Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome.

The term diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) may be used to describe a clinico-pathological syndrome, as well as an incidental finding on histological examination, although there are obvious differences between these two scenarios. According to the World Health Organization, the definition of DIPNECH is purely histological. However, DIPNECH encompasses symptomatic patients with airway disease, as well as asymptomatic patients with neuroendocrine cell hyperplasia associated with multiple tumourlets/carcinoid tumours.

Classification of different patterns of pulmonary adenocarcinomas.

The epidemic increase of adenocarcinoma histology accounting for more than 50% of primary lung malignancies and the advent of effective molecular targeted-therapies against specific gene alterations characterizing this tumor type have led to the reconsideration of the pathologic classification of lung cancer. The new 2015 WHO classification provided the basis for a multidisciplinary approach emphasizing the close correlation among clinical, radiologic and molecular characteristics and histopathologic pattern of lung adenocarcinoma. The terms 'bronchioloalveolar carcinoma' and 'mixed adenocarcinoma' have been eliminated, introducing the concepts of 'adenocarcinoma in situ', 'minimally invasive adenocarcinoma' and the use of descriptive predominant patterns in invasive adenocarcinomas (lepidic, acinar, papillary, solid and micropapillary patterns).

Does Immunohistochemistry Represent a Robust Alternative Technique in Determining Drugable Predictive Gene Alterations in Non-Small Cell Lung Cancer?

Immunohistochemistry (IHC) is a widely-tested, low-cost and rapid ancillary technique available in all laboratories of pathology. This method is generally used for diagnostic purposes, but several studies have investigated the sensitivity and specificity of different immunohistochemical antibodies as a surrogate test in the determination of predictive biomarkers in non-small cell lung cancer (NSCLC), particularly for Epidermal Growth Factor Receptor (EGFR) gene mutations, Anaplastic Lymphoma Kinase (ALK) gene and ROS1 rearrangements. In this review, a critical examination of the works comparing the consistency of IHC expression and conventional molecular techniques to identify genetic alterations with predictive value in NSCLC is discussed.