Inflammatory and Immune-Mediated Myopathies, What Do We Know?

Inflammatory myopathies or myositis encompass diseases characterized by the presence of inflammatory cellular infiltrates, mainly polymorphonuclear cells and/or lymphocytes, in muscle. This is in contrast to most forms of muscle disease characterized by myodegeneration that results in macrophage infiltration. Inflammatory myopathies could have infectious or noninfectious causes. Noninfectious causes consist of primary (genetic, autoimmune) or acquired immune-mediated disease. Focal, multifocal or diffuse, acute or recurrent forms of disease can occur. This article will mainly review immune-mediated myopathies in horses. Myositis directly caused by infection such as Clostridium spp and others will not be discussed here.

Aggregatibacter actinomycetemcomitans infection in children: two case reports and a review of the literature.

Aggregatibacter actinomycetemcomitans (Aa), a Gram-negative coccobacillus commonly associated with endocarditis, poses a rare diagnostic challenge in pediatric cases. The presentation of two pediatric cases-myositis and chest mass-highlights novel aspects, including unusual symptom presentations in children which can be mistaken for malignancy. The limited sensitivity of standard blood tests complicates diagnosis, leading to delayed diagnosis and treatment. Representative samples must be taken, especially if blood cultures are negative. Despite advances in detection methods, diagnosing Aa infection remains difficult due to its rarity in children and variable clinical presentation. In conclusion, a comprehensive understanding of Aa infection in children is essential for early and effective diagnostic and therapeutic management.

[Pneumonia and benign acute myositis of childhood due to Mycoplasma pneu-moniae associated with encephalitis: A case report]. / Neumonía y miositis aguda benigna de la infancia por Mycoplasma pneumoniae asociado a encefalitis: reporte de caso.

One of the leading causes of pneumonia in children between 5 to 15 years is Mycoplasma pneumoniae, a bacterium that causes atypical clinical manifestations such as myositis and encephalitis. We report a 5-year-old girl who presented functional limitations of the lower extremities preceded by an upper respiratory infection. Later on, she developed pneumonia and encephalitis. Antibiotics and antivirals were administered due to the clinical deterioration of the patient. IgM serology for Mycoplasma pneumoniae was positive, while the other viral studies were negative. The clinical course was favorable with a progressive decrease in respiratory distress, sensorial disorder, and improvement in the functional limitations of the lower limbs after 15 days of treatment.

Una de las principales causas de neumonía en niños entre 5 y 15 años es el Mycoplasma pneumoniae, una bacteria que causa manifestaciones clínicas atípicas como la miositis y encefalitis. Reportamos un caso de una niña de cinco años que presentó limitación funcional en extremidades inferiores precedida por una infección respiratoria superior. Posteriormente, se complicó con neumonía y encefalitis. Se administraron antibióticos y antivirales debido al deterioro clínico del paciente. La serología de inmunoglobulinas para Mycoplasma pneumoniae fue positiva; mientras que los demás estudios virales fueron negativos. El curso clínico fue favorable con disminución progresiva de la dificultad respiratoria, trastorno del sensorio y mejoría en la limitación funcional en las extremidades inferiores a los 15 días de tratamiento.

Rare case of extensive streptococcal myositis.

A rare case of extensive streptococcal myositis is reported. A 46-year-old man was admitted following acute swollen right elbow joint associated with localised pain, erythema and hypoaesthesia. Multiple tense blisters subsequently developed around the affected elbow joint extending to the axilla. He was treated for suspected soft tissue infection and septic arthritis. Blood test investigations demonstrated raised creatine kinase (894 U/L) and inflammatory markers (white cell count 21.1×109/L; C reactive protein 370 mg/L). Emergency CT scan reported extensive myositis affecting the triceps, latissimus dorsi and pectoralis major muscle with no fascial involvement. He was escalated to intensive care unit and treated for infectious myositis. Further investigation revealed positive streptococcal antibody (anti-streptodornase B titre >1600 U/mL). He was managed conservatively with microbiologist specialist input and supportive care. The patient made good recovery after receiving 10 days of intravenous antibiotics and subsequently switched to oral antibiotics. He was discharged on day 30 of admission after receiving intensive inpatient physiotherapy.

Single Amino Acid Replacements in RocA Disrupt Protein-Protein Interactions To Alter the Molecular Pathogenesis of Group A Streptococcus.

