What is the Role of Different Macrophage Subsets in the Evolution of Juvenile Xanthogranulomas?

There are several activated forms of macrophages: 2 main groups are designated M1 and M2. While M1 macrophages have proinflammatory, bactericidal, and phagocytic functions and are the dominant phenotype observed in the early stages of inflammation, M2 macrophages are involved in constructive processes such as tissue repair; they play a role in wound healing and are required for revascularization and re-epithelialization. Juvenile xanthogranuloma (JXG) is the most common non-Langerhans cell histiocytosis. Its pathogenesis is not well understood, but it is not considered a neoplastic entity. JXGs possibly appear as a reaction to a nonspecific injury such as trauma or viral infection, although a genetic predisposition has been suggested in some cases. Tissue damage leads to a histiocytic response. JXGs appear, evolve toward maturation, and then most of them spontaneously regress. Young JXGs are characterized by small macrophages scattered in the dermis, in apposition close to the epidermis. As the lesion matures, the number of foamy macrophages and Touton cells increases and other cell types such as plasma cells, lymphocytes, and polymorphs are observed. Regressing xanthogranulomas will show numerous spindle cells in Significant values are in bold.a storiform distribution, interstitial fibrosis, and few foamy and Touton cells. In this study, we studied the immunophenotypic profile of macrophages found in cutaneous JXGs according to their stage of maturation. We examined the skin biopsies from 25 patients; all were embedded in paraffin and stained with hematoxylin and eosin and for immunohistochemistry. Typically, all JXGs were positive for factor XIIIa and CD4, and were negative for CD1a. The following histiocyte markers were used: CD68, CD204, CD163, MAC387, and HAM56. Images were analyzed by Image J software; data were statistically evaluated by SAS 9.0 software. The cases showed a slight predominance of males and the preference of the JXGs for the axial skin. Lesions occupied the papillary and reticular dermis in 85% of the cases and extended to the subcutaneous fat in the remainder. Compared with mature and regressing JXGs, younger lesions had a higher density of M1 macrophages, stained with MAC387. This antibody labels the histiocytes that have recently arrived in the areas of inflammation. As the lesions matured, there was an overwhelming predominance of M2 macrophages. These cells tended to cluster against the epidermis, except in the 2 cases in phase of regression. This suggests that there is a cross-talk between the epidermis and macrophages and that receptors, cytokines, chemokines, and adhesion molecules may play a role in the development and evolution of JXGs. These results indicate that, for most of their life, JXGs are formed by repairing M2 macrophages and are not just an M1 macrophagic response to a local antigen. The process appears to be influenced by chemical-mediator epidermal-macrophage cross-talking, considering the tendency of these cells to accumulate against the dermoepidermal junction.

Immunocompromised cutaneous district, isotopic, and isopathic phenomena-Systematic review.

BACKGROUND: Although the development of lesions in skin areas that have undergone injury has long been known, understanding of its pathogenesis is limited. Depending on their peculiarities, those events have been described as isomorphic, reverse isomorphic, pseudoisomorphic, isotopic, and isopathic phenomena. Ruocco's immunocompromised cutaneous district (ICD) concept was proposed to include all those phenomena. AIMS: We performed a systematic review and critically evaluated the current understanding about ICD and its relationship with the isotopic and isopathic phenomena. METHODS: To illustrate the complexity of the theme, we present a case of subclinical leprosy, whose manifestation was brisk in an old tattoo. The possible interaction between the approached phenomena, acting in the genesis of the disease, made this a pertinent study. The research was conducted under the PRISMA-P guidelines, in seven biomedical databases between 1996 and 2018. The eligibility criteria were systematic reviews, meta-analyses, clinical studies, and case series, written in English, French, Italian, Portuguese, or Spanish. RESULTS: Using standardized keywords, 1220 articles were identified. After applying the eligibility criteria, 53 studies were selected. CONCLUSION: This review ratifies that all these phenomena are aspects of one single condition. They can be integrated into the ICD concept with the pathogenesis including: (a) neural damage (peripheral or central) and (b) chronic lymphedema. Both may change the local neuroimmune interaction. The identification of these phenomena and the understanding of their pathogenesis are of paramount importance, to define the diagnosis and choose the therapeutic strategy.

