Fibrous Tissue Infiltration Research Articles

Application experience of bioresorbable implants in correcting the volume of the pleural cavity and their biocompatibility assessment

Objective: To substantiate experimentally the possibility of using bioresorbable biopolymer pleural implants made of polylactide and polycaprolactone (PLA/PCL) to correct the volume of the chest. Materials and methods. Rabbits were used as experimental animals — mature females of the Chinchilla breed, age 1–1.5 years, weight 3500–4300 g. The number of individuals were 5. For studying changes in implants and local tissue reactions in vivo, as close as possible to clinical conditions, the method of intrapleural implantation was used. Bio-resorbable highly porous samples based on polylactide and polycaprolactone (PLA/PCL) with different polymer ratios and porosity degrees were used as implants. The implant and local tissue reactions were evaluated over five implantation periods: 7, 21, 54, 66 and 78 weeks. Results. The study of morphology in implants during a long experiment showed good biocompatibility, which was confirmed by the absence of necrosis in implants and surrounding tissues. In the first and second implantation periods minimal reactive changes were detected in the adjacent soft tissues (lung, pleura, soft tissues of the chest wall), existing as a focal fibrosis of muscle fibers, focal mononuclear infiltration of fibrous tissue. Conclusion: As a result of studying morphological changes in the implant and adjacent tissues of the chest wall, the absence of necrosis and purulent-inflammatory changes both in the implant itself and in the surrounding tissues of the chest wall and lung was confirmed. It has been proven that a highly porous pleural implant based on polylactide and polycaprolactone is a safe and promising material for correcting the volume of the chest, which can be in demand both in general thoracic surgery and for the surgical treatment of patients with advanced pulmonary tuberculosis.

The Immune Response to the Myxozoan Parasite Myxobolus cerebralis in Salmonids: A Review on Whirling Disease.

Salmonids are affected by the economically significant whirling disease (WD) caused by the myxozoan parasite Myxobolus cerebralis. In the past, it was endemic to Eurasia, but it has now spread to different regions of North America, Europe, New Zealand, and South Africa. Among salmonids, rainbow trout is considered the most highly susceptible host. Upon entering to the host's body, the parasite invades the spine and cranium, resulting in whirling behaviour, a blackened tail, and destruction of cartilage. The disease is characterized by the infiltration of numerous inflammatory cells, primarily lymphocytes and macrophages, with the onset of fibrous tissue infiltration. Several efforts have been undertaken to investigate the role of various immune modulatory molecules and immune regulatory genes using advanced molecular methods including flow cytometry and transcriptional techniques. Investigation of the molecular and cellular responses, the role of STAT3 in Th17 cell differentiation, and the inhibitory actions of suppressors of cytokine signaling (SOCS) on interferons and interleukins, as well as the role of natural resistance-associated macrophage proteins (Nramp) in WD have significantly contributed to our understanding of the immune regulation mechanism in salmonids against M. cerebralis. This review thoroughly highlights previous research and discusses potential future directions for understanding the molecular immune response of salmonids and the possible development of prophylactic approaches against WD.

Histopathological Characterization of Abdominal Aortic Aneurysms from Patients with Multiple Aneurysms Compared to Patients with a Single Abdominal Aortic Aneurysm.

The aim of this study was to investigate histopathological differences in abdominal aortic aneurysms (AAAs) between patients with multiple and single arterial aneurysms, as we suspect that there are different underlying mechanisms in aneurysm formation. Analysis was based on a previous retrospective study on patients with multiple arterial aneurysms (mult-AA; defined as at least four, n = 143) and a single AAA (sing-AAA, n = 972) who were admitted to our hospital for treatment between 2006 and 2016. Available paraffin-embedded AAA wall specimens were derived from the Vascular Biomaterial Bank Heidelberg (mult-AA, n = 12 vs. sing-AAA, n = 19). Sections were analyzed regarding structural damage of the fibrous connective tissue and inflammatory cell infiltration. Alterations to the collagen and elastin constitution were assessed by Masson-Goldner trichrome and Elastica van Gieson staining. Inflammatory cell infiltration, response and transformation were assessed by CD45 and IL-1β immunohistochemistry and von Kossa staining. The extent of aneurysmal wall alterations was assessed by semiquantitative gradings and was compared between the groups using Fisher's exact test. IL-1β was significantly more present in the tunica media in mult-AA compared to sing-AAA (p = 0.022). The increased expression of IL-1β in mult-AA compared to sing-AAA indicates inflammatory processes play a role in aneurysm formation in patients with multiple arterial aneurysms.

