Luis E De Las Casas

Medical University of Ohio at Toledo, Toledo, Ohio, United States

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Publications (34)67.29 Total impact

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    ABSTRACT: Kaposi sarcoma is a vascular tumor manifesting as nodular lesions on skin, mucous membranes, or internal organs. This is a case of a 42-year-old human immunodeficiency virus- (HIV) positive bisexual male, not on highly active antiretroviral therapy (HAART) since diagnosis four years ago. He presented with a three-day history of abdominal pains, fever, vomiting, and a one-week history of melena stools. Endoscopy revealed Kaposi sarcoma in the stomach and duodenum. Postendoscopy, he developed acute abdomen. Exploratory laparotomy revealed extensive Kaposi sarcoma of the gastrointestinal tract with appendiceal involvement. The patient underwent appendectomy and had an uneventful recovery. A review of the literature discusses appendiceal Kaposi sarcoma with appendicitis, a rare but critical manifestation of gastrointestinal Kaposi sarcoma.
    Southern medical journal 04/2011; 104(4):278-81. · 0.92 Impact Factor
  • Cytopathology 11/2010; 22(6):418-20. · 1.71 Impact Factor
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    ABSTRACT: To the best of our knowledge, there are currently no recorded cytologic features of any effusion from rheumatoid peritonitis showing cytologic findings linked to rheumatoid pleural disease, although rheumatoid nodules have been described in the peritoneum. A 75-year-old man with longstanding, poorly controlled rheumatoid arthritis was seen in our hospital after a motor vehicle collision. Computed tomography showed free fluid in the abdominal cavity. Laparoscopic examination revealed a large amount of nonhemorrhagic ascitic fluid and no traumatic intraabdominal injuries. Abdominal and peritoneal surfaces appeared completely normal. The ascitic fluid was aspirated through the laparoscope and sent for cytologic examination. Cytospin preparations revealed histiocytes and loosely cohesive clusters of small cytologically bland epithelioid cells amid acute inflammatory cells and granular necrotic debris. Cell block material displayed transected fibroconnective tissue fragments lined by hyperplastic mesothelium with squamous metaplasia. Immunohistochemical studies revealed that the mesothelial cells were positive for calretinin, cytokeratin 5/6, and p63. The ascites was attributed to peritoneal disease from rheumatoid arthritis, based on the cytologic findings, immuno-profile, exclusion of other possible causes (i.e., cirrhosis, nephrotic syndrome, protein-losing enteropathy, or drugs), and patient's clinical setting.
    Acta cytologica 01/2010; 54(6):1123-6. · 0.69 Impact Factor
  • Acta Cytologica - ACTA CYTOL. 01/2010; 54:1123-1126.
  • Source
    Olga L Bohn, Luis E De las Casas, Marino E Leon
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    ABSTRACT: Metastatic disease to thyroid gland is a rare event. Although renal cell carcinoma (RCC) has been reported to metastasize the thyroid gland, metastatic RCC to a thyroid neoplasm is very unusual. We report a case of a 68-year-old man with history of RCC who presented with a 2.5-cm thyroid nodule. Histologic examination demonstrates a renal cell carcinoma metastatic to a papillary carcinoma of the thyroid. The clinicopathologic features of metastatic disease into a thyroid gland neoplasm are shown, and a review of the literature is presented.
    Head and Neck Pathology 12/2009; 3(4):327-30.
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    ABSTRACT: Intraoperative cytologic evaluation of brain tumors has been used either to render a preliminary interpretation or more often as a complement to frozen section examination. Central neurocytoma is a intraventricular neoplasm, typically located in the region of the foramen of Monro, affecting mostly young to middle age adults. Histologically, central neurocytomas are characterized by monotonous cells with round nuclei and neuronal differentiation within a rich capillary network. Their distinction during intraoperative consultations from oligodendroglioma, ependymoma (mainly clear cell ependymoma), and non-Hodgkin lymphoma can be a diagnostic challenge. We report a case of a 19-year-old female with an intraventricular tumor where imprint cytology preparations were crucial for the intraoperative diagnosis of central neurocytoma. Imprint cytology preparations show a round cell neoplasm associated with neuropil clumps and short straight capillaries admixed with tumor cell clusters. To the best of our knowledge, only a few cases describing the cytologic findings of central neurocytomas have been reported in the medical literature. The differential diagnosis, tissue correlation, clinical-radiologic features, and ancillary studies are discussed.
