Atypical Clinical Presentation Research Articles

Colon Cancer: An Atypical Clinical Presentation

Colon Cancer: An Atypical Clinical Presentation

Differential diagnosis of ischemic stroke in the arteries of the vertebrobasilar system

Stroke in the arteries of the vertebrobasilar system is characterized by a variety of nonspecific symptoms, many mimickers, and often atypical clinical presentation, which, together with the low sensitivity of CT and MRI of the brain, leads to incorrect and untimely diagnosis. This article addresses in detail the issues of differential diagnosis of this disease with Guillain–Barre syndrome, myasthenic crisis, central pontine myelinolysis, multiple sclerosis, Wernicke encephalopathy, vestibular neuronitis, Meniere's disease, and vestibular migraine.

Takotsubo Cardiomyopathy in Aneurysmal Subarachnoid Hemorrhage with an Atypical Clinical Presentation: A Case Report

Takotsubo Cardiomyopathy in Aneurysmal Subarachnoid Hemorrhage with an Atypical Clinical Presentation: A Case Report

Clinical profile of pathological urticarial vasculitis: A retrospective study

AbstractBackgroundAs there are no definite classification criteria for urticarial vasculitis (UV), its diagnosis is often challenging and usually proposed when urticarial lesions and pathological vasculitis coexist. By analysing the final diagnosis of patients whose skin biopsies showed both urticaria and vasculitis, we sought to decipher the clinical heterogeneity of this condition.ObjectivesTo describe the characteristics of patients with pathological signs of urticaria and vasculitis.MethodsWe conducted a retrospective, descriptive, single‐centre study within Lille University Hospital and included adult patients with a skin biopsy performed between 2000 and 2021, and whose pathological report mentioned the codes for “leukocytoclastic angiitis” and “urticaria”. Clinical data were then collected from medical records.ResultsWe identified 61 patients with pathological diagnosis of UV and classified them into four groups according to the final diagnosis made by the managing clinicians: 14 patients were diagnosed with UV (normo‐[NUV] or hypocomplementemic UV [HUV]), 10 with urticaria (including 8 chronic urticaria [CU]), 24 with an “undetermined diagnosis” (when elements did not allow firm diagnosis between CU and UV, due to an atypical clinical presentation of urticarial lesions), and 13 with an “other but well‐defined diagnosis”. Fibrinoid necrosis, classically associated with UV, was observed in 4/9 patients (44%) in the urticaria group. Antihistamines were effective not only in all patients with urticaria, but also in NUV and “undetermined diagnosis” group.ConclusionsThese data suggest that pathological signs of UV may be shared by various clinical situations, raising the hypothesis of a continuous spectrum between CU and UV.

Longitudinal clinical, cognitive and biomarker profiles in dominantly inherited versus sporadic early-onset Alzheimer's disease.

Approximately 5% of Alzheimer's disease cases have an early age at onset (<65 years), with 5-10% of these cases attributed to dominantly inherited mutations and the remainder considered as sporadic. The extent to which dominantly inherited and sporadic early-onset Alzheimer's disease overlap is unknown. In this study, we explored the clinical, cognitive and biomarker profiles of early-onset Alzheimer's disease, focusing on commonalities and distinctions between dominantly inherited and sporadic cases. Our analysis included 117 participants with dominantly inherited Alzheimer's disease enrolled in the Dominantly Inherited Alzheimer Network and 118 individuals with sporadic early-onset Alzheimer's disease enrolled at the University of California San Francisco Alzheimer's Disease Research Center. Baseline differences in clinical and biomarker profiles between both groups were compared using t-tests. Differences in the rates of decline were compared using linear mixed-effects models. Individuals with dominantly inherited Alzheimer's disease exhibited an earlier age-at-symptom onset compared with the sporadic group [43.4 (SD ± 8.5) years versus 54.8 (SD ± 5.0) years, respectively, P < 0.001]. Sporadic cases showed a higher frequency of atypical clinical presentations relative to dominantly inherited (56.8% versus 8.5%, respectively) and a higher frequency of APOE-ε4 (50.0% versus 28.2%, P = 0.001). Compared with sporadic early onset, motor manifestations were higher in the dominantly inherited cohort [32.5% versus 16.9% at baseline (P = 0.006) and 46.1% versus 25.4% at last visit (P = 0.001)]. At baseline, the sporadic early-onset group performed worse on category fluency (P < 0.001), Trail Making Test Part B (P < 0.001) and digit span (P < 0.001). Longitudinally, both groups demonstrated similar rates of cognitive and functional decline in the early stages. After 10 years from symptom onset, dominantly inherited participants experienced a greater decline as measured by Clinical Dementia Rating Sum of Boxes [3.63 versus 1.82 points (P = 0.035)]. CSF amyloid beta-42 levels were comparable [244 (SD ± 39.3) pg/ml dominantly inherited versus 296 (SD ± 24.8) pg/ml sporadic early onset, P = 0.06]. CSF phosphorylated tau at threonine 181 levels were higher in the dominantly inherited Alzheimer's disease cohort (87.3 versus 59.7 pg/ml, P = 0.005), but no significant differences were found for t-tau levels (P = 0.35). In summary, sporadic and inherited Alzheimer's disease differed in baseline profiles; sporadic early onset is best distinguished from dominantly inherited by later age at onset, high frequency of atypical clinical presentations and worse executive performance at baseline. Despite these differences, shared pathways in longitudinal clinical decline and CSF biomarkers suggest potential common therapeutic targets for both populations, offering valuable insights for future research and clinical trial design.

