Cutaneous vasculitis in Behçet's disease: a clinical and histopathologic study of 20 patients

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

A new tool supporting the diagnosis of childhood-onset Behçet's disease: venous wall thickness

OBJECTIVES

The lower extremity venous wall thickness (VWT) of Behçet's disease (BD) patients was reported to be significantly increased in adults, suggesting its use for the support of BD diagnosis. This prospective study aimed to investigate the lower extremity VWT in childhood-onset definite and incomplete BD patients and compare it to healthy age-matched controls.

METHODS

Paediatric patients classified with BD according to the 2015 international paediatric BD criteria in our centre were included in the study. Intima-media thickness of the lower extremity veins to evaluate VWT was measured by ultrasonography, including common femoral vein (CFV), femoral vein (FV), vena saphena magna, vena saphena parva and popliteal vein (PV).

RESULTS

In this cross-sectional study, VWT was measured in 35 patients (63% male) and 27 healthy controls (55% male). Thirteen (37%) of 35 patients met the criteria for the diagnosis of BD. The remaining 22 (63%) had incomplete BD and met two criteria. The median VWT values of both definite and incomplete BD patients were significantly higher than the control group in all veins on both sides. Regarding the best cut-off values of VWT for all lower extremity veins, the sensitivity rates were between 63% and 86%, while specificity rates were between 71% and 100%.

CONCLUSION

Increased VWT was present not only in BD patients with vascular involvement but also in those without. We suggest that VWT may be a new criterion in supporting the diagnosis of childhood BD both in definite and incomplete BD patients.

Superficial (nodular) thrombophlebitis as a heterogeneous entity with distinctive clinico-pathological aspects: Correlation with the underlying conditions

BACKGROUND

Superficial (nodular) thrombophlebitis, referring to a thrombo-inflammatory disorder of dermal-subcutaneous veins, encompass a spectrum of nodular lesions often associated with inflammatory, infectious, neoplastic or thrombophilic diseases.

OBJECTIVE

We postulate that distinct clinico-pathological features may correlate with the underlying conditions.

METHODS

We conducted a retrospective monocentric study of all patients seen in our dermatology department for a superficial thrombophlebitis, completed with a literature review. Clinical and pathological data were extracted from the patient files and articles.

RESULTS

A total of 108 cases of superficial thrombophlebitis was analysed. Forty-five percent manifested as elongated nodules clearly evoking vascular involvement, while the other 55% were presenting as nodules or plaques. The elongated phenotype was strongly associated with malignancy or thrombophilia if a pure thrombosis was demonstrated histopathologically, while tuberculosis was the main underlying condition if a granulomatous vasculitis was present. Panniculitis-like lesions were mainly corresponding to erythema-nodosum-like lesions of Behçet's disease, characterized by the distinctive feature of thrombotic veins with an associated leukocytoclastic vasculitis.

LIMITATIONS

Retrospective design and risk of publication bias.

CONCLUSION

Superficial (nodular) thrombophlebitis is a heterogeneous entity with a distinct clinico-pathological presentation that strongly points to the nature of the underlying medical condition, thus guiding the medical workup.

Update on the Diagnosis of Behçet's Disease

Behçet's disease (BD) is a systemic inflammatory disease with unknown etiology. It is characterized by recurrent mucocutaneous lesions and major organ disease such as ocular, neurologic, vascular, and gastrointestinal manifestations. The diagnosis of BD is mainly based on clinical manifestations after ruling out other potential causes. There are no specific laboratory, histopathologic, or genetic findings for the diagnosis of BD. The International Study Group (ISG) criteria set is still the most widely used set for the diagnosis. The main limitation of this criteria set is the lack of major organ manifestations such as vascular, neurologic, and gastrointestinal involvement. The ICBD 2014 criteria are more sensitive, especially in early disease. However, patients with such as spondyloarthritis can easily meet this criteria set, causing overdiagnosis. Diagnosing BD can be a big challenge in daily practice, especially in patients presenting with only major organ involvement such as posterior uveitis, neurologic, vascular, and gastrointestinal findings with or without oral ulcers. These patients do not meet ISG criteria and can be diagnosed with "expert opinion" in countries with high BD prevalence. The pathergy test is the only diagnostic test used as diagnostic or classification criteria for BD. Our recent studies showed that common femoral vein (CFV) thickness measurement can be a valuable, practical, and cheap diagnostic tool for BD with sensitivity and specificities higher than 80% for the cut-off value of 0.5 mm. However, the diagnostic accuracy of CFV measurement should be investigated in other disease groups in the differential diagnosis of BD and in also different ethnic populations.

