ملف:Atypical carcinoid tumor of lung metastatic to the adrenal gland Case 255 (8268009504).jpg

A focus of early necrosis is present in the tumor nest in center of the image. Atypical carcinoid tumor of the lung is currently defined as a neoplasm with the neuroendocrine growth pattern that exhibits 2-10 mitosis/10 high power fields or necrosis. No mitoses are seen in this image. The term atypical carcinoid may be somewhat misleading since it may give the impression of a low grade of malignancy when if fact these are fully malignant neoplasms in which distant metastases are present in about 20% of patients at presentation and the disease free survival after 10 years is about 50%. An alternate name - neuroendocrine carcinoma grade 2 - has been suggested. I believe that this is preferable to atypical carcinoid but others are unwilling to accept this terminology.