Ayman Tawil

American University of Beirut · Department of Pathology & Laboratory Medicine

Publications

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    ABSTRACT: Background and study aims: Celiac disease is increasingly recognized worldwide, but guidelines on how to detect the condition and diagnose patients are unclear. In this study the prevalence and predictors of celiac disease were prospectively determined in a cross-sectional sample of Lebanese patients undergoing esophagogastroduodenoscopy (EGD). Patients and methods: Consecutive consenting patients (n = 999) undergoing EGD answered a questionnaire and had blood taken for serologic testing. Endoscopic markers for celiac disease were documented and duodenal biopsies were obtained. The diagnosis of celiac disease was based on abnormal duodenal histology and positive serology. Risk factors were used to classify patients to either high or low risk for celiac disease. Independent predictors of celiac disease were derived via multivariate logistic regression. Results: Villous atrophy (Marsh 3) and celiac disease were present in 1.8 % and 1.5 % of patients, respectively. Most were missed on clinical and endoscopic grounds. The sensitivity of tissue transglutaminase (tTG) testing for the diagnosis of villous atrophy and celiac disease was 72.2 % and 86.7 %, respectively. The positive predictive value of the deamidated gliadin peptide (DGP) test was 34.2 % and that of a strongly positive tTG was 80 %. While the strongest predictor of celiac disease was a positive tTG (odds ratio [OR] 131.7, 95 % confidence interval [CI] 29.0 - 598.6), endoscopic features of villous atrophy (OR 64.8, 95 %CI 10.7 - 391.3), history of eczema (OR 4.6, 95 %CI 0.8 - 28.8), anemia (OR 6.7, 95 %CI 1.2 - 38.4), and being Shiite (OR 5.4, 95 %CI 1.1 - 26.6) significantly predicted celiac disease. A strategy of biopsying the duodenum based on independent predictors had a sensitivity of 93 % - 100 % for the diagnosis of celiac disease, with an acceptable (22 % - 26 %) rate of performing unnecessary biopsies. A strategy that excluded pre-EGD serology produced a sensitivity of 93 % - 94 % and an unnecessary biopsy rate of 52 %. Conclusion: An approach based solely on standard clinical suspicion and endoscopic findings is associated with a significant miss rate for celiac disease. A strategy to biopsy based on the derived celiac disease prediction models using easily obtained information prior to or during endoscopy, maximized the diagnosis while minimizing unnecessary biopsies.
    Endoscopy 02/2014; 46(2):110-9. · 5.74 Impact Factor
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    ABSTRACT: Analysis of human epidermal growth factor receptor 2 (HER-2) status has become standard of care in breast cancer patients due to its important prognostic and therapeutic implications. Immunohistochemistry (IHC) is the most commonly used primary method for detection of HER-2 overexpression. Controversy exists on the interpretation of samples that are equivocal for HER 2 status (IHC 2+). Recent guidelines state that samples equivocal for HER 2 status require validation with fluorescent in situ hybridisation (FISH). The use of FISH, however, despite higher accuracy comes at a higher cost that is not affordable to all patients. This study is a retrospective study conducted at the American University of Beirut Medical Center, including women diagnosed with breast cancer with equivocal IHC scores presenting between 2009 and 2011. We attempted to correlate clinicopathological characteristics of patients diagnosed with breast cancer that can influence conclusions made on HER 2 status when analysing IHC equivocal samples in an effort to decrease the need for FISH testing. 113 patients in our records were included; charts were reviewed for different patient clinical characteristics and samples were analysed for pathological characteristics. Using logistic regression, progesterone receptor status and HER-2 staining of the normal glands around the tumour by IHC were the two statistically significant variables that showed association with FISH results. The strength of progesterone receptor status positivity and HER-2 staining of the normal glands around the tumour were proportional to the likelihood of a negative FISH. Also, the presence of strong and diffuse hormone receptor positivity in low-grade tumours was predictive of negative HER-2 status. In countries where resources are strained, oncologists need to think of measures to minimise the increasing financial burden of cancer care. Our study serves to highlight a few clinicopathological characteristics that might eliminate the need for further testing through FISH.
