Cutaneous sarcoidosis: updates in the pathogenesis

Sarcoidosis Resembling Angiokeratomas: A Case Report

Sarcoidosis, a multifaceted systemic disorder characterized histologically by the presence of non-caseating granulomas, has a wide array of cutaneous manifestations. We describe a case of a 74-year-old woman with a complex medical history, who presented with asymptomatic hyperpigmented papules on her lower extremities. Histological examination of a punch biopsy specimen showed nodular and angiocentric patterns of granulomatous inflammation consistent with sarcoidosis, and chest radiography demonstrated bilateral hilar opacities, supporting the diagnosis. To our knowledge, this specific cutaneous presentation of sarcoidosis has not been described before, and it can easily be mistaken for other conditions. Therefore, this case underscores the importance of recognizing atypical cutaneous morphologies of sarcoidosis, particularly in patients with complex medical histories, to facilitate accurate diagnosis and timely intervention. We aim to increase awareness among clinicians regarding the diverse manifestations of sarcoidosis, thereby enhancing diagnostic acumen and patient care.

Extrapulmonary Sarcoidosis With Multi-Organ Involvement Presenting Primarily as Hypercalcemia

Sarcoidosis is a highly variable disease. The majority of cases affect the lungs, but they can involve other organs as well. Extrapulmonary sarcoidosis is rare, and it can present in many ways. Therefore, the diagnosis can be challenging. We hereby present a case of a patient presenting with hypercalcemia and diagnosed with extrapulmonary sarcoidosis with multi-organ involvement. This article was previously presented as a meeting abstract at the MI-ACP 2022 Annual Scientific Meeting on October 14, 2022.

Immunohistochemical Features of MMP-9 and pSTAT1 in Granuloma Annulare and Sarcoidosis: A Comparative Study of 62 Cases

Background

Granuloma annulare (GA) and sarcoidosis are granulomatous inflammatory diseases that share similarities.

Objective

To identify the histological and immunohistochemical (IHC) features of GA and sarcoidosis.

Methods

A retrospective review of 36 patients with GA and 26 with sarcoidosis was performed. Results from hematoxylin and eosin (H&E) staining and IHC staining of MMP-9 and pSTAT1 within the skin lesions of GA and sarcoidosis were analyzed, and random forest was applied for developing a predictive model.

Results

Significantly greater expressions of MMP-9 (especially in elastic fibers, EFs, P < 0.0001) and pSTAT1 (P = 0.0003) were observed in lesion samples of GA versus sarcoidosis patients. In GA patients, MMP-9 was significantly upregulated in the interstitial type (P = 0.0222), while staining of pSTAT1 was positively correlated with the area of mucinous collagen in palisading GA (R = 0.5356, P = 0.0484). In sarcoidosis patients, MMP-9 (R = -0.7127, P = 0.0009) and pSTAT1 (R = -0.5604, P = 0.0067) were found to show stronger expressions in lesions with less lymphocyte infiltration. The predictive model demonstrated an AUC of 0.9675.

Conclusion

These results indicate that MMP-9 and pSTAT1 might exert roles in granulomatous inflammation in different modes, and the presence of more robust MMP-9 staining in EFs appears to be more suggestive of GA.

Histopathology of Red Tattoo Reactions

BACKGROUND

Despite popularity of tattoos, complications may occur. In particular, red tattoo reactions due to allergic reactions are the most frequent chronic tattoo reactions. However, little is known about its histopathology and underlying pathomechanisms.

OBJECTIVE

The aim of this article is to analyze the histopathology of red tattoo reactions for diagnostic purposes and to acquire more insight into pathogenesis.

METHODS

A retrospective cross-sectional study was conducted by reviewing the histopathology of 74 skin biopsies of patients with allergic red tattoo reactions. Histopathological findings, such as inflammation patterns, inflammatory cells and pigment depth and color, were semi-quantified with an in-house validated scoring system by 2 independent senior investigators.

