Rare glomus tumor formation following trauma to the first digit.

INTRODUCTION: Glomus tumors are rare and few cases are reported in the literature. They typically occur in females on the digits of the hands. CASE PRESENTATION: We report a case of a 30 year-old woman who presented with a mass that developed on the distal tip of her right thumb after traumatic injury. Magnetic resonance imaging (MRI) was conducted and mass resection was performed. Histopathology confirmed that the mass was a glomus tumor. CLINICAL DISCUSSION: Clinical presentations of glomus tumors are typically non-specific, mainly consisting of a small mass with chronic pain, with a lengthy time to diagnosis and potentially improper management. MRI is the preferred diagnostic step, followed by curative surgical excision and pathological confirmation. CONCLUSION: Glomus tumors can cause significant discomfort for patients, and clinicians should be aware of the rare diagnosis when treating painful masses on the extremities, as surgical excision is often curative.

Gastrointestinal stromal tumors: a comprehensive review.

Gastrointestinal stromal tumors (GISTs) are rare neoplasms of the gastrointestinal tract associated with high rates of malignant transformation. Most GISTs present asymptomatically. They are best identified by computed tomography (CT) scan and most stain positive for CD117 (C-Kit), CD34, and/or DOG-1. There have been many risk stratification classifications systems which are calculated based on tumor size, mitotic rate, location, and perforation. The approaches to treating GISTs are to resect primary low-risk tumors, resect high-risk primary or metastatic tumors with imatinib 400 mg daily for 12 months, or if the tumor is unresectable, neoadjuvant imatinib 400 mg daily followed by surgical resection is recommended. Sunitinib is required for KIT exon 9, 13, and 14 mutations, while ponatinib is used for exon 17 mutations and regorafenib for highly refractory tumors. High-risk tumors should be monitored for recurrence with serial abdominal CT scans. Radiofrequency ablation has shown to be effective when surgery is not suitable. Newer therapies of ipilimumab, nivolumab, and endoscopic ultrasound alcohol ablation have shown promising results. This report addresses the epidemiology, clinical presentation, diagnostic imaging, histologic diagnosis, classification and risk stratification, staging and grading, surgical treatment, adjuvant treatment, and metastasis of GISTs.

Facebook Discussion Groups Provide a Robust Worldwide Platform for Free Pathology Education.

CONTEXT: - Facebook (Menlo Park, California) is one of many online sites that provide potential educational tools for pathologists. We have each founded Facebook groups dedicated to anatomic pathology, in which members can share cases, ask questions, and contribute to discussions. OBJECTIVES: - To report our experiences in founding and maintaining these Facebook groups and to characterize the contributed content. DESIGN: - We circulated a survey among the group founders, then compiled and analyzed the responses. RESULTS: - The groups varied in membership and in the quality of member contribution. Most posts were of pathology cases, although other topics (such as research articles) were also shared. All groups remained active and received posts from users all over the world, although all groups had many noncontributing members and received unwanted messages (which were screened and removed). Most founders were glad they had founded the groups because they provided an opportunity to both teach and learn. CONCLUSIONS: - Each analyzed Facebook group had a different character, and some downsides exist, but the groups all provided a no-cost way for pathologists and others across the world to interact online with many colleagues.

Multinucleated giant cells in atherosclerotic plaques of human carotid arteries: Identification of osteoclast-like cells and their specific proteins in artery wall.

UNLABELLED: The mechanism(s) mediating atherosclerotic calcification may be similar to those governing bone remodeling, and osteoblast-like cells have been observed in plaque. We tested the hypothesis that osteoclast-like cells (OLCs) also exist in atherosclerotic arteries. In 205 tissue blocks obtained from 21 patients undergoing carotid endarterectomy, we performed histopathologic analysis, histochemical staining for tartrate-resistant acid phosphatase (TRAP), and immunohistochemical analysis for osteoclast and macrophage antigens, including CD68, colony stimulating factor-1 receptor (CSF-1R), cathepsin K (cat-K), receptor activator of nuclear factor-κB (RANK), and osteoprotegerin (OPG). Lesions were classified according to the AHA system, and further grouped as calcified or non-calcified (with necrotic cores or suture granulomas). Multinucleated giant cells morphologically similar to osteoclasts were frequently seen, sometimes exhibited morphologic evidence of polarization, were closely associated with regions of calcification, fibrosis, or granulomatous tissue, and also appeared to be associated with neovascularization and regions of intraplaque hemorrhage. TRAP-positive cells often expressed the osteoclast-associated antigens cat-K, RANK, and OPG. Calcification typically occurred at the base of plaque or in necrotic cores in various morphologies, including a fine powdery pattern, a diffuse pattern of larger deposits near cholesterol clefts and necrotic centers, and nodular forms. Regions of frank ossification were rarely observed. CONCLUSION: OLCs are frequently found in plaque, and co-localize with sub-regions of cholesterol deposition, mineralization, and necrotic and foreign debris. True bone tissue is rare in carotid plaque, although more common in other arteries. Our findings suggest that arterial OLCs might degrade mineral deposits, prevent formation of calcification or both and therefore counterbalance the activity of the osteoblast-like cells in atherosclerosis.

