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.

Possibilities of a cytological method in the diagnosis of small cell lung cancer

“…вклейке). В большинстве случаев (около 40%) на образце малой биопсии из-за недостаточного количества материала недооценивается пролиферативная активность опухоли [10][11][12][13][14].…”

“…При комбинированном МРЛ компонент немелкоклеточного рака составляет не менее 10% объема опухолевого узла. По данным литературы [13], комбинированный МРЛ составляет 10-28% наблюдений: сочетание с крупноклеточным раком -16%, аденокарциномой -9% и плоско-клеточной карциномой -3%. Морфологи не всегда отмечают комбинированный характер опухоли.…”

Quantitative 3D Assessment of 68Ga-DOTATOC PET/MRI with Diffusion-Weighted Imaging to Assess Imaging Markers for Gastroenteropancreatic Neuroendocrine Tumors: Preliminary Results

“…According to the World Health Organization classification, NETs are divided into grade 1 (#2% Ki-67 index), grade 2 (3%-20% Ki-67 index), and grade 3 tumors (.20% Ki-67 index), depending on their proliferative activity (2). The 5-y survival rates for grade 1 tumors are estimated to be 89%, compared with 70% for grade 2 tumors and less than 57% for grade 3 (3), making tumor grading a valuable tool for prognostic assessment.…”