Common Mimics Research Articles

Motor Neuron Disease: To Identify the Mimics and Chameleons at the Early Stage

Motor neuron disease is a devastating progressive neurodegenerative disease, which is irreversible. Delay in the diagnosis is the norm among neurologists and other medical practitioners. It can affect both central and peripheral nervous systems. It also manifests by upper neuron, lower motor neuron signs or a mix of the above two and can affect the bulbar system. Because the disease is primary progressive, it mimics many other neurological deficits at different stages. Unfortunately, there is no one test to confirm the diagnosis at the early stage, typically during the first 12 months. Probably, all the differential diagnosis that reversible and treatable should be ruled out specifically. Patient may be referred to different specialities before being referred to general neurologist. Furthermore, general neurologist may need to refer the patient to motor neuron specialist; motor neuron specialist would like to make sure that he eliminated all the mimics before breaking the bad news with the patient and family that the motor neuron disease is the most probable diagnosis. It is of paramount important that the patient received the diagnosis as early as possible so he/she can benefit from multidisciplinary and interdisciplinary care team and to alleviate his/her symptoms and also to arrange advanced care planning, and assessment of ceiling of the goals of the care. It is of note that currently, patient may benefit from assisting dying if he/she fulfills the criteria. This review aims to include most common mimics and chameleons in the clinical practice and to discuss the diagnostic tools that should be performed for those who has been considered possible motor neuron disease. And to discuss the avenue for assessment by multidisciplinary care team which includes general neurologist, motor neuron specialist, respiratory physician, gastroenterologist, psychologist and psychiatrist, general physician, and allied health.

Primer on the Differential Diagnosis and Workup for Transthyretin Cardiac Amyloidosis

Amyloidosis has often been referred to as a "great masquerader," mimicking other systemic and cardiac diseases. As diagnostic techniques such as echocardiography with longitudinal strain, cardiac magnetic resonance imaging, and nuclear scintigraphy have advanced, identification of cardiac amyloidosis has become less daunting. This review covers the differential diagnosis and workup of patients with transthyretin cardiac amyloidosis, with a specific focus on developing a clinical suspicion through demographic, clinical, and echocardiographic features of the disease. The most common mimics of cardiac amyloidosis, i.e., conditions that likewise cause heart failure with preserved or mildly reduced ejection fraction, are also explored with respect to differential diagnosis, both for patients with normal and increased ventricular wall thickness. Ultimately, this review aims to demystify the diagnostic process by offering an algorithmic approach to the identification of transthyretin cardiac amyloidosis.

Inducible Laryngeal Obstruction Differential Diagnosis in Adolescents and Adults: A Tutorial.

Inducible laryngeal obstruction (ILO), formerly referred to as paradoxical vocal fold motion and vocal cord dysfunction, is a complex disorder of the upper airway that requires skillful differential diagnosis. There are several medical conditions that may mimic ILO (or which ILO may mimic) that should be considered in the differential diagnosis before evidence-supported behavioral intervention is initiated to mitigate or eliminate this upper airway condition. A key in treatment planning is determination of an isolated presentation of ILO or ILO concurrent with other conditions that affect the upper airway. Accurate, timely differential diagnosis in the clinical assessment of this condition mitigates delay of targeted symptom relief and/or insufficient intervention. Accurate assessment and nuanced clinical counseling are necessary to untangle concurrent, competing conditions in a single patient. This tutorial describes the common and rare mimics that may be encountered by medical professionals who evaluate and treat ILO, with particular attention to the role of the speech-language pathologist. Speech-language pathologists receive referrals for ILO from several different medical specialists (allergy, pulmonology, and sports medicine), sometimes without a comprehensive team assessment. It is paramount that speech-language pathologists who assess and treat this disorder have a solid understanding of the conditions that may mimic ILO. Summary tables that delineate differential diagnosis considerations for airway noise, origin of noise, symptoms, triggers, role of the speech-language pathologist, and β-agonist response are included for clinician reference. A clinical checklist is also provided to aid clinicians in the critical assessment process.