SAT244 Hypercalcemia Induced By Inconspicuous Histoplasmosis Infection

Abstract Disclosure: M. Alkhathlan: None. Y. Li: None. A. Siddiqui: None. S. Goud: None. Background: Hypercalcemia is a common condition with a variety of etiologies. In general, it can be categorized as either parathyroid hormone (PTH) dependent or independent. In those with non-PTH mediated hypercalcemia, elevated 1, 25 vitamin D is one of the causes and among pathologies behind it are sarcoidosis, malignancy, and to less extent infectious process. An important determinant in the management of elevated 1,25vitD is to identify the source of 1,25vitD overproduction as the choice of treatment can affect the outcomes and increase the risk of mortality. Clinical Case: Our patient is an 81-year-old man who had been admitted to the hospital for nonspecific fatigue and weakness for two months. He was discharged from another hospital with similar complaints without resolution. At the time of admission, he was noted to have elevated total calcium 12.5 mg/dL (8.4-10.2) with albumin 3.0 g/dL (3.5-5.2), subacute kidney injury with creatinine 3.46 mg/dL (0.7-1.3), suppressed parathyroid hormone (PTH) and markedly elevated 1,25-dihydroxy vitamin D (1,25OH2D) 128 pg/mL (19.9-79.3). His calcium and kidney function were normal 4 months ago. The hypercalcemia was refractory to intravenous fluid, loop diuretic or calcitonin administration. Extensive workup eventually revealed disseminated histoplasmosis infection with blood and urine positive for histoplasmosis antigens. Bone marrow aspiration showed scattered non-necrotizing granulomas. With antifungal treatment, his calcium level returned to the normal range in two weeks (8.9 mg/dL) and was maintained in the normal range. Conclusion: Hypercalcemia is a rare presentation of histoplasmosis. Pubmed keyword search of hypercalcemia and histoplasmosis returned 18 clinical case reports from 1977 to 2021. The case review showed a striking similarity in atypical clinical presentation and diagnosis challenges. Hypercalcemia is most developed in histoplasmosis disseminated cases with elevated 1,25vitD levels and pathology identification of granulomas in some of the cases. With successful antifungal treatment, patients will have prompt recovery of hypercalcemia. Steroid treatment is a well know and effective treatment by suppressing 1-alpha hydroxylation of 25-vitD. However, treatment with steroids before establishing diagnosis due to Inconspicuous presentations or delay in diagnosis may lead to mortality quickly. Presentation: Saturday, June 17, 2023

