Metin Ozdemirli

Georgetown University, Washington, D. C., DC, USA

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Publications (33)99.85 Total impact

  • Article: Solid-pseudopapillary neoplasm of the pancreas: Awareness of unusual clinical presentations and morphology of the clear cell variant can prevent diagnostic errors.
    Po Zhao, Pedro Debrito, Metin Ozdemirli, Mary K Sidawy
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    ABSTRACT: Solid-pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm predominantly reported in young women. It classically presents as a large tumor with cystic and solid components. The major differential diagnosis includes pancreatic neuroendocrine tumor (PanNET). This study presents our experience with this tumor with emphasis on the morphologic features of the clear cell variant of SPN. Fifteen histologically confirmed SPN were identified in our files. Endoscopic ultrasound-guided fine needle aspirations (EUS-guided FNA) were performed in 8/15 cases. Patients' demographics, cytohistologic correlation and tumor characteristics were evaluated. Eleven of the 15 subjects were female and four were male with an age range of 17-73 years. Twelve SPN were located in the pancreatic body/tail, and three in the head. Tumor size ranged from 1.5 to 8.5 cm and 11 were solid. Of the eight EUS-guided FNA, four were diagnosed as SPN, two as SPN vs. PanNET, one as malignant with signet ring features, and one was nondiagnostic. Immunohistochemistry was performed on six/eight FNA cell blocks and 13/15 surgical specimens. Two of the 15 cases were classified as clear cell variants of SPN. Our study shows that SPN may occur in males and older adults, and present as a small or solid tumor. The clear cell variant of SPN, characterized by vacuolated cytoplasm and signet cell morphology, may pose a diagnostic challenge on FNA. Awareness of the wide spectrum of SPN clinical presentations, the morphology of its clear cell variant and the appropriate use of ancillary immunohistochemistry can prevent diagnostic errors. Diagn. Cytopathol. 2013. © 2013 Wiley Periodicals, Inc.
    Diagnostic Cytopathology 04/2013; · 1.16 Impact Factor
  • Article: Indolent CD8-positive T-cell lymphoid proliferation of the ear: a report of two cases.
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    ABSTRACT: The current classification of primary cutaneous T-cell lymphoma (CTCL) of the World Health Organization (WHO) includes primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma as a provisional entity awaiting cumulative data. Recent reports identify CD3/CD8-positive clonal T-cell lymphoid proliferations arising in the ear and nose that behave indolently and therefore defy currently established subclassification. Here, we report two cases of clonal CD8-positive/granzyme-B-negative T-cell lymphoid proliferations that arose in the ear and behaved indolently. Collectively, these cases suggest that an additional category of cutaneous indolent CD8-positive T-cell lymphoma may be necessary among the existing classification schemes.
    Journal of Cutaneous Pathology 03/2012; 39(7):696-700. · 1.56 Impact Factor
  • Article: Polypoid dysplasia in Barrett's esophagus: case report and qualitative systematic review of the literature.
    Sushil K Ahlawat, Metin Ozdemirli
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    ABSTRACT: Dysplasia in Barrett's esophagus (BE) occurs as a flat, grossly undetectable lesion. Dysplasia growing as a polypoid lesion in BE is extremely rare. Only a handful of cases are reported in the literature. BE associated polypoid dysplastic lesions have been referred to as "adenomas" because of their histologic similarity to a colonic adenoma. We describe a patient with esophageal polypoid lesion associated with BE and review clinical and pathological features of other cases of BE associated polypoid dysplasia or "adenomas" as reported in the literature.
    Acta gastro-enterologica Belgica 03/2012; 75(1):49-54. · 0.64 Impact Factor
  • Article: Histiocytic sarcoma transdifferentiated from follicular lymphoma presenting as a cutaneous tumor.
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    ABSTRACT: Histiocytic sarcoma represents a rare and poorly understood tumor of histiocytic/dendritic cell lineage that can rarely present in the skin. Previously reported cases of histiocytic sarcoma after follicular lymphoma suggested that follicular lymphoma can transdifferentiate into histiocytic sarcoma. We describe another case involving a 40-year old male who developed histiocytic sarcoma in his right thigh 4 years after the diagnosis of grade 1 follicular lymphoma in the left neck. The two neoplasms were morphologically and immunophenotypically different but had identical immunoglobulin heavy chain gene and bcl-2 gene rearrangements, as demonstrated by polymerase chain gene reaction analysis, and the presence of t(14;18)(q32;q21) translocation was confirmed via fluorescence in situ hybridization (FISH) analysis. Because of spindle cell morphology and focal S-100 positivity, malignant peripheral nerve sheath tumor and melanoma diagnoses were made initially and extensive workup was required to discover the correct diagnosis. Lineage transdifferentiation can occur in mature lymphoid neoplasms and awareness of this phenomenon and appropriate workup is crucial for correct diagnosis, as different treatment protocols and prognosis may vary.
