Well-established Diagnostic Criteria Research Articles

T-Large Granular Lymphocytic Leukemia with Hepatosplenic T-Cell Lymphoma? A Rare Case of Simultaneous Neoplastic T-Cell Clones Highlighted by Flow Cytometry and Review of Literature.

Lymphoproliferative diseases are a heterogeneous set of malignant clonal proliferations of lymphocytes. Despite well-established diagnostic criteria, the diagnosis remains difficult due to their variety in clinical presentation and immunophenotypic profile. Lymphoid T-cell disorders are less common than B-cell entities, and the lack of a clear immunophenotypic characteristic makes their identification hard. Flow cytometry turned out to be a useful tool in diagnosing T-cell disorders and to resolve complicated cases, especially if the number of analyzable neoplastic cells is small. We present a case of a 55-year-old man with simultaneous lymphoproliferative neoplastic T-cell clones, one αβ and the other γδ, identified and characterized by flow cytometry (FC), exploiting the variable expression intensity of specific markers. However, the patient's rapid decline made it impossible to define a differential diagnosis in order to confirm the identity of the γδ clone, which remains uncertain. This case is added to the few other cases already documented in the literature, characterized by the co-existence of T-large granular lymphocytic leukemia (T-LGLL)-αβ and T-LGLL-γδ/Hepatosplenic T-cell lymphoma (HSTCL). Our case underlines the key role of sensitive diagnostic tools in the assessment of potential relationship between the diagnosis, prognosis, and treatment in the two pathologies.

Assessment of Progression Markers for Cirrhosis in Cystic Fibrosis Patients

Cystic Fibrosis is an autosomal dominant disease that affects the CFTR gene, which is responsible for producing a protein that regulates the transport of chloride ions across the cell membrane. This alteration results in obstruction in the body's ducts and channels, primarily affecting the pulmonary system. Additionally, other systems can be affected. Cystic Fibrosis-related liver disease is a common complication that can lead to steatosis, fibrosis, and multifocal biliary cirrhosis; however, there are no well-established diagnostic criteria yet. The present study was conducted at the Cystic Fibrosis Outpatient Clinic of the Hospital de Clínicas, Federal University of Paraná, examining 98 medical records of patients with cystic fibrosis for at least 10 years. Patients with hepatitis B, hepatitis C, alcohol consumption, or pregnancy were excluded. The objective was to determine the best predictor for the outcome of cirrhosis, and for this purpose, demographic parameters, laboratory tests, and imaging were collected. The statistical analysis was performed using SPSS® software, with quantitative variables described as mean ± standard deviation and categorical variables presented as the number of observations and percentage. ROC curves were adjusted to determine the best predictor, using the Youden index to establish the optimal cutoff point and the corresponding area under the curve to determine the model's efficacy. The study included 80 patients, and 10 of them (12.5%) were diagnosed with Cystic Fibrosis-related cirrhosis. The average age of the cirrhosis group was 21.6 years, with a predominance of males. The most accurate parameter for predisposition to cirrhosis was the APRI score, with a cutoff value of 0.27. Univariate analysis showed that gender, hepatic changes on ultrasound, splenomegaly, increased portal vein diameter, presence of vomiting, levels of alanine transaminase, aspartate transaminase, platelet count, and FIB-4 score were significantly associated with an APRI score value greater than 0.27. This study suggests the hypothesis that the APRI score is the most sensitive and specific tool for defining cirrhosis in patients with cystic fibrosis.

Frequency of epistaxis and telangiectasia in patients with hereditary hemorrhagic telangiectasia (HHT) in comparison with the general population: Curaçao diagnostic criteria revisited

PurposeThe Curaçao criteria are well-established diagnostic criteria for hereditary hemorrhagic telangiectasia (HHT), but they lack details regarding a predictive presentation of epistaxis and telangiectasias. This study collects and compares data in HHT and population cohorts to inform the application of these criteria. MethodsIn-person interviews regarding epistaxis and targeted examination for telangiectases in a general population cohort (n = 204) and an HHT cohort (n = 432) were conducted. ResultsFrequency of epistaxis, rather than intensity or duration, was the best discriminator of HHT. A cutoff of ≥4 nosebleeds per year alone yielded a diagnostic sensitivity of 97%, and specificity of 84%. The mean number of telangiectases at the sites investigated was 0.4 in the general population cohort and 26.5 in the HHT cohort. The most distinctive sites for telangiectases in HHT were lips and palmar fingers, whereas telangiectases of the face and dorsum of the hand were comparable in both cohorts. ConclusionWe propose that the Curaçao criteria be modified to include the following cutoffs: (1) epistaxis frequency of ≥4 nosebleeds per year and (2) telangiectasia count of at least 2 in characteristic locations (palmar aspect of fingers, lips, and oral cavity), and that cutaneous telangiectases at other sites not be considered relevant for diagnostic purposes.

