Positive predictive value of the immunoassay for Clostridium difficile toxin A and B detection at a private hospital. / Valor predictivo positivo de la prueba de inmunoanálisis para detección de toxina A y B de Clostridium difficile en un hospital privado.

INTRODUCTION: Clostridium difficile (C. difficile) is a Gram-positive bacillus that is a common cause of diarrhea in the hospital environment, with a documented incidence of up to 10%. There are different methods to detect it, but a widely used test in our environment is the immunoassay for toxins A and B. AIMS: The aim of our study was to 1) estimate the positive predictive value of the immunoassay for the detection of the C. difficile toxins A and B, 2) to establish the incidence of C. difficile-associated diarrhea in the hospital, and 3) to know the most common associated factors. METHODS: A diagnostic test accuracy study was conducted within the time frame of January 2010 to August 2013 at the Hospital Christus Muguerza® Alta Especialidad on patients with symptoms suggestive of C. difficile-associated diarrhea that had a positive immunoassay test and confirmation of C. difficile through colon biopsy and stool culture. RESULTS: The immunoassay for toxins A and B was performed in 360 patients. Fifty-five of the cases had positive results, 35 of which showed the presence of C. difficile. Incidence was 10.2% and the positive predictive value of the test for C. difficile toxins A and B was 0.64 (95% CI, 0.51-0.76). Previous antibiotic therapy (n=29) and proton pump inhibitor use (n=19) were the most common associated factors. CONCLUSIONS: C. difficile incidence in our environment is similar to that found in the literature reviewed, but the positive predictive value of the test for toxin A and B detection was low.

Carcinoma de células pequeñas en la unión gastroesofágica / Gastroesophageal junction small cell carcinoma

Resumen Los tumores de células pequeñas extrapulmonares pueden aparecer en múltiples órganos y forman una rara afección clínico-patológica de tumores neuroendocrinos, con gran proliferación epitelial y con comportamiento biológico agresivo. El tubo gastrointestinal es la fuente más común de tumores de células pequeñas extrapulmonares. Nuestro caso clínico describe un paciente con carcinoma de células pequeñas en la unión gastroesofágica, que fue diagnosticado en el contexto de sangrado de tubo digestivo alto. Se excluyó un tumor pulmonar primario; el paciente recibió quimioterapia, quimiorradioterapia y radioterapia cerebral profiláctica, con buena evolución clínica. Nuestro caso se trata de una rara afección clínica, lo que evidencia la importancia de diagnosticar enferemedades poco frecuentes. Existe poca evidencia en la bibliografía de cómo deben tratarse estos pacientes.

Abstract Extrapulmonary small cell carcinomas (EPSCC) can arise in multiple organ sites and form a rare clinicopathological entity of high proliferative epithelial neuroendocrine tumors with aggressive biological behavior. Gastrointestinal is the most common source of EPSCC. We report a case of gastroesophageal junction small cell carcinoma, which was diagnosed in the context of upper gastrointestinal bleeding. A primary small cell lung carcinoma was excluded. Chemotherapy, neoadjuvant chemoradiotherapy and prophylactic cranial radiotherapy were given, with good clinical outcome. Our case of a very rare condition highlights the importance of recognizing atypical pathologic diagnoses. More research needs to be conducted with EPSCC patients in order to better characterize disease pathogenesis, and an optimal disease management.