Proposal for a standardized pathology report of gastroenteropancreatic neuroendocrine tumors: prognostic significance of pathological parameters

Analysis of Prognostic Risk Factors of Endoscopic Submucosal Dissection (ESD) and Curative Resection of Gastrointestinal Neuroendocrine Neoplasms

Objective

To explore the prognostic risk factors of ESD curative resection of gastrointestinal-neuroendocrine neoplasms (GI-NENs).

Methods

A total of 97 patients treated with ESD successfully in our hospital were selected, their surgical site, size, number of resection lesions, operation time, intraoperative complications (such as bleeding and perforation), and treatment status were recorded, and the number of hemostatic clamps used after the postoperative follow-up results and the independent risk factors for ESD complications were obtained through the comparison between the noncomplication group and the ESD complication group using regression analysis.

Results

A total of 97 patients with gastrointestinal neuroendocrine tumors were treated with ESD. 61 were males, 36 were females, the ratio of male to female was 1.7 : 1, onset age was 20–78 years old, and median onset age was 50 years old. In 81 cases, tumors were located in the stomach, 10 in the duodenum, and 6 in the rectum. A total of 103 lesions were detected by endoscopy, including 1 case with 2 sites in the stomach, 5 cases with 2 sites in the rectum, and the rest were single. The tumor diameter was 0.3 ∼ 2.5 cm, and the median diameter was 0.6 cm; there were 25 sites with a diameter less than 5 cm. There were 57 places with 10 mm, 16 places with 10–15 mm, and 5 places with >15 mm. All ESD operations were performed in one piece, with a total resection rate of 100%; 89.6% (60/67) of postoperative pathology showed negative basal, and 90.3% (56/62) showed negative resection margin, with a complete resection rate of 88.9% (48/54). ESD's operation time is 6 ∼ 66 min, and the median time is 18 min. During the operation, 5 cases had small amount of bleeding, 3 cases were perforated, 2 cases of delayed postoperative bleeding, 1 case of bleeding was caused by the patient's failure to follow the advice of the doctor to eat a large amount of solid food too early, and 1 case of delayed perforation (all recovered and discharged). ESD operation that bled, age, gender, and perforation location, pathological grade, pathological classification, tumor diameter, tumor surface, operation time, number of titanium clips, origin, echo uniformity, and echo level were statistically insignificant (P > 0.05). Postoperative bleeding was related to the operation time (P=0.017), but it was not an independent risk factor for postoperative bleeding (P=0.118; OR, 0.226; 95% CI, 0.035–1.461). 59 cases were followed up by endoscopy after the operation, and recurrence or no new tumors were found.

Conclusion

ESD is an effective and safe treatment method for gastrointestinal neuroendocrine tumors with a diameter of 1-2 cm without invading the muscularis propria. The intraoperative complications seem to have little relationship with the patient; postoperative delayed bleeding is closely related to the ESD operation time but it is not an independent risk factor.

Standardization of the pathologic diagnosis of appendiceal mucinous neoplasms

Although the understanding of appendiceal mucinous neoplasms (AMNs) and their relationship with disseminated peritoneal mucinous disease have advanced, the diagnosis, classification, and treatment of AMNs are still confusing for pathologists and clinicians. The Gastrointestinal Pathology Study Group of the Korean Society of Pathologists (GPSG-KSP) proposed a multicenter study and held a workshop for the “Standardization of the Pathologic Diagnosis of the Appendiceal Mucinous Neoplasm” to overcome the controversy and potential conflicts. The present article is focused on the diagnostic criteria, terminologies, tumor grading, pathologic staging, biologic behavior, treatment, and prognosis of AMNs and disseminated peritoneal mucinous disease. In addition, GPSG-KSP proposes a checklist of standard data elements of appendiceal epithelial neoplasms to standardize pathologic diagnosis. We hope the present article will provide pathologists with updated knowledge on how to handle and diagnose AMNs and disseminated peritoneal mucinous disease.