Idiopathic Multicentric Castleman Disease Interactive Disease Awareness and Educational Tool for Pathologists

Background: Idiopathic multicentric Castleman disease (iMCD) is a rare systemic lymphoproliferative disease that is challenging to diagnose. Diagnostic criteria require the identification of characteristic histopathology in the context of supportive clinical, radiologic, and serologic findings. However, the histologic features of iMCD can be subtle and nonspecific, which delays an accurate diagnosis. Timely diagnosis and early intervention are essential to reduce patient mortality. Developing a disease awareness and educational tool for pathologists may support the identification of future iMCD cases. Methods: International pathologists were identified to support the development of an interactive pathology tool for iMCD. To validate the tool, a selection of pathologists attended a virtual workshop to provide insight and help shape the content and format of the tool. Prior to workshop, attendees were asked to complete a 14-question survey on the diagnosis of iMCD, including exclusion of other diseases, conditions with similar histopathological features, and features specific to iMCD. Results: The educational tool is currently in development and takes into consideration the varied diagnostic journeys in different centers/countries. Histopathologic criteria for iMCD require evaluation of the degree of plasmacytosis, regressed germinal centers, follicular dendritic cell proliferation, vascular proliferation, and hyperplastic germinal centers. While the differences between high grade (grade 3) and normal (grade 0) findings are straightforward, differentiating grade 1 from grade 2 (the diagnostic cut-off) is challenging and subjective. The tool will focus on these diagnostic grey-zones to include points of differentiation between Grades 1 and 2 iMCD, disease exclusion criteria, and the use of diagnostic images that can be explored. Thus far, development of the tool has shown there is a need for standardized disease terminology between pathologists, that the use of template reports and language guidance may support the diagnostic process, and that patient case studies and the use of real-world examples support disease recognition. The educational tool is anticipated to be ready for release in September 2022. Conclusions: Diagnosis of iMCD is complex, and, despite the existence of well-established diagnostic criteria, pathological differentiation remains a challenge. Increasing awareness of iMCD-specifically the key diagnostic criteria-will assist with both timely diagnoses and the treatment of this disease.

Early-stage differentiation between Alzheimer's disease and frontotemporal lobe degeneration: Clinical, neuropsychology, and neuroimaging features.

Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD) are the two most common forms of neurodegenerative dementia. Although both of them have well-established diagnostic criteria, achieving early diagnosis remains challenging. Here, we aimed to make the differential diagnosis of AD and FTLD from clinical, neuropsychological, and neuroimaging features. In this retrospective study, we selected 95 patients with PET-CT defined AD and 106 patients with PET-CT/biomarker-defined FTLD. We performed structured chart examination to collect clinical data and ascertain clinical features. A series of neuropsychological scales were used to assess the neuropsychological characteristics of patients. Automatic tissue segmentation of brain by Dr. Brain tool was used to collect multi-parameter volumetric measurements from different brain areas. All patients' structural neuroimage data were analyzed to obtain brain structure and white matter hyperintensities (WMH) quantitative data. The prevalence of vascular disease associated factors was higher in AD patients than that in FTLD group. 56.84% of patients with AD carried at least one APOE ε4 allele, which is much high than that in FTLD patients. The first symptoms of AD patients were mostly cognitive impairment rather than behavioral abnormalities. In contrast, behavioral abnormalities were the prominent early manifestations of FTLD, and few patients may be accompanied by memory impairment and motor symptoms. In direct comparison, patients with AD had slightly more posterior lesions and less frontal atrophy, whereas patients with FTLD had more frontotemporal atrophy and less posterior lesions. The WMH burden of AD was significantly higher, especially in cortical areas, while the WMH burden of FTLD was higher in periventricular areas. These results indicate that dynamic evaluation of cognitive function, behavioral and psychological symptoms, and multimodal neuroimaging are helpful for the early diagnosis and differentiation between AD and FTLD.

Critical update, systematic review, and meta-analysis of oral erythroplakia as an oral potentially malignant disorder.