Prognostic significance of cyclooxygenase 2 and phosphorylated Akt1 overexpression in primary nonmetastatic and metastatic cutaneous melanomas.

Cyclooxygenase 2 (COX-2) and phosphorylated Akt1 (p-Akt1) are associated with tumor spreading, cell proliferation, high metabolism, and angiogenesis in solid tumors. This study aimed to investigate COX-2 and p-Akt1 expression in primary and metastatic melanomas by correlating with the cellular proliferation index (as revealed by minichromosome maintenance 2 expression) and the outcome of patients with malignant melanomas. Seventy-seven biopsies of malignant melanomas, including 42 primary nonmetastatic melanomas (PNMMs), 12 primary metastatic melanomas (PMMs), and 23 metastatic melanomas (MMs), were retrospectively selected. Tissue microarrays were developed and submitted for immunohistochemical staining for COX-2, p-Akt1, and minichromosome maintenance 2. Increased COX-2 cytoplasmic staining patterns were observed in PMM and MM when compared with PNMM (P=0.0011). Higher nuclear and cytoplasmic expression of p-Akt1 was more closely associated with PMM than with MM and PNMM (P<0.00001). Coexpression of these biomarkers was closely correlated with lower overall survival rates in melanomas. Furthermore, we observed a statistically significant positive correlation between the mitosis index and increased COX-2 expression (P=0.0135) and between p-Akt1 (P=0.0038) and the cellular proliferation index (P=0.0060). Taken together, our findings demonstrate that COX-2 and p-Akt1 play an important combined role during melanoma progression and are associated with highly metastatic tumors and survival rates in patients with MM. In addition, these biomarkers can be used to predict melanoma prognosis independently of metastatic status. However, further studies are required to elucidate the biological role of these biomarkers during the progression of MM events.

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.

Non-invasive method distinguishes chronic telogen effluvium from mild female pattern hair loss: clinicopathological correlation.

BACKGROUND: The distinction between chronic telogen effluvium (CTE) and female pattern hair loss (FPHL) is important because of their different prognosis and treatment. Non-invasive methods have been described to be useful in differentiating FPHL from CTE. This prospective study investigated the use of the washing method to differentiate CTE from mild FPHL. METHODS: Twenty patients with CTE and 17 with FPHL were recruited and followed for 18 months. The diagnosis was established through clinical, laboratory, and histological studies. The patients were asked to abstain from washing their hair for 5 days and then shampoo and collect all hair shed in the process. Hair shafts were then counted and divided into two groups: up to 3 cm in length or longer. RESULTS: In the CTE group, the mean hair count was high (438), and in all cases, <10% were short. In patients with FPHL, the mean count was not as high (215) and in only one patient, short hairs comprised <10% of the total. The greater the number of long hairs, the higher was the density of terminal follicles seen histologically. The CTE group presented a greater number of patients with serum iron values <70 µg/dl. Ferritin levels ranged from 6.98 to 128.33, average of 66.65 (CTE), and 16.5-304.8, average of 114.97 ng/ml (FPHL), but no significant differences were found. CONCLUSION: The washing test can be useful to avoid biopsy procedures. Iron serum levels are possibly an additional parameter that may improve CTE diagnosis if combined with an earlier test.

Keratoacanthoma and Keratoacanthoma-Like Squamous Cell Carcinoma: Similar Morphology but Different Pathogenesis.