Mucocutaneous manifestations of Behçet's disease: Pathogenesis and management from perspectives of vasculitis

Behçet's disease (BD) is a systemic inflammatory disorder characterized by vasculitis affecting blood vessels of any caliber or type. It can present with a wide spectrum of vasculitic lesions, including erythema nodosum-like lesions and retinal vasculitis, and may also lead to larger vessel diseases, such as aortic aneurysm and deep vein thrombosis. The full etiology of BD remains unclear, but it is considered a polygenetic disease with multiple genetic risk factors that promote immune dysregulation and thrombophilia. Inflammation can be triggered by environmental factors, such as bacteria or viruses, and the dysregulation of innate and adaptive immune cell subsets. Neutrophils and lymphocytes are the primary players involved in BD pathogenesis, with specific innate (i.e., neutrophil-derived reactive oxygen species and neutrophil extracellular traps) and adaptive (i.e., anti-endothelial cell antibodies) processes inducing endothelial cell activation and chemotaxis of inflammatory cells, leading to coagulation and vasculitis. These inflammation-induced vasculitic or vasculopathic features are observed in most mucocutaneous BD lesions, although vasculitis per se is often pathologically evident only during a brief period of the disease process. Due to the multifactorial nature of BD-associated inflammation, broad-spectrum anti-inflammatory medications, including glucocorticoids and immunosuppressive drugs, have been the mainstay for managing BD. In addition, inhibitors of interleukin (IL)-1, tumor necrosis factor (TNF)-α, and IL-17, which target innate and adaptive immune functions dysregulated in BD, have emerged as promising new therapeutics. In this review, we discuss the muco-cutaneous manifestations of BD by focusing on the underlying vasculitic components in their pathologies, as well as the current array of treatment options.

Neutrophilic Dermatoses: a Clinical Update

Purpose of Review

Neutrophilic dermatoses are defined by the presence of a sterile neutrophilic infiltrate on histopathology. This review focuses on the pathogenesis, epidemiology, clinicopathological features, diagnosis, and management of four disorders: Sweet syndrome, pyoderma gangrenosum, Behçet syndrome, and neutrophilic eccrine hidradenitis.

Recent Findings

Recent studies have provided insight into the complex pathogenesis of neutrophilic dermatoses. Evidence supports an intricate interplay of abnormal neutrophil function and inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic predisposition.

Summary

Neutrophilic dermatoses have diverse cutaneous and extracutaneous manifestations and may be associated with significant morbidity and mortality. Common underlying associations include infectious, inflammatory, and neoplastic disorders, as well as drug reactions. Emerging diagnostic and therapeutic frameworks identify an expanding role for biologic and targeted anti-inflammatory therapies.

Femoral vein wall thickness measurement: A new diagnostic tool for Behçet's disease

OBJECTIVES

Diagnosing Behçet's disease (BD) is a challenge, especially in countries with a low prevalence. Recently, venous wall thickness (VWT) in lower extremities has been shown to be increased in BD patients. In this study, we aimed to investigate the diagnostic performance of common femoral vein (CFV) thickness measurement in BD and whether it can be used as a diagnostic tool.

METHODS

. Patients with BD (n = 152), ankylosing spondylitis (n = 27), systemic vasculitides (n = 23), venous insufficiency (n = 29), antiphospholipid syndrome (APS; n = 43), deep vein thrombosis due to non-inflammatory causes (n = 25) and healthy controls (n = 51) were included in the study. Bilateral CFV thickness was measured with ultrasonography by a radiologist blinded to cases.

