Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review

Unlocking immunotherapy targets: programmed death 1 and its ligand and their correlation with tumour grade in feline injection site sarcoma

In this study, the immunohistochemical expression of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1), which could facilitate a novel approach to immunotherapy for feline injection site sarcomas (FISSs), was investigated. Treatment strategies based on the suppression of this pathway are possible for tumours expressing PD-1/PD-L1. In this context, FISSs were histologically classified, the grade of sarcoma and the intensity of lymphocyte infiltration determined and PD-1 and PD-L1 expression evaluated in tumours of different grade. Tumours were immunolabelled for vimentin, S100, smooth muscle actin and sarcomeric actin. Fibrosarcoma was diagnosed in eight cases, undifferentiated sarcoma in one case, liposarcoma in one case and rhabdomyosarcoma in one case. PD-1 expression was found mainly in lymphoid infiltrations and macrophage-like cells, while PD-L1 was found primarily in tumour cells and infiltrated macrophage-like cells. By Pearson correlation analysis, tumour differentiation was found to have a moderate correlation with PD-1 (P <0.05) and a high correlation with PD-L1 (P <0.01). Tumour grade had a low correlation with PD-1 and a moderate correlation with PD-L1 (P >0.05). A moderate correlation was also detected between PD-1 and PD-L1 (P <0.05). It was concluded that the increased expression of PD-1 and PD-L1 may be associated with poor tumour differentiation and, therefore, poor prognosis in FISS.

Comparison of the local safety of two multi-component feline vaccines, adjuvanted (1 mL) versus non-adjuvanted at reduced volume (0.5 mL), using computed tomography imaging

In 2020, a new 0.5 mL presentation of PUREVAX® RCP FeLV was registered and introduced in Europe. The objectives of this study were to investigate the local safety of this non-adjuvanted vaccine at reduced volume by classical methods (clinical examination, histopathology) and to evaluate the suitability of an alternative non-invasive methodology, the computed tomography (CT). For this purpose, the course of local reactions was assessed for 3 months after subcutaneous injection of PUREVAX® RCP FeLV 0.5 mL and compared to an adjuvanted vaccine, LEUCOFELIGEN® FeLV/RCP 1.0 mL. Injection site reactions consisted mainly of swelling reactions, which were more frequent, more pronounced and long-lasting in the adjuvanted vaccine group. Microscopically, in this group, moderate to severe inflammatory reactions were observed on day 7 (D7) and D21 post-injection and still present on D84, while mild inflammatory lesions were observed in the non-adjuvanted vaccine group only on D7 and D21. With the adjuvanted vaccine, inflamed areas were measurable by CT scan in all cats on D7 and D21, whereas they were detected only on D7 and only in 20 % of cats from the non-adjuvanted vaccine group. Besides the higher frequency, the mean inflamed volume was nearly 300 times larger in adjuvanted vaccine group on D7. Using different methodologies, the favorable safety profile of PUREVAX® RCP FeLV 0.5 mL was confirmed. Furthermore, the vaccine is aligned with current vaccination guidelines by inducing less inflammatory reactions, being adjuvant-free and injectable under a reduced volume, thus improving the convenience of administration in recommended sites (eg, legs). CT scan proved to be a suitable non-invasive method for the experimental follow-up of injection site reactions, yielding results consistent with clinical assessment and histopathology on D7 and D21. CT scan substantiated large differences between the investigated vaccines with a more prominent inflammatory reaction after injection of an adjuvanted vaccine.

Sarcoma felino posvacunal (FISS), reporte de caso en Colombia

El sarcoma felino posvacunal o sarcoma de sitio de inyección (FISS) en una neoplasia poco descrita en felinos en Colombia, se presenta posterior al uso de vacunas inactivas con adyuvante. El objetivo fue describir la presencia de un sarcoma felino posterior a la vacunación con leucemia felina virus inactivo, primer caso documentado en Colombia. Un felino, macho, mestizo, de 7 años de edad, esterilizado, vacunado con leucemia felina inactiva desde hace 3 años, desarrolla un nódulo de 5 cm de diámetro en la región dorsal, firme y no doloroso. En dermis profunda y músculo estriado, se evidencia proliferación neoplásica de células fusiformes, de crecimiento principalmente expansivo y en menor medida invasivo, que se organiza y forma haces cortos y fascículos largos que se entrecruzan, con focos densos y laxos y en focos se dispone en un patrón de espina de pescado. Las células presentan morfología fusiforme, ligeramente ovoide, irregular, algunas redondeadas, con citoplasma eosinófilo tenue e intenso en otros focos más densos. Se evidencia pleomorfismo celular y anisocitosis moderadas. Los núcleos presentan morfología redonda, ovoide e irregular. Se evidencia la presencia de uno o más nucléolos en algunas de sus células, cromatina principalmente granular fina, pleomorfismo nuclear y anisocariosis moderada. Se contabilizaron 4 mitosis en 10 campos con el objetivo de alto poder en 2,37 mm2, no se observa aparente invasión linfovascular, se evidencia compromiso de bordes laterales. Adicionalmente, discretos focos de necrosis multifocal < 50%, infiltrado inflamatorio mixto polimorfonuclear, neutrófilos moderados multifocales e infiltrado mononuclear linfocítico multifocal.

