von Hippel-Lindau Disease-Associated Hemangioblastomas Are Derived from Embryologic Multipotent Cells

BACKGROUND: To determine the origin of the neoplastic cell in central nervous system (CNS) hemangioblastomas in von Hippel-Lindau disease (VHL) and its role in tumor formation and distribution, we characterized and differentiated neoplastic cells from hemangioblastomas removed from VHL patients. METHODS AND FINDINGS: A total of 31 CNS hemangioblastomas from 25 VHL patients were resected and analyzed. Tumor cells from the hemangioblastomas were characterized, grown, and differentiated into multiple lineages. Resected hemangioblastomas were located in the cerebellum (11 tumors), brainstem (five tumors), and spinal cord (15 tumors). Consistent with an embryologically derived hemangioblast, the neoplastic cells demonstrated coexpression of the mesodermal markers brachyury, Flk-1 (vascular endothelial growth factor-2), and stem cell leukemia (Scl). The neoplastic cells also expressed hematopoietic stem cell antigens and receptors including CD133, CD34, c-kit, Scl, erythropoietin, and erythropoietin receptor. Under specific microenvironments, neoplastic cells (hemangioblasts) were expanded and differentiated into erythrocytic, granulocytic, and endothelial progenitors. Deletion of the wild-type VHL allele in the hematopoietic and endothelial progeny confirmed their neoplastic origin. CONCLUSIONS: The neoplastic cell of origin for CNS hemangioblastomas in VHL patients is the mesoderm-derived, embryologically arrested hemangioblast. The hematopoietic and endothelial differentiation potential of these cells can be reactivated under suitable conditions. These findings may also explain the unique tissue distribution of tumor involvement

Development and validation of a scoring system for advanced colorectal neoplasm in young Korean subjects less than age 50 years

Background/Aims Colorectal cancer incidence among patients aged ≤50 years is increasing. This study aimed to develop and validate an advanced colorectal neoplasm (ACRN) screening model for young adults aged <50 years in Korea. Methods This retrospective cross-sectional study included 59,575 consecutive asymptomatic Koreans who underwent screening colonoscopy between 2003 and 2012 at a single comprehensive health care center. Young Adult Colorectal Screening (YCS) score was developed as an optimized risk stratification model for ACRN using multivariate analysis and was internally validated. The predictive power and diagnostic performance of YCS score was compared with those of Asia-Pacific Colorectal Screening (APCS) and Korean Colorectal Screening (KCS) scores. Results 41,702 and 17,873 subjects were randomly allocated into the derivation and validation cohorts, respectively, by examination year. ACRN prevalence was 0.9% in both cohorts. YCS score comprised sex, age, alcohol, smoking, obesity, glucose metabolism abnormality, and family history of CRC, with score ranges of 0 to 10. In the validation cohort, ACRN prevalence was 0.6% in the low-risk tier (score, 0–4), 1.5% in the moderate-risk tier (score, 5–7), and 3.4% in the high-risk tier (score, 8–10). ACRN risk increased 2.5-fold (95% confidence interval [CI], 1.8–3.4) in the moderate-risk tier and 5.8-fold (95% CI, 3.4–9.8) in the high-risk tier compared with the low-risk tier. YCS score identified better balanced accuracy (53.9%) than APCS (51.5%) and KCS (50.7%) scores and had relatively good discriminative power (area under the curve=0.660). Conclusions YCS score based on clinical and laboratory risk factors was clinically effective and beneficial for predicting ACRN risk and targeting screening colonoscopy in adults aged <50 years

Clinical Practice Guideline for Accurate Diagnosis and Effective Treatment of Gastrointestinal Stromal Tumor in Korea

Despite the rarity in incidence and prevalence, gastrointestinal stromal tumor (GIST) has emerged as a distinct pathogenetic entity. And the clinical management of GIST has been evolving very rapidly due to the recent recognition of its oncogenic signal transduction pathway and the introduction of new molecular-targeted therapy. Successful management of GIST requires a multidisciplinary approach firmly based on accurate histopathologic diagnosis. However, there was no standardized guideline for the management of Korean GIST patients. In 2007, the Korean GIST study group (KGSG) published the first guideline for optimal diagnosis and treatment of GIST in Korea. As the second version of the guideline, we herein have updated recent clinical recommendations and reflected changes in diagnosis, surgical and medical treatments for more optimal clinical practice for GIST in Korea. We hope the guideline can be of help in enhancing the quality of diagnosis by members of the Korean associate of physicians involving in GIST patients's care and subsequently in achieving optimal efficacy of treatment

Hematopoietic Progenies Are Derived from Hemangioblastoma Tumor Cells

<div><p>(A) Giemsa staining of the vacuolated neoplastic stromal cell of the hemangioblastoma.</p> <p>(B) Giemsa staining of early (arrows), late (arrowheads), and dividing (open arrow) nucleated erythrocytes expanding in an erythropoietin-enriched medium.</p> <p>(C) Giemsa staining of immature (arrow) and mature (arrowhead) polynuclear granulocytes expanding in an erythropoietin-enriched medium.</p> <p>(D) While loss of heterozygosity was not detected in peripheral blood mononuclear cells (PB), deletion of the wild-type <i>VHL</i> allele occurred in cultured hemangioblastoma (T) and cultured nucleated erythrocytes (NE), confirming the hemangioblastic origin of the nucleated erythroid cells.</p></div

Distribution of Hemangioblastomas in the Central Nervous Systems of Study Patients

<div><p>(A) Schematic representation of the distribution of CNS hemangioblastomas (red dots) in the 25 von Hippel-Lindau disease patients on MRI. Most (98%) of hemangioblastomas were found below the level of the tentorium in the cerebellum, brainstem, and spinal cord.</p> <p>(B–D) Contrast-enhanced MRI demonstrating representative locations of hemangioblastomas including the cerebellum (B), brainstem (C) and spinal cord (D). (B) Axial view through the cerebellum demonstrating a hyperintense enhancing hemangioblastoma (arrow) with surrounding edema (hypointense area surrounding the tumor) that frequently is associated with these lesions. (C) Sagittal view through the posterior fossa demonstrating a hyperintense enhancing brainstem (medullary) hemangioblastoma (arrow) with surrounding edema. (D) Sagittal view through the thoracic and lumbar spinal cord demonstrating two hyperintense enhancing hemangioblastomas (arrows). The superior tumor is associated with a large intraspinal cyst (syrinx) that is common with these neoplasms (arrowhead).</p></div