Neuroimaging for differential diagnosis of transient neurological attacks.

Rapid yet comprehensive neuroimaging protocols are required for patients with suspected acute stroke. However, stroke mimics can account for approximately one in five clinically diagnosed acute ischemic strokes and the rate of thrombolyzed mimics can be as high as 17%. Therefore, to accurately determine the diagnosis and differentiate mimics from true transient ischemic attacks, acute ischemic stroke is a challenge to every clinician. Medical history and neurological examination, noncontract head computed tomography, and routine magnetic resonance imaging play important roles in the assessment and management of patients with transient neurological attacks in the emergency department. This review attempts to summarize how neuroimaging can be utilized to help differentiate the most common mimics from transient ischemic attack and acute ischemic stroke. Although imaging can help direct critical triage decisions for intravenous thrombolysis or endovascular therapy, more detailed medical history and neurological examination are crucial for making a prompt and accurate diagnosis for transient neurological attack patients.

Prehospital Stroke Care, Paramedic Training Needs, and Hospital-Directed Feedback in Lithuania.

Background: Emergency medical services (EMS) are the first health care contact for the majority of stroke patients. However, there is a lack of data on the current paramedics’ hospital-directed feedback and training needs across different health care settings. We aimed to evaluate paramedics’ prehospital stroke care knowledge, training needs, and current status of feedback on suspected stroke patients. Methods: We surveyed paramedics from the Vilnius region from September to November 2019 and compared the answers between the city and the district agencies. The questionnaire content included questions on paramedics’ demographic characteristics, prehospital stroke care self-assessment, knowledge on stroke mimics, stroke training needs, and the importance of hospital-directed feedback on suspected stroke patients. Results: A total number of 161 paramedics (or 49.4% of all paramedics from our stroke care network) were surveyed, with more district paramedics rating their prehospital stroke care knowledge as inadequate (44.8% (95% confidence interval (CI) 32.8–57.6) vs. 28.1% (95% CI 20.1–27.8), p = 0.028). In addition, more district paramedics indicated a need for additional stroke training (83.1% (95% CI 71.5–90.5) vs. 69.8% (60.0–78.1), p = 0.043). However, respondents reported being the most confident while dealing with stroke (71.3%, 95% CI 63.8–77.7) compared to other time-critical conditions (p < 0.001). Vertigo (60.8%, 95% CI 53.0–68.0), brain tumors (56.3%, 95% CI 48.5–63.8), and seizures (54.4%, 95% CI 46.7–62.0) were indicated as the most common stroke mimics. Only 6.2% (95% CI 3.4–11.1) of respondents received formal feedback on the outcome of suspected stroke patients brought to the emergency department. Conclusions: A high proportion of paramedics self-perceive having inadequate stroke knowledge and an urgent need for further stroke training. The EMS staff indicate receiving insufficient feedback on suspected stroke patients, even though its usefulness is perceived as paramount.

Molecular Analysis of HPV-independent Primary Endometrial Squamous Cell Carcinoma Reveals TP53 and CDKN2A Comutations : A Clinicopathologic Analysis With Re-evaluation of Diagnostic Criteria.