    Diagnostic Cytopathology 09/2009; 38(3):202-7. · 1.49 Impact Factor
  • Soheila Korourian, Luis De Las Casas
    01/2008: pages 33 - 58; , ISBN: 9780470753293
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    ABSTRACT: Low-grade fibromyxoid sarcoma is an uncommon, deceptively bland mesenchymal neoplasm that typically occurs in the deep soft tissues of the proximal extremities of young to middle-aged patients. Intra-abdominal low-grade fibromyxoid sarcomas are distinctly rare. We describe the first reported example of this sarcoma involving the ovary. The 42-year-old patient presented with progressing abdominal pain and urinary frequency. Computed tomographic imaging of the abdomen and pelvis showed a 14-cm left-sided pelvic mass. The patient underwent surgical resection and, intraoperatively, a left ovarian mass was identified that extended to both the left hypogastric artery and the left ureter. The resected specimen consisted of a 17-cm tan, fleshy mass containing grossly recognizable nodules of gelatinous, myxoid tissue and a small rim of normal ovary. Microscopic examination of the neoplasm revealed a cytologically bland spindle cell proliferation set in a collagenized stroma that abruptly transitioned to nodules of a myxoid stroma with a well-formed capillary vasculature, features characteristic of low-grade fibromyxoid sarcoma. On the basis of the diagnosis, the patient was clinically staged as a retroperitoneal sarcoma with secondary ovarian involvement. The patient has stable residual disease 11 months postoperatively. This case adds to the literature of intra-abdominal low-grade fibromyxoid sarcoma and expands the list of malignant mesenchymal neoplasms that may involve the ovary.
    International Journal of Gynecological Pathology 05/2007; 26(2):173-6. · 1.41 Impact Factor
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    ABSTRACT: Chorioamnionitis is the maternal and fetal response to an ascending intrauterine infection. The fetal response is manifested by funisitis and chorionic vasculitis, or as neutrophils within pulmonary spaces. Human hematopoiesis occurs in the liver primarily during the 6th to 22nd weeks of gestation. To establish the relationship between the presence of an intrauterine infection and the degree of fetal hepatic myelopoiesis in second- and third-trimester fetuses. Liver and lungs from 49 fetal autopsies, 20 to 41 weeks of gestational age, and their associated placentas and membranes were analyzed for evidence of intrauterine infection and hepatic myelopoiesis. Hematoxylin-eosin-stained sections from fixed tissues were evaluated for the presence of amnionic fluid infection, defined by the presence of acute chorioamnionitis or funisitis. The degree of portal hematopoiesis, myelopoiesis and intra-alveolar neutrophils was assessed semiquantitatively with hematoxylin-eosin-stained sections and immunohistochemically with antimyeloperoxidase. The Kruskal-Wallis 1-way analysis of variance and the Wilcoxon-Mann-Whitney test were used to determine the significance of any observed difference. The degree of portal and lobular myelopoiesis was significantly greater with the presence of inflammation in both the membranes and umbilical cord, and correlated with the presence of intra-alveolar neutrophils (P < .001). A high correlation between the hematoxylin-eosin and immunohistochemistry assessment of myeloid cells was noted. There is increased portal and lobular myelopoiesis in 20-week to 41-week gestational age fetal livers that is associated with intrauterine ascending infection. The presence of increased portal or lobular myelopoiesis suggests the presence of an active fetal response to an intrauterine ascending infection.
    Archives of pathology & laboratory medicine 12/2006; 130(12):1786-91. · 2.78 Impact Factor
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    ABSTRACT: Overexpression of the epidermal growth factor type II receptor HER-2/neu has been associated with resistance to chemotherapy and poor survival in several human tumors. In the current study, the authors have determined the frequency and clinical significance of HER-2/neu gene amplification in uterine serous papillary endometrial carcinoma (USPC), a highly aggressive variant of endometrial carcinoma. Fluorescence in situ hybridization (FISH) assay was used to analyze gene amplification in paraffin blocks from 30 women harboring Stage IA-IV USPC treated at the University of Arkansas for Medical Sciences (Little Rock, AR) from 1997 to 2004. Chromosome 17 polysomy status by FISH was also assessed in all specimens. USPC patient survival in relation to HER-2/neu gene amplification was analyzed using Kaplan-Meier curves in conjunction with the log-rank test. Amplification of the HER-2/neu gene by FISH was observed in 14 of the 30 (47%) cases. Heterogeneity was noted in 4 of 14 cases in the amplification of the HER-2/neu gene within the same tumor samples with pockets of amplified tumor cells amidst nonamplified tumor cells. Patients with USPC harboring tumors with HER-2/neu gene amplification had a significantly shorter survival time from diagnosis to disease-related death when compared with FISH-negative patients (P = 0.0008). African-American (AA) patients were found to have a poorer prognosis compared with Caucasian (C) women (P = 0.01) and to harbor USPC with significantly higher levels of HER-2/neu gene amplification (P = 0.02). HER-2/neu gene amplification in USPC was found to be an important prognostic indicator for poor outcome that occurs more frequently in AA when compared with C patients. Determination of HER-2/neu gene amplification may guide clinical management of patients with USPC and may have important implications for the implementation of novel treatment strategies.