RESULTS

Histiocytes and lymphocytes were both present in >93%. Histiocytes were the predominant inflammatory cells in 74.3%, but well-defined granulomas were mostly absent (78.0%). Eosinophils were uncommon (8.1%) The predominantly histiocytic reaction combined with interface dermatitis was the main inflammation pattern (37.9%). Most biopsies showed more than one reaction pattern. Interface involvement was observed in 64.8%, despite the intended depth of standard tattoo procedures, in which pigment is placed deeper, in the upper- and mid-dermis. Statistical analyses showed a significant association between inflammation severity and pigment depth (P = 0.024). In 6 cases (8.1%) pigments could not be retrieved histologically.

CONCLUSIONS

In this cohort we demonstrated that cutaneous reactions to red tattoo ink are frequently characterized by the combination of dermal predominantly histiocytic infiltrates and epidermal interface dermatitis. Allergic reactions to red tattoo pigments probably represent a combination of a subtype IVa and IVc allergic reaction. Clinicians should be aware of the specific histopathology of these reactions and therefore the importance of taking a diagnostic skin biopsy.

Ichthyosiform sarcoidosis: Report of a case and comprehensive review of the literature

Sarcoidosis is a disease that can affect a multitude of organs and manifest as cutaneous disease. Cutaneous manifestations of sarcoidosis vary widely in morphology, earning the nickname of "great imitator," and the diagnosis often requires clinicopathologic correlation and additional laboratory and radiographic workup. We present the case of a 42-year-old African American woman with ichthyosiform sarcoidosis on the bilateral lower extremities. As one of the rarest specific variants of cutaneous sarcoidosis, ichthyosiform is understudied and has been primarily documented in case reports and series. We undertake a comprehensive review of the literature to identify key clinicopathologic features including the characterization of sites of cutaneous and systemic involvement, as well as typical histopathological findings. Lower extremities were the most involved body site (85.7%). Extracutaneous organ involvement centered around pulmonary (65.7%), lymph node (57.1%), and ocular (31.4%) involvement. Of the histopathological features reported, hyperkeratosis (51.4%) and diminished stratum granulosum (62.9%) were most frequently reported in conjunction with dermal granulomas (100%). We hope that these findings will serve to aid clinicopathological correlation and accurate diagnosis of ichthyosiform sarcoidosis.

Association of Propionibacterium acnes with the efficacy of minocycline therapy for cutaneous sarcoidosis

BACKGROUND

Although tetracycline has been used to treat cutaneous sarcoidosis, the mechanism of action for this treatment remains unclear. This study evaluated the efficacy of minocycline treatment on cutaneous sarcoidosis and the relationship between its efficacy and the presence of Propionibacterium acnes in skin sarcoid lesions.

METHODS

We retrospectively reviewed results in 13 patients with cutaneous sarcoidosis treated with minocycline at Saitama Medical Center between 2010 and 2017. To demonstrate the presence of P. acnes in the skin lesions, skin biopsy specimens from 11 of the 13 patients were evaluated with immunohistochemistry using a specific monoclonal antibody against P. acnes (PAB antibody).

RESULTS

Of the 13 patients treated with minocycline, six patients (46%) achieved a complete response (CR) and seven (54%) had a partial response (PR). The skin lesions regressed in 1.5-5 months (average, 3.2 months) after treatment with minocycline. No relapse had occurred during the minocycline therapy. Elevated serum angiotensin-converting enzyme levels were observed in five of the patients, and the levels reduced after treatment with minocycline. P. acnes, identified as round bodies that reacted with PAB antibody, were observed in the skin sarcoid granulomas in all patients tested. The number of PAB-positive round bodies was significantly higher in the skin lesions of patients who had CR than in those who had PR.

CONCLUSIONS

These results suggest the effectiveness of minocycline for the treatment of cutaneous sarcoidosis and an association of P. acnes with the efficacy of minocycline therapy for cutaneous sarcoidosis.