Surgical Repair and Augmentation of a Midsubstance Chronic Achilles Tendon Rupture with a Novel Biocomposite Scaffold: A Case Report

Case A 31-year-old male presented with a midsubstance chronic ‘cavitation’ tear of his right Achilles tendon, significant retraction of the tendon, and infiltration of dense fibrous tissue into the gap. A 23x30mm BioBrace implant was cut in half length-wise in order to create two strips that were sutured in place to augment the strength and promote healing of the repair. Six months after surgery, the patient demonstrated markedly improved function and MRI showed near complete fill-in of the defect with new tendon-like tissue that was integrated with the underlying native tendon and BioBrace®. Conclusion Repair of a chronic tear of the Achilles tendon with associated cavitation within the body of the tendon can be a true surgical challenge. Augmentation of the repair with BioBrace to increase strength and potential for tissue healing at the time of surgical repair may accelerate recovery and return to function. It may also improve the ultimate quality of the healed tendon tissue.

Arrhythmogenic Right Ventricular Cardiomyopathy: The Role of Genetics in Diagnosis, Management, and Screening.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a predominantly autosomal dominant genetic condition in which fibrous and fatty tissue infiltrate and replace healthy myocardial tissue. This uncommon yet debilitating condition can cause ventricular arrhythmias, cardiac failure, and sudden cardiac death. Management focuses primarily on prevention of syndrome sequelae in order to prevent morbidity and mortality. Genetic testing and screening in affected families, although utilized clinically, has not yet been incorporated in guidelines due to lack of larger studies and data. We aim herein to identify causative gene mutations, present advancements in diagnosis and management, and describe the role of genetic screening and counseling in patients with ARVC. With the advancement of genetic testing and therapy, diseases such as ARVC may become more accurately diagnosed and more effectively managed, ultimately significantly reducing morbidity and mortality.

Aneurysm of the membranous septum. A potential cause of sudden death

Aneurysms of the membranous septum are extremely rare malformations that are usually asymptomatic. However, they have the potential for varied complications including sudden cardiac death. Reported here is a case of sudden death in a 25-year-old woman. A medico-legal autopsy revealed a large aneurysm of the membranous septum. It is speculated that the infiltration of fibrous tissue from the aneurysm into the atrioventricular conduction axis may have led to the observed mortality.

SUBSEQUENT THERAPEUTIC TREATMENT OF MEMBRANE EXPOSURE AFTER GBR IN THE ANTERIOR MAXILLAE: A CASE REPORT

Guided bone regeneration (GBR) aims to augment the areas with osseous defects in compromised dentition. Bone grafting materials, barrier membranes and growth factor therapies have been utilized to minimize the dimensional changes in the bone morphology and architecture occurring postextraction. GBR procedures are performed using materials such as autografts, allografts, xenografts, or synthetic bone grafts or combination. Barrier membranes are used to maintain the space and prevent the infiltration of fibrous tissue. Such membranes are: non-resorbable PTFE membranes, collagen-based absorbable membranes, synthetic absorbable membranes, titanium mesh membranes and PRF. In this case report, a 67 years-old lady was referred for implant rehabilitation in the right anterior maxilla. The reason of tooth loss was vertical root fracture. GBR was performed at the area of #12 and #13, due to severe bone defect. A combination of 50:50 allograft and xenograft bone grafting material, non-resorbable titanium membrane and PRF membranes was used. One-month post-op exposure of the membrane was noticed. At this point, it is important to be mentioned that on the day of the surgery primary closure was not achieved at the area #13, due to lack of soft tissue thickness. Replacement of the first membrane by a collagen based absorbable one and tension free suturing was performed. One month after the second intervention, soft and hard tissue healing was completed unhindered.

