Distribution of molecular subtypes of advanced lung adenocarcinoma and clinical outcomes in a center of Argentina.

The prevalence of relevant oncogenic drivers in lung adenocarcinoma varies in our region and data on clinical outcomes is scarce. The objective of the study was to describe the prevalence of KRAS, BRAF and EGFR mutations and ALK translocations in patients with advanced lung adenocarcinoma, and to depict the clinical outcome according to treatment strategies. Patients with adequate tumor biopsy sampling were included. KRAS, BRAF and EGFR mutations were studied by Sanger sequencing. ALK translocations were studied by fluorescent in situ hybridization (FISH) and immunohistochemistry (IH) with antibodies against ALK with clones D5F3 and 5A4. Informed consent was signed by 118 patients and 84 (72%) with complete molecular analysis were included. KRAS mutations were detected in 16 samples (19%), EGFR in 11 (13%), 9 of them conferring sensitivity to EGFR inhibitors, and BRAF mutations in 1 (1%). ALK translocations were detected in 3 samples (4%). Median follow-up was 42.4 [interquartile range (IQR): 27.0-64.2] months. Globally, median overall survival was 10.3 [IQR: 5.6-20.2] months. Median survival was 10.8 [IQR: 6.0-20.3] months in the group of patients without detectable molecular alteration, 9.6 [IQR: 3.7-16.1] months in KRAS mutant population (HR: 1.08; p = 0.82) and 32.5 [IQR: 19.6-38.4] months in patients with ALK translocations or sensitizing EGFR mutated tumors treated with tyrosine kinase inhibitors (HR: 0.27; p = 0.03). In conclusion, the prevalence of molecular alterations and outcomes in our population is similar to that reported in other studies in Western countries.

The pan-caspase inhibitor Emricasan (IDN-6556) decreases liver injury and fibrosis in a murine model of non-alcoholic steatohepatitis.

BACKGROUND & AIMS: Hepatocyte apoptosis, the hallmark of non-alcoholic steatohepatitis (NASH) contributes to liver injury and fibrosis. Although, both the intrinsic and extrinsic apoptotic pathways are involved in the pathogenesis of NASH, the final common step of apoptosis is executed by a family of cysteine-proteases termed caspases. Thus, our aim was to ascertain if administration of Emricasan, a pan-caspase inhibitor, ameliorates liver injury and fibrosis in a murine model of NASH. METHODS: C57/BL6J-mice were fed regular chow or high fat diet (HFD) for 20 weeks. All mice were treated with vehicle or Emricasan. RESULTS: Mice fed a HFD diet demonstrate a five-fold increase in hepatocyte apoptosis by the TUNEL assay and a 1.5-fold and 1.3-fold increase in caspase-3 and-8 activities respectively; this increase in apoptosis was substantially attenuated in mice fed a HFD treated with Emricasan (HFD-Em). Likewise, liver injury and inflammation were reduced in mice fed HFD-Em as compare to HFD by measuring serum aspartate aminotransferase and alanine aminotransferase levels, NAS histological score and IL 1-ß, TNF-α, monocyte chemoattractant protein (MCP-1) and C-X-C chemokine ligand-2 (CXCL2) quantitative reverse-transcription polymerase chain reaction (qPCR). These differences could not be attributed to differences in hepatic steatosis as liver triglycerides content were similar in both HFD groups. Hepatic fibrosis was reduced by Emricasan in HFD animals by decreasing αSMA (a marker for hepatic stellate cell activation), fibrosis score, Sirius red staining, hydroxyproline liver content and profibrogenic cytokines by qPCR. CONCLUSION: In conclusion, these data demonstrate that in a murine model of NASH, liver injury and fibrosis are suppressed by inhibiting hepatocytes apoptosis and suggests that Emricasan may be an attractive antifibrotic therapy in NASH.

Molecular pathology of acute kidney injury in a choline-deficient model and fish oil protective effect.