Human papillomavirus (HPV)-independent primary endometrial squamous cell carcinoma (PESCC) is a rare but aggressive subtype of endometrial carcinoma for which little is known about the genomic characteristics. Traditional criteria have restricted the diagnosis of PESCC to cases without any cervical involvement. However, given that modern ancillary techniques can detect HPV and characteristic genetic alterations that should identify the more common mimics in the differential diagnosis, including endometrial endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma, those criteria may benefit from revision. To further characterize PESCC, we identified 5 cases of pure squamous cell carcinoma dominantly involving the endometrium that had the potential to be PESCC: 1 case involving only the endometrium and 4 cases with some involvement of the cervix. Clinicopathologic features were assessed and immunohistochemical analysis (p16, estrogen receptor, progesterone receptor, and p53), HPV RNA in situ hybridization (high-risk and low-risk cocktails and targeted probes for 16 and 18), and molecular studies were performed. All tumors showed aberrant/mutation-type p53 expression, were negative for estrogen receptor, progesterone receptor, and p16, and had no detectable HPV. Per whole-exome sequencing, 4 of the 5 tumors demonstrated comutations in TP53 and CDKN2A (p16). Four patients died of disease within 20 months (range, 1 to 20mo; mean, 9mo), and 1 patient had no evidence of disease at 38 months. PESCC represents a unique, clinically aggressive subtype of endometrial cancer with TP53 and CDKN2A comutations. This characteristic profile, which is similar to HPV-independent squamous cell carcinoma of the vulva, is distinct from endometrioid carcinoma with extensive squamous differentiation and HPV-associated primary cervical squamous cell carcinoma and can be used to distinguish PESCC from those mimics even when cervical involvement is present. Diagnostic criteria for PESCC should be relaxed to allow for cervical involvement when other pathologic features are consistent with, and ancillary techniques are supportive of classification as such.

Added Value of Arterial Spin Labeling in Detecting Posterior Reversible Encephalopathy Syndrome as a Stroke Mimic on Baseline Neuroimaging: A Single Center Experience.

Differentiating stroke from stroke mimics is a diagnostic challenge in every day practice. Posterior Reversible Encephalopathy Syndrome (PRES) is an important stroke mimic with nonspecific symptomatology, making prompt and accurate diagnosis challenging. Baseline neuroimaging plays a pivotal role in detection and differentiation of stroke from many common mimics and is thus critical in guiding appropriate management. In particular, MR perfusion (MRP) imaging modalities provide added value through detection and quantification of multiple physiological parameters. Arterial Spin Labeling (ASL) is a non-contrast, noninvasive MRP technique increasingly used in clinical practice; however, there is limited description of ASL in PRES in the existing literature. In this single center retrospective pilot study, we investigate the added value of ASL in detecting PRES in the largest series to date. We hope this study can serve as the basis for larger scale investigations exploring the utility of ASL in detecting stroke mimics such as PRES for accurate and efficient management of such patients.

Renal Cell Carcinoma Subtypes and Associated Renal Malignancies: A Pictorial Review—Part II

In this second article in this series, we present a pictorial review of common renal neoplasms and renal malignancy mimics, including urothelial carcinoma, liposarcoma, oncocytoma, renal pseudotumors, and renal metastases. Renal cell carcinoma (RCC) subtypes and their respective radiologic findings were discussed in Part I of this series. Principles of management of select RCC subtypes and other renal neoplasms, including urothelial carcinoma and angiomyolipoma (AML), will be discussed. Management of solitary renal masses via active surveillance (AS) or surgical intervention and the indications for renal mass biopsy as part of the diagnostic workup will also be reviewed.

Abstract TP170: Pediatric Acute Stroke Team Activation: Differentiating Stroke From Mimics

