: 80% vs WT: 20%) and systemic disease (BRAF V600E: 40% vs WT: none). Radiographic features of CNS-JXG varied but typically included enhancing CNS mass lesion(s) with associated white matter changes in a subset of BRAF V600E neoplasms. After clinical-radiographic correlation, pediatric ECD was diagnosed in the BRAF V600E cohort. Treatment options varied, including surgical resection, chemotherapy, and targeted therapy with BRAF-inhibitor dabrafenib in one mutated case. BRAF V600E CNS-JXG neoplasms appear associated with male gender and aggressive disease presentation including pediatric ECD. We propose a revised diagnostic algorithm for CNS-JXG that includes an initial morphologic diagnosis with a final integrated diagnosis after clinical-radiographic and molecular correlation, in order to identify cases of pediatric ECD. Future studies with long-term follow-up are required to determine if pediatric BRAF V600E positive CNS-JXG neoplasms are a distinct entity in the L-group histiocytosis category or represent an expanded pediatric spectrum of ECD.

Intradural Juvenile Xanthogranuloma with Involvement of Multiple Nerve Roots: A Case Report and Review of the Literature

BACKGROUND

Juvenile xanthogranuloma (JXG) is a rare, non-Langerhans cell histiocytic disorder that primarily presents as multiple cutaneous lesions in young males. Solitary lesions in the spinal column are an especially rare presentation of this disease, and central nervous system involvement can portend a poor prognosis. We report an unusual case of an adult woman with an unresectable JXG of the lumbar spine. A review of the reported cases of thoracolumbar JXG and the current data regarding diagnosis and treatment are presented.

CASE DESCRIPTION

A 28-year-old woman presented with back pain and worsening lower extremity pain, numbness, and weakness. Magnetic resonance imaging demonstrated an enhancing lumbar mass. However, at surgery, no discrete mass was identified. Multiple roots were grossly enlarged, and electrical stimulation identified the L4 root with the most abnormal findings. Despite an attempt at debulking, most of the mass could not be safely removed. The patient experienced incomplete improvement of the symptoms postoperatively but elected to forgo chemotherapy. The 3-month follow-up imaging study showed active lumbar spinal disease, and imaging and follow-up examinations at 27 months revealed no changes. Her symptoms were satisfactorily controlled with conservative therapy.

CONCLUSIONS

JXG of the spine is a rare disease with nonspecific clinical and radiographic findings that can make it difficult to diagnose and dictates the use of immunohistochemical staining. If possible, total surgical resection will offer the best outcomes; however, other modalities such as chemotherapy can be viable alternatives or adjuvant modalities.

The clinical diagnosis and management options for intracranial juvenile xanthogranuloma in children: based on four cases and another 39 patients in the literature

BACKGROUND

Juvenile xanthogranulomas (JXGs) are uncommon non-Langerhans cell histiocytic proliferations which occur most often in children. Rare cases of intracranial JXGs in children have been reported. The precise treatment strategy for intracranial JXG with high fatality is still unclear.

METHOD

We present four cases of intracranial JXG with 2-6 years of follow-up. Review of the previous literature since 1980 revealed another 39 pediatric intracranial JXGs.

RESULTS

Their clinical characteristics varied significantly. Most intracranial JXGs presented in young children (88 %). Males (72 %) were affected more often than females. The differential diagnosis included two important components: the magnetic resonance imaging (MRI) characteristics and the pathohistiocytic markers. Statistical analysis suggested that there were no significant association between resection of intracranial lesions, multiple intracranial lesions, systematic lesions and clinic outcome (p = 0.12, p = 0.13, p = 0.60 respectively). Also, the manifestation with multiple intracranial lesions did not have a significant association with systematic JXG (p = 0.26).

CONCLUSIONS

We found no significant associations between clinic characteristics, surgical resection and outcome. When feasible, total surgical resection of intracranial lesion may be curative.