PURPOSE: The aim of this work was to investigate the potential protective effects of fish oil on the basis of kidney transcriptomic data on a nutritional experimental model. METHODS: Male weanling Wistar rats were divided into four groups and fed choline-deficient (CD) and choline-supplemented (CS) diets with vegetable oil (VO) and menhaden oil (MO): CSVO, CDVO, CSMO and CDMO. Animals were killed after receiving the diets for 6 days. Total RNA was purified from the right kidney and hybridized to Affymetrix GeneChip Rat Gene 1.0 ST Array. Differentially expressed genes were analyzed. RESULTS: All CSVO, CSMO and CDMO rats showed no renal alterations, while all CDVO rats showed renal cortical necrosis. A thorough analysis of the differential expression between groups CSMO and CDMO was carried out. There were no differential genes for p < 0.01. The analysis of the differential expression between groups CSVO and CSMO revealed 32 genes, 11 were over-expressed and 21 were under-expressed in CSMO rats. CONCLUSIONS: This work was part of a large set of experiments and was used in a hypothesis-generating manner. The comprehensive analysis of genetic expression allowed confirming that menhaden oil has a protective effect on this nutritional experimental model and identifying 32 genes that could be responsible for that protection, including Gstp1. These results reveal that gene changes could play a role in renal injury.

[Prolonged survival after local excision of a rectal leiomyosarcoma]. / Sobrevida prolongada luego de la resección local de un leiomiosarcoma de recto.

Leiomyosarcoma is a stromal tumor, originated from smooth muscle cells. The pathologic diagnosis represents a challenge in terms of differentiation from leiomyomas and gastrointestinal stromal tumors (GIST), defined by immunohistochemistry techniques. Its location in the rectum is extremely rare. So, management is not standardized. However, in the largest published series it was found that the abdominoperineal resection leads to better results in the prevention of local recurrence compared with local excision. We present here the case of a 44-year-old woman, whose first clinical manifestation of the disease was fever of prolonged course. A 5 cm leiomyosarcoma was diagnosed at 4 cm from the anal margin. A local transanal resection was performed. The patient is free of disease after 8 years.

[Clinical-pathological features and gene profile in colorectal cancer]. / Caracteres clínico-patológicos y perfil genético en el carcinoma colorrectal.

Colorectal cancer is the third most frequent cancer in men and the second most frequent in women, with a worldwide incidence of approximately 1.2 million new cases per year. Our primary objective was to study the relationship between clinical and histological features of individuals with colorectal cancer and the mutational status of codons 12 and 13 of the KRAS gene (7 validated mutations), in order to find a histopathological marker to mutated tumors. The secondary objective was to determine how many patients had additional mutations in codons 15 and 61 of the KRAS gene, and codon 600 of the BRAF gene, which could modify the tumor phenotype. Sixty individuals with colorectal cancer (30 wild-type subjects and 30 with validated mutations in codons 12 and 13 of the KRAS gene) were selected. Exons 2 and 3 of the KRAS gene, and exon 15 of the BRAF gene were amplified and sequenced. The data collected were reviewed by a descriptive, univariate and/or multivariate analysis, as appropriate. In conclusion, no relation was found between clinical and histological features of individuals with colorectal cancer and their mutational status for codons 12 and 13 of the KRAS gene. This suggests that those easily available data do not allow predicting the response to anti-EGFR therapy. In patients with advanced colorectal adenocarcinomas and KRAS wild-type status, further study of codon 600 of the BRAF gene could be required.

Icteric Variant of Stauffer Syndrome as a Paraneoplastic Manifestation of Type 1 Papillary Renal Cell Carcinoma.

Intrahepatic cholestasis as a paraneoplastic manifestation was first described by Dr. Maurice H. Stauffer in 1961. This paraneoplastic manifestation was primarily associated with renal cell carcinoma characterized by abnormal liver enzymes without hepatic metastasis. Stauffer syndrome is classified into 2 types: classical and jaundice variants. Indeed, the jaundice variant is extremely rare and only described in 13 published cases. We report a case of intrahepatic cholestasis associated with a type 1 papillary renal cell carcinoma with complete resolution after surgical treatment.

[Unexpected cause of tracheal obstruction: pleomorphic adenoma with lipometaplasia]. / Adenoma pleomorfo con lipometaplasia: inesperada causa de obstrucción traqueal.