    Journal of clinical pathology 10/2013; · 2.43 Impact Factor
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    ABSTRACT: To report a rare case of Transglottic Basaloid Squamous cell carcinoma of the larynx and review the pathologic features of these lesions. A 64 year old male, heavy smoker and alcohol abuser, presented with a 6 month history of hoarseness. Laryngoscopy revealed a right transglottic lesion involving the epiglottis, aryepiglottic fold, ventricle and true vocal fold. Microscopically, the tumor was characterized by infiltrating solid sheets of basaloid cells showing palisading pattern along the edges. In areas of solid growth, tumor cells displayed scant cytoplasm, and hyperchromatic nuclei. A portion of the tumor abutting the thyroid cartilage showed squamous differentiation. An island of tumor cells with comedonecrosis was also noted. Immunohistochemical staining for a number of markers was performed. Basaloid squamous cell carcinoma displays a biphasic histology. The stage of the disease at presentation is invariably advanced with metastatic lymphadenopathy in two thirds of the patients.
    Middle East journal of anaesthesiology 06/2013; 22(2):229-32.
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    ABSTRACT: Incidence of various Hodgkin (HL) and non-Hodgkin lymphoma (NHL) subtypes and association with viruses in Lebanon are not known. We undertook a nationwide study of 272 patients diagnosed with lymphoma in 2007. HL comprised 32.7 % (n = 89) of cases while NHL represented 67.3 % (n = 183). Consistent with the literature, nodular sclerosis was the most predominant HL subtype (n = 57/89). Among NHL, B-cell NHL represented 88 % (n = 161/183), T-cell NHL 9 % (n = 17/183), whereas in 2.7 % it was not classifiable. The B-cell NHL comprised predominantly diffuse large B-cell lymphoma (46 %) and follicular lymphoma (23 %). 81 cases were reviewed by a panel of pathologists with 87.6 % concordance rate. Serology was negative for hepatitis C in 122 tested cases. HIV was positive in 2 cases. Two adult T-cell leukemia/lymphoma were HTLV-I positive. EBV IgG were positive in 88.5 % of cases. 38 EBV seropositive cases [27 NHL (24 B-cell, 3 T-cell) and 11 HL] were studied for EBV genome expression using EBV-encoded RNA (EBER)-in situ hybridization. EBER expression was positive in 8 (21 %) cases (6 HL, 2 T-cell NHL). The distribution of lymphoma subtypes in Lebanon appears similar to that of Western countries. The high rate of EBV positivity in HL and T-cell lymphoma by EBER deserves further investigation.
    Pathology & Oncology Research 05/2013; · 1.56 Impact Factor
  • British Journal of Haematology 01/2013; · 4.94 Impact Factor
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    ABSTRACT: There are eight reported cases in the literature of osteosarcomas secreting β-hCG. Our primary aim was to investigate the rate of β-hCG expression in osteosarcoma and attempt to understand the characteristics of osteosarcomas that secrete β-hCG. We reviewed 37 histopathology slides (14 biopsies and 23 surgical specimens) from 32 patients with osteosarcoma. The slides were retrospectively stained for β-hCG expression. Patient and tumour characteristics, including age, gender, tumour location, subtype, proportion of necrosis, presence of metastases and recurrence were recorded. A total of five of the 32 tumours were found to be positive for β-hCG expression (one strongly and four weakly). This incidence of this expression was found in tumours with poor histological response to neoadjuvant chemotherapy. The use of β-hCG expression as a diagnostic, prognostic or follow-up marker is questionable and needs further investigation with a larger sample size.