Aerossacolitis and Pneumonia in an Indian Peafowl Caused by Lactobacillus agilis

Background: The peafowl is an ornamental bird that has the habit of eating directly from the earthy soil, which makes this bird more susceptible to endoparasites. One important endoparasite is Eucoleus contortus, which leads to inflammatory processes that alter the local microbiota, potentializing disease. By the other way, a member of the bird’s microbiota there is the genus Lactobacillus, but when occurs some imbalance, these bacteria can overgrowth and even cause some infection. This report describes the pathological and microbiological findings of chronic necrotizing pneumonia and aerossacolitis caused by Lactobacillus agilis in a peafowl, associated with parasitism by E. contortus. Case: A peafowl (Pavo cristatus), adult, male, who lived on a farm with contact with other species of animal, was submitted to post-mortem examination due to sudden death. This animal lived in an extensive system on the property and was the only one of its species. During the gross evaluation, the air sacs were filled with solid yellowish crumbly material. The same material was observed forming well-defined nodules that occupied > 50% of the lung parenchyma. Histological analysis showed multiple parabronchi dilated and filled with caseous necrosis, characterized by abundant cellular debris and fibrin deposition. These areas were surrounded by the proliferation of fibrous connective tissue and inflammatory infiltrate of macrophages, giant cells, lymphocytes, and plasma cells. The air sacs parenchyma showed fibrin deposition and mixed inflammatory infiltrate. Multiple gram-positive bacilli were observed within the caseous foci in Gram-stained slides. In the crop and esophageal mucosa, cross-sections of filiform nematodes morphologically compatible with E. contortus were associated with chronic inflammatory infiltrate and epidermal hyperkeratosis. A lung section was submitted to Gram-Brown-Hopps and Ziehl-Neelsen (ZN) stains for bacterial investigation, and Grocott's methenamine silver (GMS) stain for fungal investigation. Short gram-positive bacilli bacteria are observed within the caseous foci in Gram-stained slides. By the other way, no agents were identified on the ZN and GMS stains. Following the analysis, lung fragments were cultivated at aerobic and microaerophilic conditions on sheep blood agar and McConkey agar. All the microbial cultures were incubated at 37°C to 48 h. Pure culture, in microaerophilic condition, of Gram-positive bacilli, was observed. The isolated bacterium was identified by MALDI-TOF MS as L. agilis.Discussion: Although uncommon, L. agilis was the single bacterium identified and therefore, associated as a primary cause of necrotic pneumonia and aerossacolitis in the studied peafowl. The presence of E. contortus could induce the aspiration of regurgitated of little amount of material from the gastrointestinal tract with sufficient bacterial load to initiate an infection, but not enough to smother the animal. The gradual aspiration can induce a chronic inflammatory condition. Infections by bacteria from the host microbiota have been observed in animals and humans with immunodeficiency. In summary, both the parasitosis and the inflammation could be resulted by the parasite and the aspiration of gastric product, which probably interfered in the immune response and allowed the overgrowth of L. agilis. In the current case report, based on macroscopic, microscopic and bacteriological results, we have provided insights to understand how the parasitosis made possible a pneumonia from a bacterium from the host's microbiota. Finally, to the best of our knowledge, this is the first report of L. agilis as causal agent of fatal necrotic pneumonia and aerossacolitis in peafowl.Keywords: respiratory infection, ornamental birds, secondary infection, parasitosis.