Pleomorphic adenoma of the trachea is a benign tumor, extremely rare, that generates obstructive symptoms and sometimes is confused with asthma, which delays its diagnosis. We present the case of a 40-year-old woman with history of asthma and airway obstruction, of 8-months duration. Fibrobronchoscopy showed polypoid, pedunculated lesion in first tracheal ring which occluded 80% of the lumen, that was resected. The histopathological diagnosis was pleomorphic adenoma with lipometaplasia. Treatment of these tumors consists in complete resection of the lesion and long-term follow-up due to low probability of recurrence, malignancy and metastasis.

El adenoma pleomorfo de tráquea es un tumor benigno, infrecuente, que genera cuadros obstructivos, pudiendo confundirse con asma, lo que retrasa su diagnóstico. Presentamos el caso de una mujer de 40 años con antecedentes de asma y episodios de obstrucción respiratoria de 8 meses de evolución. La fibrobroncoscopía mostró una lesión polipoide, pediculada, en el primer anillo traqueal, con oclusión de 80% de la luz, que se resecó. El diagnóstico histopatológico fue adenoma pleomorfo con lipometaplasia. El tratamiento de estos tumores consiste en la resección completa de la lesión y seguimiento a largo plazo por la baja probabilidad de recurrencia, malignización y metástasis.

Clinical implementation of a cervical cancer screening program via co-testing at a university hospital.

The Human Papillomavirus (HPV) test is a crucial technology for cervical cancer prevention because it enables programs to identify women with high-risk HPV infection who are at risk of developing cervical cancer. Current U.S. Preventive Services Task Force recommendations include cervical cancer screening every three years with cervical cytology alone or every five years with either high-risk HPV testing alone or high-risk HPV testing combined with cytology (co-testing). In Argentina, 7,548 new cervical cancer cases are diagnosed each year with 3,932 deaths attributed to this cause. Our study aims to show the clinical implementation of a cervical cancer screening program by concurrent HPV testing and cervical cytology (co-testing); and to evaluate the possible cervical cancer screening scenarios for Latin America, focusing on their performance and average cost. A cervical cancer screening five year program via co-testing algorithm (Hybrid-2-Capture/cytology) was performed on women aged 30-65 years old at a university hospital. Statistical analysis included a multinomial logistic regression, and two cancer screening classification alternatives were tested (cytology-reflex and HPV-reflex). A total of 2,273 women were included, 91.11% of the participants were double-negative, 2.55% double-positive, 5.90% positive-Hybrid-2-Capture-/negative-cytology, and 0.44% negative-Hybrid-2-Capture/positive-cytology. A thorough follow-up was performed in the positive-Hybrid-2-Capture group. Despite our efforts, 21 (10.93%) were lost, mainly because of changes on their health insurance coverage which excluded them from our screening algorithm. Of the 171 women with positive-Hybrid-2-Capture results and follow-up, 68 (39.77%) cleared the virus infection, 64 (37.43%) showed viral persistence, and 39 (22.81%) were adequately treated after detection via colposcopy/biopsy of histological HSIL (High-Grade Squamous Intraepithelial Lesion). The prevalence of high-risk HPV in this population was 192 women (8.45%), with HSIL histology detection rates of 17 per 1,000 screened women. A multinomial logistic regression analysis was performed over the women with positive-Hybrid-2-Capture considering the follow up (clearance, persistence and HSIL) as dependent variable, and the cytology test results (positive- or negative-cytology and Atypical Squamous Cells of Undetermined Significance, ASC-US) as independent variable. The model supported a direct association between cytology test results and follow up: negative-cytology/clearance, ASC-US/persistence, and positive-cytology/HSIL with the following probabilities of occurrence for these pairs 0.5, 0.647 and 0.647, respectively. Cytology could be considered a prognostic-factor in women with a positive-Hybrid-2-Capture. These findings suggest that the introduction of co-testing could diminish the burden of cervical cancer in low-and middle-income-countries, acting as a tool against inequity in healthcare.

Diagnosis of an adenocarcinoma of Müllerian origin made as a result of its metastasis in the mouth floor.