    Cancer 11/2005; 104(7):1391-7. · 5.20 Impact Factor
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    ABSTRACT: To evaluate and compare HER2/neu protein overexpression and gene amplification in uterine serous papillary endometrial cancer (USPC). Immunohistochemical (IHC) and fluorescent in situ hybridization (FISH) assays were used to analyze and compare HER2/neu protein expression and gene amplification, respectively, in paraffin blocks from 26 women harboring stage IA to IV USPC treated at the University of Arkansas for Medical Sciences from 1997 to 2004. Chromosome 17 polysomy status by FISH was also assessed in all specimens. Moderate-to-strong expression of HER2/neu protein was noted in 16 (62%) of 26 USPC samples evaluated, with 7 (27%) samples showing moderate staining (2+) and 9 (35%) showing strong staining (3+) for HER2/neu. Amplification of the ERBB2 gene by FISH was observed in 11 of the 26 (42%) cases. Protein overexpression and gene amplification were found to correlate in 100% (9 of 9) of the 3+ positive tumors and 2 out of 7 (29%) of the 2+ positive tumors. Heterogeneity was noted in 3 cases in the amplification of the HER2/neu gene within the same tumor samples with pockets of amplified tumor cells amidst nonamplified tumor cells. None of the 10 USPC cases scored by IHC as 0 or 1+ was found positive for ERBB2 amplification by FISH. Amplification of the HER2/neu oncogene represents a common finding in USPC. FISH analysis should be used for confirmation of gene amplification in USPC showing 2+ expression of HER2/neu. Prior screening and selection of appropriate immunohistochemistry-positive areas may be beneficial in the selection of some USPC patients undergoing FISH analysis.
    Gynecologic Oncology 08/2005; 98(1):24-30. · 3.93 Impact Factor
  • Soheila Korourian, Jesse Mckenney, Luis E de Las Casas
    American Journal of Surgical Pathology 04/2005; 29(3):424; author reply 424. · 4.87 Impact Factor
  • Luis E. De Las Casas
    Diagnostic Cytopathology 01/2005; 33(2):144-144. · 1.49 Impact Factor
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    ABSTRACT: The distinction of cystic squamous-cell carcinoma (SCC) from benign cystic squamous lesions (BCSLs) of the head and neck can be problematic on fine-needle aspiration biopsy (FNAB) material, particularly when BCSLs display epithelial reactive atypia or when SCC is well differentiated. Glucose transporter 1 (GLUT-1), a facilitative cell surface glucose transport protein, is aberrantly expressed in many cancers including oral and hypopharyngeal SCC. We evaluated the expression of GLUT-1 by immunochemistry on FNAB material to determine its value in distinguishing cystic SCC from BCSL of the head and neck. A 5-yr retrospective review of all head and neck cystic squamous lesions having FNAB specimens with cell block material, radiological studies, and histological confirmation was performed at our institution. Cell block material from 24 cystic squamous lesions, including 8 (33%) BCSL (7 branchial cleft cysts and 1 thyroglossal duct cyst[TDC]) and 16 (67%) metastatic SCCs with cystic/liquefactive degeneration, was retrieved and immunostained with anti-GLUT-1. GLUT-1 expression was considered positive when at least 10% of squamous cells exhibited distinct cell membrane reactivity. Positive GLUT-1 immunostaining was detected in all 16 SCCs and in none of the 8 BCSLs. In the carcinoma cases, the majority of malignant cells exhibited GLUT-1 reactivity; only a minor population of well-differentiated SCC cells displaying keratinization and arranged as squamous pearls did not express GLUT-1. GLUT-1 expression in cell block material can help to distinguish cystic SCCs from BCSLs of the head and neck. In conjunction with clinical and radiological correlation, GLUT-1 immunoreactivity can be an important diagnostic aid when the cytological findings are ambiguous.
