Changes in Neuroendocrine Tumor Microenvironment with WHO Tumor Grading

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Introduction: The microenvironment of neuroendocrine neoplasias (NEN) in view of tumor grading (WHO classification of 2000 und 2010) has not yet been validated. Both classifications distinguish between well and poorly differentiated neuroendocrine tumors, including proliferation rate, mitotic index and histomorphology. The WHO classification of 2000 further evaluates tumor location, size, angioinvasion, invasion of the muscle layer, functionally active tumors and metastases.

Aim(s): We analysed tumor and stromal markers in view of these classifications.

Materials and methods: 55 different primary tumors were analysed: 32 small intestinal, 13 colorectal and 10 pancreatic NEN. Immunohistochemistry was performed on paraffin sections. As tumormarker chromogranin, CD56 and S100 were used. Stromal markers were α-SMA and Desmin. Markers for endothelial cells were CD34 and vWF. CD68 and KiM1P were used as markers for macrophages and fibrohistiocytes. Lymphocytes were stained with CD3+ for T-cells and CD20+ for B-cells. Analysis of cell-count and staining-intensity was computer-based and visually controlled.

Conference: 12th Annual ENETSConcerence (2015)

Presenting Author: Cameron S

Authors: Cameron S, Skupin J, Füzesi L,

Keywords: NEN stroma,