Granuloma Faciale: A Cutaneous Lesion Sharing Features With IgG4-associated Sclerosing Diseases

Cutaneous vasculitis: insights into pathogenesis and histopathological features

The mechanisms underlying the onset and progression of vasculitis remain poorly understood. This condition is characterized by damage to the vascular wall, recruitment of inflammatory cells, and subsequent structural remodeling, which are hallmarks of vasculitis. The histopathological classification of vasculitis relies on the size of the affected vessel and the predominant type of inflammatory cell involved - neutrophils in acute cases, lymphocytes in chronic conditions, and histiocytes in granulomatous forms. Pathological changes progress in every context, and a single vasculitic pattern can be associated with various systemic conditions. Conversely, a single causative agent may lead to multiple distinct clinical and pathological manifestations of vasculitis. Moreover, many cases of vasculitis have no identifiable cause. A foundational understanding of the normal structure of the cutaneous vascular network is crucial. Similarly, identifying the cellular and molecular participants and their roles in forming the "dermal microvascular unit" is propedeutical.

This review aims to elucidate the complex mechanisms involved in the initiation and progression of vasculitis, offering a comprehensive overview of its histopathological classification, underlying causes, and the significant role of the cutaneous vascular network and cellular dynamics. By integrating the latest insights from studies on NETosis and the implications of lymphocytic infiltration in autoimmune diseases, we seek to bridge gaps in current knowledge and highlight areas for future research. Our discussion extends to the clinical implications of vasculitis, emphasizing the importance of identifying etiological agents and understanding the diverse histopathological manifestations to improve diagnostic accuracy and treatment outcomes.

The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

A rare case of granuloma faciale presenting with ulceration: A case report

Granuloma faciale is an uncommon inflammatory dermatosis characterized by persistent dermal plaques, typically on the face, that mimic granulomatous disorders like sarcoidosis. Ulceration of granuloma faciale has very rarely been reported, and the plaques are usually asymptomatic and of cosmetic impact. We present a case of an 83-year-old male with recurrent granuloma faciale with spontaneous ulceration and monoclonal gammopathy of undetermined significance. Intralesional triamcinolone, 10 mg/mL monthly for 5 months, with pimecrolimus cream twice daily resolved the ulceration and the lesion continues to flatten and lighten. Ulceration is rare and atypical in granuloma faciale lesions which can be treated.

Eosinophils in skin diseases

Eosinophil infiltration is a common finding in a broad spectrum of skin diseases, despite the fact that the skin is devoid of eosinophils under physiologic conditions. Although cutaneous eosinophilia is reactive, cytokine-mediated in most cases, diseases with an intrinsic mutation-mediated clonal expansion of eosinophils can also manifest on the skin. As eosinophils are involved in host defense, regulate immune responses, generate pruritus, induce remodeling and fibrosis, and can cause tissue damage, they have the capacity to actively contribute to the pathogenesis of diseases. Recent research provided deeper insights in the mechanisms, e.g., bacterial and viral clearance, blister formation, recruitment of cytotoxic T cells, and generation of pruritus, by which eosinophils might come into action. This review aims at providing an overview on the clinical presentations of eosinophil-associated dermatoses and the current understanding of their pathogenic role in these diseases. Further, we discuss the effects of therapies targeting eosinophils.

Immunoglobulin-G4-related skin disease

Immunoglobulin-G4-related disease (IgG4-RD) is an autoimmune-mediated spectrum of diseases, characterized by infiltration of IgG4+ plasma cells into one or multiple organs, with the pancreas being the most commonly affected organ. The disease mostly affects middle-aged to elderly men. Diagnosis requires an integration of clinical, radiologic, pathologic, and serologic studies. Histologically, there is an increased infiltration of IgG4+ plasma cells, elevated ratio of IgG4+/IgG plasma cells of more than 40%, and a storiform pattern of fibrosis. There may be eosinophilia, along with elevated IgG4 levels. IgG4-RD can mimic several diseases and should be differentiated from inflammatory and neoplastic processes. Recently, there has been increased awareness of cutaneous involvement by IgG4-RD either as an isolated lesion or primary involvement or as a secondary involvement from a systemic disease. Clinically, cutaneous IgG4+-related disease presents as papules, plaques, and nodules involving the head and neck areas. We have provided a systematic review of the literature of this new and challenging entity of cutaneous IgG4-RD.

