Alterations in the expression of p53, KLF4, and p21 in neuroendocrine lung tumors.

Context: Neuroendocrine lung neoplasms are a heterogeneous group of tumors with different clinical behavior and prognosis.

Objectives: To evaluate the expression of p53, KLF4, and p21 in neuroendocrine lung neoplasms and to analyze the influence that expression has on the prognosis of those tumors.

Design: All neuroendocrine lung neoplasms (N = 109) resected in our institution were reviewed, with the collection of histologic slides and paraffin blocks of 47 typical carcinoids (43%), 9 atypical carcinoids (8%), 35 large cell neuroendocrine carcinomas (32%), and 18 small cell lung carcinomas (17%), as well as 10 tumorlets (100%).

Epstein-Barr virus-associated adenocarcinomas and squamous-cell lung carcinomas.

The association of Epstein-Barr virus with pulmonary neoplasms has been restricted to lymphoepithelioma-like carcinomas in Asian patients. We have selected 19 pulmonary adenocarcinomas and squamous-cell carcinomas from 1545 pulmonary neoplasms diagnosed from 1996 to 2007 in an occidental population. All of them showed a low-power appearance confusing between an epithelial and a lymphoid neoplasm, with a dense lymphocytic infiltrate intermingled with neoplastic cells giving an image akin to lymphoepithelial complexes.