Giant cells in dermatology

Advances in Understanding and Management of Erdheim-Chester Disease

Erdheim Chester Disease (ECD) is a rare histiocytic disorder marked by infiltration of organs with CD68+ histiocytes. ECD stems from mutations of BRAF and MAP2K1 in hematopoietic stem and progenitor cells (HSPCs), which further differentiate into monocytes and histiocytes. Histopathology reveals lipid-containing histiocytes, which test positive for CD68 and CD133 in immunohistochemistry. Signs and symptoms vary and depend on the organ/s of manifestation. Definitive radiological results associated with ECD include hairy kidney, coated aorta, and cardiac pseudotumor. Treatment options primarily include anti-cytokine therapy and inhibitors of BRAF and MEK signaling.

The Aging Lacrimal Gland of Female C57BL/6J Mice Exhibits Multinucleate Macrophage Infiltration Associated With Lipid Dysregulation

Purpose

Loss of function of the lacrimal gland (LG), which produces the aqueous tear film, is implicated in age-related dry eye. To better understand this deterioration, we evaluated changes in lipid metabolism and inflammation in LGs from an aging model.

Methods

LG sections from female C57BL/6J mice of different ages (young, 2-3 months; intermediate, 10-14 months; old,  ≥24 months) were stained with Oil Red-O or Toluidine blue to detect lipids. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blotting of LG lysates determined differences in the expression of genes and proteins related to lipid metabolism. A photobleaching protocol to quench age-related autofluorescence was used in LG sections to evaluate changes in immunofluorescence associated with NPC1, NPC2, CTSL, and macrophages (F4/80, CD11b) with age using confocal fluorescence microscopy.

Results

Old LGs showed increased lipids prominent in basal aggregates in acinar cells and in extra-acinar sites. LG gene expression of Npc1, Npc2, Lipa, and Mcoln2, encoding proteins involved in lipid metabolism, was increased with age. NPC1 was also significantly increased in old LGs by western blotting. In photobleached LG sections, confocal fluorescence microscopy imaging of NPC1, NPC2, and CTSL immunofluorescence showed age-associated enrichment in macrophages labeled to detect F4/80. Although mononuclear macrophages were detectable in LG at all ages, this novel multinucleate macrophage population containing NPC1, NPC2, and CTSL and enriched in F4/80 and some CD11b was increased with age at extra-acinar sites.

Conclusions

Lipid-metabolizing proteins enriched in F4/80-positive multinucleated macrophages are increased in old LGs adjacent to sites of lipid deposition in acini.

Giant cells: multiple cells unite to survive

Multinucleated Giant Cells (MGCs) are specialized cells that develop from the fusion of multiple cells, and their presence is commonly observed in human cells during various infections. However, MGC formation is not restricted to infections alone but can also occur through different mechanisms, such as endoreplication and abortive cell cycle. These processes lead to the formation of polyploid cells, eventually resulting in the formation of MGCs. In Entamoeba, a protozoan parasite that causes amoebic dysentery and liver abscesses in humans, the formation of MGCs is a unique phenomenon and not been reported in any other protozoa. This organism is exposed to various hostile environmental conditions, including changes in temperature, pH, and nutrient availability, which can lead to stress and damage to its cells. The formation of MGCs in Entamoeba is thought to be a survival strategy to cope with these adverse conditions. This organism forms MGCs through cell aggregation and fusion in response to osmotic and heat stress. The MGCs in Entamoeba are thought to have increased resistance to various stresses and can survive longer than normal cells under adverse conditions. This increased survival could be due to the presence of multiple nuclei, which could provide redundancy in case of DNA damage or mutations. Additionally, MGCs may play a role in the virulence of Entamoeba as they are found in the inflammatory foci of amoebic liver abscesses and other infections caused by Entamoeba. The presence of MGCs in these infections suggests that they may contribute to the pathogenesis of the disease. Overall, this article offers valuable insights into the intriguing phenomenon of MGC formation in Entamoeba. By unraveling the mechanisms behind this process and examining its implications, researchers can gain a deeper understanding of the complex biology of Entamoeba and potentially identify new targets for therapeutic interventions. The study of MGCs in Entamoeba serves as a gateway to exploring the broader field of cell fusion in various organisms, providing a foundation for future investigations into related cellular processes and their significance in health and disease.