Eosinophilic Dermatoses: Recognition and Management

Eosinophilic dermatoses encompass a broad spectrum of diseases of different etiologies hallmarked by eosinophilic infiltration of the skin and/or mucous membranes, with or without associated blood eosinophilia. The wide range of dermatological manifestations of this spectrum, including nodules and plaques, pustules, blisters, ulcers, and urticarial lesions, is reflected in a non-univocal classification system. We identified six groups of eosinophilic dermatoses based on the predominant anatomic level of involvement: (1) epidermal; (2) of the dermal-epidermal junction; (3) dermal; (4) of the hypodermis and muscle fascia; (5) of the pilosebaceous unit; and (6) vascular/perivascular. We review clinicopathologic features and management of diseases belonging to each group, particularly: (1) pemphigus herpetiformis and atopic dermatitis as prototypes of the epidermal group; (2) bullous pemphigoid as prototypic eosinophilic dermatosis of the dermal-epidermal junction; (3) eosinophilic cellulitis (Wells syndrome), hypereosinophilic syndromes, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome, eosinophilic dermatosis of hematologic malignancy and chronic spontaneous urticaria as paradigmatic dermal eosinophilic dermatoses; (4) eosinophilic fasciitis as an eosinophilic dermatosis with predominant involvement of the hypodermis and muscle fascia; (5) eosinophilic pustular folliculitis as a model of the pilosebaceous unit involvement; and (6) granuloma faciale, angiolymphoid hyperplasia with eosinophilia, and eosinophilic granulomatosis with polyangiitis, belonging to the vascular/perivascular group.

Assessment of Treatment of Refractory Granuloma Faciale With Intralesional Rituximab

IMPORTANCE

Granuloma faciale (GF) is a rare, benign inflammatory dermatosis of unknown cause. Some reports have suggested that it could be part of the spectrum of IgG4-related sclerosing diseases. Granuloma faciale is characterized by single or multiple red-brown nodules, most frequently occurring on the face, and it can produce severe disfigurement. Treatment is difficult, and poor outcomes are often seen. Rituximab is a monoclonal antibody against CD-20 approved by the US Food and Drug Administration for treatment of some autoimmune and tumoral diseases.

OBJECTIVE

To evaluate the treatment of refractory GF with intralesional rituximab.

DESIGN, SETTING, AND PARTICIPANTS

In this case series, 3 patients with biopsy-proved refractory GF who underwent treatment at a dermatology outpatient clinic of a tertiary referral hospital were evaluated. The study was conducted from August 2015 to December 2017.

INTERVENTIONS

Doses of 0.5 to 1 mL/cm2 of intralesional rituximab, 10 mg/mL, were administered monthly for 6 months and thereafter depending on clinical response. In 2 patients, peripheral blood B-cell counts were monitored before and during treatment, and in 1 patient, only during treatment.

MAIN OUTCOMES AND MEASURES

Reduction in size of the lesions, ultrasonography evaluation, subjective improvement, and adverse events were monitored throughout the course of therapy.

RESULTS

All 3 of the patients were men (ages from 30s to 60s). They showed a significant reduction in the size and thickness of GF both clinically and on ultrasonography evaluation. Two patients had a complete response and the third, a partial response. A reduction in peripheral blood B-cell count was observed in the 3 patients, suggesting that the action of rituximab could be systemic. No severe adverse reactions were reported.

CONCLUSIONS AND RELEVANCE

Intralesional rituximab may represent a novel and well-tolerated therapy for refractory GF.

Eosinophilic Angiocentric Fibrosis: A Review and Update of Its Association With Immunoglobulin G4-Related Disease

Eosinophilic angiocentric fibrosis is a rare indolent lesion of the head and neck region that has characteristic histologic findings of onionskin fibrosis and prominent eosinophils. Its pathogenesis has been poorly understood and has been most commonly attributed to hypersensitivity or previous trauma. Recently, the lesion has been included in the spectrum of immunoglobulin G4 (IgG4)-related disease. However, few of the existing cases of eosinophilic angiocentric fibrosis have been evaluated for IgG4⁺ and IgG⁺ plasma cells. Therefore, we provide an update on the clinical and histologic features of eosinophilic angiocentric fibrosis to increase awareness of the entity and encourage its further characterization as an IgG4-related disease.

Late-Stage Erythema Elevatum Diutinum Mimicking a Fibroblastic Tumor: A Potential Pitfall

Erythema elevatum diutinum (EED) is a rare dermatosis with evolving histopathological features that vary according to the age of the lesions, with a variable fibrosis and a fascicled proliferation of spindle cells in late phases. The authors present an otherwise healthy 57-year-old woman with multiple indurated nodules on the inner aspect of both feet. Skin biopsy showed storiform interlacing bundles of spindled cells with plump nuclei and some areas with neutrophils and leukocytoclasia. CD34 and S100 were negative. This case is noteworthy clinically due to its location and its histopathological presentation that comprises a wide differential diagnosis, including inflammatory pseudotumor, dermatofibrosarcoma protuberans, superficial nodular fasciitis, hyalinized leiomyoma, sclerosing spindle cell perineuroma, and sclerotic fibroma. The authors have reviewed the main histopathological and immunohistochemical features that help in the differential diagnosis of this rare variant of EED. A careful search for leukocytoclasia and neutrophilic vasculitis is mandatory to establish the right diagnosis of nodular or late-stage EED and avoid the pitfall of considering this a neoplastic process.