RESULTS

Bilateral CFV thickness was significantly increased in BD compared with all control groups (P < 0.001 for all). The area under the receiver operating characteristic curve for bilateral CFV thicknesses in all comparator groups was >0.95 for the cut-off value (0.5 mm). This cut-off value also performed well against all control groups with sensitivity rates >90%. The specificity rate was also >80% in all comparator groups except APS (positive predictive value: 79.2-76.5%, negative predictive value: 92-91.8% for right and left CFV, respectively).

CONCLUSION

Increased CFV thickness is a distinctive feature of BD and is rarely present in healthy and diseased controls, except APS. Our results suggest that CFV thickness measurement with ultrasonography, a non-invasive radiological modality, can be a diagnostic tool for BD with sensitivity and the specificity rates higher than 80% for the cut-off value ≥0.5 mm.

Cutaneous arteriolitis: A novel cutaneous small vessel vasculitis disorder clinicopathologically different from cutaneous polyarteritis nodosa and cutaneous venulitis

Cutaneous vasculitis can be classified into two types based on the affected vessel size: small vessel vasculitis predominantly affecting dermal venules, and muscular vessel vasculitis as found in cutaneous arteritis predominantly affecting arteries located at the dermal-subcutaneous junction. We describe two cases with a novel small vessel vasculitis disorder, which exclusively affected arterioles in the mid-dermis, and show clinical and pathological difference distinct from cutaneous polyarteritis nodosa and cutaneous venulitis. Both patients were male, and presented with painful infiltrative plaques, involving the palms, soles, and thighs without extracutaneous involvement except for fever and arthralgia. Histopathological examination revealed vasculitis in the mid-dermis characterized by a predominant infiltration of neutrophils with vessel wall fibrinoid necrosis and leukocytoclasia identical to the features of leukocytoclastic vasculitis, except that the affected vessels were arterioles rather than venules. Serological examinations showed normal levels of serum complements, immune complexes, and antineutrophil cytoplasmic antibodies, and vasculitis disorders associated with systemic diseases were excluded in both patients. The patients showed a good response to short-term treatment with prednisolone up to 30 mg. This novel cutaneous arteriolitis clinicopathologically different from both cutaneous venulitis and cutaneous arteritis appears to be a skin-limited disorder.

[Ulcerations of the extremities: An unusual manifestation of Behçet's disease]

BACKGROUND

Although cutaneous and mucosal involvement is a major manifestation in Behçet's disease, ulcerated lesions of the extremities are exceptional and poorly known.

CASE REPORT

A 57-year-old male patient was diagnosed 7 years ago with Behçet's disease. This diagnosis was made in the presence of recurrent bipolar aphtous ulcers, pseudofolliculitis lesions and retinal vasculitis. After having been lost to follow up for two years, during which his treatment was discontinued, he presented centimetric necrotic ulcerations of the fingers of the hand and of the right big toe. The biopsy revealed leucocytoclastic and necrotizing vasculitis. The patient improved with antibiotic, oral corticosteroids, colchicine and local care.

CONCLUSION

Linking extremity ulcers with Behçet's disease, though sometimes difficult, is essential for proper management.

[Cardiovascular involvement in Behçet's disease]

Vascular involvement is a common complication of Behçet's disease (BD) and affects up to 40% of BD patients. These complications worsen the prognosis of BD. The concept of vasculo-Behçet has been adopted for cases in which vascular complications dominate the clinical features. Vascular manifestations affect particularly young men, during the first years following onset of the disease. Venous complications are the most frequent vascular complications, affecting 14 to 40% of BD patients. Superficial and deep lower limb thrombosis is the most frequent venous complications but one third of venous thrombosis concern large vessels (such as cerebral venous thrombosis, pulmonary embolism, and inferior or superior vena cava, etc.). Budd-Chiari syndrome is the worst prognostic factor increasing mortality by 9 times. Arterial complications (2 to 17% of BD patients) include aneurysms and occlusions/stenosis. Main locations of arterial lesions are aortic (abdominal and thoracic), femoral, pulmonary and iliac arteries. Aneurysms are the most severe arterial complications, particularly pulmonary aneurysms associated with a high risk of massive bleeding. Cardiac complications (up to 6% of BD patients) include pericarditis, endocardial lesions (aortic regurgitation and less often mitral insufficiency), myocardial lesions (myocardial infarction, myocarditis and endomyocardial fibrosis) and intracardiac thrombosis (right ventricle and atrium). Coronary lesions complicated to myocardial infarction are the most severe cardiac complications. Treatment is based on corticosteroids and immunosuppressive drugs. The use of anticoagulation in venous thrombosis is still controversial.