Fatal juvenile xanthogranuloma presenting as a sellar lesion: case report and literature review

INTRODUCTION

Juvenile xanthogranuloma (JXG) is a histiocytic condition in the spectrum of non-Langerhans histiocytosis that preferentially affects children. Rarely this condition can involve the central nervous system (CNS) with devastating consequences.

METHODS

The authors report the unique case of an 11-year-old child who initially presented with a sellar lesion without evidence of the cutaneous stigmata typical of JXG. She was later discovered to have JXG following initial diagnosis of granulomatous hypophysitis, with development of widespread intracranial disease and subsequent neurological deterioration. She underwent subtotal resection of her sellar lesion followed by whole brain radiation and systemic chemotherapy; however, she succumbed to her disseminated disease within 1 month of the JXG diagnosis.

CONCLUSIONS

This is a rare case of fatal disseminated intracranial JXG without cutaneous manifestations. Additionally, the initial presentation as a sellar lesion is particularly unusual and seldom described in the literature.

Spontaneous regression of infantile dural-based non-Langerhans cell histiocytosis after surgery: case report

The authors report the case of a large left occipital mass lesion in an 8-month-old boy who presented with seizure. Neuroimaging demonstrated an approximately 5-cm extraaxial tumor, and the patient underwent partial resection. The tumor was strongly attached to the tentorium and falx. In the postoperative course the residual lesion regressed spontaneously, and after 5 years only a slight residual tumor remained along the tentorium. Histopathological examination of the tumor revealed non-Langerhans cell histiocytosis (non-LCH). However, the tumor was not diagnosed as juvenile xanthogranuloma (JXG) because it lacked Touton giant cells. Hence, the authors described this lesion as a fibroxanthogranuloma. Most intracraniospinal non-LCHs have been reported as JXG; however, several cases of xanthomatous tumors with histopathological features resembling those of JXG have been described as fibrous xanthoma, xanthoma, fibroxanthoma, and xanthogranuloma. Among JXG and the xanthomatous tumors, a review of the literature revealed several cases of dural-based tumors; these dural-based tumors have had favorable courses, including the case described in this report. In addition, the patient in the present case experienced spontaneous regression of the residual tumor. The authors report this unique case and review the literature on isolated intracraniospinal non-LCHs, especially in cases of dural-based lesion.

Disseminated intracranial juvenile xanthogranulomatosis in a neonate without cutaneous lesions

Juvenile xanthogranuloma (JXG) is a rare disease that is part of a spectrum of histiocytic dendritic cell disorders. The authors report an unusual case of a 6-week-old male who presented with seizures. Neuroimaging revealed disseminated intracranial disease involving the optic apparatus, basal ganglia, lateral ventricles, and brainstem. The patient did not have any cutaneous lesions or evidence of extracranial disease. The patient underwent open biopsy of a large right midbrain lesion; pathology was consistent with JXG. He underwent postoperative chemotherapy and is doing well 7 months after surgery with regression of the intracranial lesions. To the best of the authors' knowledge, this is the first report of a neonate with disseminated intracranial JXG without cutaneous stigmata.

Diagnostic and management difficulties in a case of multiple intracranial juvenile xanthogranuloma

INTRODUCTION

Juvenile xanthogranuloma (JXG) preferentially occurs in childhood, and its characteristics have been thought to be benign and with slow growth. JXG is classified as an inflammatory disease, which forms multiple lesions in the patients' head, neck, and other organs and typically skin. JXG is rare, and few case reports have been published in the past, particularly with multiple intracranial lesions, which as in our case, is an extremely rare finding.

CASE

Patient is a 4-year-old boy who presented with polydypsia and polyuria for 1 year. He had been followed up only under l-deamino-8-D-arginine vasopressin until he started vomiting and his level of consciousness deteriorated. Then, magnetic resonance imaging (MRI) revealed multiple intracranial lesions. He underwent biopsy via small craniotomy, and pathology was confirmed as juvenile xanthogranuloma. The patient received chemotherapy, in complete compliance with JLSG-02 protocol.