Granuloma Faciale and Eosinophilic Angiocentric Fibrosis: Similar Entities in Different Anatomic Sites

BACKGROUND

Eosinophilic angiocentric fibrosis (EAF) and granuloma faciale (GF) share several histopathologic features, including eosinophil-rich inflammation, microangiitis, and progressive fibrosis. Concurrent presentation of EAF and GF suggests a pathogenetic link between them.

OBJECTIVES

To identify histologic findings that tell them apart and construe the pathogenetic mechanisms behind each morphologic variable, 14 immunohistochemical markers were used to study the cells subpopulations in 14 cases of GF and 3 cases of EAF.

MATERIALS AND METHODS

The lesions were classified according to their stage of development. The antibodies studied were: CD4, Foxp3, CD8, granzymes A and B, perforin, granulysin, CD20, CD56, CD68, ICAM-1, CD34, CD105, and 1A4.

RESULTS

The intensity of the sclerotic response and the density of 1A4-immunostained cells were significantly higher in EAF. In both diseases, CD68 cells were the most numerous, followed by CD20, CD8, and CD4 cells. About 30% of cells expressed ICAM-1. Among cells with cytotoxic granules, granulysin-positive cells were the most frequent.

CONCLUSIONS

Differences between GF and EAF were found to be mostly like due to anatomic site (usually skin of the face vs. sinonasal cavity) and stage of the disease development (usually earlier in cutaneous lesions because of their visibility). Innate and adaptive immunity, including B cells, T cells, and cytotoxic granules have a role in their pathogenesis.

IgG4-related skin disease may have distinct systemic manifestations: a systematic review

IgG4-related disease (IgG4-RD) is an increasingly prevalent protean multisystem disorder characterized by single or multi-organ infiltration of IgG4-bearing plasma cells. Skin involvement has been recognized and is relevant to proper diagnosis. A systematic literature review of 50 cases involving the skin reveals that patients with IgG4-related skin disease show predominant involvement of the head and neck and have a distinct pattern of systemic involvement, also favoring the head and neck - lymphatics, orbit, salivary, and lacrimal glands - but generally lacking pancreaticobiliary involvement (16% of cases), which by contrast is a predominant manifestation in systemic IgG4-RD (60% with pancreaticobiliary involvement). We summarize clinical and pathologic descriptive data from this systematic review. We review differential diagnosis and propose a diagnostic scheme for stratifying probability of disease based upon comprehensive integration of clinical, histopathologic, and laboratory data. Plasmacyte infiltration and storiform fibrosis are prominent in IgG4-related skin disease, but obliterative venulitis is less common than in the prototypical IgG4-related disease manifestation of autoimmune pancreatitis. IgG4 tissue and serum values, with a mean (±95% CI) in the reviewed cases of 132.8 ± 32.6 IgG4-positive plasma cells per high-power field and 580 ± 183.8 mg/dl, respectively, are incorporated into the suggested criteria. The distinct set of manifestations identified by this systematic review and the proposed diagnostic considerations, while requiring further validation in prospective studies, highlight the need to consider that IgG4-related skin disease defines a unique systemic disease complex along the spectrum of IgG4-RD.

Collagen Anomalies as Clues for Diagnosis: Part 1

BACKGROUND

Collagen is the most abundant protein in the body and the main structural component of the skin.

OBJECTIVE

To provide a review of the histopathology of collagen alterations and to propose a classification with the most important types of collagen anomalies in dermatopathology. The authors describe some of the main morphological clues of collagen anomalies for specific diagnosis of some cutaneous inflammatory and neoplastic conditions.

METHODS

The authors review histopathologic collagen anomalies, concerning both morphology and disposition in some inflammatory and neoplastic cutaneous conditions, and they review previous terminology and proposed a classification of the most important types of collagen anomalies that can be seen in dermatopathological practice.