Differential diagnosis between keratoacanthoma (KA) and squamous cell carcinoma (SCC) is difficult due to their similarities. The mechanisms that drive their distinct biological behavior are poorly understood. To investigate whether the assessment of microvessel density (MVD) could be helpful in KA and SCC differential diagnosis and to gain insight into the pathogenesis of KA-like neoplasms, we compared the density of CD105- and CD34-stained vessels in KAs and SCCs and their relation to the expression of the p53 oncoprotein and proliferation marker Ki67. This is an observational retrospective cohort study. Forty lesions with clinical appearance of KAs (29 KAs and 11 SCCs) entered the study. A biopsy was taken from each lesion at presentation and the natural clinical course was monitored for at least 1 month. Growing or minimally regressing lesions were submitted to complete surgical excision. The diagnoses were established on combined clinical, histological, and follow-up evaluations. The MVD and p53 or Ki67 expression in neoplastic cells were assessed through morphometry. The MVD did not show discriminating power between KAs and SCCs. The Ki67 proliferation rate was significantly higher in SCCs. Although neoangiogenesis (CD105-MVD) in KAs was associated with cell proliferation, in SCCs it was not. There was significant correlation between p53 expression and neoplasia size in SCCs but not in KAs. From our results, we may conclude that KA and SCC have similarities, as CD105- and CD34-MVD. However, the low Ki67 proliferation index and the positive correlation between Ki-67 index and neovascularization in KA suggest a dependence in neovascularization to grow in KA, pointing to involvement of distinct pathogenesis.

Histological features of the nasal mucosa in hematopoietic stem cell transplantation.

BACKGROUND: Immunosuppression is the leading cause of recurrent sinus infections after hematopoietic stem cell transplant (HSCT), with increased incidence of sinusitis in patients with chronic graft versus host disease (GVHD). Histological descriptions of the oral mucosa, lung ciliary epithelium, and intestinal mucosa related to HSCT have been described. However, few have described the nasal mucosa. We, therefore, sought to elucidate the histological and ultrastructural features of the nasal mucosa in patients after HSCT to better understand the pathophysiology of the immune response. METHODS: Uncinate processes from 24 HSCT patients and 12 immunocompetent patients were subjected to histological analyses via light and transmission electron microscopy (TEM). RESULTS: TEM revealed aberrant cilia structure, altered mitochondria quantity, microvilli, and cytoplasm vacuolization. All HSCT patients with rhinosinusitis had significant loss or absence of cilia (p = 0.018). Apoptotic bodies were increased and Goblet cells decreased in nasal epithelium from patients with chronic GVHD (p = 0.04). CONCLUSION: This tissue destruction likely enhances pathogen penetration resulting in recurrent infection.

Perforin and granzyme B expression in oral and cutaneous lichen planus - a comparative study.

BACKGROUND: Although cutaneous and oral lichen planus (LP) share similar histopathological features, oral LP often follows a recalcitrant course while LP skin lesions tend to be self-limiting. Apoptosis, mediated by cytotoxic T-cells in LP, may be triggered by the release of molecules such as perforin and granzyme B. As variation in clinical behavior can reflect differences in LP immune expression, we studied the role of those cytotoxic molecules in oral and cutaneous LP. METHODS: We analyzed 16 cases of cutaneous LP and 29 of oral LP. The sections were studied on hematoxylin and eosin, CD4, CD8, perforin and granzyme B staining. RESULTS: The mean number of immunostained cells expressing each cytotoxic molecule was significantly higher in oral LP than in cutaneous LP. A higher number of single necrotic keratinocytes (apoptotic bodies) was found in oral LP lesions when compared to cutaneous LP. Only in oral LP lesions, a higher number of CD4-positive cells was found in active lesions when compared to regressive lesions. CONCLUSIONS: Our results confirm increased expression of granzyme B and perforin in oral LP lesions as compared to cutaneous LP. The increased expression suggests a relationship with the clinical behavior of the disease.

Histological features of the nasal mucosa in hematopoietic stem cell transplantation.

BACKGROUND: Immunosuppression is the leading cause of recurrent sinus infections after hematopoietic stem cell transplant (HSCT), with increased incidence of sinusitis in patients with chronic graft versus host disease (GVHD). Histological descriptions of the oral mucosa, lung ciliary epithelium, and intestinal mucosa related to HSCT have been described. However, few have described the nasal mucosa. We, therefore, sought to elucidate the histological and ultrastructural features of the nasal mucosa in patients after HSCT to better understand the pathophysiology of the immune response. METHODS: Uncinate processes from 24 HSCT patients and 12 immunocompetent patients were subjected to histological analyses via light and transmission electron microscopy (TEM). RESULTS: TEM revealed aberrant cilia structure, altered mitochondria quantity, microvilli, and cytoplasm vacuolization. All HSCT patients with rhinosinusitis had significant loss or absence of cilia (p = 0.018). Apoptotic bodies were increased and Goblet cells decreased in nasal epithelium from patients with chronic GVHD (p = 0.04). CONCLUSION: This tissue destruction likely enhances pathogen penetration resulting in recurrent infection.