FINDINGS

JXG is characteristic with homogenous enhancement with contrast matter and, most importantly, high intensity on diffusion-weighted image (DWI). The DWI was high when the degree of diffusion of water is restricted, as seen in inflammation and, additionally, the change of intensity after administration of steroid would reflect its anti-inflammatory nature. However, though the steroid therapy made high-intensity lesions decrease signal intensity, the size and the number of lesions did not change at all. As we expected, after we stopped steroid administration to the patient, his consciousness deteriorated and we found again the very-high-intensity lesions. We consider the intensity on DWI to reflect progression of the lesions.

Solitary juvenile xanthogranuloma mimicking intracranial tumor in children

Juvenile xanthogranuloma (JXG) is primarily a benign cutaneous disorder of non-Langerhans hystiocytic proliferation. Systemic involvement occurs in 4% of patients; isolated central nervous system (CNS) lesions are rare. We report solitary CNS-JXG lesions in two patients. A 3.5-year-old boy with a parietal-occipital lesion underwent total resection with no surgical morbidity and no recurrence at 16-month follow-up. A 3.5-year-old girl underwent subtotal resection of a tumor extending from the left Meckel's cave and invading the cavernous sinus and left orbit with extensive cranial nerve involvement. Tumor regrowth with leptomeningeal spread at 9-month and 12-month follow-up was managed with steroids and chemotherapy (vinblastine and later cladribine). We present our experience and review the literature pertaining to rare reports of solitary CNS-JXG.

Use of radiation in treatment of central nervous system juvenile xanthogranulomatosis

Juvenile xanthogranulomatosis (JXG) represents a subset of non-Langerhan cell histiocytosis that typically manifests in younger children with skin lesions. Unresectable central nervous system (CNS) disease is difficult to treat. We describe the case of a 13-year-old successfully treated with adjuvant radiation therapy for symptomatic intracranial and leptomeningeal JXG. An extensive literature review was performed to identify all previous CNS JXG cases utilizing radiation, of which six of eight total patients demonstrated temporary or long-term improvement of neurologic disease. This suggests that radiation should be considered in cases unresponsive to conventional treatment options.

Intracranial non-Langerhans cell histiocytosis presenting as an isolated intraparenchymal lesion

Non-Langerhans cell histiocytosis in the absence of cutaneous or other organ involvement is very rare. A Caucasian boy age 3 years 11 months presented with episodes of recurrent right-side seizures over 2 weeks. Brain CT and MR imaging showed a single enhancing left frontal lobe lesion. Stereotactic biopsy was performed and histological examination showed diffuse infiltrate of macrophages with foamy cytoplasm. Four months later there was recurrence of seizure activity despite anti-epileptic medication and a repeat MR scan showed a persistent enhancing lesion in the left frontal lobe. Histological examination of the resection specimen resembled juvenile xanthogranuloma (JXG) involving the central nervous system. In the absence of skin lesions a diagnosis of non-Langerhans cell histiocytosis was made. The child made a full recovery following surgery with resolution of his symptoms.

Solitary, extracutaneous, skull-based juvenile xanthogranuloma

We report a case of an 18-month-old female who presented an occipital bone lesion with progressive growth. Imaging studies showed a left extradural, skull-based tumor partially occupying the posterior fossa. Histopathological and immunohistochemical studies confirmed a juvenile xanthogranuloma (JXG). Partial surgical resection, chemotherapy, and conformational radiotherapy were used. Exclusive extracutaneous JXG with an intracranial, vertebral, or skull-based localization is extremely rare.

Intracranial solitary juvenile xanthogranuloma in an infant

BACKGROUND

Juvenile xanthogranuloma (JXG) is a disorder of histiocyte proliferation. Most cases present with a solitary cutaneous lesion. JXG with systemic involvement is rare with significant morbidity. Intracranial solitary JXG may be misdiagnosed before operation.