THU619 Atypical Clinical Presentation Of Adrenal Hemorrhage

Abstract Disclosure: T.L. Madsen-Barbosa: None. F.H. Antoni: None. A. Ghazi: None. Introduction: Adrenal hemorrhage (AH) is an uncommon condition that is challenging to diagnose due to its nonspecific findings. We illustrate a case of AH that presented with acute clinical deterioration and had catecholamine overproduction. Case: A 58-year-old woman with a history of migraine headaches and prediabetes presented to the emergency department for “the worst headache of her life” and palpitations of 4 hours duration. On admission, her blood pressure was 224/139 mmHg and heart rate was 102 bpm. Her physical examination was significant for diaphoresis and active vomiting. Initial laboratory tests showed hyperglycemia and leukocytosis. Her ECG, non-contrast CT scan of the head and CT angiography of the head and neck were unremarkable. Her hospital course was complicated by recurrent hypertensive episodes, arrhythmias including Torsades de pointes, and left flank pain. A CT chest, abdomen, and pelvis revealed a large left retroperitoneal hemorrhagic collection which seemed to arise from the inferior aspect of the left adrenal gland. She subsequently underwent successful IR embolization of the left inferior suprarenal artery. Further workup showed elevated urinary fractionated metanephrine and normetanephrine levels, as well as elevated levels of plasma free metanephrine and normetanephrine. Given concern for pheochromocytoma, phenoxybenzamine was started. A repeat CT abdomen after six days demonstrated shrinkage in hematoma and a 7 mm hypoattenuating nodule arising from the medial limb of the left adrenal gland. Outpatient follow-up CT abdomen showed left adrenal thickening with a 2.3 cm nodular area with 78.9 Hounsfield units and absolute washout of 60.9% suggestive of adenoma. After one month, repeat catecholamine levels normalized. Discussion: The clinical manifestation of AH varies widely. Acute adrenal insufficiency is seen if bilateral glands and 90% of the cortices are compromised. However, unilateral AH is most often asymptomatic - found incidentally on imaging. Having elevated catecholamines is described in 30% of patients in one case series. Differentiating spontaneous AH from hemorrhagic adrenal tumors is also a dilemma. Among the hemorrhagic adrenal masses, pheochromocytoma is the most common. Conclusion: This case highlights that clinicians should be aware of clinical manifestations of catecholamine excess when evaluating patients with AH. A catecholamine producing adrenal mass (pheochromocytoma) should also be ruled out in these situations. Reference:1- Elhassan YS, Ronchi C, Wijewickrama P, Balvedeweg SE. Approach to the patient with adrenal hemorrhage. J Clin Endocrinol Metab. 2023, 108 (4):995-1006.2- Karwacka IM, Obolonczyk L, Sworczak K. Adrenal hemorrhage: a single center experience and literature review. Adv Clin Exp Med. 2018; 27 (5): 681-687. Presentation: Thursday, June 15, 2023

FRI499 The Importance Of Identifying Atypical Presentation Of Thyroid Storm

Abstract Disclosure: D.H. Sacoto: None. C.A. Villavicencio: None. A. Franco-Akel, MD: None. R. Belokovskaya: None. Thyroid storm is a rare and life-threatening syndrome. Despite treatment and supportive measures, it has an estimated mortality around 8–25%. Identifying atypical clinical presentation such as psychosis is crucial since prompt diagnosis and treatment is paramount for survival. We present an unusual case of psychosis as the manifesting symptom of thyroid storm.A 54-year-old female with a history of major depressive disorder, hypertension, and Graves’ disease presented to the ED with a 3-day history of bizarre behavior noted by the family. At the time of examination, the patient had pressured and circumferential speech, flight of ideas, labile mood, and paranoid ideations. On further questioning, patient reported palpitations and lack of sleep on days previous to presentation. Vital signs revealed hypertension (182/101 mmHg), tachycardia (176 beat per minute), tachypnea, and a temperature of 99.6 °F. Warm skin, fine tremors, and patellar hyperreflexia were noted on physical examination. Subsequent studies showed a suppressed TSH (&amp;lt;0.01uIU/mL), an elevated T3 (227ng/dL) and free T4 (2.1ng/dL). TSH receptor antibody was found positive. Patient’s clinical presentation combined with a Burch-Wartovsky scale of 55 stablished the diagnosis. Further history was notable for non-adherence to methimazole. Iodine-131 was administered. Further treatment with prednisone, propranolol, and cholestyramine was started. Patient showed subsequent clinical improvement. Thyroid storm is a rare complication of hyperthyroidism. It is commonly precipitated by infection, surgery, or medication non-adherence. Atypical presentation of thyroid storm can be disguised as psychiatric condition or substance abuse disorder. These manifestations can be the result of a generalized hypermetabolism generated by an increase in NA+/K+ ATPAse activity, raising the basal metabolism, resulting in thermogenesis. In addition, upregulation of beta-adrenergic receptors lead to increased central nervous system sympathetic response. This results in a catecholamine surge which may manifest as psychosis, mania, or coma. Being aware of atypical presentation in thyroid storm such as active psychosis is key in early diagnosis and prompt management. Presentation: Friday, June 16, 2023