Outcome with Surgical Treatment of Canine Soft Tissue Sarcoma in the Region of the Ischiatic Tuberosity: A Veterinary Society of Surgical Oncology Retrospective Study

OBJECTIVE

To determine the outcome of dogs with soft tissue sarcoma (STS) within the region of the ischiatic tuberosity (ITSTS) treated surgically.

STUDY DESIGN

Multi-institutional retrospective study ANIMALS: Fifty-two client-owned dogs with histologically confirmed STS in the region of the IT treated with surgical resection between March 1st, 2009, and March 1st, 2021, and a minimum follow-up time of six months.

METHODS

Data collected included signalment, preoperative diagnostics, surgical intent/method, complications, histopathology, margins, outcome, and cause of death. Statistical analyses were performed to determine significant factors in treatment and prognosis of ITSTS.

RESULTS

Fifty-two dogs with histopathologically-confirmed ITSTS included resulting in 24 grade I, 20 grade II, and seven grade III tumors. Overall survival time and disease progression were negatively associated with tumor grade while recurrence was positively associated with grade and incomplete margins. Overall survival time and progression-free survival time was not reached for tumors graded as I or II and was 255 and 268 days respectively for grade III. Median time to recurrence was not reached for tumors excised with complete margins and 398 days for incomplete margins. There was a 25% reported surgical complication rate.

CONCLUSION

Ischiatic tuberosity soft tissue sarcoma was not found to be a unique clinical entity in dogs. Treatment recommendations and prognosis were similar to STS in other locations. The outcome was influenced by histologic grade and margins.

CLINICAL SIGNIFICANCE

Ischiatic tuberosity soft tissue sarcoma of dogs does not behave more aggressively than those in other locations. Surgical complications were common but not life-threatening. Overall prognosis, including survival and disease recurrence, appears to depend on histological grade and surgical margins. This article is protected by copyright. All rights reserved.

Expression of Platelet Derived Growth Factor a, Its Receptor, and Integrin Subunit Alpha V in Feline Injection-Site Sarcomas

Injection-site sarcomas are considered an important entity in veterinary oncology, especially in cats. The current study investigated the immunohistochemical expression of platelet-derived growth factor A (PDGFA), platelet-derived growth factor receptor-α (PDGFR-α), and integrin alpha subunit v in feline injection-site sarcomas (FISS). A total of 14 paraffin-embedded tissue samples previously diagnosed as soft tissue sarcomas were selected from the departmental archive and sectioned at 5µm using a microtome. Tissue sections were stained with Hematoxylin & Eosin, Alcian blue-Periodic Acid Schiff (AB-PAS), Masson’s Trichrome, and immunohistochemically for PDGFA, PDGR-α, and integrin alpha v. The majority of the tumors were fibrosarcomas (n=13/14), except one case of myxoid liposarcoma. The tumors occurred at sites commonly used for injections or vaccine administration. Histologically, tumors were characterized by peripheral infiltration of mononuclear cells mainly lymphocytes, variable sized central necrotic areas, and many multinucleated tumor giant cells. AB-PAS staining revealed the presence of myxoid or mucinous areas in (8/14) tumors while trichrome staining demonstrated a variable amount of collagenous stroma in 12/14 tumors. Vimentin immunoreactivity was observed in all the tumors while smooth muscle actin and muscle actin staining was noticed in four and two cases, respectively. PDGFA and PDGFR-α immunoexpression was observed in all 14 cases while integrin alpha v in 13/14 cases. The results of the current study indicate that fibrosarcoma is the major morphologic phenotype of FISS. The PDGFA, its receptor, and integrin alpha v immunoexpression are increased in these tumors in cats which elucidates their role in the pathogenesis of FISS.