METHODS

A 5-month-old boy showed an elevated anterior fontanel but no other abnormalities on admission. Brain MRI showed a large mass in the right parietal region.

RESULTS

The tumor was removed with the encroached meninges. A JXG in the right parietal region was diagnosed pathologically.

CONCLUSION

Total excision of the tumor may be curative with a prerequisite of ensuring normal vital signs and nervous function.

Central nervous system juvenile xanthogranuloma with malignant transformation

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder that typically manifests in the skin. Here, we describe a patient with JXG diffusely involving the central nervous system (CNS), whose disease responded to therapy but subsequently underwent dissemination to the peritoneum and bone marrow. Repeat biopsy at dissemination revealed pleomorphic histiocytes with tetraploidy, suggesting evolution to a clonal histiocytic neoplasm. Despite further chemotherapy, the patient died of disease progression. This case highlights the clinical and pathological heterogeneity of JXG and the difficulty of treating multi-focal CNS disease.

Subdural effusion in a CNS involvement of systemic juvenile xanthogranuloma: a case report treated with vinblastin

Juvenile xanthogranuloma (JXG) is one of the most common non-Langerhans cell histiocytosis in children. Usually cutaneous, there are disseminated forms. However, neurological localization remains exceptional. A 7-month-old boy had been admitted for subdural effusion due to non-accidental head injury and skin nodular lesions. A biopsy of a skin lesion was considered suggestive of JXG. Skin, eyes, brain, lungs, liver, and testicles were involved. Systemic treatment of JXG was begun with vinblastine. It allowed the regression of skin, lung, and CNS lesions. At age of 11 years, he had not reappearance of the xanthogranuloma. This report emphasizes the possible presentation of xanthogranuloma with subdural effusions, the organs which should be examined in case of disseminated forms and the efficiency of vinblastin.

Intracranial solitary juvenile xanthogranuloma successfully treated with stereotactic radiosurgery

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis, which primarily affects the skin in young children. Although intracranial involvement is rare, it differs from other systemic JXG because its responsiveness to non-surgical treatment is poor. We present the case of a 2-year-old boy with left abducens nerve palsy. Imaging studies revealed a mass in the left Meckel's cave. Systemic examination showed no other abnormalities including his skin. After partial removal, JXG was diagnosed based on immunohistochemical evaluation. He underwent a stereotactic radiosurgery. Then, the mass decreased, and his abducens nerve palsy improved. This is the seventh case with isolated intracranial JXG, and the first case to be treated with radiosurgery. We consider that stereotactic radiosurgery is an excellent choice for treatment of intracranial JXG.

MRI features of neurodegenerative Langerhans cell histiocytosis

CNS complications of LCH include "space occupying" lesions corresponding to histiocytic granulomas and "neurodegenerative" presentation (ND-LCH) characterized by a progressive cerebellar ataxia. Studies analyzing specifically the MRI presentation of ND-LCH are scarce. We present here the MRIs of 13 patients registered as isolated ND-LCH. Posterior fossa was involved in 12 patients (92%), showing a symmetrical T2 hyperintensity of the cerebellar white matter areas in seven cases with a circumscribed T1 hyperintensity of the dentate nuclei in five cases, definite hyperintense T2 areas in the adjacent pontine tegmentum white matter in nine cases associated with a hyperintensity of the pontine pyramidal tracts in four cases. A cerebellar atrophy was noted in eight cases. The supratentorial region was involved in 11 patients, showing T2 hyperintense lesions in the cerebral white matter in eight cases and a discrete symmetrical T1 hyperintense signal in the globus pallidus in eight patients. A diffuse cortical atrophy was present in three cases and a marked focal atrophy of the corpus callosum in three cases. This series allows us to establish a not previously reported evocative semeiologic MR presentation to precisely orientate to the diagnosis of the pure neurodegenerative form of LCH.