SAT274 Multilocus Imprinting Disorder Due To Genome-wide Paternal Uniparental Disomy Associated With Adrenocortical Tumors

Abstract Disclosure: E.M. Pinto: None. E. Lalli: None. G. Wu: None. R. Ribeiro: None. G. Zambetti: None. Pediatric adrenocortical tumor (ACT) is an uncommon malignancy frequently associated with Li-Fraumeni syndrome, a familial cancer predisposition disorder caused by germline mutations in the tumor suppressor TP53. ACT is also associated with other genetic constitutional disorders, such as Beckwith-Wiedemann syndrome (BWS) which results from the deregulation of a gene cluster on chromosome 11p15. We report here the identification of three pediatric patients with ACT and additional tumors, two of which received a clinical diagnosis of BWS. Family histories of these two probands include multiple unsuccessful pregnancies. All patients have wild-type TP53 sequence and no evidence for germline chromosome 11p15 alterations. Molecular analyses by whole genome sequencing revealed genome-wide copy neutral loss of heterozygosity (cnLOH) in all tumors. Microsatellite STR and MS-MLPA confirmed genome-wide cnLOH with the selective loss of all maternal chromosomes and duplication of paternal chromosomes in each tumor. Analysis of skin fibroblasts showed mosaic paternal uniparental disomy with partial LOH for all chromosomes, while no LOH was detected in blood DNA. The most prominent clinical feature of genome-wide cnLOH is an unbalanced monoallelic and parent-of-origin specific expression of imprinted genes known as multilocus imprinting disorder (MID). MID has been associated with maternal-effect variants that alter the maintenance of methylation at germline-derived differentially methylated regions (DMRs) in early embryogenesis. In addition, causative trans-acting factors in imprinting disorders, including the subcortical maternal complex (SCMC), have the potential to affect multiple DMRs across the genome, resulting in a multilocus imprinting disorder. Our study identifies three pediatric patients who developed ACT and other tumors that have undergone genome wide cnLOH that specifically selected against all maternal chromosomes. None of three patients presented with germline alterations in TP53 or 11p15, typical of pediatric ACT. WGS data revealed a germline mutation (p.M573T) in the histone methyltransferase NSD1 in the mother of patient #2. NSD1 mutations are reportedly associated with recurrent miscarriages, tissue overgrowth and increased cancer risk. Alterations in other epigenetic regulators, such as SETD1B (p.R226C), a component of a histone methyltransferase complex and TNRC18 (p.P454L), that enables chromatin binding activity were observed in both mother and child in each family. Further analysis of maternal-effect variants associated with abnormal pregnancies and MID will be important for understanding the mechanisms underlying genome-wide cnLOH. Our results support the molecular testing of multiple loci in atypical clinical presentations of patients with pediatric ACT. Presentation: Saturday, June 17, 2023

Assessing the genetic risk of nodular melanoma using a candidate gene approach.

