Spontaneous regression of orbital Langerhans cell granulomatosis in a three-year-old girl

Orbital histiocytosis and fibrohistiocytosis: the clinicopathological characteristics of 117 patients, over a decade of experience

PURPOSE

To describe the clinicopathological features of a large cohort of patients with orbital histiocytoses and fibrohistiocytosis, such as Langerhans cell histiocytosis (LCH) and non-LCH disorders, and correlate patients' clinical characteristics with their pathological diagnosis.

METHODS

In this retrospective study, medical records of patients presenting to Farabi Eye Hospital, a tertiary eye care center in Tehran, Iran, from 2010 until 2022, were reviewed. Patients' demographics, chief complaint, location and laterality of the tumor, best-corrected visual acuity, presence of bone erosion on imaging, and their pathological diagnosis were retrieved. Excisional biopsy was performed and evaluated through light microscopy and immunohistochemistry study for their respective markers, including CD1a, CD68, CD207, and S100.

RESULTS

A total of 117 patients with 11 pathological subtypes of histiocytoses and fibrohistiocyosis were identified, with 56.4% male and 43.6% female patients. The mean age at presentation was 23.4 years (range 1.5 months-73 years). Swelling and palpable mass were the most common chief complaints. LCH was the most common pathology (32.5%), followed by juvenile xanthogranuloma (26.5%) and adult xanthogranuloma (21.4%). Age, lesion location, and bone erosion had a statistically significant difference among the various diagnosed subtypes.

CONCLUSIONS

Histiocytoses and fibrohistiocytosis are diverse and rare disorders potentially involving multiple organ systems. Ophthalmic manifestations of these diseases are even more uncommon. We reviewed their orbital presentation along with their respective histopathological findings. Our results also suggested that an orbital CT scan can be of diagnostic value to discriminate LCH from other histiocytic pathologies.

Spontaneous regression of an orbital Langerhans cell histiocytosis after biopsy: A case report. Spontaneous regression of an orbital Langerhans cell histiocytosis

Langerhans histiocytosis or Langerhans cell histiocytosis (LCH) is a rare benign pathology representing less than 1% of orbital tumors. It can cause either localized or generalized lesions, leading to the destruction of hard and soft tissues. Eosinophilic granuloma is the most benign form and the predominant clinical presentation of LCH. We report a case of eosinophilic granuloma with orbital involvement in an 18-year-old male patient. Orbital radiotherapy was initially planned, but finally it was not performed due to a spontaneous regression of the lesion after the incisional biopsy. The presented case supports an expectant attitude given the possibility of a spontaneous regression after the biopsy, especially in small lesions. However, long-term follow-up is essential given the risk of recurrence.

Resolution and Re-ossification of Orbital Wall Langerhans Cell Histiocytosis Following Stereotactic Needle Biopsy

Introduction Langerhans cell histiocytosis (LCH) is a rare disease that encompasses a spectrum of clinical syndromes. It is characterized by the proliferation and infiltration of white blood cells into organs or organ systems. Reports of management of these lesions have included biopsy, resection, curettage, radiation and/or chemotherapy. Case Presentation A 40-year-old man presented with a history of right proptosis and retro-orbital pain and was found to have a lytic mass involving the greater wing of the sphenoid extending into the right orbit. A stereotactic needle biopsy using neuronavigation demonstrated this to be LCH. After no further treatment, the mass spontaneously resolved, with virtual normalization of the orbital MRI at 10 months following the needle biopsy. The bony defect of the temporal bone caused by the mass also re-ossified following the needle biopsy. Discussion This report highlights the potential for an isolated LCH lesion to regress after simple needle biopsy, an outcome only rarely reported previously. Thus, expectant management of such lesions following biopsy or initial debridement should be considered prior to proceeding with additional treatment.

Clinical spectrum and management outcomes of Langerhans cell histiocytosis of the orbit

Purpose

To describe the clinical spectrum and management outcomes of Langerhans cell histiocytosis (LCH) involving the orbit.

Methods

Retrospective review of patients with orbital LCH presenting at the Sankara Nethralaya, Chennai, India, over the past 15 years. Demographic details, presenting features, radiology, histopathology, immunohistochemistry, and management outcomes were analyzed.

