RESUMO
The aim of the present study was to investigate ECLomas and enterochromaffin-like (ECL) cell hyperplasia in gastric human mucosa regarding the immunohistochemical expression of chromogranin A (CgA) epitopes and to measure the same CgA epitopes in plasma samples. Eight gastric biopsies from ECLomas, seven of type I and one of type III, and biopsies from one patient showing only ECL cell hyperplasia were included in the study. Our results revealed a varying expression of region-specific CgA epitopes in the ECLomas regarding both the frequency of immunoreactive cells and intensity of immunoreactivity. CgA284-301 (pancreastatin) was not revealed in any neoplasm, whereas CgA361-372 (catestatin) was expressed in all ECLomas. However, the number of immunoreactive cells to vesicular monoamino transporter 2 (VMAT 2) or the commercial monoclonal CgA (CgA250-284) antibodies were generally higher. The plasma concentrations of the region-specific CgA radioimmunoassays differed considerably, with highest concentrations of CgA1-17 and CgA116-130 epitopes and the lowest with the CgA17-37, CgA63-76, CgA238-247 and CgA441-424 epitopes. No relationship was found between tissue expression and plasma concentration of CgA epitopes. In conclusion, this study shows that VMAT 2 and the commercial CgA antibodies seem more useful for histopathological diagnosis of ECLomas than the antibodies to the other CgA regions.
Assuntos
Biomarcadores Tumorais/sangue , Cromogranina A/sangue , Tumores Neuroendócrinos/patologia , Neoplasias Gástricas/patologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/imunologia , Cromogranina A/imunologia , Celulas Tipo Enterocromafim/metabolismo , Celulas Tipo Enterocromafim/patologia , Epitopos/imunologia , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Neoplasias Gástricas/sangue , Proteínas Vesiculares de Transporte de Monoamina/sangue , Proteínas Vesiculares de Transporte de Monoamina/imunologiaRESUMO
Gastrinomas of the stomach are extremely rare endocrine tumors producing Zollinger-Ellison syndrome. We report here the case of a patient with gastrinoma of the stomach who presented regional and hepatic metastases at the time of diagnosis. The endocrine tumor was discovered incidentally 8 yr after the onset of symptoms related to peptic ulcer, which responded to medical treatment with a proton pump inhibitor. Surgery did not cure the patient, as demonstrated by provocative tests showing serum gastrin responses indicative of residual disease. A long-term treatment with the somatostatin analog lanreotide induced a biochemical response and was associated with a substantially stable disease.