Classification of pulmonary neuroendocrine tumors: new insights.

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them.

Review article: pulmonary sarcomatoid carcinomas: a practical overview.

Pulmonary sarcomatoid carcinomas (PSCs) are currently defined as poorly differentiated non-small-cell carcinomas containing a component with sarcoma or sarcoma-like (spindle and/or giant cell) features. They consist of 5 major histological variants, namely pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. The segregation of PSCs into a distinct clinicopathologic entity seems justified on the basis of morphologic, behavioral, and genotypic/phenotypic attributes.

Expression of amino acid sequences of the chromogranin A molecule and synaptic vesicle protein 2 in neuroendocrine tumors of the lung.

Chromogranin A (CgA) and its valuable complement synaptic vesicle protein 2 (SV2) are neuroendocrine (NE) markers. Post-translational processing of CgA has been reported to vary in different NE cell types and tumors, but little is known regarding the expression of various CgA epitopes and SV2 in NE pulmonary tumors. We studied the immunoreactivity to six CgA epitopes and SV2 in ten typical (TC) and ten atypical (ACT) carcinoids, five large-cell NE carcinomas (LCNEC) and five small-cell carcinomas (SCLC), also comparing the results with clinicopathological characteristics of tumors.

CD117 immunoreactivity in high-grade neuroendocrine tumors of the lung: a comparative study of 39 large-cell neuroendocrine carcinomas and 27 surgically resected small-cell carcinomas.

Little is known about CD117 prevalence and clinicopathological implications in pulmonary large-cell neuroendocrine carcinoma. We studied CD117 immunoreactivity in surgical specimens from 39 large-cell neuroendocrine carcinomas of stages I-III and 27 limited-disease small-cell carcinomas, 56 typical and atypical carcinoids of the lung, and 10 neuroendocrine tumorlets, including the membrane and cytoplasmic immunostaining patterns. Membrane CD117 immunoreactivity in 5% or more tumor cells was documented in 30 (77%) large-cell neuroendocrine carcinomas and 18 (67%) small-cell carcinomas and 4 (7%) carcinoids, whereas cytoplasmic labeling was seen in 17 (44%) large-cell neuroendocrine carcinomas, 19 (70%) small-cell carcinomas, and 3 (5%) carcinoids.

Independent value of fascin immunoreactivity for predicting lymph node metastases in typical and atypical pulmonary carcinoids.

Immunoreactivity for fascin, an actin-bundling protein related to cell motility, has been reported in breast, ovary, pancreas, skin, and non-small cell carcinomas, and associated with more advanced disease stage and poorer prognosis. Data on pulmonary neuroendocrine (NE) tumors, however, are lacking. We evaluated the expression of fascin by immunohistochemistry--using two different monoclonal antibodies--in surgical specimens of pulmonary NE tumors of all the diverse histological types from 128 consecutive patients recruited between 1987 and 2001, and investigated its relationship with the presence of lymph node metastases.

Prognostic implications of neuroendocrine differentiation and hormone production in patients with Stage I nonsmall cell lung carcinoma.

Background: Approximately 10-20% of nonsmall cell lung carcinomas (NSCLC) show neuroendocrine (NE) differentiation, as evaluated by panendocrine markers or ultrastructural evidence of dense-core secretory granules. However, little is known regarding the prevalence and clinical implications of NE differentiation in patients with Stage I NSCLC.

Methods: The authors analyzed 220 consecutive patients with Stage I NSCLC (pT1-T2N0M0) among 2100 patients with primary lung carcinoma who underwent surgical treatment between 1987 and 1993.

p63 immunoreactivity in lung cancer: yet another player in the development of squamous cell carcinomas?

The p63 protein, a member of the p53 family of nuclear transcription factors, is characterized by different capabilities of transactivating reporter genes, inducing apoptosis, and functioning as dominant-negative agent. This study evaluated the prevalence and prognostic implications of p63 immunoreactivity in 221 patients with stage I non-small cell lung carcinoma (NSCLC) and in 57 patients with stage I-IV neuroendocrine tumours (NET). The results were correlated with the tumour proliferative fraction, the accumulation of p53 protein, and with patient survival.