title: [Grading of neuroendocrine tumors].
abstract: The current WHO classification of neuroendocrine tumors (NET) differentiates between typical carcinoids (low grade NET), atypical carcinoids (intermediate grade NET) and small cell and large cell carcinomas (high grade NET) according to the prognosis. Neuroendocrine neoplasms (NEN) of the gastrointestinal tract and the pancreas are graded in an identical way. Together with the TNM system this enables a preoperative estimation of the prognosis in biopsies and fine needle aspirates. Well-differentiated tumors are graded into G1 tumors by the number of mitoses, <2 per 10 high-power fields (HPF) and the Ki-67 (index <3 %) and G2 tumors (2-20 mitoses/10 HPF, Ki-67 3-20 %). Discrepancies between the number of mitoses and the Ki-67 index are not uncommon and in these cases the higher value of the two should be applied. The more differentiated tumors of the G3 type have to be differentiated from undifferentiated carcinomas of the small cell type and large cell type with a much poorer prognosis. Prognosis relevant grading of thyroid cancers is achieved by special subtyping so that the G1-G3 system is not applicable. The rare cancers of the parathyroid gland and of the pituitary gland are not graded. Adrenal tumors also have no grading system. The prognosis is dependent on the Ki-67 index and with some reservations on the established scoring systems.
authors.affiliation: Institute für Pathologie und Neuropathologie der Universität Hamburg, UKE, Martinistraße 52, 20246, Hamburg, Deutschland. w.saeger@uke.de.
authors.forename: W
authors.initials: W
authors.lastname: Saeger
authors.affiliation: Institut für Allgemeine und Spezielle Pathologie der Universität des Saarlandes, Homburg/Saar, Deutschland.
authors.forename: P A
authors.initials: PA
authors.lastname: Schnabel
authors.affiliation: Institut für Pathologie am Stadtspital Triemli, Zürich, Schweiz.
authors.forename: P
authors.initials: P
authors.lastname: Komminoth
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D014408:Biomarkers, Tumor / Q000032:analysis; D049109:Cell Proliferation / Q000502:physiology; D005770:Gastrointestinal Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008175:Lung Neoplasms / Q000145:classification / Q000473:pathology* / Q000628:therapy; D008940:Mitotic Index; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000145:classification / Q000473:pathology* / Q000628:therapy; D010190:Pancreatic Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D010282:Parathyroid Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D010911:Pituitary Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D013953:Thymus Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D013964:Thyroid Neoplasms / Q000145:classification / Q000473:pathology / Q000628:therapy; D014944:World Health Organization
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen
keywords: Adrenal gland; Gastrointestinal tract; Lungs; Pancreas; Thyroid gland