Results

Nine patients were reviewed. The mean age of presentation was 10.12 ± 14.31 years (range: 6 weeks to 35 years). Eyelid swelling was the most common presenting feature (4, 44.4%), followed by proptosis (3, 33.3%). The mean duration of the presentation was 2.21 ± 2.77 months. Radiological investigations revealed orbital roof osteolytic defects in six (66.6%) patients. Six patients underwent near-complete excision of the mass while three underwent incisional biopsy. Histopathology revealed histiocytes with nuclear grooving and numerous eosinophils characteristic of LCH. The cells were positive for CD1a and S 100 antigens. None of the patients had any systemic involvement. Three received systemic steroids and four received systemic chemotherapy. At a mean follow-up of 17.85 ± 23.46 months, all had complete remission without any signs of recurrence. One patient was lost to follow-up after near-complete excision while one adult patient with a mass in the intraconal space had no recurrence after near-complete excision.

Conclusion

LCH is a rare disorder of the orbit that commonly occurs in children and should be considered a differential for osteolytic lesions involving the orbit. All patients should undergo a systemic evaluation to rule out multifocal disease. The treatment depends upon disease extent and risk factors.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management and Outcome of Patients With Langerhans Cell Histiocytosis and Single-Bone CNS-Risk Lesions: A Multi-Institutional Retrospective Study

BACKGROUND

Children with Langerhans cell histiocytosis (LCH) and single-bone CNS-risk lesions have been reported to be at increased risk of diabetes insipidus (DI), central nervous system neurodegeneration (CNS-ND), and recurrence of disease. However, it is unknown whether the addition of chemotherapy or radiotherapy changes outcomes in these patients.

METHODS

Ten pediatric institutions across North America and Europe contributed data of their patients with LCH and single-bone CNS-risk lesions. Clinical information on age, sex, specific craniofacial site involvement, and intracranial extension at diagnosis, therapy, and disease course was collected for all eligible patients.

RESULTS

The final analysis included 93 eligible children who were either treated with systemic therapy (chemotherapy, chemo-radiotherapy, or radiotherapy) or local therapy (biopsy, curettage, and/or intralesional steroids). Fifty-nine patients had systemic and 34 had local therapy. The 5-year event-free survival (EFS) and overall survival (OS) were 80 ± 5% and 98 ± 2% in the systemic therapy group versus 85 ± 6% and 95 ± 5% in the local therapy group. There was no statistically significant difference between either group with regard to EFS (P = 0.26) and OS (P = 0.78). On multivariable analysis, there was no significant difference among the two treatment groups after adjusting for site and intracranial soft tissue extension, nor any trend favoring systemic therapy (HR = 2.26, 95% CI = 0.77-6.70; P = 0.14).

CONCLUSION

Systemic therapy may not reduce the risk of recurrence or late sequelae in children with LCH and single-bone CNS-risk lesions as compared to local treatment.

Approaches to treatment of unifocal langerhans cell histiocytosis: is biopsy alone enough?

BACKGROUND

Langerhans cell histiocytosis (LCH) is a variable disorder involving either single bone or multiorgan systems. The most effective treatment of unifocal osseous lesions is debated in the literature. This study describes the treatment approaches for LCH and demonstrates the effectiveness of biopsy in providing symptom resolution.

METHODS

Records of 61 patients diagnosed with LCH at a single institution over an 11-year period were reviewed. Thirty-nine patients with biopsy-confirmed diagnoses of unifocal osseous LCH were included in the analysis. At this institution, lesions are surgically treated by incisional biopsy, trocar biopsy, or curettage and grafting. Patients receive chemotherapy on a case-by-case basis, depending on the lesion location and size. A Kaplan-Meier analysis was used to compare time with symptom resolution across treatment groups.

RESULTS

In the 39 patients with unifocal osseous LCH, treatment approaches included incisional biopsy (n = 18, 46.15%), trocar biopsy (n = 8, 20.51%), incisional biopsy and chemotherapy (n = 8, 20.51%), and biopsy with bone grafting (n = 5, 12.82%). The median time from biopsy to symptom resolution was 5.43 weeks, with an average length of follow-up of 1.59 years. The median time to symptom resolution was 3.86 weeks with incisional biopsy, 5.43 weeks with biopsy and grafting, 5.64 weeks with trocar biopsy, and 16.57 weeks with biopsy and chemotherapy. Overall, there was a significant difference (P = 0.0262) in the time to symptom resolution across the different treatment approaches. Time to symptom resolution was significantly different between incisional biopsy and chemotherapy treatment compared with the incisional biopsy treatment (P = 0.0027), as well as biopsy with grafting treatment (P = 0.0264).