Soft tissue sarcoma at the site of a previous laparoscopic-assisted gastropexy in a dog

An 8-year-old, spayed female, Doberman pinscher dog was presented to the Ontario Veterinary College Health Sciences Center for evaluation of a large subcutaneous mass on the right cranial ventral abdomen. Computed tomography localized a 6 × 7 cm soft tissue mass to the site of a laparoscopic-assisted gastropexy performed 3 years earlier. Body wall resection with wide surgical margins was performed. Histological evaluation identified the mass as a grade III soft tissue sarcoma with clean surgical margins. To the authors' knowledge, this report is the first to detail a case of a soft tissue sarcoma that is suspected to have originated at and/or infiltrated into tissues that were previously incised during a surgical procedure. Key clinical message: Based on this case, there is a possibility of a clinical correlate to the feline injection site sarcoma in the canine species.

Evaluation of safety and immunogenicity of feline vaccines with reduced volume

A non adjuvanted vaccine against feline herpesvirus, feline calicivirus, feline panleucopenia and feline leukemia has been formulated in reduced volume (0.5 ml) with the same antigen content as the conventional 1 ml presentation. This paper reports studies evaluating the safety and the immunogenicity of this reduced volume vaccine in comparison with the conventional volume vaccine. The safety of both vaccines was evaluated in a small sized laboratory trial. It was further tested in a randomized controlled field trial on a total of 398 cats. Immediate and delayed local and systemic adverse events were monitored after vaccination. The immunogenicity of each vaccine was also checked by serological antibody responses against the vaccines antigens during the laboratory trial. These studies showed that the 0.5 ml vaccine was well tolerated in cats, inducing less local events, while keeping the same immunogenicity as the corresponding 1 ml vaccine. Reducing the volume of the vaccine is a way to improve the convenience of administration and to help following vaccination guidelines with the aim of reducing the incidence of adverse events following vaccination.

Unusual presentation of gouty tophus in the liver with subsequent appearance in the same site of HCC: a correlate diagnosis? Case report

Background

Although gout is a common disease, the presence of gouty tophi outside joints is rare and in literature, there is to date only one report of hepatic tophaceous nodule. We would like to highlight here the difficult diagnostic workup in a patient with history of cancer and the presence of a tophus inside the liver. Moreover, we address the possible etiologic role of chronic inflammation related to tophi and liver cancer.

Case presentation

We present the case of a 72-year-old man with a localization of gouty tophus in the liver, who thereafter developed a hepatocellular carcinoma (HCC) in the same site. The patient was followed up after surgery for left renal cancer from 1992 to 2011, when a hepatic nodule was discovered for the first time. After a detailed evaluation, the nodule was classified as a urate tophus of the liver. However, further follow-up showed that the nodule increased in size and changed its characteristics, bringing to the diagnosis of HCC.

Conclusions

With the present case report, we would discuss the possible neoplastic degeneration of a gouty tophus and its etiologic role favouring cellular degeneration linked to chronic inflammation. We would also highlight the importance of histopathological evaluation of hepatic lesions in gouty patients at high risk of liver neoplasm, due to the difficulty in characterizing gouty tophi by imaging.

Association between Degree of Anaplasia and Degree of Inflammation with the Expression of COX-2 in Feline Injection Site Sarcomas

Feline injection site sarcomas (FISSs) are mesenchymal neoplasms that develop at the sites of delivery of vaccines or other injectable products. Vaccine adjuvants can trigger an intense and persistent inflammatory response that may lead to neoplastic transformation. The proinflammatory role of cyclo-oxygenase (COX)-2 is well known and its overexpression has prognostic value in multiple neoplastic processes. One hundred and seventeen FISSs were evaluated for the degree of inflammation and anaplasia. Immunohistochemistry was used to determine the expression of COX-2 in these sarcomas. There was a significant association between the degree of inflammation and the expression of COX-2 by neoplastic cells. COX-2 expression was lower in tumours with higher degrees of anaplasia. These findings may be useful in predicting the sensitivity of FISSs to treatment with COX-2 inhibitors. The potential therapeutic use of such agents could then be restricted to tumours with lower degrees of anaplasia.

Soft tissue sarcoma affecting the right shoulder of a man with paraplegia from a remote traumatic spinal cord injury: a case report

Introduction

People with spinal cord injury (SCI) are getting older due to a combination of increased life expectancy and older age at the time of injury. This trend makes it more likely for these patients to have other chronic health conditions including cancer. Inevitably relatively rare cancers such as soft tissue sarcomas (STS), which are more common with advancing age, will occur in some SCI patients. The present case represents the first report of a limb STS in a patient with chronic paraplegia from a traumatic SCI.