Pathological features of Brucella spondylitis: A single-center study

ObjectiveTo explore the pathological features of Brucella spondylitis (BS) under the optical microscope, thus providing pathological references for the diagnosis. MethodsWe retrospectively analyzed 70 BS patients (42 males and 28 females, mean age 52.01 ± 10.77 [20–74] years) admitted in the Department of Spine Surgery, the General Hospital of Ningxia Medical University, from January 2013 to December 2020. Their medical history, clinical manifestations, laboratory test results, imaging findings and bacteriological culture results were collected. Among them, 5, 5, 43, 4 and 13 cases demonstrated involvement into the cervical vertebra, thoracic vertebra, lumbar vertebra, thoracolumbar vertebra and lumbosacral vertebra, respectively. Notably, L4 showed pathology in 32 cases. Pathological features of BS were analyzed by H&E staining of granulation tissues, sclerotic bones, sequestrums, and intervertebral discs. Results42 cases underwent bacterial culture, of which 4 were positive, and the positive rate of bacterial culture was only 9.5%. The highest Vas score was 7, the lowest was 4, and the average was 5.76 ± 0.89. The highest CRP was 153 mg/L, the lowest was 0.98 mg/L, and the average was 30.98 ± 33.79 mg/L. The highest ESR is 112 mm/h, the lowest is 5 mm/h, and the average is 49.34 ± 27.73 mm/h. Under the optical microscope, BS manifested acute or chronic inflammation. Acute inflammatory features included neutrophil and eosinophil infiltration, necrosis, and abscesses, while chronic inflammatory features included lymphocyte, plasma cell, fibrous tissue and monocyte infiltration, hyaline degeneration, angiogenesis and hyperplasia of other tissues. Other features included vasodilation, hemorrhage, granulomas and multinucleated giant cell infiltration. In the present study, chronic inflammation was observed in 25 cases, in-acute-phase chronic inflammation in 45 cases, and acute inflammation in no cases. Pathological features of BS under the microscope included foam cell reaction in 46 cases, histiocytic reaction in 24 cases and eosinophilic abscesses in 6 cases. Eosinophil infiltration was observed in 45 cases (mainly during the acute phase of chronic inflammation) and massive eosinophilic abscesses in 6 cases. Granulation tissue hyperplasia followed inflammatory repair in 25 BS cases, and was generally boosted in the acute phase of chronic inflammation. Multinucleated giant cell infiltration and granulomas were less observed in BS cases, which differed from pathological features of spinal tuberculosis. ConclusionsChronic inflammation or in-acute-phase chronic inflammation is the main pathological feature of BS, while the single acute inflammation is less observed in BS cases. Foam cell reaction and histiocytic reaction scale up during the acute phase of chronic inflammation, and some BS patients may develop massive eosinophilic abscesses. Granulation tissue hyperplasia, rather than multinucleated giant cell infiltration and granulomas, serve as pathological reference for the differential diagnosis of BS and spinal tuberculosis.

IgG4-related hepatic inflammatory pseudotumor mimicking cholangiolocellular carcinoma

Inflammatory pseudotumor (IPT) is a benign tumor mass composed of chronic infiltration of inflammatory cells and fibrous tissue. IgG4-RD (related disease) in the hepatobiliary system has been widely recognized and includes IgG4-related hepatic IPT. This report describes a patient with IgG4-related hepatic IPT with sclerosing cholangitis. A 75-year-old woman was admitted to our hospital for the treatment of rectal cancer. Abdominal contrast-enhanced computed tomography revealed a low-density mass, 2.5cm in diameter, in the left lateral lobe. Magnetic resonance imaging showed that the mass was slightly hypointense on T1-weighted images and slightly hyperintense on T2-weighted images. Based on these results, we made a diagnosis of cholangiolocellular carcinoma, and we performed a left hepatectomy. Histopathological examination showed that the mass was composed of fibrous stroma with dense lymphoplasmacytic infiltration. Immunohistochemically, IgG4-positive plasma cells were observed. The final diagnosis was IgG4-related hepatic IPT with sclerosing cholangitis. IgG4-related IPT is a relatively rare disease that can occur in any organ of the body. Although the accurate diagnosis of IgG4-related hepatic IPT remains difficult, IgG4-RD should be included in the differential diagnosis of liver tumors and histological analysis performed.

Polymer-Based Honeycomb Films on Bioactive Glass: Toward a Biphasic Material for Bone Tissue Engineering Applications.

The development of innovative materials for bone tissue engineering to promote bone regeneration while avoiding fibrous tissue infiltration is of paramount importance. Here, we combined the known osteopromotive properties of bioactive glasses (BaGs) with the biodegradability, biocompatibility, and ease to shape/handle of poly-l-co-d,l-lactic acid (PLDLA) into a single biphasic material. The aim of this work was to unravel the role of the surface chemistry and topography of BaG surfaces on the stability of a PLDLA honeycomb membrane, in dry and wet conditions. The PLDLA honeycomb membrane was deposited using the breath figure method (BFM) on the surface of untreated BaG discs (S53P4 and 13-93B20), silanized with 3-aminopropyltriethoxysilane (APTES) or conditioned (immersed for 24 h in TRIS buffer solution). The PLDLA membranes deposited onto the BaG discs, regardless of their composition or surface treatments, exhibited a honeycomb-like structure with pore diameter ranging from 1 to 5 μm. The presence of positively charged amine groups (APTES grafting) or the precipitation of a CaP layer (conditioned) significantly improved the membrane resistance to shear as well as its stability upon immersion in the TRIS buffer solution. The obtained results demonstrated that the careful control of the substrate surface chemistry enabled the deposition of a stable honeycomb membrane at their surface. This constitutes a first step toward the development of new biphasic materials enabling osteostimulation (BaG) while preventing migration of fibrous tissue inside the bone defect (honeycomb polymer membrane).