Identification of a Unique Morphological Pattern for the Diagnosis of Fungal Rhinosinusitis

Fungal rhinosinusitis (FRS) is a relatively common, but often misdiagnosed disease of paranasal sinuses. The FRS is classified into invasive and non-invasive forms. The non-invasive form includes fungal ball and allergic FRS, and invasive form includes acute invasive FRS, chronic invasive FRS, and granulomatous FRS. Invasive fungal infections are associated with high morbidity and mortality, hence requiring urgent medical and surgical intervention. The histomorphology can help identify certain fungal organisms that cannot be cultured or are rarely visible in exudates. The morphologic diagnosis of tissue invasive and non-invasive fungal infection is essential for appropriate treatment. We analyzed cases of rhinosinusitis from 2017 to 2019 in Pathology Department at a tertiary care cancer hospital, Lahore, Pakistan. All clinical information was retrieved from patient records. Paraffin-embedded tissue blocks were stained with hematoxylin and eosin (H&E), special Grocott methenamine silver stain (GMS), and periodic acid Schiff stain (PAS) according to standard protocol. They were reviewed by two pathologists blinded by fungus status. A total of 169 cases of rhinosinusitis were reviewed. FRS comprised 146 (86.4%) of them. The mean age of patients with FRS was 32.8±14 years. The male:female ratio was 1.4:1. Maxillary sinus was the main site of involvement in 39 (27%) FRS cases. Aspergillus was identified in 117 (80.1%) cases of FRS. The culture reports were available in 44/146 (30.14%) FRS cases. They were negative in 22/44 (50.0%), and Aspergillus species were isolated in 18/44 (40.9%) cases of FRS. There were 84 (57.5%) cases of non-invasive FRS and 59 (40.4%) cases of invasive FRS. Among invasive FRS, there were 56 (38.4%) chronic granulomatous FRS cases including mixed patterns. Majority cases, 54 (96.4%), of chronic granulomatous FRS showed a unique crowded giant cell pattern comprising of foreign body and Langhans type giant cells. These giant cells were arranged closely forming irregular non-caseating granulomas surrounded by lymphocytes and fibrosis. Interestingly, the giant cells were scattered haphazardly without forming a granuloma as well. Fungal organisms were identified in all 56 cases of chronic granulomatous FRS. Histologically, predominant organism was Aspergillus in 48 (85.7%) on GMS and PAS stain. Our study observed a unique crowded giant cell pattern, which is a hallmark of invasive fungal infection. If pathologists are familiar with this unique pattern, they can make a quick and accurate diagnosis on histology. The physician can start antifungal treatment timely for better prognosis.

Aggressive giant cell lesion of mandible-confusing to common: true neoplasm versus reactive lesion

Destructive lesions in the craniofacial region especially in the jawbones, if associated with giant cells, include a spectrum of lesions that pose difficulty in diagnosis. The nature of such a lesion in the jawbones is questionable about whether it is a reactive/benign lesion or aggressive/non-aggressive. Clinical, radiological and histopathological correlation may be a reliable indicator to differentiate between the qualities of the lesion, which directly accounts for effective and individual planning of the treatment. Here we present a case of a woman in her late 20s with an unusual destructive lesion of the mandible.

Histopathologic differences in granulomas of Mycobacterium bovis bacille Calmette Guérin (BCG) vaccinated and non-vaccinated cattle with bovine tuberculosis

Mycobacterium bovis (M. bovis) is the zoonotic bacterium responsible for bovine tuberculosis. An attenuated form of M. bovis, Bacillus Calmette-Guerin (BCG), is a modified live vaccine known to provide variable protection in cattle and other species. Protection for this vaccine is defined as a reduction in disease severity rather than prevention of infection and is determined by evaluation of the characteristic lesion of tuberculosis: the granuloma. Despite its recognized ability to decrease disease severity, the mechanism by which BCG imparts protection remains poorly understood. Understanding the histopathologic differences between granulomas which form in BCG vaccinates compared to non-vaccinates may help identify how BCG imparts protection and lead to an improved vaccine. Utilizing special stains and image analysis software, we examined 88 lymph nodes obtained from BGC-vaccinated and non-vaccinated animals experimentally infected with M. bovis. We evaluated the number of granulomas, their size, severity (grade), density of multinucleated giant cells (MNGC), and the amounts of necrosis, mineralization, and fibrosis. BCG vaccinates had fewer granulomas overall and smaller high-grade granulomas with less necrosis than non-vaccinates. The relative numbers of high- and low- grade lesions were similar as were the amounts of mineralization and the density of MNGC. The amount of fibrosis was higher in low-grade granulomas from vaccinates compared to non-vaccinates. Collectively, these findings suggest that BCG vaccination reduces bacterial establishment, resulting in the formation of fewer granulomas. In granulomas that form, BCG has a protective effect by containing their size, reducing the relative amount of necrosis, and increasing fibrosis in low-grade lesions. Vaccination did not affect the amount of mineralization or density of MNGC.

