Pseudorheumatoid Nodules in Adults

Pressure and Skin: A Review of Disease Entities Driven or Influenced by Mechanical Pressure

Skin perceives and reacts to external mechanical forces to create resistance against the external environment. Excessive or inappropriate stimuli of pressure may lead to cellular alterations of the skin and the development of both benign and malignant skin disorders. We conducted a comprehensive literature review to delve into the pressure-induced and aggravated skin disorders and their underlying pressure-related mechanisms. Dysregulated mechanical responses of the skin give rise to local inflammation, ischemia, necrosis, proliferation, hyperkeratosis, impaired regeneration, atrophy, or other injurious reactions, resulting in various disease entities. The use of personal devices, activities, occupations, weight bearing, and even unintentional object contact and postures are potential scenarios that account for the development of pressure-related skin disorders. The spectrum of these skin disorders may involve the epidermis (keratinocytes and melanocytes), hair follicles, eccrine glands, nail apparatuses, dermis (fibroblasts, mast cells, and vasculature), subcutis, and fascia. Clarifying the clinical context of each patient and recognizing how pressure at the cellular and tissue levels leads to skin lesions can enhance our comprehension of pressure-related skin disorders to attain better management.

Subcutaneous granuloma annulare on the heel: A case report and review of the Japanese published work

Subcutaneous granuloma annulare is a rare variant of granuloma annulare. It mostly presents as painless subcutaneous nodule(s) with or without annular lesions on the lower legs and scalp of children. We herein report a case of a 5-year-old Japanese girl with subcutaneous granuloma annulare on the right heel. The lesions improved in 15 months without any therapy. We also review 85 reported cases of subcutaneous granuloma annulare between 1 and 85 years of age in the Japanese published work. The most susceptible age was 5 years and below; however, a small peak occurred from the 40s to 60s. Subcutaneous granuloma annulare was more frequent in females (male : female ratio, 6:11). Sixty-five cases (76.4%) had multiple lesions; the average number of lesions was 4.8 ± 5.8. The most affected site was the lower legs (28 cases), followed by the dorsum of the foot (21 cases) and scalp (17 cases). The heel was an unusual location; only two cases of sole subcutaneous granuloma annulare have been reported. Twenty-one cases revealed a classical dermal change along with a subcutaneous change. Patients with classical dermal lesions were younger (P < 0.0001) and had a smaller number of lesions (P < 0.05) than those without the lesions. The lesion(s) resolved in 24 of the 44 untreated cases within 1 week to 19 months. Refractory or recurrent lesion(s) were seen in four of 21 treated cases and in four of 44 untreated cases. Because subcutaneous granuloma annulare lesions often resolve spontaneously without treatment, invasive treatments should be avoided.

Bilateral epibulbar pseudorheumatoid nodulosis with a review of ocular adnexal palisading granulomas

We describe the clinical, histopathologic, and immunohistochemical characteristics of episcleral/conjunctival pseudorheumatoid nodulosis, a new granulomatous entity that belongs among a group of related lesions. Specifically, pseudorheumatoid nodulosis should be differentiated from solitary rheumatoid nodules, rheumatoid nodulosis, accelerated rheumatoid nodules and nodulosis, and solitary pseudorheumatoid nodules. A 53-year-old man presented with bilateral painless, large, faintly yellow-gray, partially immobile, solid, circumscribed, and occasionally confluent episcleral nodules of several months' duration. He had never had clinical rheumatoid arthritis and was rheumatoid factor negative. Biopsy revealed multiple, merging episcleral/conjunctival, nonulcerated, palisading granulomas with variably sized central zones of necrobiosis of collagen. Abundant palisading CD68/163 + histiocytes admixed with fibroblasts surrounded the necrobiotic foci, which failed to stain with Alcian blue for mucopolysaccharides. No fibrinoid deposits were detected. Numerous CD3+ T lymphocytes, fewer CD 20 + B lymphocytes, and a smaller subpopulation of CD138 + plasma cells were present. Numerous CD1a + Langerhans cells were scattered among the palisading histiocytes and overlying epithelium. Immunohistochemical stains for immunoglobulins revealed concentrations of IgG, IgM, and IgA, but not IgE, in the necrobiotic zones. Special stains did not reveal evidence of infection nor did polarization microscopy display any foreign material. An extensive systemic and serologic workup was negative. We review simulating palisading or other nonrheumatic granulomas that should be distinguished from pseudorheumatoid nodules or nodulosis and explore therapeutic options.