A Pilot Study to Determine the Impact of Adipose Tissue Attachment to Polypropylene Fibers In Hernia Mesh

Introduction: Prior publications have demonstrated chemical and physical alteration of hernia mesh analyzed after explantation from the body. The specific alteration documented is oxidative degradation of polypropylene mesh fibers. An animal study recently published has demonstrated that adipose tissue attachment is present instead of reparative fibrous tissue infiltration in an average of 10.9–18.9% of the intramesh healing for a variety of clinically used knitted polypropylene mesh products; 8.0% for knitted polyester meshes. This study also found that in comparison to the knitted mesh products, non-woven polypropylene mesh reduced adipose tissue attachment to 1% or less, which was a statistically significant difference. Materials and Methods: Samples of explanted polypropylene mesh from eight patients were analyzed for the presence of adipose tissue attachment, reparative fibrous tissue infiltration, and oxidative changes. Greater adipose tissue attachment areas were compared with areas of greater reparative fibrous tissue infiltration for evidence of oxidative changes in the mesh to determine if the areas of higher adipose tissue attachment correlated with an increase in oxidative changes. Results: Intra mesh healing of clinically explanted knitted meshes demonstrated adipose tissue content from 0.0% to 49.1% per analyzed segment. The oxidation index, a measure of the degree of oxidative degradation in that portion of the mesh, was higher in seven of the eight areas of greater adipose tissue attachment than areas of greater reparative fibrous tissue infiltration. Conclusion: Adipose tissue attachment does occur in knitted and woven polypropylene hernia meshes. The presence of adipose tissue may contribute to an increase in oxidative changes in knitted polypropylene hernia mesh fibers.

Lethal infection caused by Tetratrichomonas gallinarum in black swans (Cygnus atratus)

BackgroundTetratrichomonas gallinarum is parasitic protozoa with a wide host range. However, its lethal infection is rare reported.Case presentationHere, we described the first lethal cases of T. gallinarum infection in black swans in China. Five black swans died within a week in succession without obvious symptoms except mild diarrhea. At necropsy, severe lesions were observed in caeca with thickened caecal walls and hemorrhages in the mucosa. A large number of moving trophozoites were found in the contents of the cecum by microscopic examination. The livers were enlarged with multiple bleeding spots on the surface. Histopathology of the livers showed mononuclear cell infiltration and moderate hyperplasia of fibrous tissue. The histopathology of the cecum showed that the villi of the cecum were edematous. Finally, the presence of T. gallinarum was determined by specific PCR andin-situ hybridization assay. Additionally, common pathogens that can cause similar symptoms were excluded.ConclusionsThe death of the black swan was caused by T. gallinarum, suggesting that the parasite might be a new threat to the Cygnus birds.

Accelerated Bone Regeneration by MOF Modified Multifunctional Membranes through Enhancement of Osteogenic and Angiogenic Performance

Owing to the insufficient guidance of new bone formation in orthopedic and craniomaxillofacial surgery, construction of a guided bone regeneration membrane to support vascularized bone regeneration remains a challenge. Herein, an electrospun asymmetric double-layer polycaprolactone/collagen (PCL/Col) membrane modified by metal-organic framework (MOF) crystals is developed. The optimization of the PCL/Col weight ratio (1:1 and 1:1.5) enables the composite membrane with a balanced tensile strength (only fell by 49.9% in wet conditions) and a controlled degradation rate (completely degraded at 12 weeks). The MOF crystals can provide a pH-responsive release of Zn2+ ions. In vitro experiments indicate that the barrier layer functions to prevent the infiltration of fibrous connective tissue. The MOF crystal layer functions to enhance osteogenesis and angiogenesis in vitro. Using a rat calvarial defect model, the MOF crystals exhibit a sign of osteoinductivity along with blood vessel formation after 8 weeks post-surgery. Strikingly, when assessed in a chick chorioallantoic membrane model, the MOF modified membrane demonstrates a significant angiogenic response, which can be envisaged as its outstanding merits over the commercially Col membrane. Therefore, the MOF crystals represent an exciting biomaterial option, with neovascularization capacity for bone tissue engineering and regenerative medicine.