Metastases derived from primary tumours distant to the oral and maxillofacial region account for only 1% of all malignancies at that location, usually with a poor prognosis. In women, the primary tumours that most frequently metastasise to the oral cavity are breast adenocarcinomas affecting the jawbones and soft tissues (41% and 24%, respectively), followed by adrenal glands and female genital organs to the jawbones (8%), and female genital organs to the soft tissues (15%). Metastatic tumours of the mouth are a challenging diagnosis because of their exceptional occurrence. We report on the case of an 83-year-old woman who consulted for a bleeding ulcerated tumour on the floor of the mouth. A biopsy-confirmed metastasis of an adenocarcinoma of Müllerian origin. The oral lesion was the first sign of undetected cancer. The patient agreed to surgical resection and was further referred to palliative care for her symptoms.

Menetrier's disease. A diagnostic and therapeutic challenge.

We present a rare case of hypertrophic gastropathy associated with protein loss. A 35-year-old man was hospitalized for bowel habit changes, abdominal pain, generalized edema and symptomatic anemia. Pertinent laboratory findings included iron deficiency anemia (Hb 6.7g/dl, ferritin 5 ng/ml) and marked hypoalbuminemia (albumin 2.5 g/dl). Endoscopic biopsy samples of giant gastric folds observed along the greater gastric curvature revealed foveolar hyperplasia and significant parietal cell loss. Endoscopic ultrasonography showed gastric parietal thickening with preserved architecture and normal gastric wall layers. Menetrier disease was diagnosed and the patient treated with cetuximab, a monoclonal antibody that inhibits ligand binding of transforming growth factor alpha (TGFa), preventing gastric mucosa cell proliferation. After twelve months of treatment, the patient referred symptoms improvement, and gastric biopsy levels of the proliferation marker protein Ki-67 had decreased.

Presentamos un caso infrecuente de gastropatía hipertrófica asociada a pérdida de proteínas. Un hombre de 35 años fue hospitalizado por cambios en los hábitos intestinales, dolor abdominal, edema generalizado y anemia sintomática. Los hallazgos de laboratorio pertinentes incluyeron anemia ferropénica (Hb 6.7 g/dl, ferritina 5 ng/ml) e hipoalbuminemia marcada (albúmina 2.5 g/dl). Las muestras de biopsia endoscópica de pliegues gástricos gigantes observados a lo largo de la curvatura mayor gástrica revelaron hiperplasia foveolar y pérdida significativa de células parietales. La ecografía endoscópica mostró engrosamiento parietal gástrico con arquitectura conservada y capas de pared gástrica normales. Se diagnosticó enfermedad de Menetrier y se trató al paciente con cetuximab, un anticuerpo monoclonal que inhibe la unión del ligando del factor de crecimiento transformante alfa (TGFa), evitando la proliferación de células de la mucosa gástrica. Después de doce meses de tratamiento, el paciente refirió mejoría de los síntomas y los niveles de la proteína marcadora de proliferación Ki-67 en biopsia gástrica habían disminuido.

Bezafibrate therapy in primary biliary cholangitis refractory to ursodeoxycholic acid: a longitudinal study of paired liver biopsies at 5 years of follow up.

BACKGROUND: Ursodeoxycholic acid (UDCA) is the first-line therapy for primary biliary cholangitis (PBC). However, nearly 40% of patients have an incomplete response to UDCA. The addition of bezafibrate has shown biochemical benefit in this group of patients. AIM: To evaluate the long-term effects of UDCA in combination with bezafibrate on histological outcomes in patients with UDCA-refractory PBC. METHODS: Fifty-nine patients refractory to UDCA were included. Clinical parameters were monitored and paired liver biopsy (PLB) was performed after 5 years of follow-up. RESULTS: Of the total cohort, 49 subjects were analysed and 31 had PLB at 5 years. Values for serum ALP, AST, ALT and GGT significantly improved with UDCA-bezafibrate. This beneficial effect was observed at 12 months where 86% achieved ALP at normal levels. Analyses of PLB showed a significant decrease in liver damage as reflected by Ludwig (baseline 2.29 ± 1.2, to 1.84 ± 1 at year 5, P = 0.0242) and Ishak (baseline 6.19 ± 2.2 to 4.77 ± 2.2 at year 5, P = 0.0008) scores. Overall, regression of fibrosis was attained in 48% of patients. Furthermore, we observed a significant reduction in the proportion with cirrhosis from 19% at baseline to 3% at 5 years (P < 0.001). These beneficial effects were associated with better predictive risk scores using the GLOBE and UK-PBC prognosis models. CONCLUSIONS: Adding bezafibrate to UDCA in patients with UDCA-refractory PBC showed a significant decrease in fibrosis and inflammatory histological scores at 5 years. These beneficial effects warrant further evaluation in long-term cohort studies and controlled trials.