Preoperative diagnosis of well-differentiated neuroendocrine tumor in common hepatic duct by brush cytology: A case report

The biological behavior of neuroendocrine tumors (NETs) is heterogeneous and differs from that of cholangiocarcinoma, which is the most common malignant tumor of the biliary tree. However, the preoperative diagnosis of NET in the biliary tree is extremely difficult and to our knowledge, diagnosis by brush cytology has not previously been reported. Herein, we first reported a case of biliary NET preoperatively diagnosed by brush cytology in a 33-year-old female patient. Imaging study revealed a 2.6-cm mass in the common hepatic duct. The brush cytology was characterized by loosely cohesive plasmacytoid tumor cells and scattered clusters of thin vascular septa. The tumor cells showed abundant cytoplasm and severe nuclear size variation but mitosis was not observed. Immunohistochemical staining of the cell block (CB) showed strong positivity for both synaptophysin and chromogranin A and a Ki-67 labeling index of 3.5%. The surgically resected bile duct mass was pathologically confirmed as NET, G2 with lymphovascular and perineural invasion of the tumor cells. The patient showed no evidence of tumor recurrence 10 months after operation without adjuvant chemotherapy. Suspicion of this rare tumor and immunohistochemical staining of the CB are important for the preoperative diagnosis of NET in the biliary tree.

Primary renal well-differentiated neuroendocrine tumors: report of six cases with an emphasis on the Ki-67 index and mitosis

BACKGROUND

Primary renal well-differentiated neuroendocrine tumors (WDNETs) also called carcinoid and atypical carcinoid are extremely rare, and little is known about parameters that may predict prognosis at diagnosis.

METHODS

Six cases of primary renal WDNET were collected. After reviewing slides stained with hematoxylin and eosin, proportions of each growth pattern were determined. Synaptophysin, chromogranin, CD56, and Ki-67 immunostaining and Ki-67 morphometric analysis were performed.

RESULTS

Patients included three female and three males, mean age was 53.3 years. The mean tumor size was 4.5 cm, three cases were greater than 5 cm. At the time of initial surgery, lymph node and/or distant metastasis was confirmed in two cases. In a third case, no metastasis was initially found, but lymph node metastasis was identified during follow-up. The remaining three cases did not exhibit metastasis. Histopathologically, the renal WDNETs were primarily composed of ribbon-like and sheet-like growth patterns. Most of the tumors were diffusely positive for neuroendocrine markers. Mitotic count was high (≥2/10HPF) in cases with lymph node or distant metastasis but was low (< 2/10HPF) in non-metastatic cases. Furthermore, the Ki-67 index was also higher (≥3%) in the cases with metastases than in cases without metastasis.

CONCLUSION

Three out of the six primary renal WDNETs demonstrated aggressive behavior and exhibited increased mitotic counts and Ki-67 indices. These results suggest that mitosis and the Ki-67 index could be used as prognostic indicators for renal WDNET.

Primary low-grade neuroendocrine carcinoma of the skin: An exceedingly rare entity

Low-grade neuroendocrine tumors (NETs), also known as carcinoid tumor, commonly arise from the gastrointestinal (GI) and pulmonary tracts, but rarely occur in the skin. Cutaneous NET typically occurs as metastases or high-grade primary lesions, called Merkel cell carcinoma. In the few cases described in literature, primary low-grade neuroendocrine carcinomas of the skin (LGNECS) are usually indolent cutaneous nodules, presenting on the head and trunk of elderly patients. LGNECS tumors are histologically similar to its counterparts arising in other anatomic locations. As there is no NET cut-off for the skin due to their rarity, the GI scale was used instead; low-grade NETs have a Ki-67 proliferative index of less than 3%. The distinction between primary and metastatic NET, however, is not absolute and can be difficult. A primary vs metastatic NET diagnosis relies on clinical exclusion of a NET in other, more common, anatomic locations. Here, we present a case of an LGNECS on the scalp of a 72-year-old female patient. Whole body imaging failed to identify any octreotide-avid lesions elsewhere in the patient, aside from 2 positive cervical lymph nodes, which were confirmed with a node dissection and histologic evaluation. This is the 19th reported case of LGNECS and the 2nd reported case of LGNECS with nodal metastasis.