CONCLUSIONS

Symptom resolution occurred rapidly after biopsy and did not significantly differ among patients who received incisional biopsy, trocar biopsy, or biopsy with grafting. Unifocal osseous LCH likely does not require aggressive surgical or medical management. Biopsy alone both confirms the diagnosis and precedes a predictable resolution of symptoms.

LEVEL OF EVIDENCE

Level III, retrospective comparative therapeutic study.

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.

[Orbital location of multivisceral Langerhans-cell histiocytosis]

Langerhans-cell histiocytosis is a rare disease accounting for less than 1% of orbital tumours. We report the case of an 18-month-old infant presenting with exophthalmos of the left eye lasting for 3 months in a context of deterioration of the general condition, polydipsia, and polyuria. The computed tomographic scan revealed an orbital cellular mass with a lytic bone lesion within the orbital roof and infiltration of frontopalpebral soft tissue. In addition, other secondary lesions were found at the skull, ribs, skin, liver, and spleen. The cytological study after biopsy showed infiltrates of histiocytes derived from Langerhans cells. Because the disease was multivisceral, the child was treated with chemotherapy (vinblastine) combined with a steroid and progressed well. At 30 months of follow-up, there was no evidence of recurrence or systemic involvement.

[Surgical management of solitary eosinophilic granuloma of the calvaria. Two case reports]

Langerhans cell histiocytosis is a systemic disease resulting from the oligoclonal proliferation of Langerhans cells, occurring most commonly in children and young adults. The focal form of the disease, also known as eosinophilic granuloma, most frequently involves the calvaria. We present two cases of calvarial eosinophilic granulomas that were surgically removed. These tumors are reputed to have an excellent prognosis, even if local recurrences and systemic dissemination can occur during the follow-up. The authors discuss the pathogenesis and the evolutive profile but also the therapeutic management of solitary eosinophilic granuloma of the calvaria.

Langerhans cell histiocytosis mimicking preseptal cellulitis

A 7-year-old girl presented with signs of preseptal cellulitis that initially responded to antibiotics but then relapsed. Computed tomography scan revealed a cystic lesion in the preseptal tissues with associated soft tissue swelling and lacrimal gland inflammation. Anterior orbitotomy revealed a hemorrhagic-appearing lesion extending from the preseptal tissues subperiosteally along the roof of the orbit. The lesion was excised and histopathology and immunohistochemical staining confirmed a diagnosis of Langerhans histiocytosis. Management of this condition depends on the extent of systemic involvement, with single bony lesions usually pursuing a benign course and often spontaneously regressing or resolving following biopsy. This case serves to highlight that an underlying cause for preseptal cellulitis should be sought and if there are relapses or inadequately resolving signs of preseptal cellulitis, then prompt investigation to rule out other causes is required.

Intralesional corticosteroid therapy for mandibular Langerhans cell histiocytosis preserving the intralesional tooth germ

BACKGROUND

Langerhans cell histiocytosis (LCH, histiocytosis X, ICD-O 9751/1) refers to a neoplastic proliferation of Langerhans cells. The course of the disease determines the treatment and prognosis. Solitary forms (eosinophilic granuloma) and limited multilocational lesions may be treated successfully with local surgical intervention and intralesional corticosteroid injection.

PURPOSE

Presentation of our own case will review LCH, a very rare disease entity in oral-facial surgery and will document that intralesional corticosteroid injection is a less invasive alternative to the classical surgical curettage and local radiation therapy.

CASE REPORT

In a 10-year-old boy, a progressive, pressure-sensitive swelling had developed within 1 week in the left paramandibular and submandibular area. Dental status was good. Diagnostic imaging demonstrated a diffusely contoured osteolysis caudal to tooth germ 37 with infiltration of the adjacent chewing muscles. Histological evaluation of the intraoral biopsy sample established an LCH. Having excluded a multifocal form of LCH, treatment with intralesional injection of methylprednisolone 200 mg was chosen. Symptoms of pain were quickly relieved and the swelling receded. Follow-up visits 6 weeks, 3 months, and 6 months after corticosteroid injection revealed continuous regression of mandibular osteolysis. OPG and MRI after 17 months demonstrated a good osseous consolidation in the left mandibular angle area, but a still discernible bone marrow edema. Development of the intralesional tooth germ 37 appeared normal.

CONCLUSION

Local surgical interventions continue to be central to the range of accepted therapeutic measures. However, the increasing numbers of reports on the successful treatment of solitary LCH by intralesional corticosteroid injection suggest that this treatment option should be considered especially in children to preserve tooth germs.

