Clinical needs and pathology's answers in neuroendocrine neoplasms of the lung

Lung neuroendocrine neoplasms (NENs) make up a variegated ensemble of malignancies encompassing typical carcinoid (TC) and atypical carcinoid (AC). These are low to intermediate grade neuroendocrine tumors (NETs), and large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC), which are full-fledged high-grade neuroendocrine carcinomas (NECs) showing similar clinical outcomes. Through a peer interaction between oncologist and pathologist, we herein constructed a practical approach based on questioning and answering regarding 8 practical issues aimed to provide shared solutions for clinical decision-making. These issues were itemized as sequential steps guided by clinical reasoning and concerned differential diagnosis, combined subtypes, primary and metastatic tumors, small diagnostic material, predictive biomarkers, tumor staging and, lastly, standardizing terminology. This study takes advantage of the close interaction between oncologists and pathologists as a tool to better delineate the decision-making on lung NENs.