Rol patogénico del gen supresor de tumores PTEN en cáncer ovárico asociado a endometriosis / Pathogenic role of PTEN tumor suppressor gene in ovarian cancer associated to endometriosis

Background: Endometrioid carcinoma and clear cell carcinoma of the ovary are associated to endometriosis. Somatic mutations of PTEN (10q23.3) are present in endometrial endometrioid carcinoma. Therefore, these mutations could be also present in ovarian tumors. Molecular studies show that solitary endometriotic cysts are monoclonal, have aneuploid DNA, have a loss of 9p,11q and 22q heterozygosity (LOH) and a higher cellular proliferation index of the epithelial component. Aim: To determine the cellular proliferation index using Ki 67, the immunohistochemical expression of PTEN and LOH in patients with ovarian endometriosis without atypia (EN), ovarian endometriosis with atypia (EA) and endometriosis with adjacent ovarian carcinoma (ET). Material and methods: Paraffin embedded samples of 37 endometrioid and clear cell carcinomas of the ovary (CC/CE), 15 solitary ovarian EN and 15 ovarian EA, were studied. Expression of Ki 67 and PTEN was measured by immunohistochemistry. LOH of 10q23.3 locus was measured by polymerase chain reaction. Results: Ki 67 was 5.5 and 2.3% in EA and EN, respectively (p <0.005). There was a histological correlation between EA and a higher cellular proliferation index. PTEN was negative in 5 of 15 EN, 9 of 15 EA and 30 of 37 CE/CC. There was a correlation between LOH and loss of PTEN protein in EN, EA and ET (60%). Conclusions: Negative expression on PTEN in EN; EA; ET and CE/CC is a manifestation of the inactivation of this gene. The mechanisms that cause this inactivation, must be elucidated.

Cáncer colorrectal de presentación atípica / Atypical presentation of a colorectal carcinoma

We report a 67 years old male with a history of pulmonary tuberculosis at the age of 15, that consults for malaise, weight loss and productive cough. Chest X ray examination showed a left pleural effusion. A pleural tap obtained a sterile exudate. A thorax CAT scan showed a proliferating mass in the splenic angle of the colon, with left lung and diaphragmatic invasion. Endoscopic biopsies confirmed the diagnosis of adenocarcinoma. The patient underwent a subtotal colectomy with partial excision of diaphragm and left lung. The pathological report showed a mucosecretory adenocarcinoma, infiltrating the pericolonic adipose tissue without adjacent organ infiltration and a chronic inflammatory process involving colonic serosa, diaphragm pleura, and lung. Adjuvant chemotherapy was indicated and the patient is asymptomatic and without evidences of tumor recurrence after a 24 months follow up (Rev Méd Chile 2004; 132: 985-88).

Patología molecular del cáncer pulmonar y sus lesiones precursoras: parte II patología molecular de las lesiones precursoras del cáncer pulmonar / Molecular pathology of lung cancer and its precursor lesions: part II molecular pathology of lung cancer precursor lesions

Aunque se ha avanzado en forma importante en el conocimiento de las alteraciones genéticas en las lesiones que preceden el desarrollo del cáncer pulmonar, existe una gran cantidad de interrogantes por investigar. Aun cuando la aplicación de estos resultados al diagnóstico precoz de esta neoplasia y el control de individuos en riesgo de adquirirla son promisorios, no existen estudios con gran número de pacientes que permitan conocer en forma fehaciente el real significado clínico de estas alteraciones. Este es un campo de la investigación científica básica aplicada al campo clínico que concita gran interés en la actualidad y presenta una gran actividad. Por ello, es posible que en el futuro la utilización de marcadores moleculares sea un elemento complementario al estudio diagnóstico clínico y patológico convencional

Patología molecular: aplicaciones de la biología molecular en anatomía patológica / Molecular pathology: applications of molecular biological techniques in pathology

The rapid development of molecular biology techniques as well as recent progress in the understanding of genetic and molecular basis of human diseases have had enormous impact in the practice of clinical pathology. Since new diagnostic (molecular) tools are now available, the concept of Molecular Pathology is emerging. Molecular Pathology is defined by the use of molecular biology techniques and the type of specimens that are involved in its practice, basically ARN and ADN, extracted from cytological and tissue specimens. Although most methods used in molecular pathology and their applications are still under investigation and clinical validation they have great potential in several areas of pathological diagnosis, particularly on infectious and neoplastic diseases. Introduction of these techniques in pathology laboratories in our country should significantly enhance the diagnostic and research skills in the field

Patología molecular del cáncer pulmonar y sus lesiones precursoras: parte I, patología molecular del cáncer pulmonar / Molecular pathology of lung cancer and its precursor lesions: part I molecular pathology of lung cancer

En las últimas décadas se ha producido un gran avance en el conocimiento de las alteraciones moleculares que participan en la patogenia del cáncer pulmonar. Se ha determinado que esta neoplasia es el producto de un gran número de alteraciones genéticas (estimulando entre 10 y 20) que afectarían a oncogenes recesivos y a genes supresores de tumores. Además, se han establecido patrones de alteraciones genéticas en los diferentes tipos clínico-patológicos de cáncer pulmonar. Este conocimiento se ha aplicado al estudio de las alteraciones genéticas que participan en la progresión de las lesiones precursoras de esta neoplasia y al de sarrollo de métodos de detección precoz y control de pacientes con lesiones precursoras de cáncer pulmonar