Nodular melanoma (NM) is a challenge to diagnose early due to its rapid growth and more atypical clinical presentation, making it the largest contributor to melanoma mortality. Our study aim was to perform a rare-variant allele (RVA) analysis of whole-exome sequencing of patients with NM and non-NM (minor allele frequency ≤ 1% non-Finnish European) for a set of 500 candidate genes potentially implicated in melanoma. This study recruited 131 participants with NM and 194 with non-NM from South-east Queensland and patients with NM from Victoria to perform a comparative analysis of possible genetic differences or similarities between the two melanoma cohorts. Phenotypic analysis revealed that a majority of patients diagnosed with NM were older males with a higher frequency of fair skin and red hair than is seen in the general population. The distribution of common melanoma polygenic risk scores was similar in patients with NM and non-NM, with over 28% in the highest quantile of scores. There was also a similar frequency of carriage of familial/high-penetrant melanoma gene and loss-of-function variants. We identified 39 genes by filtering 500 candidate genes based on the greatest frequency in NM compared with non-NM cases. The genes with RVAs of greatest frequency in NM included PTCH1, ARID2 and GHR. Rare variants in the SMO gene, which interacts with PTCH1 as ligand and receptor, were also identified, providing evidence that the Hedgehog pathway may contribute to NM risk. There was a cumulative effect in carrying multiple rare variants in the NM-associated genes. A 14.8-fold increased ratio for NM compared with non-NM was seen when two RVAs of the 39 genes were carried by a patient. This study highlights the importance of considering frequency of RVA to identify those at risk of NM in addition to known high penetrance genes.

A Case of Bicuspid Aorta with Stanford Type a Aortic Dissection

Bicuspid aortic valve disease (BAV) is a congenital disease that frequently produces complications during adulthood, and is considered not only a problem of valvulogenesis, but also a more complex genetic alteration that involves the development of the heart and the aorta, which entails a high morbidity and mortality in these patients. In 50% of adults with this pathology, non-valvular anomalies are observed, with dilation of the ascending aorta being the most common. Genes such as NOTCH1, UFDL1, ACTA2, eNOS, among others, have been identified as responsible for the appearance of aneurysms, which increases the risk in these patients of complications such as aortic dissection and its subsequent rupture. Painless aortic dissection may be seen in less than 5% of patients and may have an atypical clinical presentation. A case and review of the literature is presented in which we can observe the great complexity of this pathology, in the case of a patient with BAV, annulo-ectatic dilation of the aortic root and ascending aorta who developed heart failure, syncope and presented as a complication Stanford type A aortic dissection, requiring highly specialized surgical treatment.

Clinical features and mutational analysis of X-linked agammaglobulinemia patients in Malaysia.

Bruton's tyrosine kinase (BTK) is a cytoplasmic protein involved in the B cell development. X-linked agammaglobulinemia (XLA) is caused by mutation in the BTK gene, which results in very low or absent B cells. Affected males have markedly reduced immunoglobulin levels, which render them susceptible to recurrent and severe bacterial infections. Methods: Patients suspected with X-linked agammaglobulinemia were enrolled during the period of 2010-2018. Clinical summary, and immunological profiles of these patients were recorded. Peripheral blood samples were collected for monocyte BTK protein expression detection and BTK genetic analysis. The medical records between January 2020 and June 2023 were reviewed to investigate COVID-19 in XLA. Twenty-two patients (from 16 unrelated families) were molecularly diagnosed as XLA. Genetic testing revealed fifteen distinct mutations, including four splicing mutations, four missense mutations, three nonsense mutations, three short deletions, and one large indel mutation. These mutations scattered throughout the BTK gene and mostly affected the kinase domain. All mutations including five novel mutations were predicted to be pathogenic or deleterious by in silico prediction tools. Genetic testing confirmed that eleven mothers and seven sisters were carriers for the disease, while three mutations were de novo. Flow cytometric analysis showed that thirteen patients had minimal BTK expression (0-15%) while eight patients had reduced BTK expression (16-64%). One patient was not tested for monocyte BTK expression due to insufficient sample. Pneumonia (n=13) was the most common manifestation, while Pseudomonas aeruginosa was the most frequently isolated pathogen from the patients (n=4). Mild or asymptomatic COVID-19 was reported in four patients. This report provides the first overview of demographic, clinical, immunological and genetic data of XLA in Malaysia. The combination of flow cytometric assessment and BTK genetic analysis provides a definitive diagnosis for XLA patients, especially with atypical clinical presentation. In addition, it may also allow carrier detection and assist in genetic counselling and prenatal diagnosis.

