Orbital histiocytosis; From A to Z

PURPOSE

Histiocytosis is one of the most challenging diseases in medical practice. Because of the broad spectrum of clinical manifestations, systemic involvements, unknown etiology, and complex management, different types of histiocytosis are still a big question mark for us. Orbital histiocytosis is characterized by the abnormal proliferation of histiocytes in orbital tissues. It could affect the orbit, eyelid, conjunctiva, and uveal tract. Orbital histiocytosis can cause limited eye movement, proptosis, decreased visual acuity, and epiphora. In this study, we review the novel findings regarding the pathophysiology, diagnosis, and treatment of different types of histiocytosis, focusing on their orbital manifestations.

METHOD

This review was performed based on a search of the PubMed, Scopus, and Embase databases or relevant published papers regarding orbital histiocytosis on October 9th, 2023. No time restriction was proposed, and articles were excluded if they were not referenced in English.

RESULTS

391 articles were screened, most of them being case reports. The pathophysiology of histiocytosis is still unclear. However, different mutations are found to be prevalent in most of the patients. The diagnostic path can be different based on various factors such as age, lesion site, type of histiocytosis, and the stage of the disease. Some modalities, such as corticosteroids and surgery, are used widely for treatment. On the other hand, based on some specific etiological factors for each type, alternative treatments have been proposed.

CONCLUSION

Significant progress has been made in the detection of somatic molecular changes. Many case studies describe various disease patterns influencing the biological perspectives on different types of histiocytosis. It is necessary to continue investigating and clustering data from a broad range of patients with histiocytosis in children and adults to define the best ways to diagnose and treat these patients.

Extracorporeal Photopheresis in Dermatological Diseases

Extracorporeal photopheresis (ECP) is an apheresis procedure that is conventionally used as a first-line treatment for cutaneous and leukemic subtypes of T-cell lymphoma, such as Sezary's syndrome and mycosis fungoides. Over the past three decades, its immunotherapeutic properties have been tested on a variety of autoimmune conditions, including many dermatologic diseases. There is ample evidence of ECP's ability to modify leukocytes and alter cytokine production for certain dermatologic diseases that have been refractory to first-line treatments, such as atopic dermatitis. However, the evidence on the efficacy of ECP for the treatment of these dermatologic diseases is unclear and/or lacks sufficient evidence. The purpose of this paper is to review the literature on the utilization and clinical efficacy of ECP in the treatment of several [autoimmune] dermatologic diseases and discuss its applications, guidelines, recommendations, and future implementation for dermatologic diseases.

Systemic therapy of necrobiotic xanthogranuloma: a systematic review

BACKGROUND

Even though a plethora of systemic therapies have been proposed for necrobiotic xanthogranuloma (NXG), there is no systematic review on this topic in literature.

OBJECTIVE

To review all existing literature on the systemic therapy of NXG in order to identify the most effective therapies.

METHODS

All reported papers in the literature were screened for systemic treatments of NXG. Papers without proper description of the therapies, papers describing topical therapy, and articles without assessment of effectiveness were excluded. Subsequently, we analyzed 79 papers and a total of 175 cases.

RESULTS

The most effective treatments for NXG are intravenous immunoglobulins (IVIG), corticosteroids, and combination therapies including corticosteroids.

CONCLUSIONS

Corticosteroids and IVIG should therefore be considered first-line treatments in patients with NXG.

A Multicenter Cross-Sectional Study and Systematic Review of Necrobiotic Xanthogranuloma With Proposed Diagnostic Criteria

Importance

Necrobiotic xanthogranuloma (NXG) is a non-Langerhans cell histiocytosis classically associated with paraproteinemia attributable to plasma-cell dyscrasias or lymphoproliferative disorders. Despite the morbidity of NXG, the literature is limited to case reports and small studies, and diagnostic criteria are lacking.

Objective

To evaluate the characteristics of NXG and propose diagnostic criteria.

Design, Setting, and Participants

This multicenter cross-sectional study was conducted at tertiary academic referral centers and followed by a systematic review and a consensus exercise. The multicenter cohort included patients with NXG diagnosed at the Brigham and Women's and Massachusetts General Hospitals (2000-2018), the University of Iowa Hospitals and Clinics (2000-2018), and the University of Pennsylvania Health System (2008-2018). The systematic review was conducted in 2018 and included patients with NXG identified in the Cochrane, Ovid EMBASE, PubMed, and Web of Science databases. The consensus exercise was conducted by 8 board-certified dermatologists to identify diagnostic criteria.

Main Outcomes and Measures

Demographic factors, comorbidities, clinical features, and treatment response.