Acute pediatric stroke is a medical emergency requiring prompt recognition and treatment because quicker treatment improves neurologic outcomes and reduces excess resource usage on stroke mimics (non-stroke diagnoses). There is a clear need to better differentiate between strokes and their mimics. We performed a single center retrospective cohort study using data from March 1, 2017 to December 31, 2020. We included pediatric patients (&gt; 1m to &lt; 18y) evaluated in the tertiary children’s hospital ED for a stroke team activation. We compared clinical features for patients with stroke and those with a stroke mimic. Of 179 children included in the study (55% female, mean age 11.2y, SD 5.7y), 38 children (21% of total patients, 50% female, mean age 10.5 SD, 6.2 years) were diagnosed with stroke. Strokes included acute ischemic stroke (AIS) (73.7%), hemorrhagic stroke (HS) (18.4%), and cerebral venous sinus thrombosis (CVST) (10.5%). The most common stroke mimics were seizure (14.5%), headache (10.5%), Bell's palsy (5.6%), and conversion disorder (2.7%). Compared to mimics, stroke patients were less likely to have a history of neurosurgery (16.3% mimic vs 2.6% stroke, p=0.028) and more likely to have altered level of alertness (7.7% vs 18.4%, p=0.001), abnormal coordination (15.7% vs 36.4%, p=0.036), abnormal muscle strength (33.1% vs 57.9%, p=0.005) and abnormal reflexes (18.9% vs 43.8%, p=0.018). Of note, there were no significant differences in stroke and mimics for: age, sex, race, ethnicity, basic metabolic panel or CBC, and time from last seen well. Differentiating between strokes and mimics remains difficult without comprehensive diagnostic testing. Our study found that stroke patients are more likely present with altered level of alertness as well as abnormal coordination, muscle strength, and reflexes.

Abstract TP43: Incidence And Characteristics Of Transient Ischemic Attack Mimics In Emergency Department Observation Unit

Objective: Transient Ischemic Attack (TIA) observation units in the emergency department (ED) were developed to expedite medical evaluation and to reduce recurrent strokes. However, TIA remains a clinically challenging diagnosis due to its reliance on patient history and has multiple mimics including complex migraine, seizure, and peripheral vertigo. This study attempts to review the proportion of common mimics in the TIA observation unit at a comprehensive stroke center. Methods: We included 1525 patients enrolled in a TIA registry over 7 years (2013-2020) in a single comprehensive stroke center. Inclusion criteria of TIA unit admissions are age &gt;18 years with focal neurological symptoms for &lt; 24 hours. This population excludes patients with refractory hypertension, baseline immobility, or recurrent deficits. While in the ED, patients were evaluated by neurologists and assigned a final diagnosis of TIA or mimics. Data on demographics, past medical history, home medications, magnetic resonance imaging (MRI) results, and 30-day follow-up were collected. Results: The mean age was 64.2 (SD 15.2), 52.3% were women, and 76.7% were White, 6.0% were Black, 13.6% were Hispanic, and 3.7% other ethnicities. We found 44.7% of patients had neurologist-adjudicated TIA and 15.2% had diffusion-weighted imaging (DWI) positive lesions on MRI. TIA mimics comprised 42% of the cohort, of which 28.9% had migraine, 14.1% had peripheral vertigo, 4.7% had seizure and 52.1% were classified in other miscellaneous diagnoses including medication effect, recrudescence of prior stroke deficits, anxiety, and radiculopathies. Among the 394 patients with the diagnosis of TIA the 30-day recurrent stroke or death rate was 1.3%. Conclusion: In our investigation of TIA unit admissions, we found a relatively high proportion of TIA mimics. In patients with a diagnosis of TIA, however, the rate of subsequent stroke or death is lower than that in prior observational studies. The potential benefit of a TIA unit in stroke prevention needs to be tested against the cost of stroke mimic TIA unit admission.

Pre-hospital transdermal glyceryl trinitrate in patients with stroke mimics: data from the RIGHT-2 randomised-controlled ambulance trial