Detection of rupture-prone atherosclerotic plaques by time-resolved laser-induced fluorescence spectroscopy.

OBJECTIVE: Plaque with dense inflammatory cells, including macrophages, thin fibrous cap and superficial necrotic/lipid core is thought to be prone-to-rupture. We report a time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) technique for detection of such markers of plaque vulnerability in human plaques. METHODS: The autofluorescence of carotid plaques (65 endarterectomy patients) induced by a pulsed laser (337 nm, 0.7 ns) was measured from 831 distinct areas. The emission was resolved spectrally (360-550 nm range) and temporally (0.3 ns resolution) using a prototype fiber-optic TR-LIFS apparatus. Lesions were evaluated microscopically and quantified as to the % of different components (fibrous cap, necrotic core, inflammatory cells, foam cells, mature and degraded collagen, elastic fibers, calcification, and smooth muscle cell of the vessel wall). RESULTS: We determined that the spectral intensities and time-dependent parameters at discrete emission wavelengths (1) allow for discrimination (sensitivity >81%, specificity >94%) of various compositional and pathological features associated with plaque vulnerability including infiltration of macrophages into intima and necrotic/lipid core under a thin fibrous cap, and (2) show a linear correlation with plaque biochemical content: elastin (P<0.008), collagen (P<0.02), inflammatory cells (P<0.003), necrosis (P<0.004). CONCLUSION: Our results demonstrate the feasibility of TR-LIFS as a method for the identification of markers of plaque vulnerability. Current findings enable future development of TR-LIFS-based clinical devices for rapid investigation of atherosclerotic plaques and detection of those at high-risk.

Laguerre-based method for analysis of time-resolved fluorescence data: application to in-vivo characterization and diagnosis of atherosclerotic lesions.

We report the application of the Laguerre deconvolution technique (LDT) to the analysis of in-vivo time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data and the diagnosis of atherosclerotic plaques. TR-LIFS measurements were obtained in vivo from normal and atherosclerotic aortas (eight rabbits, 73 areas), and subsequently analyzed using LDT. Spectral and time-resolved features were used to develop four classification algorithms: linear discriminant analysis (LDA), stepwise LDA (SLDA), principal component analysis (PCA), and artificial neural network (ANN). Accurate deconvolution of TR-LIFS in-vivo measurements from normal and atherosclerotic arteries was provided by LDT. The derived Laguerre expansion coefficients reflected changes in the arterial biochemical composition, and provided a means to discriminate lesions rich in macrophages with high sensitivity (>85%) and specificity (>95%). Classification algorithms (SLDA and PCA) using a selected number of features with maximum discriminating power provided the best performance. This study demonstrates the potential of the LDT for in-vivo tissue diagnosis, and specifically for the detection of macrophages infiltration in atherosclerotic lesions, a key marker of plaque vulnerability.

In vivo detection of macrophages in a rabbit atherosclerotic model by time-resolved laser-induced fluorescence spectroscopy.

Accumulation of numerous macrophages in the fibrous cap is a key identifying feature of plaque inflammation and vulnerability. This study investigates the use of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) as a potential tool for detection of macrophage foam cells in the intima of atherosclerotic plaques. Experiments were conducted in vivo on 14 New Zealand rabbits (6 control, 8 hypercholesterolemic) following aortotomy to expose the intimal luminal surface of the aorta. Tissue autofluorescence was induced with a nitrogen pulse laser (337 nm, 1 ns). Lesions were histologically classified by the percent of collagen or macrophage foam cells as well as thickness of the intima. Using parameters derived from the time-resolved fluorescence emission of plaques, we determined that intima rich in macrophage foam cells can be distinguished from intima rich in collagen with high sensitivity (>85%) and specificity (>95%). This study demonstrates, for the first time, that a time-resolved fluorescence-based technique can differentiate and demark macrophage content versus collagen content in vivo. Our results suggest that TR-LIFS technique can be used in clinical applications for identification of inflammatory cells important in plaque formation and rupture.