Histopathological Evaluation of Behçet's Disease and Identification of New Skin Lesions

Behçet's disease (BD) is a multisystemic, relapsing inflammatory disorder with an obscure etiology and pathogenesis. Diagnosis depends on the clinician's ability to identify a group of nonspecific mucocutaneous lesions, which also manifest in a number of other diseases. In recent years, there has been an increase in the studies focusing on the histopathological aspects of Behçet's disease diagnostic mucocutaneous lesions. Their results emphasize the value of histopathology and direct immunofluorescence (DIF) in the differential diagnosis of Behçet's disease.

[Severe flare of Behcet's disease with intense mucucutaneous manifestations]

Behcet's disease is a multisystemic inflammatory disease with various manifestations at the skin level, especially in the form of acne-like lesions or erythema nodosum. Susceptibility to this disease is strongly linked to the presence of the HLA_B51 allele, although certain environmental factors such as infectious agents have also been implicated in its pathogenesis. We present the case of a patient with Behcet's disease who developed a severe flare characterized by lesions similar to those seen in Sweet's syndrome. Histologically we observed granulomatous vasculitis.

[Cutaneous necrotizing vasculitis in a patient with Behcet's disease; mimicking polyarteritis nodosa]

A 25-year-old-man was referred with an approximately 1-year history of recurrent fever, tonsillitis, testicular pain and testicular swelling in June 2009. He also complained of visual disturbance, some erythema nodosum (EN) like lesions on his lower extremities and oral aphthous ulcerations for 5 months. Opthalmological consultation confirmed retinochoroiditis, and ultrasonography revealed epididymitis. A biopsy of the EN like lesion showed a necrotizing vasculitis of the small and medium-sized vessels with septal panniculitis in the subcutis. The laboratory findings revealed an elevation of CRP and positive HLA-B51. He was diagnosed with incomplete Behcet's disease according to the Japanese criteria (1987). After the initiation of the therapy with 10 mg/day of prednisolone, his symptoms promptly ameliorated. In our case, although epididymitis as well as the histopathological findings suggested polyarteritis nodosa (PN), a diagnosis of BD was established on the basis of other contemporaneous findings. Necrotizing vasculitis as a cutaneous manifestation in patients with BD has been rarely reported. However, BD and PN, including cutaneous PN, have rarely described in conjunction. Therefore, we propose that PN-like necrotizing vasculitis might be the subtype of BD.

Generalized Sweet syndrome lesions associated with Behçet disease: a true association or simply co-morbidity?

Sweet syndrome or acute febrile neutrophilic dermatosis is a condition characterized by painful erythematous papules, nodules, and plaques, which demonstrate mature neutrophilic infiltration of the upper dermis histopathologically, and is usually associated with systemic symptoms such as fever and neutrophilia. Generalized Sweet syndrome lesions are usually noted in association with malignancies. Sweet syndrome lesions are rarely seen in patients with Behçet disease and, if present, are usually fewer in number. In this report, we present two female patients who developed generalized Sweet syndrome lesions during follow-up after the diagnosis of Behçet disease. The clinical and histopathologic findings in our patients together with the data in the literature suggest that generalized Sweet syndrome lesions in a patient with clinically inactive Behçet disease should remind the clinician that a strict differential diagnosis needs to be made between Sweet syndrome associated with Behçet disease and the rare cutaneous manifestation of Behçet disease that resembles the lesions of Sweet syndrome.