Cutaneous Granulomatosis: a Comprehensive Review

Cutaneous granulomatosis is a heterogeneous group of diseases, characterized by a skin inflammatory reaction triggered by a wide variety of stimuli, including infections, foreign bodies, malignancy, metabolites, and chemicals. From a pathogenic point of view, they are divided into non-infectious and infectious granulomas. Pathophysiological mechanisms are still poorly understood. Non-infectious granulomatous skin diseases include granuloma annulare, necrobiosis lipoidica, rheumatic nodules, foreign body granulomas, cutaneous sarcoidosis, and interstitial granulomatous dermatitis. Necrobiosis lipoidica is more frequent in diabetic patients. Infectious granulomas of the skin are caused by mycobacteria, in particular Mycobacterium tuberculosis or atypical mycobacteria; parasites, such as Leishmania; or fungi. Pathogenic mechanisms of M. tuberculosis-related granuloma are discussed. From a clinical point of view, it is useful to divide cutaneous granulomatosis into localized and more disseminated forms, although this distinction can be sometimes artificial. Three types of localized granulomatous lesions can be distinguished: palisaded granulomas (granuloma annulare, necrobiosis lipoidica, and rheumatoid nodules), foreign body granulomas, and infectious granulomas, which are generally associated with localized infections. Disseminated cutaneous granulomas can be divided into infectious, in particular tuberculosis, and non-infectious forms, among which sarcoidosis and interstitial granulomatous dermatitis. From a histological point of view, the common denominator is the presence of a granulomatous inflammatory infiltrate in the dermis and/or hypodermis; this infiltrate is mainly composed of macrophages grouped into nodules having a nodular, palisaded or interstitial architecture. Finally, we propose which diagnostic procedure should be performed when facing a patient with a suspected cutaneous granulomatosis.

Subcutaneous Sarcoidosis Occurring in Both Chin and Toe

Sarcoidosis is a systemic inflammatory disease characterized by non-caseating granulomas of unknown origin. Of the fewer than 6% of sarcoidosis cases that occur in subcutaneous tissue, most occur on the face or forearm, but rarely in the toe. A 33-year-old man was admitted to our institute with a 2-cm mass on his chin and a 0.5-cm mass on his right fourth toe. Based on preoperative ultrasonography, epidermal cysts were suspected, and histopathological tests were performed after removing the masses. Histopathologically, the chin and toe tissue samples showed chronic granulomatous inflammation, without necrosis, indicative of sarcoidosis. Chest computed tomography revealed a large number of small nodules in both the interlobar fissures and the peribronchial area, and a large number of small lymph nodes in both the hilar and interlobar node areas. On the basis of the histopathologic and imaging findings, the patient was diagnosed with sarcoidosis. This very rare case of sarcoidosis, occurring in both chin and toe, suggests that thorough evaluation is needed to find other mass when we find sarcoidosis in facial area.

[Sarcoidosis flare after autologous stem cell transplantation: An immune paradox?]

INTRODUCTION

Sarcoidosis is a systemic granulomatous disorder of unknown cause. Apparition or flare of previously diagnosed sarcoidosis following hematopoietic stem cell transplantation (HSCT) has rarely been reported.

OBSERVATION

We report a 62-year-old woman who presented a radiological flare of sarcoidosis post-autologous stem cell transplantation for a POEMS syndrome. Imaging findings and lymph node histology, which revealed non-caseating granuloma, were consistent with the sarcoidosis diagnosis. The patient was asymptomatic and was kept free of treatment.

CONCLUSION

Sarcoidosis must be considered ahead of compatible clinicoradiological presentation occurring after HSCT. Sarcoidosis can mimic metastatic cancer or lymphatic relapse. Tissue biopsies and exclusion of differential diagnosis of granuloma diseases are warranted to confirm sarcoidosis diagnosis.