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.

Craniospinal Langerhans cell histiocytosis in children: 30 years' experience at a single institution

OBJECTIVES

The goal of this study was to review a large series of patients with Langerhans cell histiocytosis (LCH) who had craniospinal lesions to assess the long-term course, outcome, and efficacy of treatment of the disease.

METHODS

Forty-four patients with LCH who presented to a single pediatric neurosurgical department between 1976 and 2006 were retrospectively reviewed.

RESULTS

This series included 29 boys and 15 girls, ranging in age from 2 months to 13 years, with a mean follow-up duration of 4.5 years. Twenty-seven patients (61%) had unifocal bone lesions, 12 (27%) had multifocal bone disease, 2 (5%) had solitary hypothalamic-pituitary axis lesions, and 3 (7%) had multiple organ involvement at presentation. Five (19%) of the 27 patients with unifocal bone disease and 4 (33%) of the 12 patients with multifocal bone disease had delayed development of new bone lesions during the follow-up period. The time to development of new bone lesions ranged from 1 month to 1 year. Two of the 3 patients with multiple-organ LCH died. Patient age < or = 2 years at the time of initial presentation was a risk factor for both initial multifocality and eventual dissemination. In all patients with initial multifocal bone involvement or later dissemination of unifocal bone disease, LCH was controlled by chemotherapy, except for 2 who were treated by surgery alone. Three patients had histological evidence of spontaneous resolution of their lesions.

CONCLUSIONS

Patients with unifocal LCH can be effectively treated with surgery alone. Very young patients are more likely to have multifocal disease and disseminations, and will usually require chemotherapy to control their disease. Spontaneously regressing lesions need not be resected; however, a biopsy procedure can be performed for diagnostic purposes.

MRI, CT, scintigraphic and histological features of a vanishing scapular eosinophilic granuloma

INTRODUCTION

Vanishing bone lesions have been previously described in patients with eosinophilic granuloma.

MATERIALS AND METHODS

We present the magnetic resonance imaging, computed tomography, scintigraphic and histological findings in a 26-year-old woman presenting with a painful scapular mass that subsequently completely resolved, compatible with the diagnosis of eosinophilic granuloma.

CONCLUSION

Clinicians should be aware of the multimodality appearances and natural history of resolving eosinophilic granuloma.

Ocular adnexal Langerhans cell histiocytosis clinical features and management

PURPOSE

To review the clinical features, investigations, management, and outcomes of Langerhans cell histiocytosis (LCH) with ocular adnexal involvement.

MATERIALS AND METHODS

Retrospective, non-comparative, chart review of 30 patients with LCH involving the ocular adnexa treated at 6 major Australian hospitals. Clinical features, imaging findings, treatment, local and distant recurrence and outcome were evaluated.

RESULTS

Twenty-four patients (80%) were male with a mean age of presentation of 9.5 years. Females presented at an earlier age (mean age 4.1 years) with more severe involvement. Eighty percent of the cases presented with periorbital swelling. Computed tomography usually showed destructive osteolytic lesions centred on the frontal bone. Twenty-four patients (80%) had unifocal, unisystem disease. From this group, none of 13 treated with excision alone had recurrence whereas 2 of 6 treated with excision followed by chemotherapy recurred.

CONCLUSIONS

Unifocal, unisystem LCH often presents to the ophthalmologist and can usually be diagnosed on clinical and imaging grounds. Computed tomography and magnetic resonance imaging are complementary imaging studies. Biopsy is essential to confirm diagnosis. Unifocal, unisystem disease can be treated with local excision and curettage. Incomplete excision, recurrent disease or multifocal disease may require systemic chemotherapy.

Langerhans cell histiocytosis of the orbit: a need for interdisciplinary dialogue

PURPOSE

To explore specialty-related perceptions and treatment strategies in Langerhans cell histiocytosis (LCH) of the orbit.

DESIGN

A perspective.

METHODS

We reviewed the reported ophthalmic experience with unifocal LCH of the orbit, analyzed current oncologic clinical trial protocols, and provided a brief summary of contemporary knowledge and theory of LCH pathogenesis.