    Journal of Cutaneous Pathology 08/2011; 38(12):999-1003. · 1.56 Impact Factor
  • Article: De novo intra-pancreatic cholangiocarcinoma following liver transplantation for advanced primary sclerosing cholangitis.
    Journal of Surgical Oncology 07/2011; 104(6):699-700. · 2.10 Impact Factor
  • Article: Acute promyelocytic leukemia following chemotherapy for EBV-associated hemophagocytic lymphohistiocytosis.
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    ABSTRACT: We report a case of chemotherapy-related acute promyelocytic leukemia (APL) following therapy with VP-16/etoposide for EBV-associated hemophagocytic lymphohistiocytosis (HLH). A 17-month-old male presented with fever and lymphadenopathy. Bone marrow and liver biopsies showed hemophagocytosis. He responded well to chemotherapy including dexamethasone, VP-16/etoposide, and cyclosporine. One and a half year later, he developed fever and pancytopenia. Clinical work-up revealed APL with t(15;17)(q22;q12);PML-RARα translocation. He underwent chemotherapy for APL and is in remission 8 years after diagnosis. Alternative non-leukemogenic agents to effectively treat HLH would be desirable.
    Pediatric Blood & Cancer 05/2011; 56(5):850-2. · 1.89 Impact Factor
  • Article: Esophageal polypoid mass in a 78-year-old woman.
    Gastroenterology 02/2011; 140(2):405, 737. · 11.68 Impact Factor
  • Article: Donor transmission of pineoblastoma in a two-yr-old male recipient of a multivisceral transplant: a case report.
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    ABSTRACT: Transplant-transmitted malignances are rare but devastating events. Primary brain tumors are the least common among reported donor-derived malignancies. We report a case of donor-transmitted pineoblastoma, a PNET, in a two-yr-old male recipient, who presented with a rapidly growing mass in the right mandible, four months after multiple visceral organ transplantation. The recipient had liver, pancreas, and small bowel transplants because of end-stage liver failure and short gut syndrome, which was secondary to large bowel resection for management of gastroschisis complicated by intestinal volvulus. The donor autopsy results became available seven wk after transplantation, which found a pineoblastoma with meningeal spread. Evaluation of eyes, adrenal glands, bone marrow, and other organs did not identify metastasis outside the CNS. A biopsy of the recipient's right mandibular mass revealed a malignant small round blue cell tumor with the immunohistochemistry profile of a PNET. Staging evaluation revealed the tumor in the right mandible with bone marrow involvement. Further investigation showed that recipient's tumor and donor's pineoblastoma shared the same immunophenotype and HLA type, suggesting the recipient's tumor is a donor-transmitted pineoblastoma. This is the first case report of donor-transmitted pineoblastoma post-organ transplant.
    Pediatric Transplantation 01/2011; 16(4):E110-4. · 1.48 Impact Factor
  • Article: Arsenic trioxide inhibits human cancer cell growth and tumor development in mice by blocking Hedgehog/GLI pathway.
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    ABSTRACT: The Hedgehog (Hh) pathway is activated in some human cancers, including medulloblastoma. The glioma-associated oncogene homolog (GLI) transcription factors are critical mediators of the activated Hh pathway, and their expression may be elevated in some tumors independent of upstream Hh signaling. Thus, therapies targeting GLI transcription factors may benefit a wide spectrum of patients with mutations at different nodal points of the Hh pathway. In this study, we present evidence that arsenic trioxide (ATO) suppresses human cancer cell growth and tumor development in mice by inhibiting GLI1. Mechanistically, ATO directly bound to GLI1 protein, inhibited its transcriptional activity, and decreased expression of endogenous GLI target genes. Consistent with this, ATO inhibited the growth of human cancer cell lines that depended on upregulated GLI expression in vitro and in vivo in a xenograft model of Ewing sarcoma. Furthermore, ATO improved survival of a clinically relevant spontaneous mouse model of medulloblastoma with activated Hh pathway signaling. Our results establish ATO as a Hh pathway inhibitor acting at the level of GLI1 both in vitro and in vivo. These results warrant the clinical investigation of ATO for tumors with activated Hh/GLI signaling, in particular patients who develop resistance to current therapies targeting the Hh pathway upstream of GLI.
    The Journal of clinical investigation 01/2011; 121(1):148-60. · 15.39 Impact Factor
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    Article: A seventeen-year-old female with hepatosplenic T-cell lymphoma associated with parvoviral infection.