The lady with the dragon tattoo

BACKGROUND

Though the skin is affected in sarcoidosis in about one-third of cases, granulomatous tattoo reactions are an unusual manifestation of the disease. It is important phenomenon to recognize, as it frequently leads to the diagnosis of systemic sarcoidosis.

CASE PRESENTATION

A 35-year-old Caucasian female with multiple tattoos presented with a 5-week history of tenderness of the black dye in a tattoo depicting a dragon. She also described a 15-month history of fatigue, polyarthralgia, and mild dyspnea. Skin biopsy demonstrated multiple dermal non-caseating granulomata with associated tattoo ink. Further investigation revealed the presence of systemic sarcoidosis. Her symptoms and skin changes improved with conservative management.

CONCLUSION

Sarcoidal tattoo reactions in those without systemic sarcoidosis are a rare occurrence, and their presence should prompt a search for systemic involvement. The accurate identification of skin involvement in sarcoidosis is important, as it tends to occur early in the course of disease, and the skin is a readily accessible site for biopsy, allowing for prompt diagnosis.

Histologic features of granulomatous skin diseases. Part 1: Non-infectious granulomatous disorders

Granulomatous disorders affecting the skin belong to a heterogeneous group of diseases. With the exception of granulomas induced by infectious agents or foreign bodies, the etiopathogenesis of granulomatous disorders is still poorly understood. The knowledge of histopathologic changes is of great importance for understanding clinical presentation and disease course.

The "mystery" of cutaneous sarcoidosis: facts and controversies

The reason why the cutaneous form of sarcoidosis is well known in the literature is because of its spectrum of manifestations granting it the fame of a Great Imitator. The mystery shrouding the pathogenesis of this rare cutaneous disease is still there (in spite of the fundamental progress of the various diagnostic methods in current day medicine). The production of the morphological substrate - the epithelioid cell granuloma - which is considered to be characteristic of skin sarcoidosis, could, however, also be the end result of a reaction to i) various specific infectious agents such as Leishmaniasis cutis, coccidioidomycosis, etc., ii) certain residual bacterial or other mycobacterial antigens which, at the moment of setting the diagnosis are - by definition - non-infectious but still immunogenic, as well as iii) different tumor antigens in lesional tissue or other location. Often, differentiating between sarcodiosis and a sarcoid-like reaction, based on the updated criteria for cutaneous sarcoidosis, is problematic to downright impossible. A future characterization of the genetic signature of the two conditions, as well as the implementation of additional mandatory panels for i) the identification of certain infectious or ii) non-infectious but immunogenic and iii) tumor antigens in the epithelioid cell granuloma (or in another location in the organism), could be a considerable contribution to the process of differentiating between the two above-mentioned conditions. This will create conditions for greater accuracy when setting the subsequent therapeutic approaches.

Chitotriosidase in the Pathogenesis of Inflammation, Interstitial Lung Diseases and COPD

As a member of 18 glycosyl hydrolase (GH) family, chitotriosidase (Chitinase 1, CHIT1) is a true chitinase mainly expressed in the differentiated and polarized macrophages. CHIT1 is an innate immune mediator that digests the cell walls of chitin-containing eukaryotic pathogens, such as fungi. However, CHIT1 is dysregulated in granulomatous and fibrotic interstitial lung diseases characterized by inflammation and tissue remodeling. These include tuberclosis, sarcoidosis, idiopathic pulmonary fibrosis, scleroderma-associated interstitial lung diseases (SSc-ILD), and chronic obstructive lung diseases (COPD). CHIT1 serum concentration correlates with the progression or the severity of these diseases, suggesting a potential use of CHIT1 as a biomarker or a therapeutic target. Recent studies with genetically modified mice demonstrate that CHIT1 enhances TGF-β1 receptor expression and signaling, suggesting a role in initiating or amplifying the response to organ injury and repair. This additional CHIT1 activity is independent of its enzymatic activity. These studies suggest that CHIT1 serves a bridging function; it is both an innate immune mediator and a regulator of tissue remodeling. This review will focus on recent data linking CHIT1 to the pathogenesis of inflammation, interstitial lung disease, and COPD.