    Journal of Bone and Joint Surgery - British Volume 03/2012; 94(3):419-24. · 2.69 Impact Factor
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    Gastrointestinal cancer research: GCR 03/2012; 5(2):59-63.
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    ABSTRACT: Objective The aim of this work was to determine the role of MRI in interpreting abnormal signals within bones and soft tissues adjacent to tumor bulk of osteosarcoma and Ewing’s sarcoma in a pediatric population by correlating MR findings with histopathology. Materials and methods Thirty patients met the inclusion criteria, which included (1) osteosarcoma or Ewing’s sarcoma, (2) MR studies no more than 2 months prior to surgery, (3) presence of abnormal MR signal surrounding the tumor bulk, (4) pathological material from resected tumor. The patients received standard neoadjuvant chemotherapy. Using grid maps on gross pathology specimens, the abnormal MR areas around the tumor were matched with the corresponding grid sections. Histopathology slides of these sections were then analyzed to determine the nature of the regions of interest. The MR/pathological correlation was evaluated using Mann–Whitney U test and Fisher’s exact test. Results Twenty-seven patients had osteosarcoma and three patients had Ewing’s sarcoma. Of the studied areas, 17.4% were positive for tumor (viable or necrotic). There was no statistically significant correlation between areas positive for tumor and age, gender, signal extent and intensity on MRI, or tissue type. There was, however, a statistically significant correlation between presence of tumor and the appearance of abnormal soft tissue signals. A feathery appearance correlated with tumor-negative areas whereas a bulky appearance correlated with tumor-positive regions. Conclusions MR imaging is helpful in identifying the nature of abnormal signal areas surrounding bone sarcomas that are more likely to be tumor-free, particularly when the signal in the soft tissues surrounding the tumor is feathery and edema-like in appearance.
    Skeletal Radiology 01/2012; 41(11). · 1.74 Impact Factor
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    ABSTRACT: Male breast cancer (MaleBC) is a rare tumor that has been insufficiently described in the Middle East. The purpose of this study is to report the first MaleBC series in Lebanon, describing its clinicopathologic and immunohistochemical phenotype, and how it compares with MaleBC in the West and with female breast cancer in Lebanon and the Middle East. Forty-seven cases of MaleBC were reviewed. Results showed younger ages at presentation (62 years versus 67 years), higher incidence of lobular carcinoma (6% versus 1%), and more frequent p53 positivity and axillary node metastases in our series than in those reported about MaleBC. Other results such as higher estrogen receptor (ER) positivity and lower HER-2/neu over-expression were comparable to the literature. These findings suggest that MaleBC in our region may represent a biologically different tumor with potentially distinct prognostic and therapeutic implications.
    The Breast Journal 10/2011; 18(1):65-8. · 1.83 Impact Factor
  • Faysal A Fedda, Ayman N Tawil, Fouad I Boulos
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    ABSTRACT: Lipoblastic nerve sheath tumor is a recently described benign soft tissue tumor consisting of lipoblasts in a neural/schwannian background. The 6 reported cases have exclusively comprised signet ring lipoblasts and showed no cellular atypia. The authors describe the first lipoblastic nerve sheath tumor to harbor multivacuolated lipoblasts and degenerative atypia, underscoring its important differential diagnosis with well-differentiated liposarcoma. The purpose of this report is to expand the morphologic spectrum of this unusual neoplasm, and reemphasize the potential of benign nonadipocytic tumors to harbor multivacuolated lipoblasts and mimic liposarcoma.