Correlation between PD-L1 expression (clones 28-8 and SP263) and histopathology in lung adenocarcinoma.

Lung cancer is the leading cause of cancer-related death worldwide. Recent advances in the management of non-small cell carcinoma are focused on the discovery of targeted therapies and novel immunotherapy strategies for patients with advanced disease. Treatment with anti PD-(L)1 immune checkpoint inhibitors requires the development of predictive biomarkers to select those patients that can most benefit from these therapies. Several immunohistochemical biomarkers have been developed in different technological platforms. However, the most useful and accessible for the daily clinical practice need to be selected. The objective of this study was to compare PD-L1 expression by automated immunohistochemistry in lung adenocarcinoma (ADC) FFPE samples with clones 28-8 and SP263 performed with the BenchMark GX automated staining instrument. To further determine interobserver agreement between two pathologists, and to correlate the results with histologic and pathology variables. FFPE tissue from 40 samples obtained from patients with lung ADC were reviewed retrospectively. Among all studied specimens, 53% of samples presented <1% of positive tumor cells with the 28-8 clone and 50% had <1% of PD-L1 expression in tumor cells with the SP263 clone; PD-L1 expression between ≥1 and <5% was observed in 18% and 24%; ≥5 and <50% PD-L1 expression in 18% and 21%; and ≥50% PD-L1 expression in 11% and 5% of samples, respectively. Similar results between antibodies were observed in 84% of cases for each of the four PD-L1 cutoff groups (Pearson's score 0.90, p < 0.00001). The interobserver degree of agreement calculated with Kappa was 0.75 (95%CI: 0.57-0.93), z = 7.08; p < 0.001. Lepidic, acinar and mucinous patterns had predominantly <1% PD-L1 expression, and the solid pattern subtype had high levels of PD-L1 staining using both clones. PD-L1 expression in less than 1% of tumor cells was similar in stages I/II compared to III/IV. No significant differences were observed in PD-L1 staining and quantification pattern between IHC antibodies 28-8 and SP263.

[Mutational status of BRAF and histopathological characteristics in cutaneous malignant melanoma]. / Estado mutacional de BRAF y parámetros histopatológicos en melanoma maligno cutáneo.

Malignant melanoma (MM) is the more aggressive form of skin cancer with a mortality rate in Argentina 1997-2001 = 1.1/100 000 in men and 0.6 in women. BRAF proto-oncogene is focus of intense research; its mutation is one of the main tumor promoters and occurs in approximately 50% of MM. Several drugs with clinical activity on BRAF mutations have been approved. The aim of the study is to evaluate the mutational status of BRAF (exon 15) in cutaneous MM biopsies and its relationship with histopathological characteristics. We carried out an observational, retrospective study of samples fixed in formaldehyde and paraffin embedded; reviewing age, sex, diagnosis, histopathological data, tumor size and percentage, viability for molecular analysis and melanin presence. We evaluated BRAF mutations with PCR/Sanger sequencing. For statistics we used Student's t test, Chi square, Wilcoxon and Fisher's exact test. We were able to purify and sequence 76% (38/49) samples, 13/38 (34%) from women and 25/38 (66%) from men, the median age being 70 years. Most frequent location: thorax 14/35 (40%). Histological type: Superficial spreading 18/38 (47%). Clark's levels, 11/38 (29%): I-II and 27/38 (71%): III, IV and V. Breslow's median: 1.6 mm. Radial growth phase 11/38 (29%) and 27/38 (71%) vertical. Presented mutations 16/38 (42%). As reported by other authors, no association was found between the mutational state of exon 15 and clinical or histopathological parameters.