RESULTS

Ophthalmic literature indicates that unifocal LCH of the orbit is usually responsive to local intervention. Current international oncologic protocols identify orbital LCH as a "central nervous system-risk" lesion (at risk for delayed-onset diabetes insipidus) and mandate a 6-month course of chemotherapy. Analysis suggests that the latter strategy is based on cases of orbital involvement in multifocal and multisystem disease. The pathologic Langerhans cell continues to define and unite the LCH variants, but cytokine activation of that cell may be an earlier pathogenetic determinant. Despite a common cellular mediator, LCH may be a heterogeneous process, with severity related to varied "upstream" trigger events.

CONCLUSION

Treatment perspectives in LCH are influenced by dissimilar patient encounters and varied interpretations of the basic disease process. Pending documentation of linkage between unifocal orbital LCH and diabetes insipidus, we recommend local intervention, with systemic treatment reserved for incomplete response or local reactivation or the appearance of lesions elsewhere. LCH underscores the need for close interaction between specialists with intersecting clinical interests.

Histiocytose langerhansienne à localisation orbitaire

PURPOSE

Langerhans' cell histiocytosis is a rare disease representing less than 1% of orbital tumors.

METHODS

We report a case of Langerhans cell histiocytosis with orbital involvement in a 9-year-old boy. He presented with an inflammatory swelling if the left lateral orbital wall. The computed tomographic scan revealed an orbital cellular mass with lytic bone lesion within the orbital roof and intracranial enlargement.

RESULTS

The cytological study after a biopsy showed infiltrates of histiocytes derived from Langerhans cells. Diagnosis was confirmed by immunohistochemistry, which identified positive staining with anti-S100 and anti-CD1a antibodies. The rapidly expanding orbital tumor, posing a threat of ocular compression as well as intracranial spreading, was treated by chemotherapy (Vinblastine) combined with a steroid.

CONCLUSION

A 2-year follow-up showed no evidence of recurrence or systemic involvement. According to this observation, the authors describe the clinicopathological and histological features of orbital involvement in Langerhans cell histiocytosis.

Biopsy-confirmed spontaneous resolution of orbital langerhans cell histiocytosis

A 17-year-old boy presented with a left upper lid swelling, headaches and diplopia. An orbital computerized tomography (CT) scan showed a mass in the left lacrimal fossa eroding bone and extending into the temporalis fossa and intracranially. An urgent biopsy without curettage was carried out and showed Langerhans cell histiocytosis. He was otherwise well and no other lesion was found. He was therefore observed and reviewed regularly. During follow-up it was noted that the mass was reducing in size. Five months after the initial biopsy a further procedure, involving curettage and an intralesional steroid, was carried out at a tertiary referral center. Histology of the material obtained showed no remaining evidence of Langerhans cell histiocytosis. Spontaneous resolution of orbital Langerhans cell histiocytosis has been described clinically and radiologically. This is the first case of spontaneous resolution to be confirmed histologically.

Eosinophilic Granuloma of the Orbit: Understanding the Paradox of Aggressive Destruction Responsive to Minimal Intervention

PURPOSE

To describe the findings and outcomes in eosinophilic granuloma (unifocal Langerhans-cell histiocytosis [LCH]) of the orbit and to explain the paradox of aggressive bone destruction responsive to minimal intervention.

METHODS

Retrospective, consecutive, interventional case series of patients treated from 1985 to 2001. Minimum inclusion criteria were demonstration of CD1a positivity or Birbeck granules, treatment by a single surgeon, systemic evaluation by a pediatric oncologist, and follow-up of 12 months. A pathogenetic construct was assembled from general LCH concepts and the specific orbital findings.

RESULTS

Seven patients met study criteria. All were male, 2 to 16 years of age. All had eyelid or forehead swelling and osteolytic defects, with symptoms of 2 to 6 weeks' duration. All underwent incisional biopsy, with frozen-section examination suggestive of LCH in 6 of 7 cases. The 2 earliest patients received low-dose irradiation after simple biopsy. The 5 most recent patients had subtotal curettage at the time of biopsy; 4 of 5 received simultaneous intralesional corticosteroid injection. In all cases, systemic evaluation showed no other focus of LCH, reossification was timely, and no local recurrence or additional focus was noted in follow-up of 1 to 17 years.

CONCLUSIONS

Transient immune dysfunction may provoke the cytokine-mediated proliferation of pathologic Langerhans cells within the hematopoietic marrow of the anterolateral frontal bone. These cells cause osteolysis through elaboration of interleukin-1 and prostaglandin E2. Corticosteroids can inhibit the mediators. We recommend incisional biopsy, frozen-section provisional diagnosis, subtotal curettage, intralesional corticosteroid instillation, postoperative systemic evaluation, and long-term surveillance.