A histopathological approach: when papulopustular lesions should be in the diagnostic criteria of Behçet's disease?

BACKGROUNDPapulopustular lesions (PPL) are commonly seen cutaneous lesions in Behçet's disease (BD). Some authorities do not recommend using cutaneous lesions for diagnostic criteria because these lesions are confused with acne vulgaris. Objective To understand if PPL have diagnostic value in BD.

METHODS

Biopsy was performed on papulopustular lesions of Behçet's patients for histopathological examination to compare with the control group composed of patients with acne vulgaris. Forty two patients with BD and 21 control patients with acne vulgaris were enrolled in the study. Histopathological findings were classified as leukocytoclastic vasculitis, lymphocytic vasculitis, superficial and/or deep perivascular infiltration, and folliculitis and/or perifolliculitis.

RESULTS

Of the specimens from 42 Behçet's disease patients, 7 (16.7%) revealed leukocytoclastic vasculitis and 3 (7.1%) had lymphocytic vasculitis, 15 (35.7%) had superficial perivascular and/or interstitial infiltration, 12 (28.6%) had superficial and deep perivascular and/or interstitial infiltration, 5 (11.9%) had folliculitis or perifolliculitis. Of the control group patients, 9 (42.9%) had folliculitis or perifolliculitis, 8 (38.1%) revealed superficial perivascular inflammation and 4 (19.0%) revealed mixed superficial and deep perivascular inflammation. Vasculitis was not encountered in any control group specimens. Vasculitis ratio was statistically higher in Behcet's disease patients (P = 0.016).

CONCLUSIONS

We evaluated more patients than previous related studies reported in the literature. Histopathological findings of vasculitis were encountered only in BD group. Non-vasculitis histopathological findings were also encountered in the control group patients. In conclusion, PPL can be used as a diagnostic criterion of BD subsequent to finding vasculitis in histopathological examination of the biopsy specimen of the PPL.

Neutrophilic dermatoses in children

The neutrophilic dermatoses are rare disorders, especially in children, and are characterized by neutrophilic infiltrates in the skin and less commonly in extracutaneous tissue. The neutrophilic dermatoses share similar clinical appearances and associated conditions, including inflammatory bowel disease, malignancies, and medications. Overlap forms of disease demonstrating features of multiple neutrophilic dermatoses may be seen. The manuscript attempts to provide an up-to-date review of (i) classical neutrophilic dermatoses, focusing on distinctive features in children and (ii) neutrophilic dermatoses which may largely be pediatric or genodermatosis-associated (Majeed, SAPHO [synovitis, severe acne, sterile palmoplantar pustulosis, hyperostosis, and osteitis] syndrome, PAPA (pyogenic sterile arthritis, pyoderma gangrenosum, and acne), PFAPA (periodic fever with aphthous stomatitis, pharyngitis, and cervical adenopathy), and other periodic fever syndromes, and congenital erosive and vesicular dermatosis healing with reticulated supple scarring).

Behçet disease in a child--emphasis on cutaneous manifestations

The diagnosis of Behçet disease is based upon clinical criteria because of the lack of pathognomonic laboratory findings. Recurrent episodes of oral and genital ulcerations, skin lesions, and ocular manifestations are seen. The disease may also involve the central nervous system, gastrointestinal tract and, less frequently, the large vessels. In general, manifestations occur in the third or fourth decade of life and are not common in children. Therefore few data concerning this age group have been found in the literature. In this study we report a child with Behçet disease beginning at 1 year of age whose cutaneous manifestations were exuberant acne-like and folliculitis-like lesions, which were crucial for diagnostic confirmation.