El melanoma maligno es la forma más agresiva de cáncer de piel, con una tasa de mortalidad en Argentina 1997-2001 = 1.1/100 000 en varones y 0.6 en mujeres. El proto-oncogén BRAF es foco de intensa investigación, su mutación es uno de los principales promotores tumorales y pueden presentarse en 50% de los melanomas. Se han aprobado varios fármacos con actividad clínica sobre las mutaciones BRAF. El objetivo del trabajo es evaluar el estado mutacional de BRAF (exón 15) en biopsias con melanoma maligno cutáneo y su relación con las características histopatológicas. Realizamos un estudio observacional, retrospectivo, de muestras fijadas en formol e incluidas en parafina. Revisamos edad, sexo, diagnóstico y datos histopatológicos, tamaño y porcentaje tumoral, viabilidad para análisis molecular y presencia de melanina. Evaluamos mutaciones de BRAF con PCR/secuenciación Sanger. Utilizamos test de Student, Chi cuadrado, Wilcoxon y prueba exacta de Fisher. De 49 casos se pudo purificar y secuenciar el 76% (38/49), 13/38 (34%) mujeres y 25/38 (66%) varones, edad mediana 70 años. Localización más frecuente: tórax con 14/35 (40%). Tipo histológico: extensivo superficial 18/38 (47%). Niveles de Clark, 11/38 (29%): I-II y 27/38 (71%): III, IV y V. Mediana del Breslow: 1.6 mm. Fase de crecimiento radial 11/38 (29%) y 27/38 (71%) vertical. Presentaron mutaciones 16/38 (42%). Como lo informado por otros autores, no se encontró asociación entre el estado mutacional del exón 15 y los parámetros clínicos o histopatológicos.

Clinical and Economic Value of p16INK4a for the Differential Diagnosis of Morphologic Cervical Intraepithelial Neoplasia 2.

The detection of high-grade intraepithelial lesions requires highly sensitive and specific methods that allow more accurate diagnoses. This contributes to a proper management of preneoplastic lesions, thus avoiding overtreatment. The purpose of this study was to analyze the value of immunostaining for p16 in the morphologic assessment of cervical intraepithelial neoplasia 2 lesions, to help differentiate between low-grade (p16-negative) and high-grade (p16-positive) squamous intraepithelial lesions. The direct medical cost of the treatment of cervical intraepithelial neoplasia 2 morphologic lesions was estimated. A retrospective observational cross-sectional study was carried out. This study analyzed 46 patients treated with excisional procedures because of cervical intraepithelial neoplasia 2 lesions, using loop electrosurgical excision procedures. Immunostaining for the biomarker was performed. For the estimation of overtreatment, percentages (%) and their 95% confidence interval were calculated. Of the 41 patients analyzed, 32 (78%) showed overexpression of p16 and 9 (22%) were negative (95% confidence interval, 11%-38%). Mean follow-up was 2.9 years, using cervical cytology testing (Pap) and colposcopy. High-risk human papillomavirus DNA tests were performed in 83% of patients. These retrospective results reveal the need for larger biopsy samples, which would allow a more accurate prediction of lesion risk. Considering the cost of p16 staining, and assuming the proper management of the low-grade lesion, an average of US$919 could be saved for each patient with a p16-negative result, which represents a global direct cost reduction of 10%.

[Flow cytometry for the study of mediastinal tumors with abundant lymphoid elements]. / La citometría de flujo en el estudio de tumores mediastinales ricos en elementos linfoides.

The anterior mediastinum is a common site of tumors with abundant lymphoid elements. Flow cytometry is a useful complementary technique to analyze this type of tumors, which provides qualitative and quantitative information. A differential diagnosis can be sometimes made between thymoma and precursor T-lymphoblastic lymphoma (T-LBL). Correct identification is of utmost importance for patient treatment. A total of 38 mediastinal tumors were analyzed, and samples were separated for flow cytometry. Flow cytometry data from thymomas and normal thymic tissue were compared with 42 cases of T-LBL from other anatomical locations. Among 38 mediastinal tumors, we found 6 benign lesions, 9 diffuse large B-cell lymphomas (DLBCL), 10 Hodgkin lymphomas (HL), 11 thymomas and 2 T-LL. Flow cytometry provided positive information in 24 cases, and defined lymphoid neoplastic cells immunophenotype or the typical lymphocytes accompanying thymomas. Flow cytometry helped differentiate 10 cases of HL and 4 benign lesions from other lymphomas (DLBCL, T-LBL, etc.). CD3, CD4 and CD8 expressions were most useful for the differential diagnosis of thymomas and T-LL. To conclude, flow cytometry is a valid complementary technique, which promptly provides information on mediastinal lesions, requiring small quantities of tissue for both early diagnosis and follow up of these diseases.