BackgroundOral erythroplakia has been classically considered as the potentially malignant disorder with the highest rate of malignant development into squamous cell carcinoma. This critical systematic review and meta‐analysis aim to estimate the malignant development rate of oral erythroplakia and identify the associated risk factors.MethodsWe performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and LILACS, with keywords “erythroplakia,” “erythroplasia,” “malignant transformation,” “malignant development,” “malignization,” “carcinogenesis,” “oral cancer,” “oral squamous cell carcinoma,” “mouth neoplasm,” and “prognosis.” Meta‐analysis was conducted using a random‐effects model.ResultsTen observational studies with 441 patients met the inclusion criteria, whose mean malignant development rate was 12.7% and with a mean follow‐up period of patients of 6.66 years. In the initial biopsy, 42.8% of oral erythroplakia were already squamous cell carcinoma. The buccal mucosa was the most frequent location of oral erythroplakia, but the floor of the mouth was the most common site of malignant development. All patients who underwent malignant development showed epithelial dysplasia on the initial diagnostic biopsy.ConclusionOverall malignant development rate of OE in the meta‐analysis was 19.9%. We could not associate any specific clinicopathological feature with the malignant development. The presence of epithelial dysplasia in the initial biopsy remains the worst prognostic factor. Further observational studies on OE are needed, with well‐established diagnostic criteria and good clinical follow‐up, in order to identify the true risk of malignant development of oral erythroplakia and the related risk factors.

Autoimmune encephalitis: suspicion in clinical practice and mimics

Despite the existence of well-established diagnostic criteria for autoimmune encephalitis, there are diseases capable of mimicking it. This study sought to retrospectively evaluate the reasons for testing and the final diagnosis of patients admitted to a Neurology ward tested for anti-NMDAR antibodies and estimate sensitivity and specificity of current diagnostic criteria. The threshold for testing was lower than that of the prevailing diagnostic criteria, and the proportion of autoimmune encephalitis mimics was high. Searching for alternative diagnoses is of pivotal importance in cases of autoimmune encephalitis suspicion, and diagnostic criteria may need expanding so that no autoimmune encephalitis is missed.

Efficacy of lenalidomide in the treatment of myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U) with the presence of deletion 5q– and trisomy 8+

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are very rare clonal myeloid characterized by the simultaneous presence of both of erythrocytic and/orgranulocytic dysplasia with myeloproliferative features. The etiology of the disease remains unknown. The MDS/MPN group is made up of five disorders: chronic myelomonocytic leukemia, atypical chronic myeloid leukemia, juvenile myelomonocytic leukemia, MDS/MPN ring sideroblasts with thrombocytosis and MDS/MPN, un classifiable (MDS/MPN-U). MDS/MPN-U remains the leastcharacterized entity. It accounts less than 5% of all myeloid disorder. The reare currently no well-established diagnostic criteria. The disease is heterogeneous with outclear management strategies. The aim of thispaperis to present a case of a 59-year-old female patient diagnosed with MDS/MPN-U with deletion 5q– and trisomy 8+, whom lenalidomide 10 mg daily has been used as monotherapy. The disease has initially manifested as severe cytopenias, multiple transfusions of blood preparations were required. Currently patientis in the 9th month of treatment. Hemoglobin, platelets and white blood cells returned to normal. The patient completely became independent of transfusion of red blood cell concentrates. No adverse events were observed.

IDIOPATHIC INTRACRANIAL HYPERTENSION IN UNIVERSITY HOSPITAL IN SAUDI ARABIA, RETROSPECTIVE STUDY

Background: Idiopathic intracranial hypertension (IIH) is one of headache syndromes that is female predominate and associated with increase intracranial pressure without obvious etiology, it has variable clinical presentation, and it needs high index of suspicion to reach diagnosis even with presence of well-established diagnostic criteria. Visual symptoms, which range from visual obscuration to blindness significantly,affect the outcome of this disease. Unfortunately, there is limited literature about IHH in Middle East and in Saudi Arabia in particular. In this retrospective study, we try to shed the light on pseudo-tumor cerebri in university hospital in Saudi Arabia. Methodology: This is a retrospective study conducted among 105 patients with IIH admitted to the university hospital in Saudi Arabia. Data on age, gender, as well as about symptoms, obesity, medication and surgeries, and CT/MRI results was collected. Results: The mean age of patients was 37.72 years old with standard deviation of 13.48 where 96.2 % of patients were females. Headache is the more common symptom presented by 96.2 % of patients followed with blurred vision and papilledema (85.7 %) and over weight (77.1 %). Considering medications taken by patients because of IIH, we found that main medications was Diamox which prescribed to 96.2 % with mean dose of 942.3 mg. Regarding surgical intervention, 4.8 % had a surgery of VP-shunt and 1.9 % had optic nerve fenestration Conclusion: We concluded that IIH incidence is higher among young women with higher body weight and associated with the use of hormonal contraceptives. The main symptoms of IIH are headache with papilledema and visual disturbances. Acetazolamide is the most common prescribed medication for IIH patients while 6.6 % of patients need surgical procedures.

