Neuroendocrine Neoplasms

Neuroendocrine neoplasms represent an important group of tumors; however, the histological characteristics of these neoplasms are similar regardless of the site of origin. It is well known that these neoplasms may occur virtually in any anatomical site; therefore, clinical and radiological information becomes an important tool in the assessment of these neoplasms. From the immunohistochemical point of view, all these neoplasms will show similar immunophenotype using the more conventional and daily neuroendocrine markers such as chromogranin, synaptophysin, and CD56. In some cases adding TTF-1, CDX-2 may aid in the assessment of primary versus metastatic disease. However, the most important element in assigning site of origin should be based on the overall information of clinical, radiological, and pathological characteristics. More specifically regarding thoracic neoplasm, these tumors can be either primary neoplasm of the lung or of the thymus. Therefore, the use of radiological information in the assessment plays a crucial role, as the histology alone cannot determine primary site.