Calcification of the coronary arteries in the absence of atherosclerotic plaque.

Arterial calcification in the coronary arteries frequently indicates concomitant atherosclerotic plaque but can be present in the medial layers with no evidence of plaque. Calcification of the medial layer of arteries is seen most often in the peripheral arteries but also is widely recognized In the coronary arteries. We describe 2 patients who had marked medial and intimal calcification of the coronary arteries with little or no accompanying atherosclerosis.

HIV-1 induces cardiomyopathyby cardiomyocyte invasion and gp120, Tat, and cytokine apoptotic signaling.

We examined heart tissues of AIDS patients with or without HIV cardiomyopathy (HIVCM) by immunohistochemistry, in situ polymerase chain reaction, in situ riboprobe hybridization, and the TUNEL technique for apoptosis. In HIVCM tissues, only inflammatory cells, but not endothelial cells or cardiomyocytes, displayed HIV-1 DNA and RNA. However, macrophages, lymphocytes, and--in a patchy fashion--cardiomyocytes and endothelial cells exhibited virus envelope protein gp120. Macrophages infiltrated the myocardium in a perivascular fashion and expressed tumor necrosis factor family ligands; adjacent cardiomyocytes suffered apoptosis. In vitro HIV-1 strongly invaded neonatal rat ventricular myocytes (NRVMs) and coronary artery endothelial cells (CAECs) and induced microvilli but did not replicate. HIV-1, gp120, or Tat induced Erk 1/2 phosphorylation, activation of caspase-3, and apoptosis of NRVMs and CAECs; all of these were inhibited by a MAPK/ERK-kinase (MEK) inhibitor U0126. The pathogenesis of HIVCM involves HIV-1 replication in inflammatory cells and induction of cardiomyocyte apoptosis by (1) the extrinsic pathway through apoptotic ligands and (2) the intrinsic pathway through direct virus entry and gp120- and Tat-proapoptotic signaling.

Role for sterol regulatory element-binding protein in activation of endothelial cells by phospholipid oxidation products.

Oxidized phospholipids, including oxidation products of palmitoyl-arachidonyl-phosphatidyl choline (PAPC), are mediators of inflammation in endothelial cells (ECs) and known to induce several chemokines, including interleukin-8 (IL-8). In this study, we show that oxidized PAPC (OxPAPC), which accumulates in atherosclerotic lesions, paradoxically depletes endothelial cholesterol, causing caveolin-1 internalization from the plasma membrane to the endoplasmic reticulum and Golgi, and activates sterol regulatory element-binding protein (SREBP). Cholesterol loading reversed these effects. SREBP activation resulted in increased transcription of the low-density lipoprotein receptor, a target gene of SREBP. We also provide evidence that cholesterol depletion and SREBP activation are signals for OxPAPC induction of IL-8. Cholesterol depletion by methyl-beta-cyclodextrin induced IL-8 synthesis in a dose-dependent manner. Furthermore, cholesterol loading of ECs by either the cholesterol-cyclodextrin complex or caveolin-1 overexpression inhibited OxPAPC induction of IL-8. These observations suggest that changes in cholesterol level can modulate IL-8 synthesis in ECs. The OxPAPC induction of IL-8 was mediated through the increased binding of SREBP to the IL-8 promoter region, as revealed by mobility shift assays. Overexpression of either dominant-negative SREBP cleavage-activating protein or 25-hydroxycholesterol significantly suppressed the effect of OxPAPC on IL-8 transcription. A role for SREBP activation in atherosclerosis is suggested by the observation that EC nuclei showed strong SREBP staining in human atherosclerotic lesions. The current studies suggest a novel role for endothelial cholesterol depletion and subsequent SREBP activation in inflammatory processes in which phospholipid oxidation products accumulate.

Immunoperoxidase staining for C4d on paraffin-embedded tissue in cardiac allograft endomyocardial biopsies: comparison to frozen tissue immunofluorescence.