Melanocytic lesions with blue naevus‐like (dendritic) morphology: an update with an emphasis on histopathological, immunophenotypic, and molecular features

An accurate diagnosis of melanocytic lesions requires a thorough histopathological evaluation accompanied by appropriate correlation with clinical examination findings. Although most melanocytic lesions can readily be classified as one of the defined diagnostic entities according to well-established diagnostic criteria, a subset of melanocytic lesions, particularly those with blue naevus-like (pigmented dendritic) morphology, have notoriously constituted an enduring challenge for pathologists. These lesions are rare and often show histological ambiguities, with features of both benignity and malignancy, thereby making accurate risk assessment and prediction of their biological behaviours difficult on histological grounds alone. Herein, we outline a practical and systematic approach for the diagnosis of melanocytic lesions with dendritic morphology, with a particular focus on histological and immunophenotypic features that help to distinguish one entity from another. In this review, we provide the most current knowledge on these melanocytic lesions in the literature and our experience with these rare entities, and we discuss the utility of molecular techniques as an ancillary tool, especially in histologically ambiguous and/or borderline lesions.

Exercise-Induced Inguinal Hydrocele: An Unconventional Presentation of a Common Problem

Inguinal hernias are very common. Well-established diagnostic criteria including examination and imaging are available. Ultrasound, herniography, CT, and MR imaging can provide additional diagnostic information when examination alone is not deemed sufficient. However, decision making should not be overly dependent on imaging but must factor in all relevant information. Described here is a case that would have been a missed diagnosis and an example of unconventional documentation that facilitated the patient getting their care.

Acute febrile encephalopathy and seizures in children with diffusion restriction lesions on magnetic resonance imaging brain

Over the last decade, several entities within the spectrum of acute febrile encephalopathy (AFE) including acute disseminated encephalomyelitis, acute necrotizing encephalitis, fever-induced refractory epilepsy syndrome, clinically mild encephalopathy with reversible splenial lesion, and autoimmune encephalitis have been recognized, all of which now have reasonably well-established clinicoradiological diagnostic criteria and therapeutic options. This case series highlights the clinical profile and outcome of seven children with the lesser-known entity of AFE with seizures and white matter diffusion restriction lesions on magnetic resonance imaging. All children had a history of acute onset fever, altered sensorium, and refractory seizures requiring multiple antiepileptic drugs and presented in shock requiring multiple organ support. All had extensive, diffusion-restricted lesions involving white matter. The infectious trigger was identified as influenza A (H3N2) in case 1, dengue virus in cases 2 and 6, and influenza B in case 4. Five children survived, each of whom had significant neurological sequelae.

Tuberous Sclerosis Complex with rare associated findings in the gastrointestinal system: a case report and review of the literature

BackgroundTuberous Sclerosis Complex (TSC) is a complex and heterogeneous genetic disease that has well-established clinical diagnostic criteria. These criteria do not include gastrointestinal tumors.Case presentationWe report a 45-year-old patient with a clinical and molecular diagnosis of TSC and a family history of cancer, presenting two rare associated findings: gastrointestinal polyposis and pancreatic neuroendocrine tumor. This patient was subjected to a genetic test with 80 cancer predisposing genes. The genetic panel revealed the presence of a large pathogenic deletion in the TSC2 gene, covering exons 2 to 16 and including the initiation codon. No changes were identified in the colorectal cancer and colorectal polyposis genes.Discussion and conclusionsWe describe a case of TSC that presented tumors of the gastro intestinal tract that are commonly unrelated to the disease. The patient described here emphasizes the importance of considering polyposis of the gastrointestinal tract and low grade neuroendocrine tumor as part of the TSC syndromic phenotype.

Metabolic syndrome and peripheral neuropathy.