RESULTS

Collagen anomalies in skin can be classified into lamellar fibrosis, sclerosis, and "balls" and "rings" of collagen. Lamellar fibrosis presents as long and thin collagen bundles forming a delicate network, which can be disposed in a parallel pattern, onion-bulb-like pattern, and storiform pattern. Sclerosis is characterized by large, thick, and eosinophilic bundles of collagen, which may present as a homogenous-diffuse pattern or as individual thick bundles of collagen with few or abundant number of fibroblasts between them. Finally, the authors propose the terms "balls" and "rings" of collagen. The term "balls" of collagen stands for thick, homogenous, eosinophilic, globular collagen bundles, with no distinguishable individual composing fibers, which include the floating sign and the free-floating sign. The term "rings" of collagen is characterized by sclerotic collagen arranged in a homogenous rimming pattern around vessels without independent fibers in its composition.

CONCLUSIONS

Collagen anomalies may be important clues to establish specific clues for specific diagnoses in dermatopathology.

Granuloma faciale: clinical, morphological and immunohistochemical aspects in a series of 10 patients

Granuloma faciale is a chronic, benign, cutaneous vasculitis with well-established clinical and morphological patterns, but with an unknown etiology. This study describes clinical and pathologic aspects of patients diagnosed with granuloma faciale. The authors analyzed demographic, clinical, morphological and immunohistochemical data from patients with a final diagnosis of granuloma faciale, confirmed between 1998 and 2012. There was a proportional and mixed inflammatory infiltrate, Grenz zones were present in almost all the samples. Immunophenotyping confirmed a higher intensity of T lymphocytes than B lymphocytes in thirteen samples, with a predominance of T CD8 lymphocytes in 64% of cases, in contrast to the literature, which indicates that the major component is T CD4 lymphocytes. All cases were positive for IgG4 but the majority (12/14) had less than 25% of stained cells. The pathogenesis of granuloma faciale remains poorly understood, making studies of morphological and immunohistochemical characterization important to better understand it.

Granuloma Faciale and Erythema Elevatum Diutinum in Relation to Immunoglobulin G4-Related Disease: An Appraisal of 32 Cases

OBJECTIVES

To elucidate whether granuloma faciale (GF) and erythema elevatum diutinum (EED), two inflammatory skin dermatoses, meet the consensus histopathologic diagnostic criteria for immunoglobulin G4-related disease (IgG4-RD).

METHODS

With institutional review board approval, we assessed the clinical, microscopic, and immunophenotypic features of skin specimens of patients with GF and EED. We compared these findings with previously published consensus diagnostic criteria for IgG4-RD.

RESULTS

Thirty-two patients (GF, n = 25; EED, n = 7) met study inclusion criteria. Histopathologic findings of small-vessel vasculitis, dermal fibrosis, and plasma cell infiltrates were uniformly present, and eosinophilic inflammation was frequent. No specimen met diagnostic criteria for IgG4-RD.

CONCLUSIONS

Our results indicate that despite some histopathologic similarities between GF/EED and IgG4-RD, the cases did not meet the consensus immunohistochemical diagnostic criteria for IgG4-RD.

Dermatologic disorders in 118 patients with autoimmune (immunoglobulin G4-related) pancreatitis: a retrospective cohort analysis

BACKGROUND

Autoimmune pancreatitis is the prototypical manifestation of immunoglobulin G4-related disease, a fibroinflammatory syndrome that can affect virtually any organ. Rarely, skin involvement has been reported in immunoglobulin G4-related disease. Isolated case reports have described other distinct associated dermatoses.

OBJECTIVE

Our objective was to determine the frequency and nature of dermatologic manifestations of immunoglobulin G4-related disease in patients with autoimmune pancreatitis.

METHODS

Retrospective analysis of dermatologic conditions of patients with autoimmune pancreatitis.

RESULTS

Among the 118 identified patients, 31 (26.3%) had a dermatologic diagnosis [mean (standard deviation; SD) follow-up 5.9 (4.6) years]. Two patients (1.7%) had necrobiotic xanthogranuloma; three (2.5%) had another xanthomatous or xanthogranulomatous process. One patient (0.8%) had pemphigus erythematosus. No patient had immunoglobulin G4-related skin disease.

CONCLUSION

Skin involvement in immunoglobulin G4-related disease appears to be rare. A disproportionately high number of patients had xanthomatous or xanthogranulomatous processes, including necrobiotic xanthogranuloma. It remains unclear whether the association between immunoglobulin G4-related disease and necrobiotic xanthogranuloma or other xantho(granulo)matous processes represents shared pathophysiology, a mutual underlying driver, or coincidence, though the results of this study cast doubt on the latter. Although pemphigus was not reported in immunoglobulin G4-related disease previously, the prominent role of the immunoglobulin G4 subclass in each condition makes this association intriguing.