[679] Histopathologic Parameters of Gastrointestinal and Pancreatic Neuroendocrine Tumors/Carcinomas Can Predict Their Clinical Behavior

Ihab Lamzabi, Shriram Jakate, Richa Jain, Lin Cheng, Paolo Gattuso. Rush University Medical Center, Chicago, IL

Background: Gastrointestinal(GI) and pancreatic(P) neuroendocrine tumors/carcinomas NET/C have a heterogeneous prognoses. WHO grading system based on mitoses and necrosis show weak prediction of clinical behavior especially for WHO grade I metastatic NET. We undertook a retrospective study to identify additional histopathologic parameters that might be useful in assessing the malignant behavior of GINEC/T and PNET/C.
Design: We searched our surgical pathology files for resection specimens of GINEC/T and PNET/C from 2000-2010. Pertinent clinico-pathological data was retrieved. Two pathologists independently reviewed several histologic parameters including nuclear size (NS) compared to the nuclei of small lymphocytes, number of very large nuclei (NVLN)(3 times larger than the nuclei of small neoplastic cells) per 10 hpf, number of mitotic figures(NMF) per 10 hpf, presence of nucleoli, apoptosis or necrosis, lymphovascular and perineural invasion (LVPNI), and presence of desmoplasia.

Results: Fifty six cases of NET/C including 6 gastric, 17 ileal, 8 appendiceal, 2 cecal, 13 pancreatic, 8 rectal and 2 liver metastases of PNET were selected. The clinico-pathologic data is summarized in table 1. The correlations between histopathologic parameters and T stage, LN and distant metastases are summarized in table 2.

Table 1: Clinicopathological data
 Stomach N=6SB N=17Pancreas N=13Appendix N=8Rectum N=8
Average Age5259593059
Grade I NET with LN metastasis010310
LN Metastases015411
Distant Metastases03201

Table 2: Correlation of Different Histological Parameters with Tumor Behavior
CorrelationsT StageLN MetastasisDistant Metastasis
Mitotic Activityr=0.1(p=0.3)r=0.2(p=0.04)r=0.1(p=0.4)

Conclusions: This study confirms that most metastatic GI and pancreatic NET/C are WHO grade I. Also, the best predictors of aggressive behavior especially LN metastases might be LVPNI, NS and NVLN. Mitotic activity showed only a weak correlation with LN metastases, while necrosis was not associated with the behavior of these tumors.
Category: Gastrointestinal

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 104, Monday Morning


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