Introduction of atypical carcinoid

Introduction of atypical carcinoid, atypical carcinoid is a carcinoid tumor, an intermediate grade neuroendocrine tumors. The biological behavior and prognosis between type of carcinoid tumors and SCLC. The main histological features are: cell nuclear sub 2-10 110HPF, with or without necrosis, the necrosis is often spotty. Atypical carcinoid has some atypia.
Introduction of atypical carcinoid, atypical carcinoid than typical carcinoid rare. The clinical manifestations of atypical and typical carcinoid carcinoid similar, can be divided into central (hilar type) and peripheral type.
(1) general pathological features: atypical carcinoid tumor generally higher, with an average diameter; slice white, but often seen spotty necrosis, no capsule, and cleared with the surrounding lung tissue.
(2) histological features: microscopic cancer was the same endocrine tumor structure. Carcinoma official samples, cords, ribbons and other neuroendocrine-like differentiation of the tumor blood vessel characteristic Results rich reticular structure. Visible interstitial amyloid deposition, bone and cartilage metaplasia. However, atypical carcinoid in the structure and morphology, and also has its own characteristics. First performance of organ-like structures is not typical, even lost organ-like structures, cells were indemnity; diffuse infiltration; Second, cancer-intensive common cancer spotty necrosis. I shaped cells of the more obvious, is characterized by the nuclear size, shape and inconsistent; visible nucleoli; nuclear fission is easy to see, on average every 10 high power field 2-10 (2-10/10HPF).
(3) addicted to silver staining, immunohistochemistry and electron microscopy: the number of atypical carcinoid small silver particles. Antigen markers of neuroendocrine small number of positive cells, weak intensity; electron microscopy, neuroendocrine small number of small size particles. Aneuploidy (aneuploidy) increase in the number. Compared with the typical carcinoid, only volume changes, no qualitative difference.
(4) clinical features: atypical carcinoid showed invasive growth, easy to vascular and lymphatic invasion; earlier of regional lymph node metastasis. 5 and 10 year survival rate lower than typical carcinoid, were 74.5% and 49.8%.
(5) described atypical carcinoid, atypical carcinoid tumor diagnosis: its not as good as the typical form of the typical carcinoid and SCLC, it is relatively difficult to diagnose. Diagnosis should pay attention to looking for structural features of neuroendocrine differentiation. Nuclear fission can be seen, but not more than 10 / 10, but not less than 2 / 10HPF. Common dot-like necrosis, rather than a ribbon or piece block. Cancer cells have some atypia. Necessary to do silver staining or immunohistochemistry.


  • intermediate grade atypical carcinoid