"An atypical pulmonary carcinoid tumour is a more aggressive variant of a pulmonary carcinoid tumour. They are less common and considered intermediate grade neoplasms and have the same “carcinoid morphology,” but with mitotic rates increased (at 2–10 mitoses per 2 mm2) where the tumour might also be punctuated with necrotic features."
"An atypical pulmonary carcinoid tumour is a more aggressive variant of a pulmonary carcinoid tumour. They are less common and considered intermediate grade neoplasms and have the same “carcinoid morphology,” but with mitotic rates increased (at 2–10 mitoses per 2 mm2) where the tumour might also be punctuated with necrotic features."