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    ABSTRACT: Hepatosplenic T-cell lymphoma (HSTL) is rare, being derived from cytotoxic T-cells, and manifests as an extranodal systemic lymphoma. We present an unusual case of a seventeen-year-old female, with no significant prior medical history, presenting with a hepatosplenic T-cell lymphoma. The diagnosis was confirmed by histological examination, immunohistochemisty, and flow cytometry. A staging work-up demonstrated bone marrow involvement by HSTL with concomitant intranuclear parvoviral inclusions.
    Pediatric reports 01/2010; 2(1):e11.
  • Article: Lethal spontaneous aortic dissection in an adolescent.
    Metin Ozdemirli, Victor E Nava
    Journal of forensic and legal medicine 08/2009; 16(5):298.
  • Article: Primary vulvar Ewing sarcoma/primitive neuroectodermal tumor: a report of 2 cases and review of the literature.
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    ABSTRACT: Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) family of tumor is a very aggressive malignant round cell tumor characterized by translocations involving EWS-FLI1 genes. They are increasingly recognized in extraosseous sites as a result of improvements in diagnostic tools. In this paper, we report 2 additional cases arising in vulva of young adults who have been treated aggressively and have survived fore more than 7 and 4 years successively. Histologic examination showed small round (blue) cell morphology in both cases. The tumor cells contained glycogen and were positive for CD99 and vimentin and negative for keratins, lymphoid markers, S-100, synaptophysin, chromogranin, and desmin. Reverse transcriptase polymerase chain reaction analysis from paraffin-embedded tissue revealed EWS-FLI1 fusion product in 1 case. Collectively, 13 cases of vulvar ES/PNET have been reported in the literature. Only 8 cases have detailed follow-up information with an average follow-up data of 28 months. Ewing sarcoma/PNET should be considered in the differential diagnosis of any undifferentiated tumors involving the lower gynecologic tract and all axillary tests including molecular tests should be performed for correct diagnosis because prolonged survival is possible for this dreadful disease after complete surgical resection, followed by adjuvant therapy.
    International Journal of Gynecological Cancer 08/2009; 19(6):1131-6. · 1.65 Impact Factor
  • Article: Absence of FLT3 and JAK2 (V617F) mutations in Langerhans cell histiocytosis.
    Leukemia research 05/2009; 33(9):e173-4. · 2.36 Impact Factor
  • Article: Primary retroperitoneal mucinous cystadenoma.
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    ABSTRACT: Primary mucinous neoplasms of the retroperitoneum, including mucinous cystadenocarcinomas, mucinous borderline tumors, and mucinous cystadenomas are uncommon tumors found exclusively in women. Since the retroperitoneum does not contain mucinous epithelium, the origin, and histogenesis of these tumors remain unclear. It is speculated that these tumors can arise from teratomas, supernumerary ovaries, or mucinous metaplasia of the retroperitoneal mesothelium. We describe a case of a primary mucinous cystadenoma of the retroperitoneum in a 44 year-old female that presented as a palpable abdominal mass. There was no evidence of recurrence 16 months after complete laparoscopic excision of the tumor. The morphology and immunohistochemical analysis in this case support the hypothesis that mucinous metaplasia of the retroperitoneal mesothelium overlying a preceding inclusion cyst can give rise to retroperitoneal mucinous tumors.
    Saudi medical journal 02/2009; 30(1):146-9. · 0.52 Impact Factor
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    Article: A thirteen year old female with primary T-cell rich B-cell lymphoma of bone masquerading as chronic recurrent multifocal osteomyelitis.
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    ABSTRACT: Primary lymphoma of the bone (PLB) accounts for 2% of all non-Hodgkin's lymphomas, and until recently it had not been well characterized in literature. Most cases present in adulthood (average age 50), with localized painful lesions in the long bones, cranium, or axial skeleton.We describe a case of multifocal PLB in an adolescent female. In this case, the initial presentation, with migratory large joint polyarthralgias and bone pain, mimicked chronic recurrent multifocal osteomyelitis (CRMO). Had a biopsy not been performed the diagnosis would have been missed.
    Pediatric reports 01/2009; 1(1):e3.
  • Article: Asymptomatic diffuse "encephalitic" cerebral toxoplasmosis in a patient with chronic lymphocytic leukemia: case report and review of the literature.