Pancreatic neuroendocrine neoplasms at magnetic resonance imaging: comparison between grade 3 and grade 1/2 tumors

Background

The grading of pancreatic neuroendocrine neoplasms (PanNENs) is associated with the choice of treatment strategy. The aim of this study is to identify the magnetic resonance imaging (MRI) features in differentiating pancreatic neuroendocrine tumors (PanNETs) grade 1/2 (G1/G2) and pancreatic neuroendocrine carcinoma grade 3 (PanNEC G3).

Patients and methods

A total of 59 patients with histologically proven PanNENs and who underwent pretreatment MRI were retrospectively analyzed. Tumor location, size, boundary, cystic or solid appearance, enhancement degree, pancreatic duct dilatation, metastases and MRI signal were evaluated. Apparent diffusion coefficients (ADCs) were measured on ADC maps. Receiver operating characteristic curve was used to determine the cut off values and the sensitivity and specificity of prediction. Spearman correlation and logistic regression analysis were adopted to identify the association between MRI features and pathological parameters.

Results

A total of 47 lesions were PanNETs G1/G2 and 12 lesions were PanNEC G3. G1/G2 tumors were more common with well-circumscribed border compared with PanNEC G3. Ill- defined boundary, big size, necrosis, low-moderate enhancement, pancreatic duct dilatation, metastases and high diffusion-weighted imaging (DWI) intensity were more common in PanNEC G3 than in PanNETs G1/G2. The ADC values of PanNEC G3 were also significantly lower compared with the PanNETs G1/G2 and normal pancreatic parenchyma. The cut off value of ADC was 0.95×10⁻³ mm²/s for differentiating PanNEC G3 from PanNETs G1/G2 with 72.3% sensitivity and 91.6% specificity, respectively. Ki-67 index and mitosis count positively correlated with tumor size, pancreatic duct dilatation and metastases (P<0.05) and negatively correlated with ADC values (P<0.01), respectively. Regression analysis further showed that metastases and ADC value were associated with PanNENs grade.

Conclusion

Metastases and ADC value may have potential for differentiating PanNEC G3 from PanNETs G1/G2.

Recent Updates on Neuroendocrine Tumors From the Gastrointestinal and Pancreatobiliary Tracts

CONTEXT

-Gastrointestinal (GI) and pancreatobiliary tracts contain a variety of neuroendocrine cells that constitute a diffuse endocrine system. Neuroendocrine tumors (NETs) from these organs are heterogeneous tumors with diverse clinical behaviors. Recent improvements in the understanding of NETs from the GI and pancreatobiliary tracts have led to more-refined definitions of the clinicopathologic characteristics of these tumors. Under the 2010 World Health Organization classification scheme, NETs are classified as grade (G) 1 NETs, G2 NETs, neuroendocrine carcinomas, and mixed adenoneuroendocrine carcinomas. Histologic grades are dependent on mitotic counts and the Ki-67 labeling index. Several new issues arose after implementation of the 2010 World Health Organization classification scheme, such as issues with well-differentiated NETs with G3 Ki-67 labeling index and the evaluation of mitotic counts and Ki-67 labeling. Hereditary syndromes, including multiple endocrine neoplasia type 1 syndrome, von Hippel-Lindau syndrome, neurofibromatosis 1, and tuberous sclerosis, are related to NETs of the GI and pancreatobiliary tracts. Several prognostic markers of GI and pancreatobiliary tract NETs have been introduced, but many of them require further validation.

OBJECTIVE

-To understand clinicopathologic characteristics of NETs from the GI and pancreatobiliary tracts.

DATA SOURCES

-PubMed (US National Library of Medicine) reports were reviewed.

CONCLUSIONS

-In this review, we briefly summarize recent developments and issues related to NETs of the GI and pancreatobiliary tracts.