Histological characteristics of the abdominal aortic wall in patients with vascular chronic Q fever

The aim of this study was to describe specific histological findings of the Coxiella burnetii-infected aneurysmal abdominal aortic wall. Tissue samples of the aneurysmal abdominal aortic wall from seven patients with chronic Q fever and 15 patients without evidence of Q fever infection were analysed and compared. Chronic Q fever was diagnosed using serology and tissue PCR analysis. Histological sections were stained using haematoxylin and eosin staining, Elastica van Gieson staining and immunohistochemical staining for macrophages (CD68), T lymphocytes (CD3), T lymphocyte subsets (CD4 and CD8) and B lymphocytes (CD20). Samples were scored by one pathologist, blinded for Q fever status, using a standard score form. Seven tissue samples from patients with chronic Q fever and 15 tissue samples from patients without Q fever were collected. Four of seven chronic Q fever samples showed a necrotizing granulomatous response of the vascular wall, which was characterized by necrotic core of the arteriosclerotic plaque (P = 0.005) and a presence of high numbers of macrophages in the adventitia (P = 0.007) distributed in typical palisading formation (P = 0.005) and surrounded by the presence of high numbers of T lymphocytes located diffusely in media and adventitia. Necrotizing granulomas are a histological finding in the C. burnetii-infected aneurysmal abdominal aortic wall. Chronic Q fever should be included in the list of infectious diseases with necrotizing granulomatous response, such as tuberculosis, cat scratch disease and syphilis.

Cutaneous necrobiotic conditions associated with rheumatoid arthritis: important extra-articular involvement

Rheumatoid arthritis (RA) presents with various skin conditions as extra-articular manifestations. Rheumatoid nodule is the representative specific skin lesion, histologically exhibiting central necrosis (necrobiosis) surrounded by palisaded macrophages, and being further perivascularly infiltrated with inflammatory cells in the outer regions. Also, there are several skin lesions which histologically show necrobiotic conditions with altered connective tissue degeneration. Necrobiosis may be closely associated with the pathogenesis of RA, i.e., collagen degeneration, recruitment of activated neutrophils, production of various cytokines, and vascular injury. On the other hand, rheumatoid nodule is suggested to develop during therapies with certain drugs such as methotrexate and biologics. These findings may be a clue to understanding the pathomechanisms of rheumatoid nodules. This paper describes several necrobiotic conditions associated with RA, and also discusses the possible pathogenesis and differential diagnosis of rheumatoid nodules. Necrobiosis is the major pathologic condition of cutaneous involvement associated with RA.

Isolated intra-articular pseudorheumatoid nodule of the knee

The authors describe a case of an isolated intra-articular pseudorheumatoid nodule of the knee in an 18-year-old male patient without a diagnosis of rheumatoid arthritis. The patient initially presented with a 3 year history of anterior knee pain and was found to have a 2.8 × 2.1 cm lobulated soft-tissue mass. Histologic findings showed fibrinoid necrosis and chronic inflammatory changes that were consistent with those of a pseudorheumatoid or rheumatoid nodule, and surgical excision of the nodule was curative. A review of the literature revealed no prior cases of an intra-articular pseudorheumatoid nodule or rheumatoid nodule in a patient without clinical or serologic evidence of rheumatoid arthritis.