[Endocrine and neuroendocrine tumors].

Endocrine tumors and here in particular gastrointestinal neuroendocrine neoplasms (GEP-NET), pheochromocytomas (PC), paragangliomas (PGL) and thyroid tumors are prime examples of the importance of molecular pathology and molecular biology for the diagnostics, classification and ultimately also the (surgical) treatment of these diseases. The GEP-NETs are graded using the Ki-67 index. This determines the type of molecular imaging (DOTA/DOPA/FDG-PET/CT), the possible treatment (surgical and/or radiopeptide therapy), antiproliferative and symptom-controlling treatment with somatostatin analogues and ultimately also the prognosis. The PC/PGLs can be hereditary (MEN2A, VHL, NF1, SDH mutations), which significantly influences the surgical treatment and preoperative medication. Molecular imaging is very important and can lead the way in cases of borderline biochemistry. Adrenal carcinomas can also be genetically determined. In the case of thyroid tumors, the pathology of the C‑cell (C-cell hyperplasia, medullary thyroid carcinoma) should be emphasized. In the case of hereditary diseases (FMTC, MEN2), early prophylactic surgery is often necessary and prevents the occurrence of advanced carcinomas; however, the determination of the extent of resection in follicular lesions or the distinction between noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and follicular variants of papillary thyroid carcinoma can also be determined with the help of specific markers. Overall, molecular pathology has an increasingly more important role in these entities and is also the topic of ongoing research projects.