Atypical carcinoid tumor of lung metastatic to the adrenal gland Case 255
HIgh magnification view showing trabecular growth, palisading of columnar cells along the periphery of the tumor nest at the left of the image, finely granular nuclear chromatin, non-prominent nucleoli and a single mitosis. This tumor contained between 2-10 mitoses/10 high power fields.
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.