    International Journal of Surgical Pathology 08/2011; 20(2):208-10. · 0.76 Impact Factor
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    ABSTRACT: Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm of follicular dendritic cells, most commonly affecting the lymph nodes and extranodal soft tissues of the head and neck, but also potentially arising in any visceral organ. FDCS with its diverse morphologies raises an occasionally challenging differential of primary and metastatic tumors with overlapping histologic and immunohistochemical features. When involving the head and neck, FDCS may be confused with squamous cell carcinoma, undifferentiated carcinoma, extracranial meningioma, and variants of papillary thyroid carcinoma. We describe here a case of FDCS showing nuclear grooves, intranuclear pseudoinclusions, diffuse epithelial membrane antigen and focal cytokeratin staining, and the first documented report of positivity for thyroid transcription factor-1. A discussion of the differential diagnosis and potential diagnostic pitfalls in FDCS brought forth by thyroid transcription factor-1 immunoreactivity and a full review of clinicopathologic and immunohistochemical features of head and neck FDCS are presented.
    Applied immunohistochemistry & molecular morphology: AIMM / official publication of the Society for Applied Immunohistochemistry 08/2011; · 1.63 Impact Factor
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    ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
    Current Orthopaedic Practice 04/2011; 22(3):272–275.
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    ABSTRACT: We report a jejuno-jejunal intussusception with a polypoid arteriovenous malformation as a lead point in a 12-year-old boy, presenting with lower abdominal pain and non-bloody non-projectile vomiting. A computed tomography scan of the abdomen and pelvis showed proximal jejuno-jejunal intussusception in the right upper quadrant. Exploratory laparotomy revealed a 5.5 × 2.5 × 2 cm polypoid mass within the wall of the jejunum. Consequently, jejunal segment resection was performed with end to end jejunostomy. Our case is distinctive because it involves a rare vascular lesion at an atypical site, the jejunum, in a child with an unusual presentation of intussusception treated surgically. Many paediatric benign and surgical conditions present with similar clinical symptoms; the physician in the emergency department should try to narrow the differential diagnosis and recognize surgical emergencies to avoid any delay in intervention that could be life-threatening.
    Acta Paediatrica 02/2011; 100(9):e141-4. · 1.97 Impact Factor
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    ABSTRACT: BACKGROUND.: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. METHODS.: We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<.25, .25-.49, .50-.74, .75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. RESULTS.: On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ≥.25. CONCLUSIONS.: Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.
    Indian journal of surgical oncology. 12/2010; 1(4):305-12.
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    ABSTRACT: Secondary malignancies and chronic end-organ sequelae are significant and steadily rising consequences of cancer therapy. The workup and management of a carcinoma of unknown primary must consider the patient's clinical presentation, radiologic and pathologic findings, and comorbidities. We present the case of a 50-year-old female survivor of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with significant treatment-related end-organ sequelae who developed a metastatic adenocarcinoma of unknown primary 15 years following curative therapy for her ALL. The complex management issues related to the investigations and choice of therapy for this patient are reviewed. This case discusses key issues related to the workup and management of a carcinoma of unknown primary. In addition, it illustrates the importance of taking patient comorbidities into consideration and tailoring investigations and therapy accordingly.
    Journal of Gastrointestinal Cancer 12/2010; 42(3):165-70.
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    ABSTRACT: We experienced unusual repeated ante-partum intra-abdominal bleedings in a woman with placenta percreta invading into the left broad ligament, in whom recombinant factor VIIa was effective for controlling severe retro-peritoneal bleeding. A 34-year-old multiparaous woman with two prior cesarean sections presented acute abdominal pain at 16 weeks of gestation. She also represented with abdominal pain at 22 weeks of gestation, and a diagnostic laparoscopy revealed hemoperitoneum, although we could not identify the exact source of bleeding. She also represented with abdominal pain without vaginal bleeding at 27 weeks of gestation, and an MRI revealed a hematoma in the lower abdomino-pelvic region and placenta percreta invading into the left broad ligament. A classical cesarean section followed by hysterectomy with partial cystectomy was performed at 32 weeks of gestation. Since the bleeding from the retro-peritoneum could not be controlled by the use of fresh frozen plasma, recombinant factor VIIa was administered, resulting in successful hemostasis.