Cutaneous Vasculitis Update: Small Vessel Neutrophilic Vasculitis Syndromes

A broad and diverse spectrum of vasculitic syndromes exists. These syndromes affect the skin with varying levels of associated systemic manifestations, running the gamut from a self-limited, localized, cutaneous phenomenon to rapidly progressive, multiorgan disease. The majority of cases of cutaneous vasculitis will show a neutrophilic small vessel vasculitis that can be either a primary (idiopathic) disorder (eg, cutaneous leukocytoclastic angiitis) or a secondary disorder that is associated with drugs, infection (eg, streptococcal infection, viral hepatitis), or underlying disease (eg, connective tissue disease, malignancy). Biopsy is the gold standard for the diagnosis of cutaneous vasculitis and also necessary for the detection of cutaneous vascular immune complexes by direct immunofluorescence. Based on the type of vessel disrupted by inflammation (small and/or muscular), the distribution of vasculitis in the dermis and subcutis, and predominate inflammatory cell-type mediating vessel wall damage, a list of relevant differential diagnoses can be generated. This histologic information coupled with extravascular findings such as tissue eosinophilia, tissue neutrophilia, and/or granulomas, plus pathophysiologic markers such as direct immunofluorescent examination for immune complexes and serologic evaluation for antineutrophil cytoplasmic antibodies allows for more accurate diagnosis of specific vasculitic entities. Herein, we review both primary and secondary vasculitic syndromes that affect the skin and show a small vessel neutrophilic mediated vasculitis.

A case of Behçet's disease associated with necrotizing small vessel vasculitis

Cutaneous manifestations are an important feature of Behçet's disease (BD) and are classified as a major diagnostic criterion by the International Study Group (ISG). Necrotizing vasculitis as a skin manifestation in patients with BD has been reported rarely. In this report, we describe a patient who fulfills ISG criteria for the diagnosis of BD with necrotizing small vessel vasculitis developed necrosis on distal part of the fifth finger of right foot and the heel.

Neutrophilic phlebitis is characteristic of intestinal Behçet's disease and simple ulcer syndrome

AIM

To characterize the histological features of intestinal Behcet's disease and simple ulcer syndrome and to clarify the possible mechanisms involved in their development by analysing the type of inflammatory infiltrates in the diseased intestine and the expression of adhesion molecules on endothelial cells.

METHODS AND RESULTS

Tissue samples from 10 patients diagnosed as having intestinal Behcet's disease or simple ulcer syndrome were studied. Immunohistochemical studies were performed on paraffin-embedded tissue using a labelled streptavidin-biotin method. In all cases, phlebitis was remarkably seen in submucosal inflammatory lesions, but the adjacent arteries were not affected. Inflammatory infiltrates around the affected vessels consisted of neutrophils and mononuclear cells, and neutrophils predominated over CD68+ macrophages and lymphocytes. The majority of mononuclear cells were CD3+ T cells, and CD4+ cells were more frequent than CD8+ T cells. As for adhesion molecule expression, intercellular adhesion molecule-1, but not vascular cell adhesion molecule-1, was expressed in most endothelial cells of the vessels with phlebitis, some of which were also positive for HLA-DR.

CONCLUSION

Neutrophilic phlebitis may be involved in the pathogenesis of intestinal Behcet's disease and simple ulcer syndrome.

Bilateral nipple necrosis in a breastfeeding woman with Behçet's disease

Behçet's disease is a chronic, multisystem disorder. A 23-year-old female patient diagnosed with Behçet's disease 3 years earlier was admitted with deep ulcers on both areolae caused by detachment of the nipples following breastfeeding since spontaneous delivery of her baby. Physical examination revealed a necrotic ulcer crater 2 cm in diameter on each breast, with the lactiferous ducts draining into these. Incisional biopsy sample from the areola ulcer border on the left breast showed leukocytoclastic vasculitis. Breastfeeding was stopped, and local wound care and systemic corticosteroid therapy were started. After 4 weeks, epithelialization tissue filled the ulcers, leveling the crater base with the areola. Bilateral nipple necrosis in a breastfeeding woman is a rare entity. It is thought that in the present case minor trauma caused by breastfeeding accompanied by neutrophilic infiltration resulting from amplified inflammatory response and leukocytoclastic vasculitis attributable to Behçet's disease was responsible for the necrosis.