Heparinization and hybridization of electrospun tubular graft for improved endothelialization and anticoagulation

Constructing biomimetic structure and immobilizing antithrombus factors are two effective methods to ensure rapid endothelialization and long-term anticoagulation for small-diameter vascular grafts. However, few literatures are available regarding simultaneous implementation of these two strategies. Herein, a nano-micro-fibrous biomimetic graft with a heparin coating was prepared via a step-by-step in situ biosynthesis method to improve potential endothelialization and anticoagulation. The 4-mm-diameter tubular graft consists of electrospun cellulose acetate (CA) microfibers and entangled bacterial nanocellulose (BNC) nanofibers with heparin coating on dual fibers. The hybridized and heparinized graft possesses suitable pore structure that facilitates endothelia cells adhesion and proliferation but prevents infiltration of fibrous tissue and blood leakage. In addition, it shows higher mechanical properties than those of bare CA and hybridized CA/BNC grafts, which match well with native blood vessels. Moreover, this dually modified graft exhibits improved blood compatibility and endothelialization over the counterparts without hybridization or heparinization according to the testing results of platelet adhesion, cell morphology, and protein expression of von Willebrand Factor. This novel graft with dual modifications shows promising as a new small-diameter vascular graft. This study provides a guidance for promoting endothelialization and blood compatibility by dual modifications of biomimetic structure and immobilized bioactive molecules.

Muscle Echogenicity and Changes Related to Age and Body Mass Index.

Muscle fibers are lost and replaced by fat- and fibrous-tissue infiltration during aging. This process decreases muscle quality and influences tissue appearance on ultrasound images over time. Increased muscle "echogenicity" represents changes caused by fat- and fibrous-tissue infiltration and can be quantified with recently developed software. To investigate skeletal muscle quality through echogenicity, estimates according to participant's body mass index (BMI) and age were taken. This was a cross-sectional study performed at the Pennington Biomedical Research Center, Baton Rouge, Louisiana with 117 participants (57 men and 60 women), with mean age (±SD) 38.9 ± 17.0 years and BMI 28.6 ± 6.2 kg/m². All participants were examined by ultrasound (LOGIQ GE Healthcare), using a 5.0-MHz linear transducer. Participants had muscle thickness measured by ultrasound at 4 anatomic locations (biceps and triceps brachial, femoral quadriceps, and calf triceps). Echogenicity was analyzed with specific software (Pixel Health) that evaluated the image in gray scale. According to BMI, 41% of participants were obese. There was a positive correlation between age and thigh-muscle echogenicity (rp = 0.534, P < .0001) and a negative correlation between thigh-muscle echogenicity and thickness (rp = -0.395, P <.0001). There was high muscle echogenicity in participants with overweight and obesity aged 50 years or older (P < .05). Older age and higher BMI were associated with stronger echogenicity signals and smaller muscle thickness. People with overweight, obesity, and/or older than 50 years old have reduced muscle quality with smaller muscle thickness, as observed with ultrasound.

Histopathology of inferior vena cava obstruction in Budd-Chiari syndrome by clamp biopsy.

ObjectiveWe aimed to analyze the pathological changes of the occlusive area of the inferior vena cava (IVC) in patients with Budd–Chiari syndrome (BCS) and to explore its possible etiology and pathogenesis.MethodsColor Doppler ultrasound and IVC angiography were used to evaluate causes of occlusion. Clamp biopsies were performed in the occlusive area of the IVC in 31 patients with BCS, and the specimens were examined pathologically. Clinical data were collected retrospectively.ResultsThe success rate of clamp biopsy was 100% (31/31) and the sensitivity of pathology was 96.8% (30/31). By microscopic analysis, we found 27 cases of fibrous connective tissue, including 8 cases of thrombosis and 19 cases of inflammatory cell infiltration, vitreous degeneration, or mucinous degeneration of fibrous connective tissue; 3 cases showed thrombus organized with fibrosis.ConclusionThe occluding lesion in the IVC of BCS may be caused by local thrombosis, followed gradually by organization and fibrosis.