    Journal of Obstetrics and Gynaecology Research 02/2010; 36(1):183-6. · 0.84 Impact Factor
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    ABSTRACT: Primary tracheal tumors are rare with the majority being malignant. Benign lesions are less frequent with primary tracheal schwannomas accounting for less than 0.5% of tracheal tumors. They are more common in females and their clinical presentation is non-specific. Chronic cough, progressive respiratory distress and even asthma-like conditions prevail as presenting symptoms and signs. Laryngotracheal endoscopy reveals a solitary, well encapsulated mass arising most often from the posterior tracheal wall. The diagnosis of tracheal schwannomas is primarily pathological. Endoscopic excision, sleeve excision or tracheal resection, are all commonly accepted treatment modalities. Proper awareness of these lesions is crucial in the pre-operative work-up of patients presenting with stridor.
    Middle East journal of anaesthesiology 02/2010; 20(4):611-3.
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    ABSTRACT: The status of the axillary lymph nodes in nonmetastatic lymph node-positive breast cancer (BC) patients remains the single most important determinant of overall survival (OS). Although the absolute number of nodes involved with cancer is important for prognosis, the role of the total number of excised nodes has received less emphasis. Thus, several studies have focused on the utility of the axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. However, most studies suffered from shortcomings, such as including patients who received neoadjuvant therapy or failing to consider the use of adjuvant therapy and tumor receptor status in their analysis. We conducted a single-center retrospective review of 669 patients with nonmetastatic lymph nodepositive BC. Data collected included patient demographics; breast cancer risk factors; tumor size, histopathological, receptor, and lymph node status; and treatment modalities used. Patients were subdivided into four groups according to ALNR value (<0.25, 0.25-0.49, 0.50-0.74, 0.75-1.00). Study parameters were compared at the univariate and multivariate levels for their effect on OS. On univariate analysis, both the absolute number of positive lymph nodes and the ALNR were significant predictors of OS. On multivariate analysis, only the ALNR remained an independent predictor of OS, with a 2.5-fold increased risk of dying at an ALNR of ⩾0.25. Our study demonstrates that ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes.
    Indian journal of surgical oncology. 01/2010; 1(1):68-75.
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    ABSTRACT: We investigated the role of zoledronic acid on the regenerate and native bone after consolidation and removal of the external fixator in a rabbit model of distraction osteogenesis using 28 New Zealand white rabbits. The rabbits were randomly distributed into two groups. The first group received three doses of zoledronic acid (ZA) 0.1 mg/kg subcutaneously at weekly intervals while the second group received injections of sterile saline. Distraction started on day 7 at a rate of 0.8 mm/day for 12 days. At week 3 the average lengthening, regenerate density, and regenerate continuity were comparable between the two groups. At week 11 the regenerate in the treated group had a significant increase in Bone Mineral Density (BMD) and Bone Mineral Content (BMC) compared to the placebo group. On axial compression, the regenerate showed an increase in the peak load and a higher modulus of elasticity in the treated group. At 6 months, radiographs demonstrated signs of osteopenia of the proximal metaphysis in the control group, and failure of new bone formation around the pin sites in the treated group. BMC and BMD value differences between the two groups were not statistically significant. Histologically, there was persistence of more bone trabeculae in the medullary canal of the regenerate with the persistence of the pin-holes in the treated group. Mechanically, the regenerates in the treated group remain stronger in resisting the axial compression. The proximal fragment in the treated group exhibited a statistically significant decrease in the peak load, toughness and efail %. In conclusion, bisphosphonate-treated rabbits have a stronger regenerate during distraction, and directly after removal of the fixator. They do not develop disuse osteopenia in their lengthened tibia. This treatment may shorten the time in the external fixator and prevent fragility fractures in the treated extremity. However, its long-term safety has not yet been established.
    Bone 10/2009; 46(2):363-8. · 3.82 Impact Factor
  • Gut 01/2009; 57(12):1681, 1737. · 10.73 Impact Factor

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