Atypical pulmonary carcinoid tumour is a subtype of pulmonary carcinoid tumor.

[1] It is an uncommon low-grade malignant lung mass that is most often in the central airways of the lung.

It is also known as "atypical lung carcinoid tumour", " atypical lung carcinoid" or "moderately differentiated neuroendocrine carcinoma".

It is a more aggressive than typical carcinoid tumors: nodal metastases in 70% vs. 5%.

Atypical carcinoid tumors have increased mitotic activity (2-10 per 10 HPF), nuclear pleomorphism or foci of necrosis.