C4d deposition in microvasculature is a marker for humoral rejection. The authors compared a recently developed C4d immunoperoxidase (IP) method for paraffin-embedded tissue to immunofluorescence (IF) of frozen tissue. Of 315 frozen endomyocardial biopsies with IF staining for C4d, 280 were negative and 35 were positive. Negative controls were 17 negative biopsies and 11 biopsies with myocyte necrosis. The extent of IP and IF staining was graded as 0 to 3+. Staining intensity and the number and type of positive vessels were recorded. Staining patterns in Quilty lesions (QL) and foci of acute cellular rejection (ACR) were also evaluated. In 34 biopsies with sufficient tissue, IP criteria of 2+/3+, or more than 10 to 20 positive vessels per 10 high-power fields detected 25.0% (1/4), 18.2% (2/11), and 84.2% (16/19) of 1+, 2+, and 3+ IF-positive biopsies, respectively, without false positives. Considering C4d IF 3+ as positive resulted in 84.2% (16/19) sensitivity and 93.0% specificity (40/43). Intensely stained capillaries predominated in six of seven biopsies when more than 100 capillaries per 10 high-power fields were positive. Seventy percent (7/10) of IP 2+ and 3+ biopsies showed positive capillaries in QLs, while 36.4% (4/11) of IP 1+ and negative biopsies did. All eight IP 2+/3+ biopsies showed positive capillaries in ACR foci, while 25.0% (1/4) of IP-negative biopsies did. Capillary staining in QLs and areas of ACR reflects overall C4d deposition. In conclusion, IP staining of 2+/3+ is highly sensitive and specific for C4d positivity. The authors recommend considering 2+ and 3+ as positive staining when using the IP technique.

Molecular, endocrine, and genetic mechanisms of arterial calcification.

Pathologists have recognized arterial calcification for over a century. Recent years have witnessed a strong resurgence of interest in atherosclerotic plaque calcification because it: 1) can be easily detected noninvasively; 2) closely correlates with the amount of atherosclerotic plaque; 3) serves as a surrogate measure for atherosclerosis, allowing preclinical detection of the disease; and 4) is associated with heightened risk of adverse cardiovascular events. There are two major types of calcification in arteries: calcification of the media tunica layer (sometimes called Mönckeberg's sclerosis), and calcification within subdomains of atherosclerotic plaque within the intimal layer of the artery. There are important similarities and differences between these two entities. Of particular interest are increasing parallels between cellular and molecular features of arterial calcification and bone biology, and this has led to accelerating interest in understanding how and why bone-like mineral deposits may form in arteries. Here, we review the two major pathological types of arterial calcification, the proposed models of calcification, and endocrine and genetic determinants that affect arterial calcification. In addition, we highlight areas requiring further investigation.

Calcification in atherosclerosis: bone biology and chronic inflammation at the arterial crossroads.

Dystrophic or ectopic mineral deposition occurs in many pathologic conditions, including atherosclerosis. Calcium mineral deposits that frequently accompany atherosclerosis are readily quantifiable radiographically, serve as a surrogate marker for the disease, and predict a higher risk of myocardial infarction and death. Accelerating research interest has been propelled by a clear need to understand how plaque structure, composition, and stability lead to devastating cardiovascular events. In atherosclerotic plaque, accumulating evidence is consistent with the notion that calcification involves the participation of arterial osteoblasts and osteoclasts. Here we summarize current models of intimal arterial plaque calcification and highlight intriguing questions that require further investigation. Because atherosclerosis is a chronic vascular inflammation, we propose that arterial plaque calcification is best conceptualized as a convergence of bone biology with vascular inflammatory pathobiology.

Molecular imaging of cardiac cell transplantation in living animals using optical bioluminescence and positron emission tomography.