Expression of bcl-2 protein in active skin lesions of Behçet's disease

BACKGROUND

Expression of bcl-2 protein has been shown to play an important role in the pathogenesis of some inflammatory as well as neoplastic disorders. In this study we have investigated the presence of bcl-2 protein in active skin lesions of Behçet's disease and compared these results with normal skin samples of Behçet's disease (BD) patients and BD unrelated leukocytoclastic vasculitis.

METHODS

Active skin lesions of 23 Behçet's disease patients, normal skin samples of seven Behçet's disease patients, and archival biopsy specimens of 23 cutaneous leukocytoclastic vasculitis were investigated for the presence of bcl-2 protein by immunohistochemical methods. Results of staining were assessed semiquantitatively. Chi-square tests were used for statistical analysis.

RESULTS

Expression of bcl-2 protein were demonstrated in 16 of 23 (69.5%) and 8 of 23 (34.7%) patients with Behçet's disease and leukocytoclastic vasculitis, respectively. There were statistically significant difference between two groups (x2 = 4.27, P < 0.05). None of the normal skin samples of Behçet's disease patients showed bcl-2 expression.

CONCLUSION

Expression of bcl-2 protein may play a particular role in the development of skin lesions in Behçet's disease by causing prolonged survival of infiltrating lymphocytes.

The multiple faces of Behçet's disease and its aetiological factors

Behçet's disease (BD) is a chronic, inflammatory multisystemic condition of unknown aetiology. It is clinically characterized by recurrent orogenital ulcerations and skin eruptions; ocular manifestations; arthritis; vasculitis and in some cases neurological and large vessel involvement. Aetiology has not been defined, but genetic, environmental, viral, bacterial and immunological factors have been proposed as causative agents. Treatment includes colchicine, thalidomide, steroids and immunosuppressive agents and it is based on the severity of systemic manifestations, such as central nervous system involvement, arterial aneurysms and thrombosis of the major veins. Mortality is related to major system involvement. In this article the different clinical features, the multiple faces of BD and a list of currently suspected aetiological factors of the disease are discussed, and treatment modalities summarized.

Histopathologic features of erythema nodosum--like lesions in Behçet disease: a comparison with erythema nodosum focusing on the role of vasculitis

Many patients with Behçet disease (BD) develop lesions that clinically resemble those of erythema nodosum (EN) but differ from that condition with regard to their microscopic features. We examined 11 sections of EN-like lesions in BD and compared them with 9 sections of classic EN using routine histopathology and immunohistochemistry so as to form a comprehensive picture of the pathologic findings in BD and to determine the role of vasculitis in the formation of lesions. Erythema nodosum-like lesions of BD are characterized by panniculitis, usually lobular or mixed septal and lobular in pattern, with variable numbers of neutrophils, lymphocytes, and histiocytes as well as variable numbers of necrotic adipocytes. Vasculitis was noted in most EN-like lesions in BD. Scattered vessels showing lymphocytic vasculitis were evident in 6 sections, and foci of leukocytoclastic vasculitis were obvious in 4 sections, sometimes with phlebitis or arteriolitis. In specimens with classic EN, we did not observe vasculitis. Only the percentages of CD3+ lymphocytes and chloroacetate esterase-positive neutrophils in the infiltrating cells showed statistically significant differences (P < 0.05) between EN-like lesions in BD and EN through immunohistochemical and enzyme cytochemical studies. Because vasculitis in the EN-like lesions in BD was extensive and not limited to areas of severe inflammation, we believe that it is primary vasculitis. We suggest that vasculitis is an important pathologic event in EN-like lesions in BD but cannot determine the extent to which other pathologic changes such as septal or lobular panniculitis, fat necrosis, neutrophilic infiltration, or microabscess formation are secondary features.