A95 DO BENIGN LIVER TUMOURS ALWAYS STAY BENIGN? A CASE REPORT OF HEPATIC INFLAMMATORY PSEUDOTUMOR AND SUBSEQUENT CHOLANGIOCARCINOMA

Abstract Background Hepatic inflammatory pseudotumors (HIPTs) are rare, benign lesions of unclear etiology which can be challenging to diagnose and differentiate from malignant processes. The optimal treatment and follow up of these lesions is controversial, and literature exists to support both surgical resection as well as conservative medical management. The natural history of HIPTs is generally benign, however there are some reports of disease recurrence, and two reports of malignant transformation to lymphoma. Aims To describe a case of HIPT with progression to malignancy. Methods Case report and review of the literature. Results A 53-year-old male presented to St. Joseph’s Healthcare Hamilton in August 2019 with a three-week history of abdominal pain and distention. He had a previous diagnosis of HIPT, incidentally found on ultrasound four years earlier. CT in January 2016 reported two well-marginated focal liver masses with peripheral rim enhancement and central hypodensity, 3.9 x 3.9cm in segment 2, and a 6 x 4.6cm central lesion, as well as diffuse fatty infiltration of the liver. Bloodwork showed a mildly elevated Ca19-9 626 kU/L, and normal CEA and AFP. Two biopsies were performed in 2016, both demonstrating dense fibrous tissue and abundant chronic inflammatory cell infiltrate composed of lymphocytes, histiocytes, eosinophils, and plasma cells, with some areas of bland spindle cell proliferation. No malignant cells, and histology was felt to be consistent with HIPT. MRI in September 2017 showed progression of disease, prompting Rheumatology to initiate immunosuppressive medications, however serial imaging continued to show increase in the size and number of lesions. Upon presentation to hospital in August 2019 ultrasound showed new ascites, with ascitic fluid analysis reporting highly atypical cells with prominent nucleoli of uncertain origin. CT showed extensive intrahepatic lesions throughout both lobes of the liver, and tumor markers were elevated with Ca19-9 16,581 kU/L, CEA 10 ug/L, Ca125 511 kU/L, and normal AFP. Repeat liver biopsy reported adenocarcinoma, likely cholangiocarcinoma, with background cirrhosis. Medical oncology did not feel he would tolerate chemotherapy, and he was thus discharged home with palliative supports. Conclusions HIPTs are benign lesions that are often initially misdiagnosed as malignancy, however this is the first case reporting progression of HIPT to cholangiocarcinoma. It is unclear if HIPT itself has premalignant potential, or whether its presence delays diagnosis of subsequent de novo malignancies. Given these uncertainties, as well as the lack of clarity on optimal management of HIPT, this case illustrates the importance of long-term clinical and radiographic follow up of these uncommon lesions, with consideration of repeat biopsy if the disease is not following the expected clinical course. Funding Agencies None