Anetodermic pilomatricoma.

A pilomatricoma, or Malherbe's calcifying epithelioma, is an uncommon tumor originating from hair matrix cells. It is clinically characterized by a solitary, firm nodule. As the skin overlying the pilomatricoma may change in color and texture, its clinical presentation can vary. We report an unusual case of pilomatricoma with associated anetoderma on the lower extremity of a 12-year-old girl. Histology revealed a thinned dermis replaced by myxomatous tissue between the surface and a deep-seated tumoral mass. This mass is formed of irregular islands of basaloid cells, shadow cells, calcified areas and discrete inflammatory and foreign-body reactions surrounding it. Anetodermic cutaneous changes may occur in pilomatricomas without histological evidence of triggering factors.

Density of dendritic cells around basal cell carcinomas is related to tumor size, anatomical site and stromal characteristics, and might be responsible for the response to topical therapy.

BACKGROUND: The dermal dendritic cell (DC) is considered to be an important component of the host defense against basal cell carcinomas (BCCs). Imiquimod, an immunologic response modifier, has recently been introduced in the topical therapy of BCCs. There is some evidence that the DC pretreatment density may affect the efficacy of imiquimod. The aim of our study was to find out which clinical or histological variables are related to the DC density at the margins of BCCs. METHODS: Thirty cases of BCCs of aggressive and 30 cases of nonaggressive subtypes were selected from our files. In histological sections, the density of FXIIIa-positive DCs and 1A4-positive myofibroblasts in the tumor surrounding stroma was quantified, as well as the stroma type, the tumor size and the DC density in the normal dermis. RESULTS: In nonaggressive BBCs, a multiple linear regression showed that a higher DC density was associated with an increased number of myofibroblasts, smaller tumors and those located on the face. For the aggressive subtypes, a higher DC density was related not only to an increased myofibroblast density, smaller BCCs or location on the face, but also to the presence of less mucinous and more granulation type stroma and an increased DC density in the normal dermis. The stability of the models was confirmed by bootstrap resampling. CONCLUSION: Our study demonstrates that the density of DCs around BCCs is related to tumor size, localization and characteristics of the surrounding tumor stroma.

Texture analysis of the epidermis based on fast Fourier transformation in Sjögren-Larsson syndrome.

OBJECTIVE: To investigate whether image analysis of routine hematoxylin-eosin (H-E) skin sections using fast Fourier transformation (FFT) could detect structural alterations in patients with Sjögren-Larsson syndrome (SLS) diagnosed by molecular biology. STUDY DESIGN: Skin punch biopsies of 9 patients with SLS and 17 healthy volunteers were obtained. Digital images of routine histologic sections were taken, and their gray scale luminance was analyzed by FFT. The inertia values were determined for different ranges of the spatial frequencies in the vertical and horizontal direction. To get an estimation of anisotropy, we calculated the resultant vector of the designated frequency ranges. RESULTS: In the prickle cell layer, SLS patients showed more intense amplitudes in spatial structures with periods between 1.2 and 3.6 microm in the vertical direction, which correlated in part with accentuated nuclei and nucleoli and perinucleolar halos in the H-E sections. In a linear discriminant analysis, the variables derived from the FFT images correctly discriminated 84.6% of the patients. Texture features derived from the gray level cooccurrence matrix were not able to separate the groups. CONCLUSION: Exploratory texture analysis by FFT was able to detect discrete alterations in the prickle cell layer in routine light microscopy slides of SLS patients. The structural changes identified by FFT may be related to abnormal cellular components associated with aberrant lipid metabolism.