Group A Streptococcus (GAS) is a human-specific pathogen and major cause of disease worldwide. The molecular pathogenesis of GAS, like many pathogens, is dependent on the coordinated expression of genes encoding different virulence factors. The control of virulence regulator/sensor (CovRS) two-component system is a major virulence regulator of GAS that has been extensively studied. More recent investigations have also involved regulator of Cov (RocA), a regulatory accessory protein to CovRS. RocA interacts, in some manner, with CovRS; however, the precise molecular mechanism is unknown. Here, we demonstrate that RocA is a membrane protein containing seven transmembrane helices with an extracytoplasmically located N terminus and cytoplasmically located C terminus. For the first time, we demonstrate that RocA directly interacts with itself (RocA) and CovS, but not CovR, in intact cells. Single amino acid replacements along the entire length of RocA disrupt RocA-RocA and RocA-CovS interactions to significantly alter the GAS virulence phenotype as defined by secreted virulence factor activity in vitro and tissue destruction and mortality in vivo In summary, we show that single amino acid replacements in a regulatory accessory protein can affect protein-protein interactions to significantly alter the virulence of a major human pathogen.

A Single Amino Acid Replacement in Penicillin-Binding Protein 2X in Streptococcus pyogenes Significantly Increases Fitness on Subtherapeutic Benzylpenicillin Treatment in a Mouse Model of Necrotizing Myositis.

Invasive strains of Streptococcus pyogenes with significantly reduced susceptibility to ß-lactam antibiotics have been recently described. These reports have caused considerable concern in the international infectious disease, medical microbiology, and public health communities because S. pyogenes has remained universally susceptible to ß-lactam antibiotics for 70 years. Virtually all analyzed strains had single amino acid replacements in penicillin-binding protein 2X (PBP2X), a major target of ß-lactam antibiotics in pathogenic bacteria. We used isogenic strains to test the hypothesis that a single amino acid replacement in PBP2X conferred a fitness advantage in a mouse model of necrotizing myositis. We determined that when mice were administered intermittent subtherapeutic dosing of benzylpenicillin, the strain with a Pro601Leu amino acid replacement in PBP2X that confers reduced ß-lactam susceptibility in vitro was more fit, as assessed by the magnitude of colony-forming units recovered from disease tissue. These data provide important pathogenesis information that bears on this emerging global infectious disease problem.

Maltotriose-based probes for fluorescence and photoacoustic imaging of bacterial infections.

Currently, there are no non-invasive tools to accurately diagnose wound and surgical site infections before they become systemic or cause significant anatomical damage. Fluorescence and photoacoustic imaging are cost-effective imaging modalities that can be used to noninvasively diagnose bacterial infections when paired with a molecularly targeted infection imaging agent. Here, we develop a fluorescent derivative of maltotriose (Cy7-1-maltotriose), which is shown to be taken up in a variety of gram-positive and gram-negative bacterial strains in vitro. In vivo fluorescence and photoacoustic imaging studies highlight the ability of this probe to detect infection, assess infection burden, and visualize the effectiveness of antibiotic treatment in E. coli-induced myositis and a clinically relevant S. aureus wound infection murine model. In addition, we show that maltotriose is an ideal scaffold for infection imaging agents encompassing better pharmacokinetic properties and in vivo stability than other maltodextrins (e.g. maltohexose).

Outbreaks of severe myositis in cultured white sturgeon (Acipenser transmontanus L.) associated with Streptococcus iniae.

Outbreaks of an infectious disease affecting cultured white sturgeon (Acipenser transmontanus) were investigated. Clinical signs included erratic swimming, arching of the back and mortality. Necropsy findings included poorly demarcated yellow to dark-red and friable lesions in the epaxial muscle, ulcerative skin lesions and haemorrhages in the swim bladder and coelomic wall. Histological evaluation revealed areas of necrotizing and heterophilic myositis with aggregates of bacterial cocci. The lumen of blood vessels in the dermis, under ulcerated areas, and in the posterior kidney, was occluded by fibrin thrombi. Aggregates of Gram-positive cocci were observed in the muscle lesions and within the fibrin thrombi in the dermis and kidney. Genetically homogeneous Streptococcus iniae strains were recovered from affected fish from different outbreaks. The isolates shared high degree of similarity at gene locus (gyrB) with previously characterized S. iniae from cultured fish in California, confirming the emergence of this particular strain of S. iniae in US aquaculture.