Myelin oligodendrocyte glycoprotein antibody‐associated disease presenting with dystonia

AbstractMyelin oligodendrocyte glycoprotein antibody‐associated disease (MOGAD) commonly presents as optic neuritis or transverse myelitis. We report an atypical clinical presentation for MOGAD in a 28‐year‐old female experiencing right‐arm dystonic episodes. MRI scans demonstrated multifocal periventricular and subcortical lesions, including in the left centrum semiovale and corona radiata. Despite the atypical presentation, her clinical, serological, and radiographic features favor a MOGAD diagnosis. This report emphasizes the heterogeneity of MOGAD phenotypes and the need to consider MOGAD, even in a non‐typical presentation.

Mediastinal lymphadenopathies and skin lesions in a 49-year-old Sinhalese man.

Leprosy is a neglected disease sporadically reported in high-income countries. Skin lesion and peripheral nerve involvement represent most common manifestations. Mediastinal lymphadenopathy in the absence of superficial lymph nodes involvement is very rare. Atypical or rare clinical presentations of disease may delay diagnosis and therapy and cause potential life-threatening manifestations and disabilities. We describe the case of a 49-year-old Sinhalese man who was admitted to our hospital with a one-month history of peripheral neurological symptoms and skin lesions on lower limbs. CT scan showed the presence of mediastinal lymphadenopathies without lung parenchymal and superficial lymph nodes involvement. Endobronchial ultrasound-guided transbronchial needle aspiration showed the presence of granulomas while skin biopsy revealed dermo-hypodermic granulomas with perineural lymphohistiocytic inflammatory reaction. Fite-Faraco staining demonstrated the presence of acid-fast bacilli in both lymph nodal and skin biopsy and polymerase chain reaction was positive for Mycobacterium leprae. Multibacillary leprosy was then diagnosed.

Closing the Gap - Detection of 5q-Spinal Muscular Atrophy by Short-Read Next-Generation Sequencing and Unexpected Results in a Diagnostic Patient Cohort.

The importance of early diagnosis of 5q-Spinal muscular atrophy (5q-SMA) has heightened as early intervention can significantly improve clinical outcomes. In 96% of cases, 5q-SMA is caused by a homozygous deletion of SMN1. Around 4 % of patients carry a SMN1 deletion and a single-nucleotide variant (SNV) on the other allele. Traditionally, diagnosis is based on multiplex ligation probe amplification (MLPA) to detect homozygous or heterozygous exon 7 deletions in SMN1. Due to high homologies within the SMN1/SMN2 locus, sequence analysis to identify SNVs of the SMN1 gene is unreliable by standard Sanger or short-read next-generation sequencing (srNGS) methods. The objective was to overcome the limitations in high-throughput srNGS with the aim of providing SMA patients with a fast and reliable diagnosis to enable their timely therapy. A bioinformatics workflow to detect homozygous SMN1 deletions and SMN1 SNVs on srNGS analysis was applied to diagnostic whole exome and panel testing for suggested neuromuscular disorders (1684 patients) and to fetal samples in prenatal diagnostics (260 patients). SNVs were detected by aligning sequencing reads from SMN1 and SMN2 to an SMN1 reference sequence. Homozygous SMN1 deletions were identified by filtering sequence reads for the ,, gene-determining variant" (GDV). 10 patients were diagnosed with 5q-SMA based on (i) SMN1 deletion and hemizygous SNV (2 patients), (ii) homozygous SMN1 deletion (6 patients), and (iii) compound heterozygous SNVs in SMN1 (2 patients). Applying our workflow in srNGS-based panel and whole exome sequencing (WES) is crucial in a clinical laboratory, as otherwise patients with an atypical clinical presentation initially not suspected to suffer from SMA remain undiagnosed.

Early diagnosis of necrotizing fasciitis: Imaging techniques and their combined application.

Necrotizing fasciitis is a clinical, surgical emergency characterized by an insidious onset, rapid progression, and a high mortality rate. The disease's mortality rate has remained high for many years, mainly because of its atypical clinical presentation, which prevents many cases from being diagnosed early and accurately, resulting in patients who may die from uncontrollable septic shock and multi-organ failure. But unfortunately, no diagnostic indicator can provide a certain early diagnosis of NF, and clinical judgement of NF is still based on the results of various ancillary tests combined with the patient's medical history, clinical manifestations, and the physician's experience. This review provides a brief overview of the epidemiological features of NF and then discusses the most important laboratory indicators and scoring systems currently employed to diagnose NF. Finally, the latest progress of several imaging techniques in the early diagnosis of NF and their combined application with other diagnostic indices are highlighted. We point out promising research directions based on an objective evaluation of the advantages and shortcomings of different methods, which provide a basis for further improving the early diagnosis of NF.