Performance Assessment of Epidermal Growth Factor Receptor Gene Sequencing According to Sample Size in Daily Practice Conditions.

Lung carcinoma is the main cause of cancer death worldwide. Adenocarcinoma molecular biomarkers have been discovered, and targeted therapies have been developed with encouraging results. The epidermal growth factor receptor gene is one of these biomarkers. Exons 18 to 21 should be studied in patients with advanced adenocarcinoma, who are candidates for treatment with tyrosine kinase inhibitors. The objective was to compare the performance of the determination in large and small samples in daily practice conditions, trying to adjust to published consensus guidelines. A retrospective observational study of 141 cases was carried out, with exons 19 and 21 sequencing. Sample size (small vs. large), including number of satisfactory polymerase chain reaction (PCR), sequencing, deletions, and mutations, were evaluated. In small biopsies, sample type, fragment number, and percentage of tumor per sample were analyzed. The results shown 114/141 (80.8) cases that met selection criteria; 60/114 (53%) were large (surgical) and 54/114 (47%) were small samples (19/54 endoscopic, 17/54 fine needle aspiration clots, 4/54 lymph nodes, 14/54 core and other). All large samples were satisfactory PCR, 56/60 (93%) satisfactory sequencing, and 12/56 (21%) had deletions in exon 19. Small samples were satisfactory PCRs in 50/54 (93%) cases, and satisfactory sequencing in 35/50 (65%), 8/35 (23%) showed alterations in exon 19, and 1/35 (3%) in exon 21. In conclusion, the proportion of samples unfit for the study of the epidermal growth factor receptor gene mutational status increased from 7% in large samples to 35% in small ones. Nineteen small samples were inconclusive, with cell blocks predominating, 10/19 (53%).

Importance of a Rapid and Accurate Diagnosis in Strongyloides Stercoralis and Human T-Lymphotropic Virus 1 Co-infection: A Case Report and Review of the Literature.

Strongyloides (S.) stercoralis and Human T-Lymphotropic Virus 1 (HTLV-1) share some endemic regions such as Japan, Jamaica, and South America and are mostly diagnosed elsewhere in immigrants from endemic areas. This co-infection has not been documented in Argentina although both pathogens are endemic in the Northwest. We present a case of S. stercoralis and HTLV-1 co-infection with an initial presentation due to gastrointestinal symptoms which presented neither eosinophilia nor the presence of larvae in stool samples in a non-endemic area for these infections. A young Peruvian woman living in Buenos Aires attended several emergency rooms and finally ended up admitted in a gastroenterology ward due to incoercible vomiting, diarrhea, abdominal pain, fever, and weight loss. Gastrointestinal symptoms started 3 months before she returned to Argentina from a trip to Peru. She presented malnutrition and abdominal distension parameters. HIV-1 and other immunodeficiencies were discarded. The serial coproparasitological test was negative. Computed tomography showed diffuse thickening of duodenal and jejunal walls. At the beginning, vasculitis was suspected and corticosteroid therapy was initiated. The patient worsened rapidly. Skin, new enteral biopsies, and a new set of coproparasitological samples revealed S. stercoralis. Then, HTLV-1 was suspected and infection was confirmed. Ivermectin and albendazole were administrated, until the stool sample remained negative for 2 weeks. Larvae were not observed in fresh stool, Ritchie method, and agar culture 1 week post-treatment. Although she required initial support with parenteral nutrition due to oral intolerance she slowly progressed favorably. It has been highly recommended to include a rapid and sensitive PCR strategy in the algorithm to confirm Strongyloides infection, which has demonstrated to improve early diagnosis in patients at-risk of disseminated strongyloidiasis.