    Diagnostic Cytopathology 12/2004; 31(5):294-9. · 1.49 Impact Factor
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    ABSTRACT: Small-cell carcinoma (SmC) and high-grade non-Hodgkin's lymphoma (NHL) are aggressive neoplasms that require prompt diagnosis and treatment. An immediate diagnosis can be obtained using fine-needle aspiration biopsy (FNAB) material from lymph nodes (LNs), which are clinically or radiologically suspicious for tumor involvement. However, in aspirates from LNs, the cytologic distinction of SmC from NHL can be challenging. The purpose of this study was to evaluate the usefulness of various cytologic features that can be used during a rapid on-site evaluation to differentiate these two entities. Twenty-seven metastatic SmC and 50 NHLs cases diagnosed by FNAB of LNs were reviewed. All NHL diagnoses (neck, 29; abdomen, 9; axilla, 6; groin, 5; and parotid, 1) were confirmed with tissue sections, flow cytometry, or immunohistochemistry. These cases were classified as follicular, 21 (42%); diffuse large B cell, 13 (26%); small lymphocytic, 7 (14%); mantle cell, 4 (8%); anaplastic large cell, 2 (4%); and 1 each (2%), Burkitt, lymphoplasmacytic, and peripheral T-cell lymphomas. Immunochemistry confirmed the cytologic diagnoses of all SmC cases (neck, 16; mediastinum, 9; abdomen, 1; and axilla, 1) with either positive chromogranin or synaptophysin. All specimens were reviewed independently by three cytopathologists who were unaware of the original diagnoses. The presence and proportion of single (noncohesive) tumor cells, lymphoglandular bodies, nuclear fragments, paranuclear blue inclusions, nuclear molding, evenly dispersed fine-granular chromatin, crush artifact, and composition of cell clusters (monomorphic vs. polymorphic) were statistically evaluated. The presence of evenly dispersed fine-granular chromatin, paranuclear blue inclusions, and nuclear fragments was each statistically significant in differentiating SmC when compared with NHL (P < 0.01). The remaining features were not significant in distinguishing SmC from NHL in LN aspirates. The identification of distinct cytologic findings such as evenly dispersed fine-granular chromatin, paranuclear blue inclusions, and nuclear fragments can be a valuable aid to accurately diagnose and differentiate metastatic SmC from NHL in FNAB preparations from LNs.
    Diagnostic Cytopathology 10/2004; 31(4):229-34. · 1.49 Impact Factor
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    ABSTRACT: To determine whether the Stratum Corneum Chymotryptic Enzyme (SCCE), a novel serine protease known to contribute to the cell shedding process by catalyzing the degradation of intercellular cohesive structures at the skin surface, is overexpressed in human cervical tumors. SCCE expression was evaluated in 18 cervical cancer cell lines (i.e., 10 primary and 8 established cell lines) as well as in 8 normal cervical keratinocyte cultures by RT-PCR. In addition, SCCE expression was evaluated by immunohistochemistry on paraffin-embedded tumor tissue. Normal cervical keratinocytes did not express SCCE. In contrast, 50% of the primary and 50% of the established cervical cancer cell lines expressed SCCE by RT-PCR. Eighty percent (i.e., four of five) of primary squamous cervical tumors and 20% (i.e., one of five) of primary adenocarcinomas expressed SCCE. Five out of five (100%) of the patients harboring SCCE-positive tumors were found to have metastatic involvement of the pelvic tumor draining lymph nodes. Immunohistochemistry staining of paraffin-embedded cervical cancer specimens confirmed SCCE expression in tumor cells and its absence on normal cervical epithelial cells. Squamous cervical cancer expressed high levels of SCCE, suggesting that this protease may play an important role in invasion and metastasis. Because SCCE appears only in abundance in tumor tissue and contains a secretion signal sequence, suggesting that SCCE is secreted, it may prove to be a useful diagnostic/prognostic tool for the detection of metastatic or recurrent disease or as a novel molecular target for cervical cancer therapy.