Origin, production and molecular determinants of macrophages for their therapeutic targeting

Macrophages, the most heterogeneous cells of the hematopoietic system and the giant eaters of the immune system that present either as tissue-resident cells or infiltrated immune cells, eliminate foreign pathogens and microbes and also play different physiological roles to maintain the body's immune response. In this review, we basically provide a broad overview of macrophages from their origin, functional diversity to M1-M2 polarization, specialized markers, and their role as important therapeutic targets in different diseases based on the current research and evidence. Apart from this, we have precisely discussed about tumor-associated macrophages (TAMs) and their role in tumor progression and newly discovered lesser-known markers of TAMs that could be used as potential therapeutic targets to treat life-threatening diseases. It is really very important to understand the diversity of macrophages to develop TAM-modulating strategies to activate our own immune system against diseases and to overcome immune resistance.

Image-Based Evaluation of In Vivo Degradation for Shape-Memory Polymer Polyurethane Foam

Shape-memory polymer (SMP) polyurethane foams have been applied as embolic devices and implanted in multiple animal models. These materials are oxidatively degradable and it is critical to quantify and characterize the degradation for biocompatibility assessments. An image-based method using high-resolution and magnification scans of histology sections was used to estimate the mass loss of the peripheral and neurovascular embolization devices (PED, NED). Detailed analysis of foam microarchitecture (i.e., struts and membranes) was used to estimate total relative mass loss over time. PED foams implanted in porcine arteries showed a degradation rate of ~0.11% per day as evaluated at 30-, 60-, and 90-day explant timepoints. NED foams implanted in rabbit carotid elastase aneurysms showed a markedly faster rate of degradation at ~1.01% per day, with a clear difference in overall degradation between 30- and 90-day explants. Overall, membranes degraded faster than the struts. NEDs use more hydrophobic foam with a smaller pore size (~150-400 μm) compared to PED foams (~800-1200 μm). Previous in vitro studies indicated differences in the degradation of the two polymer systems, but not to the magnitude seen in vivo. Implant location, animal species, and local tissue health are among the hypothesized reasons for different degradation rates.

Theoretical error of sectional method for estimation of shape memory polyurethane foam mass loss

INTRODUCTION

Measuring in vivo degradation for polymeric scaffolds is critical for analysis of biocompatibility. Traditionally, histology has been used to estimate mass loss in scaffolds, allowing for simultaneous evaluation of mass loss and the biologic response to the implant. Oxidatively degradable shape memory polyurethane (SMP) foams have been implemented in two vascular occlusion devices: peripheral embolization device (PED) and neurovascular embolization device (NED). This work explores the errors introduced when using histological sections to evaluate mass loss.

METHODS

Models of the SMP foams were created to mimic the device geometry and the tetrakaidekahedral structure of the foam pore. These models were degraded in Blender for a wide range of possible degradation amounts and the mass loss was estimated using m sections.

RESULTS

As the number of sections (m) used to estimate mass loss for a volume increased the sampling error decreased and beyond m = 5, the decrease in error was insignificant. NED population and sampling errors were higher than for PED scenarios. When m ≥ 5, the averaged sampling error was below 1.5% for NED and 1% for PED scenarios.

DISCUSSION/CONCLUSION

This study establishes a baseline sampling error for estimating randomly degraded porous scaffolds using a sectional method. Device geometry and the stage of mass loss influence the sampling error. Future studies will use non-random degradation to further investigate in vivo mass loss scenarios.

Cannabis sativa exacerbate testicular function by increased oxidative stress, altered male reproductive hormones, sperm quality/quantity and cellular architecture of the testis

The illicit use of Cannabis in Nigeria is on the increase within the last 10 years and has been implicated as one of the causes of fertility disorder among young men in Nigeria. Hence, this study aimed to ascertain the reproductive impact of n-hexane extract of Cannabis sativa on male Wistar rats. Fifteen male Wistar rats weighing between 180 and 200 g were assigned into three groups of five animals each. The first group served as control, second (low dose), and third (high dose) were fed with n-hexane extract of C. Sativa at doses of 0.75 mg/100 g and 1.5 mg/100 g body weight respectively for 28 days. The administration was done via orogastric. The results revealed the mean serum gonadotropin-releasing hormone (GnRH) concentration in LD and HD was significantly lower (p < 0.05) than in control. LH was significantly higher (p < 0.01) in both LD and HD compared to control. There was a significant increase (p < 0.01) in LD and HD compared to control. Testosterone was significantly elevated in HD (p < 0.05) compared to control. Testicular reduced glutathione and Superoxide dismutase were significantly (p < 0.05) reduced in fed rats compared to control. Testicular catalase and Malondialdehyde were significantly (p < 0.05) increased in HD compared to control. Non-motile sperm count showed a significant (p < 0.001) increase in fed rats compared to control. Total sperm count was significantly (p < 0.05) reduced in fed rats than in control. There were significant (p < 0.001) increased spermatozoa with abnormal morphology in treated groups compared to control. HDL cholesterol was significantly (p < 0.05) elevated in HD compared to control. The atherogenic index was significantly (p < 0.05) reduced in the group fed with 1.5 mg/kg compared to the control. Furthermore, total cholesterol, triglyceride, VLDL-c, and LDL-c did not reveal any significant difference statistically. Histological examination of testes and epididymis of fed rats showed an empty cavity with a reduction in spermatogenesis. This study suggests that n-hexane extract of C. Sativa had more effects on the gonads compared to the higher centres and its ingestion in whatever form could impair male reproductive function.