BackgroundPrehospital stroke trials will inevitably recruit patients with non-stroke conditions, so called stroke mimics. We undertook a pre-specified analysis to determine outcomes in patients with mimics in the second Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial (RIGHT-2).MethodsRIGHT-2 was a prospective, multicentre, paramedic-delivered, ambulance-based, sham-controlled, participant-and outcome-blinded, randomised-controlled trial of transdermal glyceryl trinitrate (GTN) in adults with ultra-acute presumed stroke in the UK. Final diagnosis (intracerebral haemorrhage, ischaemic stroke, transient ischaemic attack, mimic) was determined by the hospital investigator. This pre-specified subgroup analysis assessed the safety and efficacy of transdermal GTN (5 mg daily for 4 days) versus sham patch among stroke mimic patients. The primary outcome was the 7-level modified Rankin Scale (mRS) at 90 days.ResultsAmong 1149 participants in RIGHT-2, 297 (26%) had a final diagnosis of mimic (GTN 134, sham 163). The mimic group were younger, mean age 67 (SD: 18) vs 75 (SD: 13) years, had a longer interval from symptom onset to randomisation, median 75 [95% CI: 47,126] vs 70 [95% CI:45,108] minutes, less atrial fibrillation and a lower systolic blood pressure and Face-Arm-Speech-Time tool score than the stroke group. The three most common mimic diagnoses were seizure (17%), migraine or primary headache disorder (17%) and functional disorders (14%). At 90 days, the GTN group had a better mRS score as compared to the sham group (adjusted common odds ratio 0.54; 95% confidence intervals 0.34, 0.85; p = 0.008), a difference that persisted at 365 days. There was no difference in the proportion of patients who died in hospital, were discharged to a residential care facility, or suffered a serious adverse event.ConclusionsOne-quarter of patients suspected by paramedics to have an ultra-acute stroke were subsequently diagnosed with a non-stroke condition. GTN was associated with unexplained improved functional outcome observed at 90 days and one year, a finding that may represent an undetected baseline imbalance, chance, or real efficacy. GTN was not associated with harm.Trial registrationThis trial is registered with International Standard Randomised Controlled Trials Number ISRCTN 26986053.

Clinical Differences Between Stroke and Stroke Mimics in Code Stroke Patients.

BackgroundThe code stroke system is designed to identify stroke patients who may benefit from reperfusion therapy. It is essential for emergency physicians to rapidly distinguish true strokes from stroke mimics to activate code stroke. This study aimed to investigate the clinical and neurological characteristics that can be used to differentiate between stroke and stroke mimics in the emergency department (ED).MethodsWe conducted a retrospective observational study of code stroke patients in the ED from January to December 2019. The baseline characteristics and the clinical and neurological features of stroke mimics were compared with those of strokes.ResultsA total of 409 code stroke patients presented to the ED, and 125 (31%) were diagnosed with stroke mimics. The common stroke mimics were seizures (21.7%), drug toxicity (12.0%), metabolic disorders (11.2%), brain tumors (8.8%), and peripheral vertigo (7.2%). The independent predictors of stroke mimics were psychiatric disorders, dizziness, altered mental status, and seizure-like movements, while current smoking, elevated systolic blood pressure, atrial fibrillation on the initial electrocardiogram, hemiparesis as a symptom, and facial palsy as a sign suggested a stroke. In addition, the likelihood of a stroke in code stroke patients tended to increase as the number of accompanying deficits increased from the following set of seven focal neurological deficits: hemiparesis (or upper limb monoparesis), unilateral limb sensory change, facial palsy, dysarthria, aphasia (or neglect), visual field defect, and oculomotor disorder (P < 0.001).ConclusionSome clinical and neurological characteristics have been identified to help differentiate stroke mimics from true stroke. In particular, the likelihood of stroke tended to increase as the number of accompanying focal neurological deficits increased.

Neurofilaments can differentiate ALS subgroups and ALS from common diagnostic mimics