Case presentation

We report a case of a 50-year-old right handed male with a T6 chronic, complete SCI (American Spinal Injury Association Impairment Scale A) who presented with a large mass involving his right shoulder musculature that was determined to be a high grade spindle cell sarcoma. The patient was followed closely by Physiatry over an approximately 6-month time course including prior to his tumor diagnosis, during the pre-radiation and pre-surgical planning phase, and then post-operatively for his acute inpatient rehabilitation. He was successfully discharged home to live alone in his accessible apartment complex.

Discussion

This case is the first ever reported case of a person living with a traumatic SCI who subsequently developed a limb STS. In addition to its novelty, this case illustrates how health conditions such as rare cancers are presenting more often as the chronic SCI population is getting older, which creates both unique diagnostic and management challenges for cancer rehabilitation specialists.

Cutaneous non-epitheliotropic T-cell lymphoma associated with a fracture site in a cat

Case summary

A 7-year-old male neutered domestic shorthair cat presented for investigation of a swelling over the right forelimb. Radiographs of the right forelimb revealed significant lysis and soft tissue swelling surrounding a previously implanted surgical plate, used to repair a fracture of the distal radius 5 years prior. The implant was removed, and a biopsy was collected. Histopathological analysis and immunohistochemistry diagnosed a non-epitheliotropic T-cell cutaneous lymphoma. Staging confirmed multiple regional lymph node involvement. The cat was started on a CHOP-based protocol (vincristine, doxorubicin, cyclophosphamide and prednisolone). At week 4, the disease progressed both locally and within the regional lymph nodes. The primary lesion became severely ulcerated and the cat was euthanased, 42 days post-diagnosis.

Relevance and novel information

This is the first report of a cutaneous non-epitheliotropic lymphoma developing at the site of a previous traumatic fracture and metal implant. The cat's response to chemotherapy was poor and euthanasia was performed owing to progressive disease. More investigation is required to understand the role that malignant transformation could have at sites of chronic inflammation, bone fractures and surgical implants.

A Silk Cranial Fixation System for Neurosurgery

Cranial fixation should be safe, reliable, ideally degradable, and produce no hazardous residues and no artifacts on neuroimaging. Protein-based fixation devices offer an exciting opportunity for this application. Here, the preclinical development and in vivo efficacy verification of a silk cranial fixation system in functional models are reported by addressing key challenges toward clinical use. A comprehensive study on this fixation system in rodent and canine animal models for up to 12 months is carried out. The silk fixation system shows a superb performance on the long-term stability of the internal structural support for cranial flap fixation and bone reconnection and has good magnetic resonance imaging compatibility, and tolerability to high dose radiotherapy, underscoring the favorable clinical application of this system for neurosurgery compared to the current gold standard.

Ten Things You Might Not Know about Iron Oxide Nanoparticles

Since ultrasmall superparamagnetic iron oxides (USPIOs) are not associated with a risk of nephrogenic sclerosis, they can serve as a safer contrast agents compared with gadolinium chelates for MR angiography, tissue perfusion studies, and atherosclerotic plaque and tumor imaging; USPIOs are especially beneficial for patients with renal insufficiency or patients with uncertain creatinine laboratory values.

Amid mounting concerns about nephrogenic sclerosis and gadolinium deposition in the brain, physicians and patients alike are starting to question the use of gadolinium chelates for clinical magnetic resonance (MR) imaging. The search for safer alternatives is currently underway. In North America, the iron supplement ferumoxytol has gained considerable interest as an MR contrast agent. In Europe, ferumoxtran-10 is entering phase III clinical trials. As these agents are starting to be used by a new generation of radiologists, important clinical questions have re-emerged, including those that have been answered in the past. This article offers 10 important insights for the use of iron oxide nanoparticles in clinical MR imaging.

Loco-regional immune default: The immunocompromised district in human and comparative dermatology

Lately, the innovative concept of an immunocompromised cutaneous district (ICD) has been introduced to explain why a previously injured cutaneous site may become in time a privileged location for the onset of opportunistic infections, tumors, and immune reactions. The injuring events capable of rendering a skin region a potential ICD are various, numerous, and most of the time identifiable by means of a careful clinical history. The reason that only a small minority of injured skin areas actually becomes ICDs, with subsequent opportunistic localization of a second and unrelated skin disorder, is presently unknown. The ICD is a conceptual entity that is not limited to human dermatology. It can also apply to veterinary medicine. Development of sarcomas at the injection site in cats after routine vaccination and, occasionally, administration of pharmaceutical products, as well as insertion of any foreign body, is a repeatedly documented event. Antigen load, persistent inflammation, and fibroblastic proliferation are thought to be important factors predisposing to the onset of fibrosarcoma in cats. Recently, it has been hypothesized that a local immunosuppression caused by inhalant glucocorticoids may have favored the development of regional demodicosis in cats. In our opinion, injection-site sarcomas and feline localized demodicosis can be considered examples of veterinary ICDs.