GINGIVAL GLANDULAR ODONTOGENIC CYSTS OR GINGIVAL SALIVARY GLAND CHORISTOMA? AN UNUSUAL CASE

The gingival injures have a multifactorial etiology as hormonal influences, trauma, bacterial plaque, and rests derived from odontogenic epithelium that can cause different developmental or odontogenic anomalies. Objective: To show an unusual case with presence of ectopic glandular tissue in gingiva. Medical description: A 72-year-old woman with a medical history of mastectomy 6 years ago, presents with a swelling above the alveolar ridge at the level of the right lower premolar, translucent, fluctuating, asymptomatic, of 2 months’ duration. Radiography description: Root tip with endodontic treatment; diffuse radiolucent cervical area extending 3 mm on each side. Histopathology description: Cuts of 5 µm, from excisional biopsy, stained with hematoxylin and eosin (H & E) observed in magnitude 10 x and 40 x; a bilayer epithelium, eosinophilic cuboidal cells with a sometimes-ciliated glandular appearance, band of fibrous tissue and chronic inflammatory infiltrate. Other histochemical stains: The Alcian blue–stained epithelial structures with mucinous content, and the periodic acid-Schiff (PAS) was not observed. Conclusion: Ectopic glandular tissue in the gingiva is rare and might be related to glandular odontogenic cyst (found more often intraosseous, this case is in the alveolar ridge) or gingival salivary gland choristoma, a mature tissue in ectopic location. Therefore, pluripotential embryonic epithelial cells can develop into glandular tissue. Collaboration: Pathology Institute Mejia Jimenez (Cali, Colombia). The gingival injures have a multifactorial etiology as hormonal influences, trauma, bacterial plaque, and rests derived from odontogenic epithelium that can cause different developmental or odontogenic anomalies. Objective: To show an unusual case with presence of ectopic glandular tissue in gingiva. Medical description: A 72-year-old woman with a medical history of mastectomy 6 years ago, presents with a swelling above the alveolar ridge at the level of the right lower premolar, translucent, fluctuating, asymptomatic, of 2 months’ duration. Radiography description: Root tip with endodontic treatment; diffuse radiolucent cervical area extending 3 mm on each side. Histopathology description: Cuts of 5 µm, from excisional biopsy, stained with hematoxylin and eosin (H & E) observed in magnitude 10 x and 40 x; a bilayer epithelium, eosinophilic cuboidal cells with a sometimes-ciliated glandular appearance, band of fibrous tissue and chronic inflammatory infiltrate. Other histochemical stains: The Alcian blue–stained epithelial structures with mucinous content, and the periodic acid-Schiff (PAS) was not observed. Conclusion: Ectopic glandular tissue in the gingiva is rare and might be related to glandular odontogenic cyst (found more often intraosseous, this case is in the alveolar ridge) or gingival salivary gland choristoma, a mature tissue in ectopic location. Therefore, pluripotential embryonic epithelial cells can develop into glandular tissue. Collaboration: Pathology Institute Mejia Jimenez (Cali, Colombia).

P2275Left-sided deviation and fibrous-fatty infiltration of the right bundle branch in the elderly: implication for transcatheter aortic valve implantation (TAVI) procedure

Abstract Introduction Permanent and irreversible damage to the conduction tissue is one of the most common complications of TAVI. Detailed knowledge of the anatomy of the atrioventricular (AV) bundle is crucial to minimize the potential for injury to the His bundle branch block or complete AV block. Purpose Preexisting anatomic location and damage of the right bundle branch (RBB) may have important unrecognized clinical implications. Methods The myocardial arrangement and the presence of fibrous and fatty tissue infiltration of the AV conduction axis and right bundle branch were examined by dissection techniques and histological sections in 57 structurally normal human heart specimens (48 males, 77±7 years). Results The AV conduction axis enters the AV component of the membranous septum and is encircled by the fibrous tissue of the central fibrous body. The AV bundle is divided in a non-branching portion and a branching portion. After a short distance of the non-branching component along the septal crest, the RBB arises at the end of the branching portion of the conduction axis and is located superficially in the muscular ventricular septum. The RBB takes off from the bundle at the level of origin of the superior fascicle of the left bundle, passing then through the thickness of the ventricular septum to emerge beneath the medial papillary muscle of the tricuspid valve. In 22 hearts (49%) in which we found to have a relatively left-sided deviation of the AV bundle in relation to the interventricular membranous septum the RBB runs intramyocardial along the muscular interventricular septum. In the remaining 51% of the hearts the RBB runs subendocardially in the crest of the interventricular muscular septum. We found connective tissue and fatty infiltration along the right bundle branch in 23 hearts (40%) from its origin to its distal part. A significant correlation was found between age and the presence of RBB fibrosis (85% of hearts from individuals with age &gt;80 years). These 2 conditions may make the RBB very vulnerable to self-expanding aortic valves during or after TAVI (figure). RBB and its critical region Conclusions The presence of an intramyocardial location of the RBB with a lef-sided deviation and the fibro-fatty infiltration found in the mayority of senescent hearts are relevant anatomic determinants that may increase the risk of complete AV block following a TAVI procedure.