Results

Of 235 included patients with NXG (34 from the multicenter cohort and 201 from the systematic review results), the mean (SD) age at presentation was 61.6 (14.2) years; 147 (62.6%) were female. Paraproteinemia was detected in 193 patients (82.1%), most often IgG-κ (117 patients [50.0%]). A malignant condition was detected in 59 patients (25.1%), most often multiple myeloma (33 patients [14.0%]). The overall rate of paraproteinemia and/or a malignant condition was 83.8% (197 patients). In the multicenter cohort, evolution of paraproteinemia into multiple myeloma was observed up to 5.7 years (median [range], 2.4 [0.1-5.7] years) after NXG presentation. Cutaneous lesions consisted of papules, plaques, and/or nodules, typically yellow or orange in color (113 of 187 [60.4%]) with a periorbital distribution (130 of 219 [59.3%]). The eye was the leading site of extracutaneous involvement (34 of 235 [14.5%]). In the multicenter cohort, intravenous immunoglobulin had the best treatment response rate (9 of 9 patients [100%]), followed by antimalarial drugs (4 of 5 patients [80%]), intralesional triamcinolone (6 of 8 patients [75%]), surgery (3 of 4 patients [75%]), chemotherapy (8 of 12 patients [67%]), and lenalidomide or thalidomide (5 of 8 patients [63%]). The consensus exercise yielded 2 major criteria, which were (1) clinical and (2) histopathological features consistent with NXG, and 2 minor criteria, consisting of (1) paraproteinemia, plasma-cell dyscrasia, and/or other associated lymphoproliferative disorder and (2) periorbital distribution of cutaneous lesions. In the absence of foreign body, infection, or another identifiable cause, fulfillment of both major and at least 1 minor criterion were proposed to establish the diagnosis of NXG.

Conclusions and Relevance

Necrobiotic xanthogranuloma is a multisystem disorder associated with paraproteinemia and malignant conditions. The proposed diagnostic criteria may advance clinical research and should be validated.

Periorbital Necrobiotic Xanthogranuloma Successfully Treated with Intravenous Immunoglobulin

Background

Necrobiotic xanthogranuloma (NXG) is a rare non-Langerhans histiocytosis with cutaneous manifestations, most commonly of the periorbital skin, and is often associated with hematologic disorders such as monoclonal gammopathy. Treatment of NXG is notoriously difficult, and fraught with recurrence and progression.

Case Presentation

The authors describe a case of NXG with periorbital involvement in a patient with a complex autoimmune and hematologic medical history. The biopsy of this rare lesion prompted subsequent evaluation for an underlying disorder, which led to the diagnosis of multiple myeloma. Her NXG lesions demonstrated remarkable clinical improvement after treatment with intravenous immunoglobulin (IVIG).

Conclusions

This case demonstrates the ophthalmologist's critical role in the diagnosis and management of NXG, as early detection cannot only prevent ophthalmic consequences such as ocular perforation and blindness, but also prompt further investigation that may reveal an underlying disorder or systemic involvement, including hematologic malignancy as in this case. NXG has been effectively treated with IVIG in a handful of reported cases. To the author's knowledge, this is the third case of periorbital NXG successfully treated with IVIG, and the first in the ophthalmic literature.

Management of Uveitis and Scleritis in Necrobiotic Xanthogranuloma

Necrobiotic xanthogranuloma (NXG) is a chronic, progressive non-Langerhans histiocytic granulomatous disease. While case reports describing periorbital involvement of NXG are frequent, only a few case reports describing ocular involvement, such as scleritis and uveitis, exist. Herein, we present a case presenting initially as bilateral anterior and posterior scleritis, as well as a chronic bilateral granulomatous panuveitis, and discuss the immunosuppressant options that should be considered for this disease with protean manifestations.

Adult Xanthogranulomatous Disease of the Orbit: Clinical Presentations, Evaluation, and Management

Adult xanthogranulomatous disease of the orbit refers to a heterogeneous group of clinical syndromes with differing degrees of systemic involvement and distinct prognoses. The different syndromes all present clinically with progressively enlarging, yellowish lesions of the orbit. Histologically, the lesions are characterized by an inflammatory infiltrate of foam cells and Touton-type multinucleated giant cells. The xanthomatized histiocytes are CD68⁺, S100^-, and CD1a^-. There are 4 clinical forms of xanthogranulomatous disease of the orbit: adult xanthogranulomatous disease of the orbit, adult onset asthma and periocular xanthogranuloma, necrobiotic xanthogranuloma, and Erdheim-Chester disease. The treatment of local lesions are treated with systemic corticosteroids and other immunosuppressors. Vemurafenib, tocilizumab, and sirolimus have shown promising results in systemic disease.

Necrobiotic Xanthogranuloma in a Patient with Multiple Myeloma

An 82-year-old woman presented with a 9-month history of multiple, well-defined skin lesions on her neck and upper chest, progressively increasing in size. Histological examination of a skin biopsy showed a regular epidermis. In the dermis, granulomatous changes with central necrobiosis were found which extended focally into the subcutaneous fat. The necrobiotic areas were surrounded by Touton cells and foreign-body giant cells. Laboratory analysis revealed leucopenia. Serum electrophoresis and immunofixation disclosed the presence of an IgG-λ paraprotein. Bone marrow aspiration cytology showed 20% plasmatic cells. The skeletal X-ray revealed frontal and occipital osteolytic skull lesions as well as pubic osteolysis. Urinalysis was unremarkable without proteinuria. Based on the clinical, laboratory, and histological findings, necrobiotic xanthogranuloma in association with multiple myeloma was diagnosed. The patient was treated with bortezomib combined with oral dexamethasone. Follow-up at week 13 revealed the complete disappearance of the IgG paraproteinemia. However, the skin lesions remained unchanged. Therefore, bortezomib treatment was discontinued, and systemic corticosteroids were continued at a higher dosage. After the steroid treatment, the lesions markedly flattened.