RESUMEN
A 75-year-old man was admitted to our hospital because of unconsciousness. His plasma glucose was very low, but his serum levels of insulin and IGF-I were also low. He was found to have a giant solitary pleural tumor, which was completely resected, after which his hypoglycemia ameliorated postoperatively. Histologically, the tumor was consistent with the pathological diagnosis of a solitary fibrous tumor derived from the pleura. Immunohistochemical study revealed positive immunostaining for IGF-II in tumor cells. The presence of high molecular weight (HMW) form of IGF-II in the tumor tissue and patient's serum was confirmed by Western blot analysis. Steady-state mRNA levels of IGF-II and prohormone convertases (PC) 4, a potential protease responsible for IGF-II processing, as determined by RT-PCR were about 14-fold greater and 5-fold less in the tumor tissue than those in normal placental tissue, respectively. Therefore, it is suggested that biologically active, unprocessed HMW form of IGF-II generated from the impaired processing of IGF-II precursor by the defective PC4 expression in the tumor was responsible for the non-islet cell tumor hypoglycemia (NICTH) in the present case.
Asunto(s)
Hipoglucemia/etiología , Factor II del Crecimiento Similar a la Insulina/análisis , Proproteína Convertasas/genética , Tumor Fibroso Solitario Pleural/complicaciones , Tumor Fibroso Solitario Pleural/enzimología , Subtilisinas/genética , Anciano , Western Blotting , Expresión Génica , Humanos , Inmunohistoquímica , Insulina/sangre , Factor II del Crecimiento Similar a la Insulina/química , Factor II del Crecimiento Similar a la Insulina/genética , Masculino , Peso Molecular , Proproteína Convertasas/análisis , Proproteína Convertasas/metabolismo , Precursores de Proteínas/metabolismo , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tumor Fibroso Solitario Pleural/cirugía , Subtilisinas/análisis , Subtilisinas/metabolismoRESUMEN
The aim of this study was to analyze the diagnostic role of MMP-7 in effusion cytology. Effusions (n = 356), consisting of 307 carcinomas (184 ovarian, 55 breast, 32 lung, 36 carcinomas of other origin) and 49 malignant mesotheliomas, were analyzed for MMP-7 expression using immunohistochemistry. MMP-7 was expressed in 124/307 (40%) carcinomas and was uniformly absent in malignant mesotheliomas (0/49; 0%; P < .001). Reactive mesothelial cells were similarly MMP-7 negative in all carcinoma specimens. In carcinomas, expression was most frequent in tumors of ovarian and other female genital (cervical and endometrial) origin (P < .001). The sensitivity and specificity of this marker in the differential diagnosis between high-grade serous carcinoma and malignant mesothelioma were 46% and 100%, respectively. In conclusion, MMP-7 expression is highly specific, though only of moderate sensitivity, for the diagnosis of carcinoma in the differential diagnosis from both benign and malignant mesothelial cells.