Diabetic peripheral neuropathy and metabolic syndrome (MetS) are both global health challenges with well-established diagnostic criteria and significant impacts on quality of life. Clinical observations, epidemiologic evidence, and animal models of disease have strongly suggested MetS is associated with an elevated risk for cryptogenic sensory peripheral neuropathy (CSPN). MetS neuropathy preferentially affects small unmyelinated axons early in its course, and it may also affect autonomic and large fibers. CSPN risk is linked to MetS and several of its components including obesity, dyslipidemia, and prediabetes. MetS also increases neuropathy risk in patients with established type 1 and type 2 diabetes. In this review we present animal data regarding the role of inflammation and dyslipidemia in MetS neuropathy pathogenesis. Several studies suggest exercise-based lifestyle modification is a promising treatment approach for MetS neuropathy.

Rheumatic Fever and Rheumatic Heart Disease

Rheumatic heart disease remains a major public health problem in many parts of the world. Rheumatic heart disease (RHD), the only long-term consequence of acute rheumatic fever (ARF), continues unabated among middle-income and low-income countries and in some indigenous communities of the industrialized world. At least 15 million people are estimated to be affected by RHD worldwide. Globally, india contributes nearly 25–50% of newly diagnosed cases, dealths, hospitalization and burden of RHD. The American Heart Association (AHA) has well-established clinical diagnostic criteria for ARF—the Jones criteriaand, with some modifications and revisions, these guidelines have been accepted and utilized worldwide. The standardized criteria aim to permit rapid and consistent identification of individuals with ARF and RHD hence allow enrolment into secondary prophylaxis programs. However, important unanswered questions remain about the importance of subclinical disease (RHD on echocardiography without a clinical pathological murmur), and about the practicalities of implementing screening programs. These standardized criteria will help enable new studies to be designed to evaluate the role of echocardiographic screening in RHD control.

Clinical and Radiographic Characteristics of Neuro-Behçet's Disease in South Korea

Background and PurposeNeurological involvement in Behçet's disease [neuro-Behçet's disease (NBD)] is uncommon, but it is worth investigating since it can cause substantial disability. However, difficulties exist in understanding the clinical features of NBD due to regional variations and the lack of studies utilizing well-established diagnostic criteria. We therefore analyzed the clinical features of patients with NBD based on the recent international consensus recommendation.MethodsWe retrospectively searched electronic databases for patients with Behçet's disease (BD) between 2000 and 2017, and reviewed their medical records. Based on the recent international consensus recommendation, patients with definite or probable NBD were included.ResultsOf 9,817 patients with the diagnosis code for BD, 1,682 (17.1%) visited the neurology clinic and 110 (1.1%) were classified as NBD. Ninety-eight patients exhibited parenchymal NBD and 12 exhibited nonparenchymal NBD. Their age at the onset of NBD was 37.6±10.6 years and the male-to-female ratio was 1.24:1. Brainstem syndrome (43.9%) was the most common condition in the 98 patients with parenchymal NBD, followed by multifocal (32.7%) and spinal cord (12.2%) syndromes. 72.4% exhibited acute NBD and 27.6% exhibited a progressive disease course. Frequent manifestations included pyramidal signs (52.0%), headache (45.9%), dysarthria (42.9%), and fever (31.6%). A frequent pattern in brain MRI was an upper brainstem lesion extending to the thalamus and basal ganglia.ConclusionsApproximately 1% of the patients with suspected BD exhibited NBD. Neurologists must understand the clinical characteristics of NBD in order to perform the differential diagnosis and management of these patients.

MiRNA expression profiles in healthy OSAHS and OSAHS with arterial hypertension: potential diagnostic and early warning markers