New Pathogenesis Mechanisms and Translational Leads Identified by Multidimensional Analysis of Necrotizing Myositis in Primates.

A fundamental goal of contemporary biomedical research is to understand the molecular basis of disease pathogenesis and exploit this information to develop targeted and more-effective therapies. Necrotizing myositis caused by the bacterial pathogen Streptococcus pyogenes is a devastating human infection with a high mortality rate and few successful therapeutic options. We used dual transcriptome sequencing (RNA-seq) to analyze the transcriptomes of S. pyogenes and host skeletal muscle recovered contemporaneously from infected nonhuman primates. The in vivo bacterial transcriptome was strikingly remodeled compared to organisms grown in vitro, with significant upregulation of genes contributing to virulence and altered regulation of metabolic genes. The transcriptome of muscle tissue from infected nonhuman primates (NHPs) differed significantly from that of mock-infected animals, due in part to substantial changes in genes contributing to inflammation and host defense processes. We discovered significant positive correlations between group A streptococcus (GAS) virulence factor transcripts and genes involved in the host immune response and inflammation. We also discovered significant correlations between the magnitude of bacterial virulence gene expression in vivo and pathogen fitness, as assessed by previously conducted genome-wide transposon-directed insertion site sequencing (TraDIS). By integrating the bacterial RNA-seq data with the fitness data generated by TraDIS, we discovered five new pathogen genes, namely, S. pyogenes 0281 (Spy0281 [dahA]), ihk-irr, slr, isp, and ciaH, that contribute to necrotizing myositis and confirmed these findings using isogenic deletion-mutant strains. Taken together, our study results provide rich new information about the molecular events occurring in severe invasive infection of primate skeletal muscle that has extensive translational research implications.IMPORTANCE Necrotizing myositis caused by Streptococcus pyogenes has high morbidity and mortality rates and relatively few successful therapeutic options. In addition, there is no licensed human S. pyogenes vaccine. To gain enhanced understanding of the molecular basis of this infection, we employed a multidimensional analysis strategy that included dual RNA-seq and other data derived from experimental infection of nonhuman primates. The data were used to target five streptococcal genes for pathogenesis research, resulting in the unambiguous demonstration that these genes contribute to pathogen-host molecular interactions in necrotizing infections. We exploited fitness data derived from a recently conducted genome-wide transposon mutagenesis study to discover significant correlation between the magnitude of bacterial virulence gene expression in vivo and pathogen fitness. Collectively, our findings have significant implications for translational research, potentially including vaccine efforts.

Potential Clinical Effects of a Novel Rapid Diagnostic Panel for Pediatric Musculoskeletal Infections.

A direct-from-source rapid musculoskeletal diagnostic panel (MDP) was validated recently. We compared clinical measures to theoretical time points had MDP results been available. The MDP would have significantly decreased the time to pathogen identification (7 hours), time to definitive antimicrobial therapy (22 hours), and hospital length of stay (26.4 hours).

[Inflammatory myopathy following acute meningoccemia in a properdin-deficient patient: A case report]. / Myopathie inflammatoire post-méningococcémie aiguë chez un patient présentant un déficit en properdine : à propos d'un cas.

INTRODUCTION: Myalgia is a classical sign in invasive meningococcal diseases (IMD), but severe and persistent myalgia following an IMD have never been reported to date. CASE REPORT: A 20-year-old man presented with purpura fulminans and meningitis caused by Neisseria meningitidis serogroup Y, revealing properdin deficiency. Although meningitis symptoms improved after antibiotherapy, initial myalgia of the lower limbs increased, associated with mild rhabdomyolysis. Magnetic resonance imaging (MRI) revealed an increased STIR (Short TI inversion recovery) signal of both quadriceps muscles, without abscess. After exclusion of other causes of myopathy, a post-infectious myositis was diagnosed. A four-week course of corticosteroids led to dramatic improvement. CONCLUSION: Post-infectious inflammatory myopathy should be suspected in case of severe and persistent myalgia associated with rhabdomyolysis following an IMD, after exclusion of pyomyositis especially. A short course of corticosteroids seems to be effective.

