Browsing by Author "Popnikolov, Nikolay"

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    Genetic Alterations in Invasive Breast Carcinoma with a Glycogen-Rich Clear Cell Pattern: A Case Report
    (Karger, 2021-03-22) De la Sancha, Carlo; Ruiz-Cordero, Roberto; Popnikolov, Nikolay; Pathology and Laboratory Medicine, School of Medicine
    Invasive carcinoma with a glycogen-rich clear cell pattern (IC-GRCCP) is a rare and understudied subtype of invasive breast carcinoma of no special type (IBC-NST). Here we report the molecular characteristics of a mammary IC-GRCCP diagnosed in a 69-year-old woman. Next-generation sequencing of the tumor revealed an inv(1)(p36.12,q32.1) leading to loss-of-function of ARID1A gene, a MAP2K4 truncating mutation (p.E376), MYC amplification, a variant of uncertain significance of PTPRB gene (p.D1848N) and deep deletions of NCKAP5, CCNT2, MAP3K19, LRP1B, and KMT2A. The analysis of the involved pathways shows close resemblance to the ovarian clear cell carcinoma and indicates similarities in the molecular mechanisms of development of glycogen-rich clear cell carcinomas in different organs. Our findings and the literature review suggest new potential strategies for treatment of mammary IC-GRCCP, including epigenetic therapies, checkpoint inhibitors, radiation, or other double-strand DNA breaks-inducing agents. Nevertheless, larger studies are needed to substantiate those ideas.
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    Prominent Pseudo-Angiovascular invasion by benign gallbladder epithelium and bile emboli in a patient with delayed cholecystectomy due to COVID-19 positive test
    (BMC, 2022) Miller, Quinn; Dave, Nishi; Popnikolov, Nikolay; Bruce, Sidney D.; Mesa, Hector; Pathology and Laboratory Medicine, School of Medicine
    Lymphovascular invasion is a hallmark of malignant neoplasms, however the presence of benign epithelium within vessels has been reported in benign processes, albeit infrequently. The proposed mechanism to explain this phenomenon entails mechanical displacement of benign epithelium into the vascular spaces during surgical manipulation or diagnostic interventions. We report a case of numerous benign epithelial vascular emboli in a cholecystectomy specimen. A 29-year-old male presented with acute calculous cholecystitis. Surgery was delayed for several weeks due to COVID-19 infection. Histologic examination of the gallbladder showed subacute cholecystitis, widespread vascular epithelial emboli with associated fibrin deposition and bile embolism supporting an in vivo process. The epithelial emboli were localized in small veins and arterioles with D2–40−/CD31+/CD34+ endothelium. The displaced epithelium showed benign cytologic features, was negative for p53 expression, and had a Ki-67 labelling index like the benign background mucosa, supporting a benign process. There was no evidence of dysplasia or malignancy in the specimen after thorough sampling. Persistent inflammation, mucosal ulceration, transmural mucosal herniation (Rokitansky-Aschoff sinuses), and protracted surgical manipulation secondary to adhesive disease are favored to be the underlying causes of this unusual histologic finding. Although we presume an uneventful outcome, clinical follow up was recommended. COVID-19 infection likely contributed to this phenomenon by causing a delay in the surgical management.