Delayed diagnosis and misdiagnosis are frequent in people with amyotrophic lateral sclerosis (ALS), the most common form of motor neuron disease (MND). Neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH) are elevated in ALS patients. We retrospectively quantified cerebrospinal fluid (CSF) NFL, CSF pNFH and plasma NFL in stored samples that were collected at the diagnostic work-up of ALS patients (n = 234), ALS mimics (n = 44) and controls (n = 9). We assessed the diagnostic performance, prognostication value and relationship to the site of onset and genotype. CSF NFL, CSF pNFH and plasma NFL levels were significantly increased in ALS patients compared to patients with neuropathies & myelopathies, patients with myopathies and controls. Furthermore, CSF pNFH and plasma NFL levels were significantly higher in ALS patients than in patients with other MNDs. Bulbar onset ALS patients had significantly higher plasma NFL levels than spinal onset ALS patients. ALS patients with C9orf72HRE mutations had significantly higher plasma NFL levels than patients with SOD1 mutations. Survival was negatively correlated with all three biomarkers. Receiver operating characteristics showed the highest area under the curve for CSF pNFH for differentiating ALS from ALS mimics and for plasma NFL for estimating ALS short and long survival. All three biomarkers have diagnostic value in differentiating ALS from clinically relevant ALS mimics. Plasma NFL levels can be used to differentiate between clinical and genetic ALS subgroups.

Changing Demographics of Stroke Mimics in Present Day Stroke Code Era: Need of a Streamlined Clinical Assessment for Emergency Physicians.

Background There is an apparently high incidence of stroke mimics in the present-day stroke code era. The reason being is the intense pressure to run with time to achieve the “time is brain”-based goals. Methods The present study was a retrospective analysis of the data collected over a duration of 6 months from April 2019 to September 2019. We observed the incidence of stroke mimics among the patients for whom rapid response stroke code was activated during the study period. We also performed a logistic regression analysis to identify the clinical features which can act as strong predictors of stroke and mimics. Results A total of 314 stroke codes were activated of which 256 (81.5%) were stroke and 58 (18.5%) were the mimics. Functional disorders and epilepsy were the most common mimics (24.1% each). Female gender ( p = 0.04; odds ratio [OR] 2.9[1.0–8.8]), isolated impairment of consciousness ( p < 0.01; OR 4.3[1.5–12.6]), and isolated dysarthria ( p < 0.001) were the strong independent predictors for a stroke mimic. Hemiparesis was the strong independent predictor for a stroke ( p < 0.001; OR 0.0[0.0–0.1]). Conclusion In the present epoch of rapid response stroke management, a streamlined assessment by the emergency physicians based on the above clinical predictors may help in avoiding the misdiagnosis of a mimic as stroke.

Verrucous Carcinoma Arising Secondary to Diabetic Foot Lesions: A Systematic Review of the Literature

Verrucous carcinoma is classically considered a variant of squamous cell carcinoma, most commonly occurring in the oral cavity in association with snuff and chewed tobacco. However, the association between verrucous carcinoma of the foot and diabetes is less well known. This study presents a systematic review of all articles containing the search term “verrucous carcinoma” and “diabetic foot ulcer” in the abstract or title that have been published in PubMed before September 2020. The requirement for inclusion in our report were that the patient data had been documented in a case‐related manner and the patient diagnosed with verrucous carcinoma secondary to diabetic foot lesion. Seven descriptions of verrucous carcinoma presenting in patients with diabetic foot ulcers were presented across six case reports, and clinical case descriptions are collected here along with treatment outcomes, where available, and discussion of common mimics of verrucous carcinoma of the foot. Due to treatability and potential for extensive invasion of local structures requiring resection with wide margins, verrucous carcinoma should be carefully considered in the differential diagnosis of a warty foot lesion in the setting of the diabetic foot.

530 Restless Legs Syndrome Prevalence and Severity Among Patients Treated with Buprenorphine and Naloxone for Opioid Use Disorder