Neumonía y miositis aguda benigna de la infancia por Mycoplasma pneumoniae asociado a encefalitis: reporte de caso / Pneumonia and benign acute myositis of childhood due to Mycoplasma pneu-moniae associated with encephalitis: a case report

Una de las principales causas de neumonía en niños entre 5 y 15 años es el Mycoplasma pneumoniae, una bacteria que causa manifestaciones clínicas atípicas como la miositis y encefalitis. Reportamos un caso de una niña de cinco años que presentó limitación funcional en extremidades inferiores precedida por una infección respiratoria superior. Posteriormente, se complicó con neumonía y encefalitis. Se administraron antibióticos y antivirales debido al deterioro clínico del paciente. La serología de inmunoglobulinas para Mycoplasma pneumoniae fue positiva; mientras que los demás estudios virales fueron negativos. El curso clínico fue favorable con disminución progresiva de la dificultad respiratoria, trastorno del sensorio y mejoría en la limitación funcional en las extremidades inferiores a los 15 días de tratamiento.

One of the leading causes of pneumonia in children between 5 to 15 years is Mycoplasma pneumoniae, a bacterium that causes atypical clinical manifestations such as myositis and encephalitis. We report a 5-year-old girl who presented functional limitations of the lower extremities preceded by an upper respiratory infection. Later on, she developed pneumonia and encephalitis. Antibiotics and antivirals were administered due to the clinical deterioration of the patient. IgM serology for Mycoplasma pneumoniae was positive, while the other viral studies were negative. The clinical course was favorable with a progressive decrease in respiratory distress, sensorial disorder, and improvement in the functional limitations of the lower limbs after 15 days of treatment.

Dorsal subscapularis approach for the surgical drainage of subscapularis intramuscular abscess: a case report.

BACKGROUND: Abscess formation in the subscapularis muscle is a rare clinical condition. Few reports are available regarding the treatment methods and surgical approaches for subscapularis intramuscular abscesses. Here, we describe a case of subscapularis intramuscular abscess that was treated successfully via surgical drainage using a new approach, the "dorsal subscapularis approach". CASE PRESENTATION: A 67-year-old woman presented to our hospital with complaints of fever and disturbance of consciousness. Two days prior to visiting our hospital, right shoulder pain and limited range of motion in the shoulder were noted. Cerebrospinal fluid examination and contrast-enhanced computed tomography (CT) imaging on admission revealed a right subscapularis intramuscular abscess with concomitant bacterial meningitis. The patient's clinical symptoms improved after antibiotic administration for 3 weeks, but the right shoulder pain persisted. Contrast-enhanced CT imaging performed after antibiotic administration revealed an abscess in the right shoulder joint space, in addition to a capsule of the abscess in the right subscapularis muscle. We performed open surgical drainage for the abscess, which had spread from the subscapularis muscle to the glenohumeral joint. Using the deltoid-pectoral approach, we detected exudate and infected granulation tissue in the joint cavity. Furthermore, we separated the dorsal side of the subscapularis muscle from the scapula using a raspatory and detected infected granulation tissue in the subscapularis muscle belly. We performed curettage and washed as much as possible. After surgery, antibiotic administration continued for 2 weeks. The patient's right shoulder pain subsided and CT performed 2 months after surgery revealed no recurrence of infection. CONCLUSIONS: The present case indicated that a subscapularis intramuscular abscess could lead to severe concomitant infections of other organs via the hematogenous route. Thus, early detection and treatment are necessary. Moreover, in this case, surgical drainage using a dorsal subscapularis approach was beneficial to treating the abscess, which had spread from the subscapularis muscle to the glenohumeral joint.

Microsporidial myositis in adult-onset immunodeficiency: case-based review.

Polymyositis is a diagnosis of exclusion. In patients with odd features, it can be of infective etiology. A high index of suspicion is required for diagnosis. A 55-year-old gentleman presented with gradual-onset proximal muscle weakness. Examination revealed mild distal weakness but no rash. Muscle enzymes were raised and tests for autoantibodies were negative. Biopsy revealed microsporidiosis. In view of this unusual infection, immunodeficiency was considered and he was found to have lymphopenia which antedated his illness. Later, he developed cranial nerve palsies due to multiple lesions in the pons. In addition, he had Cytomegalovirus viremia. Literature was reviewed to identify 20 cases of microsporidial myositis, its presentation, underlying immunodeficient state, and clinical course. Infective polymyositis should be considered in a patient with paucity of clinical and serological autoimmune features. Lymphopenia can point to underlying immunodeficiency. CMV infection could be the contributor to or bystander-effect of idiopathic lymphopenia.