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    ABSTRACT: Opportunistic infections account for the majority of central nervous system lesions in adult immunosuppressed patients. In this setting, toxoplasmosis typically manifests as multiple abscesses readily seen on routine neuroimaging studies. Asymptomatic, widely disseminated Toxoplasma cysts without parenchymal reaction are also recognized. In contrast, widespread parasites in the brain parenchyma with an inflammatory "encephalitic" reaction and little or no necrosis have been reported in only four patients with acquired immune deficiency syndrome (AIDS). We describe a 70 year old male with stage IV chronic lymphocytic leukemia complicated by aplastic anemia. Neurological examination and imaging revealed no significant abnormalities. At autopsy, the brain revealed multifocal cysts and free tachyzoites of Toxoplasma gondii with diffuse microglial nodules and no necrosis. To the best of our knowledge, this case represents the first report of the "encephalitic" form of toxoplasmosis in a non-AIDS patient.
    International journal of clinical and experimental pathology 01/2009; 3(1):106-9. · 1.89 Impact Factor
  • Article: HIV-associated anaplastic large cell lymphoma: a report of three cases.
    AIDS (London, England) 10/2008; 22(14):1892-4. · 4.91 Impact Factor
  • Article: Maxillary angiocentric EBV-associated large B cell lymphoma associated with methotrexate treatment.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 08/2008; 66(7):1557-8. · 1.58 Impact Factor
  • Article: Atypical teratoid rhabdoid tumor (AT/RT) in adults: review of four cases.
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    ABSTRACT: Atypical teratoid/rhabdoid (AT/RT) tumor is a rare, highly malignant tumor of the central nervous system (CNS) most commonly found in children less than 5 years of age. Although the vast majority of cases are diagnosed in young children, there have been isolated case reports in adults. Since its histological appearance can be confused with other tumors, especially in adults, separating AT/RT from other neoplasms may be difficult. In many instances, a reliable diagnosis is not possible without demonstrating the lack of nuclear INI1 protein expression by immunohistochemical methods. The patients (three males and one female) ranged in age from 23 to 42 years (mean age, 32 years). Radiographically, two tumors were localized in the right fronto-parietal region, one was frontal and the other was found in the left temporal lobe. Varying degrees of hydrocephalus and heterogeneous enhancement were present on MRI. In all cases, diagnosis during intraoperative consultation and preliminary diagnosis was different from the final diagnosis after immunohistochemical analysis. Immunohistochemical staining showed that the tumor cells were positive for vimentin and reacted variably for keratin, epithelial membrane antigen (EMA), synaptophysin, neurofilament protein, CD34, and smooth muscle actin (SMA). All were negative for GFAP, S-100, desmin and CD99. Three of the four cases lacked nuclear expression of INI1. One patient is alive with no evidence of disease 17 years after the diagnosis. In adult examples of AT/RT, the diagnosis requires a high index of suspicion, with early tissue diagnosis and a low threshold for investigation with INI1 immunohistochemistry to differentiate this entity from other morphologically similar tumors. Although the prognosis is dismal in pediatric population, long term survival is possible in adult AT/RT cases after surgery and adjuvant radiotherapy and chemotherapy.
    Journal of Neuro-Oncology 08/2008; 88(3):321-30. · 3.21 Impact Factor
  • Article: Oligodendroglioma with neurocytic differentiation versus atypical extraventricular neurocytoma: a case report of unusual pathologic findings of a spinal cord tumor.
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    ABSTRACT: Differentiating oligodendroglioma from extraventricular neurocytoma by conventional light microscopy alone can present a diagnostic challenge. We report pathologic findings of an unusual spinal cord tumor from a 33-year-old male patient which showed hybrid features of oligodendroglioma and extraventricular neurocytoma. Magnetic resonance imaging (MRI) showed an enhancing intramedullary mass in the cervicothoracic region (C7 through T6). Histologic examination revealed a clear cell neoplasm containing ganglion-like cells and calcifications, prompting the differential diagnosis of oligodendroglioma and extraventricular neurocytoma. The immunohistochemical analysis disclosed neural differentiation of the neoplastic cells with strong synaptophysin and neurofilament staining consistent with extraventricular neurocytoma, as well as strong S-100 and glial fibrillary acidic protein (GFAP) expression. Molecular studies with fluorescent in situ hybridization (FISH) revealed chromosome 1p/(partial) 19q deletions, a finding commonly observed in oligodendroglioma. The proliferation index (using antibody MIB1) of the tumor was approximately 30%. The morphologic findings and these results strengthen the hypothesis that these tumors may share a common progenitor cell, which has also been observed by others. Because there are differences in patient management and long-term prognosis, it is important to attempt to distinguish between oligodendroglioma and neurocytoma. This unusual case and similar rare reported cases support the need to reclassify tumors showing pathologic features common to both neurocytoma and oligodendroglioma as a unique entity, while the effort continues to identify the cell of origin.
    Journal of Neuro-Oncology 05/2007; 82(2):199-205. · 3.21 Impact Factor