Abstract Introduction Restless Legs Syndrome (RLS) is a sensory-motor neurological disorder which is associated with sleep disturbance and emotional distress. Opioid medications are effective treatments for RLS, and a high percentage of patients undergoing opioid withdrawal exhibit symptoms of RLS. Despite the known connection between RLS and opioids, there has been no assessment of RLS in patients actively treated with buprenorphine and naloxone for opioid use disorder (OUD). Methods We conducted a study to determine the prevalence of RLS among patients with OUD at an outpatient buprenorphine and naloxone clinic at Lemuel Shattuck Hospital in Jamaica Plain, Massachusetts. With the help of nurses, participants completed questionnaires which inquired about demographic information, previous opioid use, current medications, and RLS. Patients were categorized as having RLS if, according to the Cambridge-Hopkins Questionnaire, they answered positively to the four essential RLS criteria and if common mimics were not endorsed. A final determination of RLS status in those with ambiguous answers to RLS mimics was made by a trained sleep medicine physician (JWW). Results Participants (n=129) were primarily male (n=86; 66.7%), white (n=101; 78.3%), and the median age was 37.5 years. Approximately half of the sample (n=59; 45.7%) used medications for depression and/or anxiety. The median duration of buprenorphine and naloxone use was 3 years. 13.2% were judged to have RLS. RLS symptoms tended to be of moderate severity, disturb sleep to a moderate degree, and occur 5–15 days per month. There were no significant demographic or clinical differences in those with and without RLS. Of the 103 participants without suspected RLS, 15.5% (n=16) were taking a non-opioid medication known to treat RLS symptoms (e.g. gabapentin). Only 1/17 people (5.9%) with RLS were taking a treatment that would control such symptoms. Conclusion Approximately 13% of this sample currently taking buprenorphine and naloxone for OUD had RLS. RLS can greatly interfere with sleep and quality of life, and those with untreated or partially treated symptoms may be motivated to use unprescribed opioids to control them. With this in mind, clinicians treating OUD should be aware that there are effective non-opioid medications that can treat RLS. Support (if any):

P100 Acute crystal arthritis: a leading cause of hospital admission, yet poorly recognised and mistreated

Abstract Background/Aims Crystal arthritis is the commonest inflammatory arthritis in adults. A common mimic is septic arthritis. Without appropriate synovial fluid analysis, a mis-diagnosis of sepsis can be made with resultant unnecessary hospitalization, inappropriate intravenous antibiotic therapy and excess cost. Such cases are frequently described as ‘culture-negative’ septic arthritis. We aimed to examine and analyse the cases of acute arthritis requiring acute hospital admission in a tertiary referral centre in Dublin. Methods A retrospective review of database between Jan - Dec 2019 at the Mater Misericordiae University Hospital, Dublin, was carried out. All cases of acute arthritis requiring acute hospital admission were identified. Cases treated at the Emergency Department, Acute Medical Unit or Outpatients which did not require hospital admission were excluded. Results 30 patients were identified during this period, 16 (53%) had an ultimate diagnosis of crystal arthritis, 8 (27%) had confirmed septic arthritis and 6 (20%) had other arthritides (e.g. haemoarthrosis). The median age for crystal arthritis was significantly higher (85.5 y) compared to septic arthritis (47 y). Apart from age, the clinical profile and biomarkers for crystal and septic arthritis were comparable. The majority of crystal arthritis cases were due to pseudogout (69 %), ultimately diagnosed by rheumatology. Septic arthritis led to more days in hospital than crystal arthritis (median 14 vs 5.5 days). All 30 patients received IV antimicrobial therapy for presumed septic arthritis. Conclusion This retrospective study showed crystal arthritis, especially pseudogout, was the commonest cause of hospital admission (53%) with acute arthritis particularly among elderly patients. Accurate diagnosis by synovial fluid analysis with appropriate equipment is extremely useful in the assessment of these cases. More awareness and training among orthopedic, emergency and acute clinicians is needed in order to avoid unnecessary admissions and interventions. Disclosure A. Abdalla: None.