Defining lymphocytic vasculitis

Vasculitis can be defined as vascular inflammation which is usually immune mediated, leading to structural and functional damage to the vessel wall. Our concept of vasculitis has been built around the events surrounding immune-complex-triggered leukocytoclastic vasculitis, while the role of lymphocyte mediated vasculitis remains largely undefined. This may be due to maintaining a stereotypic image of lymphocytic vasculitis as one associated with vascular necrosis, fibrin deposition and haemorrhage and merely substituting lymphocytes for neutrophils. Our understanding of lymphocytic vasculitis may be advanced by identifying the clinical settings in which such reactions may occur, such as autoimmune skin diseases sharing features with graft vs host disease, as well as recognizing that lymphocyte mediated inflammation may lead to a morphologically distinct group of vasculitides, apart from those associated with angiodestruction. Lymphocytic endovasculitis, lymphocytic lichenoid vasculitis and granulomatous vasculitis are potential examples of lymphocytic vasculitis that differ from the histological pattern seen in association with immune complex leukocytoclastic vasculitis. Ultimately, the proof that these vasculitides are examples of lymphocytic vasculitis will rest on new techniques emerging in molecular pathology that have the capacity of analysing the immunological events beyond the current limitations posed by routine histopathology.

[Pathology of large vessel vasculitides]

INTRODUCTION

Vasculitides can be classified according to the size of the involved vessels. The pathological patterns of large vessel vasculitides are presented here.

CURRENT KNOWLEDGE AND KEY POINTS

They concern Buerger's disease, temporal arteritis, Takayasu's disease, Behçet's disease, infectious arteritides, rheumatologic and miscellaneous diseases. Buerger's disease is a thrombotic arteriopathy with no arterial wall involvement. Temporal arteritis and Takayasu's disease belong to the group of giant cell arteritides. In temporal arteritis, the inflammation is prominent in the internal part of the media and is aggressive for the arterial wall. In Takayasu's disease, the external part of the media is prominently involved. The fibrous thickening of the arterial wall with stenosis is characteristic. Behçet's disease can involve the large arteries with a risk of arterial rupture. Infectious arteritides are not unfrequent in vascular surgery and in previous arterial lesions. Rheumatologic diseases can result in aortitis with aortic incompetence.

FUTURE PROSPECTS AND PROJECTS

These diseases have pathological characteristics which contribute to diagnosis. However, a clearcut classification of vasculitides will come from the precise knowledge of their etiology.

Neutrophilic lobular (pustular) panniculitis associated with rheumatoid arthritis: a case report and review of the literature

Rheumatoid nodules, which affect the subcutis around joints, are the most frequent specific cutaneous lesions of rheumatoid arthritis (RA). Panniculitis is a rarely reported and nonspecific complication of RA. We report a 42-year-old woman with seropositive RA who presented with a 2-month history of lower leg panniculitis. Biopsy of a leg nodule showed a lobular neutrophilic infiltrate with lipophages and central basophilic necrosis. In addition, focal changes of lipomembranous fat necrosis indicative of ischemic damage were identified at the margins of the lobular infiltrate. Neutrophilic lobular panniculitis is commonly detected in panniculitis secondary to bacterial infections, pancreatitis, and factitial causes. However, this pattern of panniculitis has also been reported in some cases of erythema nodosum-like lesions found in Behçet disease or bowel bypass syndrome and in rare cases of seropositive RA. These reported histologic findings fall into the spectrum of neutrophilic vascular reactions described by Jorizzo and Daniels for RA-associated dermatoses. In view of these findings. RA and related neutrophilic dermatoses (e.g., Behçet disease) should be included in the differential diagnosis of neutrophilic lobular panniculitis.

Behçet's disease and complex aphthosis

Behçet's disease is a complex multisystem disease diagnosed by means of clinical criteria. Clinical features include oral and genital aphthae, pustular vasculitic cutaneous lesions, and ocular, gastrointestinal, and vascular manifestations. We believe that complex aphthosis, characterized by oral or oral and genital ulcers, may be a forme fruste of Behçet's disease. Although the pathogenesis of both Behçet's disease and complex aphthosis remain unknown, immune factors, infectious agents, and effector mechanisms are implicated. Treatment is based on the severity of systemic involvement and includes topical therapies as well as colchicine, dapsone, thalidomide, and immunosuppressive agents.