Meningeal tumors of childhood and infancy. An update and literature review

Meningeal derived tumors of the first 2 decades of life are often diagnostically challenging due to the wide morphologic spectrum encountered and the rarity of most individual entities. The 2 most common patterns include the dural/leptomeningeal-based mass and neoplastic meningitis. Both primary and secondary meningeal presentations may occur, either early or late in the course of various meningothelial, mesenchymal, embryonal, glial, hematopoietic, histiocytic, melanocytic, and inflammatory tumors. As in other areas of pediatric pathology, there are significant differences between this patient cohort and adults, differences which will be emphasized in this review.

Isolated Central Nervous System Hemophagocytic Lymphohistiocytosis: Case Report

OBJECTIVE AND IMPORTANCE:

The first case of histologically proven hemophagocytic lymphohistiocytosis (HLH) isolated to the central nervous system (CNS) is reported. HLH affecting the CNS mimics several neurological disorders and may be misdiagnosed. The diagnostic and therapeutic problems of this disease are discussed.

CLINICAL PRESENTATION:

We report a case of a 5-year-old girl with a 2-month history of right hemiparesis. The initial magnetic resonance imaging scan mimicked the appearance of malignant glioma or cerebral infarction. By use of neuroimaging alone, it was extremely difficult to reach an appropriate diagnosis.

INTERVENTION:

Pathological examination of a surgical specimen of the lesion revealed histological characteristics typical of HLH. Because of the absence of both physical and blood chemical findings of systemic HLH, the patient was diagnosed as having HLH isolated in the CNS without systemic HLH. Radiotherapy with corticosteroid administration led to complete resolution of the CNS lesions, but the duration of remission was only 3 months. The patient died secondary to refractory progression of the CNS lesion.

CONCLUSION:

Radiotherapy with corticosteroid administration led to a complete resolution of the lesions, although for only a transitory remission. Although HLH is extremely rare, the existence of this disease isolated in the CNS should be documented, and further case accumulation and therapeutic investigations are needed to clarify the pathophysiological characteristics of this disease.

Xanthogranuloma of the Sciatic Nerve: Case Report

OBJECTIVE AND IMPORTANCE:

Xanthogranulomas involving the central or peripheral nervous system are extraordinarily rare. None have been reported in the lower extremity. Here, we report and characterize the first case of xanthogranuloma of the sciatic nerve.

CLINICAL PRESENTATION:

A 58-year-old woman presented with poorly localized right back and groin pain. Magnetic resonance imaging studies revealed an enhancing lesion of the sciatic nerve in the right gluteal region.

INTERVENTION:

The sciatic nerve xanthogranuloma was resected without complication.

CONCLUSION:

Our report indicates that xanthogranuloma, although extremely rare, may occur throughout the nervous system. Our evaluation demonstrates that such lesions involving the peripheral nervous system have similar pathological characteristics to xanthogranulomas that more commonly occur in the skin.

Preoperative stent placement for intradural vertebral artery stenosis from a rare xanthogranuloma

✓ In this report, the authors discuss a novel use of intradural vertebral artery (VA) stent placement to protect a tumor-encased vessel from injury during lesion resection. The tumor was a rare foramen magnum region xanthogranuloma and a component of Erdheim—Chester disease (ECD). This 64-year-old man presented with large masses encasing and compressing the intracranial segments of each VA. Preoperatively, a left VA stent was placed to protect the arterial wall during resection of the tumor. Histopathological study results on the subtotally resected mass were consistent with xanthogranuloma, a rare benign histiocytic tumor frequently occurring in patients with ECD. Further radiographic evaluation in the patient revealed an osteolytic lesion of the eleventh thoracic vertebra supporting the diagnosis of ECD disease. Based on this case study, the authors recommend the following: 1) tumor-encased vessels can be protected preoperatively by stent placement to assist with tumor debulking; and 2) patients diagnosed with a xanthogranuloma should be evaluated for multisystem involvement consistent with ECD.