Atypical presentation of bartonellosis with hepatolienal lesions

Cat scratch disease is caused by the gram-negative intracellular bacterium Bartonella henselae (B. henselae). Human infection occurs mainly through cat scratches and bites. In typical cases, the clinical course is presented by a primary affect on the skin and regional lymphadenitis. The atypical presentation of infection can occur with fever, abdominal, ocular and neurological manifestations. A special feature of the abdominal form is the presence of solitary or multiple hypo/anechoic foci of different size and shape in the liver and spleen. B. henselae infection is one of the most common mimics of malignant lymphoma, when the spleen is involved in combination with B symptoms (weight loss, night sweats and prolonged fever). A history of recent contact with cats and diagnostic IgG titers to B. henselae indicate infection. There is no consensus on the choice of antimicrobial drug and the duration of therapy for systemic forms. The article presents its own experience in the diagnosis and treatment of such patients. The patient's parents agreed to use the information, including the child's photo, in scientific research and publications.

Mesenteric and Retroperitoneal Mucinous Cystic Neoplasms: A Case Series.

Aims. Mucinous cystic neoplasms (MCNs) are cystic neoplasms with mucinous epithelium surrounded by ovarian-like stroma. Extraovarian MCN occurring in the liver and pancreas have been well characterized. However, only rare case reports of MCN arising outside of these locations have been reported. MCNs arising in unusual locations should enter the differential diagnosis of mucinous intra-abdominal tumors and must be distinguished from more common mimics. Therefore, we aimed to examine a series of MCNs of the retroperitoneum and mesentery to characterize the clinicopathologic features of this entity. Methods and results. Seven MCNs arising in the abdominal mesentery or retroperitoneum were retrospectively identified. A clinicopathologic, histologic, and immunohistochemical (keratin 7, keratin 19, keratin 20, calretinin, inhibin-α, steroidogenic factor-1 (SF-1), estrogen receptor (ER), progesterone receptor (PR), PAX8, CDX2, and CD10) analysis was performed. All 7 MCNs were from females with a median age of 41 years old and a median size of 8 cm. All cases demonstrated mucinous with or without concomitant non-mucinous epithelium overlying spindle cell ovarian-like stroma. Luteinized cells were noted. The epithelium was positive for keratin 7 and keratin 19 in all 7 cases, while the stroma expressed ER, PR, and SF-1 in all cases stained. Calretinin was focally positive in the stroma of 3 of 7 cases, while inhibin-α was focally expressed in 5 of 6 cases. Conclusions. These results highlight the clinicopathologic, histologic, and immunophenotypic similarities between MCNs of the mesentery, retroperitoneum, pancreas, and liver. Overlapping features suggest a common histogenesis for all MCNs, which could include periductal fetal mesenchyme, aberrant migration of primordial germ cells, or abnormal differentiation or metaplasia of the embryonic coelomic epithelium.

Mesenteric lymphadenitis; a common diagnostic mimic to acute appendicitis. With radiology it is no more a diagnosis of exclusion, laparoscopy or surgery

Mesenteric lymphadenitis (ML) is an inflammatory response to viral infections, bacterial infections, inflammatory bowel disease, or lymphoma in the ileocecal regions. It is a common diagnostic mimic to acute appendicitis. It is a self-limited inflammatory process that affects mesenteric lymph nodes in the right lower quadrant (RLQ). We present a 15 year-old-girl with low grade fever and RLQ pain. Initial physical examination and laboratory investigations suggested acute appendicitis. However, diagnosis of ML was established by the finding abnormal lymph nodes that are usually: (a) clusters of &gt; 3 tender ones anterior to right psoas muscle or in the small bowel mesentery, (b) &gt; 5 mm in diameter of short axis, and (b) rounded in shape. In addition; the ileal or ileocecal wall is thickened (&gt; 3 mm) over at least 5 cm of the bowel and the appendicular wall is normal and its lumen is patent. In conclusion; this case reports indicates tha with radiology; ML can be differentiated from acute appendicitis and limits the role of invasive laparoscopy or surgery in exclusion of the latter.&#x0D; Keywords: appendicitis, CT, mesenteric lymphadenitis, radiology, US.