Solitary pityriasis versicolor an uncommon presentation as a large single patch Report of three cases and review of unusual clinical forms

Pityriasis versicolor (PV) is a common disease, easy recognizable, that usually affects the trunk and upper limbs with multiple rounded scaly lesions which can vary in color from case to case. However, infrequent localizations have been reported, as well as diverse unusual clinical presentations, including atrophic, hyperkeratotic, annular, or inverse forms, among other. We describe 3 cases presenting with a single large lesion in the neck, which can hinder the diagnosis. No description of this form was found neither in large series of PV, nor in extensive reviews. This solitary variety would be just another atypical clinical presentation of PV. Clinicians should be aware of this variety in order to avoid unnecessary studies.

Pediatric Pilomatrixomas: Four Atypical Clinical Presentations

Pilomatrixoma, also called Malherbe's calcifying epithelioma or pilomatrixoma, is a benign adnexal tumor that originates from keratinocytes (cells of the hair matrix, the internal sheath of the hair root or the cortex) and constitutes the second most prevalent skin neoplasm in children. These lesions are typically slow-growing, firm, nodules located on the head, neck, trunk, and extremities (in decreasing order of frequency). Due to the rarity, combined with their varied clinical presentations, pilomatrixomas are often misdiagnosed. Current pilomatrixoma classification schemes remain controversial. In this article, we present 4 pediatric patients that exemplify different clinical and atypical scenarios of the same tumor. Accordingly, we invite future studies to create a novel system for the classification of pilomatrixomas based on atypical clinical characteristics, including lesion morphology, number, size, and anatomic location.

Large B-cell lymphoma with IRF4 rearrangement-Fine needle biopsy-Report of a case with an atypical presentation.

We describe a case of a 17-year-old girl with a mediastinal large B-cell lymphoma with IRF4 rearrangement (LBCL-IRF4r) with an atypical clinical presentation in an unusual location, diagnosed by fine needle biopsy, flow cytometry and FISH. We review the literature and discuss the differential diagnosis, clinical presentation, cytological and immunophenotypical characteristics of this unique case that raises very interesting questions regarding this new entity.

Can clinical decision support systems be an asset in medical education? An experimental approach

BackgroundDiagnostic accuracy is one of the major cornerstones of appropriate and successful medical decision-making. Clinical decision support systems (CDSSs) have recently been used to facilitate physician’s diagnostic considerations. However, to date, little is known about the potential assets of CDSS for medical students in an educational setting. The purpose of our study was to explore the usefulness of CDSSs for medical students assessing their diagnostic performances and the influence of such software on students’ trust in their own diagnostic abilities.MethodsBased on paper cases students had to diagnose two different patients using a CDSS and conventional methods such as e.g. textbooks, respectively. Both patients had a common disease, in one setting the clinical presentation was a typical one (tonsillitis), in the other setting (pulmonary embolism), however, the patient presented atypically. We used a 2x2x2 between- and within-subjects cluster-randomised controlled trial to assess the diagnostic accuracy in medical students, also by changing the order of the used resources (CDSS first or second).ResultsMedical students in their 4th and 5th year performed equally well using conventional methods or the CDSS across the two cases (t(164) = 1,30; p = 0.197). Diagnostic accuracy and trust in the correct diagnosis were higher in the typical presentation condition than in the atypical presentation condition (t(85) = 19.97; p < .0001 and t(150) = 7.67; p < .0001).These results refute our main hypothesis that students diagnose more accurately when using conventional methods compared to the CDSS.ConclusionsMedical students in their 4th and 5th year performed equally well in diagnosing two cases of common diseases with typical or atypical clinical presentations using conventional methods or a CDSS. Students were proficient in diagnosing a common disease with a typical presentation but underestimated their own factual knowledge in this scenario. Also, students were aware of their own diagnostic limitations when presented with a challenging case with an atypical presentation for which the use of a CDSS seemingly provided no additional insights.