Polymorphisms in Regulator of Cov Contribute to the Molecular Pathogenesis of Serotype M28 Group A Streptococcus.

Two-component systems (TCSs) are signal transduction proteins that enable bacteria to respond to external stimuli by altering the global transcriptome. Accessory proteins interact with TCSs to fine-tune their activity. In group A Streptococcus (GAS), regulator of Cov (RocA) is an accessory protein that functions with the control of virulence regulator/sensor TCS, which regulates approximately 15% of the GAS transcriptome. Whole-genome sequencing analysis of serotype M28 GAS strains collected from invasive infections in humans identified a higher number of missense (amino acid-altering) and nonsense (protein-truncating) polymorphisms in rocA than expected. We hypothesized that polymorphisms in RocA alter the global transcriptome and virulence of serotype M28 GAS. We used naturally occurring clinical isolates with rocA polymorphisms (n = 48), an isogenic rocA deletion mutant strain, and five isogenic rocA polymorphism mutant strains to perform genome-wide transcript analysis (RNA sequencing), in vitro virulence factor assays, and mouse and nonhuman primate pathogenesis studies to test this hypothesis. Results demonstrated that polymorphisms in rocA result in either a subtle transcriptome change, causing a wild-type-like virulence phenotype, or a substantial transcriptome change, leading to a significantly increased virulence phenotype. Each polymorphism had a unique effect on the global GAS transcriptome. Taken together, our data show that naturally occurring polymorphisms in one gene encoding an accessory protein can significantly alter the global transcriptome and virulence phenotype of GAS, an important human pathogen.

Comparison of Musculoskeletal Infections due to Nontyphoidal Salmonella Species and Staphylococcus aureus in Immunocompetent Children.

BACKGROUND: Nontyphoidal Salmonella species (NTS) rarely cause musculoskeletal infections in healthy children. Data on NTS musculoskeletal infections in healthy children are limited. No previous studies have directly compared children with NTS musculoskeletal infections with those with Staphylococcus aureus. METHODS: This was a case-control study of children 30 days-18 years old seen at Texas Children's Hospital between 2010 and 2017 with NTS musculoskeletal infections. Controls were children with S. aureus musculoskeletal infections matched on date of infection. Patients with known predisposing conditions were excluded. Demographic and clinical risk factors between the 2 groups were compared. RESULTS: From 2010 to 2017, 27 cases of NTS musculoskeletal infections were identified, 12 (46.0%) of which occurred in healthy children. The control group had 53 patients. Predictors of NTS musculoskeletal infections included exposure to reptiles [odds ratio (OR) 8.50, 95% confidence interval (CI): 11.24-58.23] and preceding gastrointestinal symptoms (OR 5.63, 95% CI: 1.45-21.89). Children with NTS musculoskeletal infections had greater odds of pelvic and/or spinal involvement than S. aureus controls (OR 5.32, 95% CI: 1.42-20.13). Complications occurred in 16.7% of NTS cases versus 32% of S. aureus controls. CONCLUSIONS: Healthy children with NTS musculoskeletal infections more frequently report reptile exposure and preceding gastrointestinal symptoms and have pelvic and spinal involvement compared with children with musculoskeletal infections due to S. aureus. NTS should be considered as a potential cause of musculoskeletal infections in children with these risk factors. In contrast to previous case reports and case series, children with NTS musculoskeletal infections had a low rate of complications.

Gene fitness landscape of group A streptococcus during necrotizing myositis.

Necrotizing fasciitis and myositis are devastating infections characterized by high mortality. Group A streptococcus (GAS) is a common cause of these infections, but the molecular pathogenesis is poorly understood. We report a genome-wide analysis using serotype M1 and M28 strains that identified GAS genes contributing to necrotizing myositis in nonhuman primates (NHP), a clinically relevant model. Using transposon-directed insertion-site sequencing (TraDIS), we identified 126 and 116 GAS genes required for infection by serotype M1 and M28 organisms, respectively. For both M1 and M28 strains, more than 25% of the GAS genes required for necrotizing myositis encode known or putative transporters. Thirteen GAS transporters contributed to both M1 and M28 strain fitness in NHP myositis, including putative importers for amino acids, carbohydrates, and vitamins and exporters for toxins, quorum-sensing peptides, and uncharacterized molecules. Targeted deletion of genes encoding 5 transporters confirmed that each isogenic mutant strain was significantly (P < 0.05) impaired in causing necrotizing myositis in NHPs. Quantitative reverse-transcriptase PCR (qRT-PCR) analysis showed that these 5 genes are expressed in infected NHP and human skeletal muscle. Certain substrate-binding lipoproteins of these transporters, such as Spy0271 and Spy1728, were previously documented to be surface exposed, suggesting that our findings have translational research implications.