    Gynecologic Oncology 09/2004; 94(2):283-8. · 3.93 Impact Factor
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    ABSTRACT: Serine proteases are redundant enzymes implicated in the extracellular modulation required for tumor growth and invasion. Tumor-associated differentially expressed gene-14 (TADG-14) is a novel transmembrane serine protease recently reported by our group to be highly overexpressed in ovarian carcinomas. The goal of this study was to investigate the frequency of expression of the TADG-14 gene in human cervical tumors. TADG-14 expression was evaluated in 19 cervical cancer cell lines (11 primary and 8 established cell lines) as well as in 8 normal cervical keratinocyte cultures by reverse transcriptase polymerase chain reaction. In addition, to validate gene expression data at the protein level, TADG-14 expression was evaluated by immunohistochemistry on paraffin-embedded tissue from which all 11 primary tumor cell lines were established. TADG-14 was found to be highly expressed in 82% (9/11) primary cervical cancer cell lines and in 87% (7/8) established cervical cancer cell lines by reverse transcriptase-polymerase chain reaction. Expression of TADG-14 by primary squamous cervical tumors was 100% (6/6), whereas 60% (3/5) of primary adenocarcinomas expressed TADG-14. In contrast, none of the normal cervical keratinocyte control cultures (n=4) or flash frozen normal cervical biopsy specimens (n=4) expressed TADG-14. Immunohistochemistry staining of paraffin-embedded cervical cancer specimens confirmed TADG-14 expression in tumor cells and its absence on normal cervical epithelial cells. Cervical cancer expressed a high level of TADG-14, suggesting that this protease may play an important role in invasion and metastasis. Because TADG-14 appears only in abundance in tumor tissue and contains a secretion signal sequence, suggesting that TADG-14 is secreted, it may prove to be a useful diagnostic tool for the early detection of recurrent/persistent cervical cancer after standard treatment or as a novel molecular target for cervical cancer therapy.
    American Journal of Obstetrics and Gynecology 02/2004; 190(1):60-6. · 3.88 Impact Factor
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    ABSTRACT: Touch preparation cytology (TPC) has proven to be a quick and accurate intraoperative diagnostic tool for excisional breast biopsy, margins and sentinel nodes. We hypothesized that TPC of core needle biopsy (CNB) specimens can provide a same-day diagnosis in the outpatient setting. Outpatients presenting with breast lesions underwent TPC of biopsy cores performed by biopsy gun or vacuum-assisted CNB. The TPC results were compared with the final diagnosis of CNB specimens. In all, 199 CNB and TP were performed between August 1997 and October 2002. Twenty-nine percent of lesions were malignant. Touch preparation was deferred in 21% of cases. In the remaining 157 evaluable cases, TPC had an accuracy of 89% and a false negative rate of 26%. The sensitivity, specificity, positive predictive value and negative predictive value of TPC were 74%, 97%, 93%, and 86% respectively. Touch preparation cytology on CNB can be performed simply in the outpatient setting. Collaboration between the surgeon and pathologist allows TP to be an accurate means of same-day pathological determination.
    The American Journal of Surgery 01/2004; 186(6):737-41; discussion 742. · 2.52 Impact Factor
  • Acta Cytologica - ACTA CYTOL. 01/2004; 48:32-38.
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    ABSTRACT: To establish cytomorphologic criteria that might facilitate the identification of malignant melanoma (MM) cells with epithelioid (nevoid) morphology, in fine needle aspiration biopsy material from the liver. Aspirated material from 18 cases of MM with epithelioid features and 24 cases of benign liver lesions (BLL) were examined. The cases were selected based on the availability of corresponding tissue biopsies, adequate cell block material or sufficient number of direct smears to perform immunocytochemical staining. The presence or absence of 7 cytologic criteria were reviewed, and the results were evaluated by multivariate regression analysis. All evaluated criteria were significant for identifying MM cells and differentiating them from reactive hepatocytes (P < .001). Uniform atypia, cell dyscohesion, eccentric nuclei and irregular nuclear membranes supported MM, whereas, monolayered sheets or cordlike arrangement; coarse, granular cytoplasm; and occasional transgressing endothelium in true tissue fragments were evidence of BLL. A systematic evaluation of the cytomorphologic features described in this study, in conjunction with the clinical and radiologic findings, can be used to render an immediate, confident and accurate diagnosis of MM metastatic to the liver.
    Acta cytologica 01/2004; 48(1):32-8. · 0.69 Impact Factor

Publication Stats

282 Citations
67.29 Total Impact Points


  • 2010
    • Medical University of Ohio at Toledo
      Toledo, Ohio, United States
  • 2009
    • University of Colorado
      • Department of Radiology
      Denver, CO, United States
    • Texas Tech University Health Sciences Center
      • Department of Pathology
      El Paso, Texas, United States
  • 2008
    • Loyola University Maryland
      Baltimore, Maryland, United States
  • 2002–2005
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States
  • 2004
    • University of Arkansas for Medical Sciences
      Little Rock, Arkansas, United States
  • 2003
    • University of Missouri - Kansas City
      • Department of Pathology
      Kansas City, MO, United States
  • 2000–2001
    • University of Wisconsin, Madison
      • Department of Pathology and Laboratory Medicine
      Madison, MS, United States
  • 1999
    • East Carolina University
      • Department of Pathology & Laboratory Medicine
      Greenville, NC, United States
  • 1998
    • University of South Carolina School of Medicine - Greenville
      Greenville, South Carolina, United States