Intestinal carcinoids are potentially malignant neoplasms. Their histogenesis and pathogenesis are currently uncertain. The morphological and histochemical characteristics of twenty intestinal carcinoids are studied. The primary sites of three mucin-producing tumors were examined by electron microscope. Furthermore 11 appendiceal carcinoids were analysed by the polymerase chain reaction (PCR) for the detection of ras and p53 point mutations. Microscopically all carcinoids were of mixed type. Focal mucin production was evident in three carcinoids that metastasised to regional lymph nodes. HID-Alcian blue staining proved that mucin in both primary and secondary foci did not belong to the sulphated group. The secretory granules and mucin droplets found in a single neoplastic cell suggest that carcinoids of the small intestine and some of the appendix arise from the endoderm. Neither ras nor p53 mutations were detected. It seems that ras oncogenes are probably not involved in the pathogenesis of appendiceal carcinoids.
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http://dx.doi.org/10.1053/paor.1999.0193 | DOI Listing |
Oncologist
January 2025
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, United States.
Objectives: Well-differentiated neuroendocrine tumors (NET) are highly vascular tumors characterized by their expression of vascular endothelial growth factor (VEGF). This trial investigated the activity of ramucirumab, a monoclonal antibody that targets VEGF receptor-2 (VEGFR-2) and inhibits activity of VEGF, in combination with somatostatin analog therapy in patients (pts) with advanced extra-pancreatic NET.
Methods: We conducted a single-arm phase II trial enrolling pts with advanced, progressive extra-pancreatic NET.
Adv Anat Pathol
November 2024
Department of Radiology, School of Medical Sciences, State University of Campinas (Unicamp), Campinas, Brazil.
Horseshoe kidney is a rare congenital anomaly with an unusually higher frequency of neuroendocrine tumors. Symptoms are rare, and, in most of the cases, are incidentally diagnosed. The clinical behavior of these tumors is heterogeneous and can be difficult to predict based on histology alone.
View Article and Find Full Text PDFSmall intestine neuroendocrine tumours (SI-NETs) are often diagnosed late with a UK median of 3 years and high misdiagnosis rates. Previous studies, largely based on patient surveys, offer little data on improving diagnosis. In 2017, the South Wales NET service underwent a nationally commissioned, systematic transformation, aiming to improve diagnosis through the development of a gastroenterology and surgical referral network, and education of these specialities.
View Article and Find Full Text PDFGastroenterology
February 2025
Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Palo Alto, California.
Description: Gastric cancer (GC) is a leading cause of preventable cancer and mortality in certain US populations. The most impactful way to reduce GC mortality is via primary prevention, namely Helicobacter pylori eradication, and secondary prevention, namely endoscopic screening and surveillance of precancerous conditions, such as gastric intestinal metaplasia (GIM). An emerging body of evidence supports the possible impact of these strategies on GC incidence and mortality in identifiable high-risk populations in the United States.
View Article and Find Full Text PDFJ Cancer Res Ther
December 2024
Department of Pathology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
Mature cystic teratoma (MCT) is the most common germ cell tumor of the ovary, comprising 20% of all ovarian neoplasms. Malignant transformation (MT) is an uncommon complication and occurs in approximately 1-3% of all MCTs. The most common histological type of MT is squamous cell carcinoma.
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