Fatal Streptoccocus canis Necrotizing Fasciitis and Myositis in a Free-Ranging Iberian Lynx (Lynx pardinus).

A free-ranging Iberian lynx (Lynx pardinus) was found dead after 16 mo of being reintroduced. On gross necropsy, necrotic areas in the left biceps femoris and intercostal muscles were identified. Streptococcus canis was isolated from both groups of muscles and was confirmed by PCR, corroborating a necrotizing myositis diagnostic.

Piomiositis primaria del músculo esternocleidomastoideo: reporte de un caso y revisión de la literatura / Primary pyomyositis of the sternocleidomastoid muscle: a case report and review of the literature

RESUMEN La piomiositis es una infección bacteriana del músculo estriado, siendo extremadamente rara la afectación de la musculatura cervical. Se ha asociado en nuestro medio a enfermedades crónicas como la diabetes y a la inmunodepresión. Presentamos a un paciente de 67 años que acude al servicio de urgencias por tumoración laterocervical de rápido crecimiento, negando antecedentes de interés a excepción de diabetes mellitus tipo II. Se le realizó estudio de imagen con tomografía computarizada con contraste, observándose aumento de volumen del músculo esternocleidomastoideo izquierdo y se empezó tratamiento empírico con antibióticos endovenosos. Dada la evolución tórpida finalmente se realizó drenaje quirúrgico bajo anestesia general con mejoría de los parámetros clínicos y analíticos. La piomiositis de los músculos cervicales es muy rara (0,4%-1% de todos los casos) siendo el esternocleidomastoideo el músculo del cuello más frecuentemente afectado. La tomografía computarizada representa la prueba de imagen de elección, permitiendo un rápido diagnóstico llegando a poder diferenciar este cuadro de otros similares. Considerando que muchos de estos pacientes presentan comorbilidades asociadas y/o inmunosupresión, es de extrema importancia diagnosticarlos precozmente y empezar un tratamiento adecuado que dependerá del grado y extensión de la infección. A pesar de ser una entidad poco frecuente, su incidencia está en aumento en nuestro medio asociada a la infección por VIH y otras condiciones de inmunodepresión. Hay que tenerla en mente en el diagnóstico diferencial de las tumoraciones laterocervicales porque solo con una alta sospecha clínica se podrá llevar al cabo un diagnóstico precoz y un tratamiento adecuado.

ABSTRACT Pyomyositis is a bacterial infection of the striated muscle that may affect the cervical musculature in very few cases. In the occidental world it has been associated with chronic diseases as diabetes and immunosuppression. We present a 67 years old patient attended to the Emergency Department because of a laterocervical fast growth tumor, without an interesting clinical history with the exception of type II diabetes mellitus. A CT scan with contrast showed an increased volume in the left sternocleidomastoid muscle, so an empiric treatment with intravenous antibiotics was started. Because of a bad evolution we finally performed a surgical drainage of the abscess under general anesthesia with an improvement of symptoms and laboratory markers. The pyomyositis of cervical muscles is very rare (0.4-1% of all cases) and the sternocleidomastoid muscle is the most commonly affected cervical muscle. CT scan is the gold standard imaging technique, because it allows to diagnose this disease and rule out other similar entities. If we consider that many patients present with associated comorbidities and/ or immunosuppression, it's very important to perform a rapid diagnosis and to begin a correct treatment that depends on the grade and extension of the infection. Although polymyositis of the sternocleidomastoid muscle is rare, its incidence is increasing associated to HIV infection and other immunosuppressive conditions. We have to keep in mind this pathology in the differential diagnosis of laterocervical tumors because high clinical suspicion is necessary to make a rapid diagnosis and a correct treatment.