Sarcoidosis presenting as isolated gingival enlargement: a rare case entity

Sarcoidosis is a non-caseating granulomatous disease . It is a multiorgan inflammatory disorder of unknown etiology. Conditions affecting skin or other organs frequently involve oral cavity and rarely manifest as gingival disease. Here we are reporting a rare case in which gingival hyperplasia was the initial symptom which finally led to the diagnosis of sarcoidosis. Oral mucous membrane needs to be examined carefully as it may constitute in presenting first sign of systemic sarcoidosis.

Dimethyl fumarate - only an anti-psoriatic medication?

Fumaric acid esters have been used successfully in the therapy of psoriasis vulgaris since 1959. In the last 17 years, many of the underlying mechanisms of anti-psoriatic action, such as a Th1/Th2 shift, a suppression of important leukocyte adhesion molecules, the induction of pro-apoptotic pathways in T-cells and recently anti-angiogenic action, have been discovered. Based on the knowledge of these immunomodulatory characteristics, fumaric acid esters have been shown to be effective or potentially effective in a multitude of dermatological as well as non-dermatological diseases. The range of new therapeutic targets reaches from multiple sclerosis to illnesses such as necrobiosis lipoidica, granuloma annulare and sarcoidosis. Experimental approaches offer promising, although preliminary, results on the treatment of cancer, malaria, chronic inflammatory lung diseases, and Huntington disease, to name but a few. This valued and well-known drug mainly prescribed by dermatologists is now experiencing a renaissance far beyond dermatologic applications.

[Cutaneous and pulmonary sarcoidosis. Successful therapy with fumaric acid esters]

A 43-year-old man with cutaneous and pulmonary sarcoidosis was treated with fumaric acid esters (Fumaderm®) for 11 months because of the cutaneous lesions. During the treatment the cutaneous lesions and pulmonary changes vanished completely. In addition, serum angiotensin converting enzyme (ACE) levels normalized after end of therapy. This case report is one of a few examples of the successful treatment of cutaneous and pulmonary sarcoidosis with fumaric acid esters (Fumaderm®).

Sarcoidosis and molecular mimicry--important etiopathogenetic aspects: current state and future directions

Sarcoidosis is a disease of uncertainty in terms of its cause, presentation, and clinical course. The disease has a worldwide distribution and affects all ages, races, and both sex. Sarcoidosis of the skin may have an extremely heterogeneous clinical presentation, so that the definitions of 'great imitator' and 'clinical chameleon' have long been used. The factors that influence clinical picture and severity of the disease are probably linked to the etiopathogenesis of sarcoidosis, which continues to be shrouded in mystery. The current state of the art on the pathogenesis of sarcoidosis is that it is an immunological response in a genetically susceptible individual to an as-yet undefined antigenic stimulus. How exposure occurs in genetically predisposed patients is not completely clear, but the most likely explanation is that these agents or antigens are either inhaled into the lungs or enter through contact with the skin, as these are the common target organs that are constantly in contact with the environment. An autoimmune etiology of sarcoidosis could possibly occur through a process of molecular mimicry of infectious or other environmental antigens to host antigens. This could lead to a cross-mediated immune response and induction of autoimmune disease. This molecular mimicry may probably be responsible for the heterogeneous clinical presentations of the disease. Several investigations and studies have provided valuable evidence on the etiopathogenesis of sarcoidosis, which may lead to the future development of targeted and innovative treatment strategies. Nevertheless, we are still a long way from unravelling the underlying cause of this mysterious disease.

Sarcoidosis

Sarcoidosis is a multisystem, granulomatous disease. In this article, the various clinical manifestations, approach to, and management of, pulmonary and extrapulmonary sarcoidosis are reviewed.