BackgroundObstructive sleep apnea-hypopnea syndrome (OSAHS) is prone to being complicated with various cardiovascular, cerebrovascular and metabolic conditions. OSAHS, due to its multifactorial nature, entails individualized and comprehensive treatment. So far, no well-established diagnostic criteria for the disease are available. In recent years, miRNA has been shown to be a sensitive biomarker suggestive of the progression and prognosis of many diseases. In this study, we examined some serum miRNAs in healthy OSAHS (OSAHS patients without complication) and OSAHS with arterial hypertension, with an attempt to understand the potential effects on the disease, improve the diagnosis of OSAHS and find OSAHS-related diagnostic markers.MethodsAgainst various diagnostic criteria, participants were divided into three groups: healthy OSAHS, OSAHS with arterial hypertension and healthy controls. Their serum miRNA profiles were assessed by microarray technology, and then differentially expressed miRNAs were verified by quantitative real-time PCR (qRT-PCR). The receiver operating characteristic (ROC) curves of miRNAs were constructed and the areas under the curve (AUC) were calculated. Meanwhile, the miRNAs were subjected to logistic regression analysis. The target genes were bioinformatically assessed, their functions and signaling pathways further determined and eventually an miRNA-gene network was established.ResultsAnalysis with the miRNA array exhibited that, compared with the control group, 12 differentially expressed miRNAs were found in healthy OSAHS, and 33 were found in OSAHS with arterial hypertension. The expression of miR-126-3p, let-7d-5p, miR-7641 and miR-1233-5p, miR-320b, miR-145-5p, miR-107, miR-26a-5p were validated by using qRT-PCR. Bioinformatics analysis predicted that the potential target genes of these miRNAs might be involved in metabolism, and the regulation of endothelial cells and nervous system. Moreover, the ROC analysis showed that the using miR-145-5p and let-7d-5p in combination can identify the healthy OSAHS, presence of miR-126-3p, miR-26a-5p and miR-107 was well indicative of OSAHS with arterial hypertension.ConclusionsA cluster of dysregulation miRNAs have been found to be involved in the development of OSAHS patients. Moreover, these miRNAs might be used to be potential diagnostic and early warning markers.

IPF and CPFE - the two different entities or two different presentations of the same disease?

In this article the co-existence of pulmonary emphysema with lung fibrosis of typical pattern and distribution for usual interstitial pneumonia (UIP) was compared with idiopathic pulmonary fibrosis (IPF) alone. Author discusses the etiopathogenesis of these diseases, differences in signaling pathways and the role of senescent cells. Moreover, clinical course, pulmonary function tests as well as main complications are reviewed. However, the lack of well-established diagnostic criteria for CPFE along with mainly retrospective character of the studies make current knowledge about this entity rather deficient.

Characterization of the first symptoms of multiple sclerosis in a Brazilian center: cross-sectional study.

Multiple sclerosis (MS) is a chronic, immune-mediated and degenerative central nervous system (CNS) disease with well-established diagnostic criteria. Treatment can modify the course of the disease. The objective of this study was to describe the initial symptoms of multiple sclerosis in a Brazilian medical center. Descriptive study, conducted in a Brazilian reference center for multiple sclerosis treatment. Data on 299 patients with confirmed diagnoses of MS were included in the study. Their medical files were evaluated and the data were analyzed. The most common symptom involved the cranial nerves (50.83%) and unifocal manifestation was presented by the majority of this population (73.91%). The mean time between the first symptom and the diagnosis was 2.84 years. Unifocal symptoms correlated with longer time taken to establish the diagnosis, with an average of 3.20 years, while for multifocal symptoms the average time taken for the diagnosis was 1.85 years. Unifocal onset was related to greater diagnostic difficulty. MS is a heterogeneous disease and its initial clinical manifestation is very variable.

Clinicopathological features of a kindred with SCG5-GREM1–associated hereditary mixed polyposis syndrome

Since first characterized in 1997, patients with hereditary mixed polyposis syndrome (HMPS) have been difficult to identify because of lack of well-established diagnostic criteria. Recently, HMPS was found to be caused by a duplication on chromosome 15 spanning the 3' end of the SCG5 gene and a region upstream of the GREM1 locus. Clinical testing for the duplication is available; however, the clinical characteristics of hereditary mixed polyposis to support testing are ill defined. The clinicopathological findings of 10 HMPS patients with confirmed germline SCG5-GREM1 duplication were reviewed. Mean age at presentation was 33.3 years. Fifty-one colonoscopies yielded 207 polyp specimens, all of which were reexamined. Adenomas (n = 80) and a fairly unique polyp composed of a mixture of hyperplastic polyp and inflammatory polyp-type changes (n = 74) were the most common findings; however, other polyps, including hyperplastic (n = 28), mixed inflammatory polyp/adenoma (n = 8), inflammatory polyp (n = 7), prolapse-type polyp (n = 6), and lymphoid aggregates (n = 4), were encountered. None of the patients developed colorectal malignancy during surveillance, demonstrated extracolonic manifestations, or underwent colectomy on follow-up (mean, 26.2 years). SCG5-GREM1 duplication-associated polyposis is characterized by a few polyps per endoscopy with a mixture of phenotypes, most commonly adenoma and nondysplastic mixed hyperplastic/inflammatory polyps. Nine of 10 patients had at least 1 mixed hyperplastic-inflammatory polyp, which is the characteristic lesion of SCG5-GREM1 duplication-associated HMPS.