Cytogenomics of Feline Cancers: Advances and Opportunities

Relative to the dog, integration of the cat into the “One Health” concept has been more restricted, particularly in the field of molecular oncology. Beyond the continual need to enhance the sophistication of feline healthcare per se, the unique spectrum of naturally-occurring cancers in the cat offers tremendous opportunities for comparative and translational advances that may have mutual benefit for human and veterinary medicine. The study of feline cancers additionally may generate new insight into underexplored aspects of tumor biology that are less accessible in other species, such as the relationship between chronic inflammation and neoplasia, and the role of viruses in malignant transformation. Several factors that have hindered molecular studies of feline cancers have now been surmounted, with the most fundamental step forward coming from the development of a high-quality reference genome sequence assembly for the cat. This article reviews landmark studies that have led to our current appreciation of feline genome architecture, and outlines techniques used in cancer cytogenomics, from conventional karyotyping analysis through to the development of genomic microarrays and beyond. A summary of progress in the identification and characterization of chromosomal aberrations in feline cancers is provided using examples from studies of injection-site sarcomas, lymphomas and mammary tumors.

Hypertrophic osteopathy in a cat with a concurrent injection-site sarcoma

Case summary An 11-year old neutered female domestic shorthair cat presented for investigation of a large, partially ulcerated skin mass in the area of the left scapula. The cat had been vaccinated 6 weeks previously in the same area. Haematology showed a marked neutrophilia and monocytosis. Tru-cut biopsies were taken and histopathology was consistent with a high-grade soft tissue sarcoma. Thoracic radiographs and abdominal ultrasound revealed no abnormalities. Moderate mixed (palisading, brush border and smooth) periosteal reaction was seen on the diaphysis of long bones at the time of the radiographic examination. Magnetic resonance imaging of the mass showed infiltration within deeper tissues and the owners elected euthanasia. Post-mortem examination confirmed the presence of hypertrophic osteopathy with a concurrent injection-site sarcoma. No evidence of intra-thoracic or intra-abdominal disease was found.

Relevance and novel information To our knowledge, this is the first report where hypertrophic osteopathy has been described in a cat with a soft tissue sarcoma, most likely an injection-site sarcoma.

Fibrosarcoma arising from gouty tophi: report of a unique case and review of literature

Fibrosarcoma is a malignant mesenchymal tumor. To the author's best knowledge, no previous case of fibrosarcoma arising from gouty tophi has been reported. Here we reported the first case of fibrosarcoma arising from gouty tophi. A case of 58-year-old man was presented with a mass with ulcer and infection in the second joint of left middle finger for 2 months, with long standing gouty tophi. The tumor was biopsied and the biopsy showed complete excision of the tumor. With the pathological and immunohistochemical features considered, the diagnosis of fibrosarcoma associated with gouty tophi was made. The clinical findings, pathological characteristics and treatment were described.

Subcutaneous fluid port-associated soft tissue sarcoma in a cat

A 20-year-old male castrated domestic longhair cat was evaluated for assessment of its chronic kidney disease (CKD) and a non-healing ulcerated mass at the site of a previously placed and subsequently removed GIF tube. The cat had been diagnosed with CKD 10 years prior and two GIF tubes had been placed over a 5-year period, the second of which was associated with secondary infection. Biopsy of the non-healing ulcerated mass was consistent with grade 2 soft tissue sarcoma. At necropsy there was a discrete, serpentine, subcutaneous mass measuring approximately 8 mm in diameter that extended approximately 20 cm along the dorsum to the caudal thorax, following the path of the GIF tube, from the main intrascapular, ulcerated mass where the fluid port injection site was located. This is the first report of a fibrosarcoma arising at the site of a subcutaneous fluid port in a cat. Although the cat's owners were pleased with the 4 years of quality of life provided by this device, this complication should be considered when a decision to place ports for long-term management of disease is made.

2013 AAFP Feline Vaccination Advisory Panel Report

RATIONALE

This Report was developed by the Feline Vaccination Advisory Panel of the American Association of Feline Practitioners (AAFP) to provide practical recommendations to help clinicians select appropriate vaccination schedules for their feline patients based on risk assessment. The recommendations rely on published data as much as possible, as well as consensus of a multidisciplinary panel of experts in immunology, infectious disease, internal medicine and clinical practice.