Cranial Mandibular Fibrosis Syndrome in Adult Farmed Rainbow Trout Oncorhynchus mykiss

An unusual condition affecting market size rainbow trout was investigated. This condition was prevalent for several years at low levels but affected a large proportion of stock during 2018 and 2019. Chronic fibrosis affecting cranial tissues and the jaw was observed in samples collected in 2018. A larger sampling was then conducted in 2019 to investigate the presence of an infectious agent(s). An extensive inflammatory response in the mandibular region was the main finding, however infectious agents in the lesions were not identified through classical virology and bacteriology analysis. Tetracapsuloides bryosalmonae infection, calcinosis, and a Gram-positive bacterial infection of a single fish cardiac tissue was observed, however, a correlation of these pathologies and the cranial mandibular fibrosis (CMF) syndrome was not established. The gene expression of a panel of 16 immune-related genes was studied. Among these, tgf-b, sIgM, il11, hspa, and the antimicrobial peptides lys and cath1 were up-regulated in jaw sections of CMF-affected fish, showing a strong positive correlation with the severity of the lesions. Idiopathic chronic fibrosis with the activation of the Tfg-B pathway and local hyper-immunoglobulaemia was therefore diagnosed. Initiating factors and causative agent(s) (biotic or abiotic) of CMF remain, at present, unclear.

A clinicopathological study of 17 cases of ocular surface xanthogranuloma in dogs

OBJECTIVE

To evaluate the clinical, histopathological, and immunohistochemical features of 17 cases of ocular surface xanthogranuloma (OSX) in dogs.

METHODS

Archived records from the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched for cases of canine OSX. Cases were evaluated for lipid-laden macrophages and Touton giant cells. Seventeen cases matching those criteria were identified (1993-2018). Clinical and epidemiological data were collected from the submission forms and additional follow-up survey.

RESULTS

Ocular surface xanthogranuloma in dogs presented as small bland nodules. OSX commonly occurred at the limbus (8/17) or cornea (4/17). Three of 17 affected animals were less than 1-year-old and the average age was 6.9 years (range 0.7-14 years). Fourteen of 17 cases did not report any lipid or metabolic abnormalities. Histologically, lesions were composed mainly of dense sheets of vacuolated lipid-laden macrophages and Touton giant cells with scant additional inflammatory cells and an intact overlying epithelium. No recurrence was noted in cases where complete surgical resection was achieved, and medical treatment either pre or post-resection led to only partial resolution.

CONCLUSIONS

Xanthogranulomas are histiocytic lesions characterized by abundant lipid-laden macrophages. The authors use the term, ocular surface xanthogranuloma, to describe nodules with rigidly defined cellular characteristics. Although these lesions share characteristics with human limbal xanthogranulomas, further investigation is needed to suggest the different subsets that have been reported in the medical literature. Complete surgical excision is the most effective treatment for OSX in dogs, and intralesional triamcinolone and topical steroids can be useful adjunctive therapies to surgery.

Diagnóstico incidental de Enfermedad de Erdheim-Chester en paciente con presentación inusual

La enfermedad de Erdheim-Chester (ECD), es un padecimiento raro, descrito por primera vez en 1930, por Jakob Erdheim y William Chester. La presentación más común de la enfermedad consiste en dolor óseo. Su diagnóstico se realiza mediante la confirmación histopatológica junto a las manifestaciones clínicas de la enfermedad, así como con los auxiliares radiológicos. La presentación de un caso inusual nos invita a no dar por sentada ninguna manifestación clínica o paraclínica en los pacientes.

Delayed Diagnosis of Basal Cell Carcinoma of the Upper Lip: The Possible Role of Incidental Multinucleated Foreign Body Giant Cells

Herpes simplex and basal cell carcinoma (BCC) can have similar clinical presentations due to overlapping lesional morphology. We describe the unusual case of a BCC masquerading as herpes labialis due to a possible false-positive Tzanck smear. The confounding diagnosis led to a failed trial of valacyclovir and subsequent loss of the patient for 1 year before the lesion was biopsied and diagnosed as a BCC. This case report highlights the importance of careful inspection of herpetic lesions and that further investigation should be pursued if the etiology is uncertain or if the treatment is not yielding the expected results.