BACKGROUND: The current method of analyzing myocardial cell transplantation relies on postmortem histology. We sought to demonstrate the feasibility of monitoring transplanted cell survival in living animals using molecular imaging techniques. METHODS AND RESULTS: For optical bioluminescence charged-coupled device imaging, rats (n=20) underwent intramyocardial injection of embryonic rat H9c2 cardiomyoblasts (3x10(6) to 5x10(5)) expressing firefly luciferase (Fluc) reporter gene. Cardiac bioluminescence signals were present for more than 2 weeks with 3x10(6) cells: day 1 (627 000+/-15%), day 2 (346 100+/-21%), day 4 (112 800+/-20%), day 8 (78 860+/-24%), day 12 (67 780+/-12%), and day 16 (62 200+/-5% p x s(-1) x cm(2-1) x sr(-1)). For micro-positron emission tomography imaging, rats (n=20) received cardiomyoblasts (3x10(6)) expressing mutant herpes simplex type 1 thymidine kinase (HSV1-sr39tk) reporter gene. Detailed tomography of transplanted cells is shown by 9-(4-[18F]-fluoro-3hydroxymethylbutyl)guanine ([18F]-FHBG) reporter probe and nitrogen-13 ammonia ([13N]-NH3) perfusion images. Within the transplanted region, there was a 4.48+/-0.71-fold increase of in vivo [18F]-FHBG activity and a 4.01+/-0.51-fold increase of ex vivo gamma counting compared with control animals. Finally, the in vivo images of cell survival were confirmed by ex vivo autoradiography, histology, immunohistochemistry, and reporter protein assays. CONCLUSIONS: The location(s), magnitude, and survival duration of embryonic cardiomyoblasts were monitored noninvasively. With further development, molecular imaging studies should add critical insights into cardiac cell transplantation biology.

Genetic loci for diet-induced atherosclerotic lesions and plasma lipids in mice.

Genetic factors independent of those affecting plasma lipid levels are a major contributor to risk for atherosclerosis in humans, yet the basis for these is poorly understood. This study examined plasma lipids and diet-induced atherosclerosis in 16-month-old female mice of strains C56BL/6J and DBA/2J. Mice of the parental strains, from recombinant inbred strains derived from these (BXD RI), and F(2) progeny were fed an atherogenic diet for 16 weeks, beginning at 1 year of age. This induced atherosclerotic lesion formation in both parental strains, accompanied by increased plasma LDL levels. However, individual BXD RI strains and the BXD F(2) mice demonstrated a range of atherosclerotic lesion formation that was not or at best weakly correlated with plasma lipid levels. Quantitative trait locus (QTL) analysis of the BXD F(2) mice identified a locus with significant linkage (lod 4.5) for aortic lesion size on Chromosome (Chr) 10 that was independent of plasma lipids. Other loci with suggestive or significant linkage for various plasma lipid measures were identified on Chr 2, 3, 4, 5, 6, 7, 11, and 17. In this intercross, the genes primarily influencing atherosclerosis are distinct from those controlling plasma lipid levels.

Cartilaginous metaplasia in calcified diabetic peripheral vascular disease: morphologic evidence of enchondral ossification.

The mechanism of arterial calcification is not clear. We examined histological sections of major arteries from lower extremities of two patients with longstanding type II (or non-insulin-dependent) diabetes mellitus, and found morphological evidence of cartilaginous metaplasia and ectopic ossification with associated severe medial arterial calcification and atherosclerosis. Hematoxylin and eosin, alcian blue, and toluidine blue stains were applied for the demonstration of cartilage cells and their specific matrix proteins, and immunohistochemical studies for type II collagen. To our knowledge, cartilaginous metaplasia has not previously been described in medium-sized human muscular arteries. This observation supports the hypothesis that active enchondral ossification may be a pathway leading to arterial calcification in diabetic obstructive peripheral vascular disease.

Genetic characterization of the Dyscalc locus.

Calcification occurs frequently in the development of atherosclerotic lesions, and studies in mice have indicated a genetic contribution. We now show that one genetic factor contributing to aortic calcification is the Dyscalc locus, previously shown to contribute to myocardial calcification. Thus, the Dyscalc locus, on proximal mouse Chromosome (Chr) 7, segregated with vascular calcification in a large cross between susceptible strain DBA/2J and resistant strain C57BL/6J. Further evidence was observed by analysis of recombinant inbred strains derived from various susceptible and resistant parental strains. Myocardial and vascular calcifications are importantly influenced by multiple modifier loci as well as the Dyscalc gene, making fine mapping of Dyscalc difficult. In order to allow more detailed genetic and biochemical characterization of Dyscalc, we have identified congenic strains containing the Dyscalc locus from resistant strain C57BL/10 on the background of susceptible strain C3H/DiSnA. The congenic strains exhibit little or no myocardial or vascular calcification, unlike the background HcB C3H strain, and the calcification segregated as a Mendelian factor, allowing finer mapping of Dyscalc.