Early diagnosis and treatment of gastrointestinal neuroendocrine tumors

The aim of the present retrospective analysis on the macroscopic appearance and pathological characteristics of gastrointestinal neuroendocrine tumors (NETs) was to investigate methods for their early diagnosis and treatment. A total of 78 patients were divided into submucosal NET and deeper invasion NET groups, according to the depth of tumor invasion exhibited by the patients. The clinicopathological characteristics and survival time of the NET patients were analyzed and compared. The pathological characteristics of the submucosal NETs group were investigated according to the diameter of the tumor (≤5.0 mm, 5.1-10.0 mm or >10.0 mm). The depth of invasion at diagnosis was observed to significantly correlate with histopathological classification, diameter of the tumor, macroscopic appearance, growth pattern, lymphatic-vascular involvement, lymph node (LN) metastasis and distant metastasis. In the submucosal NETs group, high-grade tumors with lymphatic or venule invasion and distant metastasis were associated with an increased risk of nodal metastases. In patients with minute tumors (≤5.0 mm), no lymphatic-vascular involvement, LN or distant metastasis was observed. By contrast, patients with tumors measuring 5.1-10.0 mm in diameter exhibited high lymphatic-vascular involvement and LN metastasis rates (46.2 and 30.8%, respectively). Survival time was significantly longer in patients with submucosal NETs compared with deeper invasion NETs and in patients with NET G1 and NET G2 compared with NEC. The results of the present study indicate that gastrointestinal submucosal NETs are closely associated with a slightly elevated macroscopic type, low-grade tumors and a small diameter. These features may contribute to early diagnosis of gastrointestinal NETs. Therefore, a tumor diameter of <5.0 mm, with slightly elevated macroscopic appearance may indicate an absolute requirement for endoscopic resection, while tumors measuring 5.1-10.0 mm in diameter must be considered carefully.

Prognostic Validity of the American Joint Committee on Cancer and the European Neuroendocrine Tumors Staging Classifications for Pancreatic Neuroendocrine Tumors: A Retrospective Nationwide Multicenter Study in South Korea

OBJECTIVES

Pancreatic neuroendocrine tumors (pNETs) are diverse diseases with different prognosis. The American Joint Committee on Cancer (AJCC) and the European Neuroendocrine Tumor Society (ENETS) introduced 2 different tumor node metastasis (TNM) stages, and the World Health Organization (WHO) proposed WHO 2010 grading system for pNETs. Therefore, we aimed to validate the prognostic relevance of these 3 systems for pNETs in South Korea.

METHODS

The Korean Society of Gastrointestinal Cancer created a retrospective registry of pNETs in 153 patients from 15 hospitals between 2002 and 2012.

RESULTS

On the basis of the WHO 2010 grade, 2-year progression-free-survival (PFS) rates for G1, G2, and G3 were 92%, 62%, and 25% (P < 0.01). According to ENETS and AJCC staging, 2-year PFS rates for stages I through IV were 94%, 87%, 49%, 20%, and 92%, 61%, 60%, 20%, respectively (P < 0.01). A Cox multivariate regression analysis revealed that the only statistically significant prognostic factor was the TNM classification of either the AJCC or the ENETS stage (P < 0.01). In addition, the κ value between the AJCC and the ENETS stages was 0.46 indicating a "moderate" agreement (P < 0.01).

CONCLUSIONS

The AJCC and ENETS TNM classifications for pNETs are prognostic for PFS and can be adopted in clinical practice in South Korea.

Pancreatic neuroendocrine tumors: Correlation between the contrast-enhanced computed tomography features and the pathological tumor grade

OBJECTIVE

To determine whether CT features can predict the pathological tumor grades of pancreatic neuroendocrine tumors (PanNETs) according to the recent WHO classification.

MATERIALS AND METHODS

In all, 28 patients with histologically confirmed PanNETs underwent preoperative contrast CT examinations. Thirteen tumors were classified as G1 and 15 as G2. Two radiologists independently evaluated the CT features (tumor delineation, peripancreatic vascular involvement, upstream pancreatic duct dilatation, N (regional lymph node metastasis) and M (distant metastasis) grades, tumor homogeneity, cystic or necrotic change, and tumor conspicuity). The tumor sizes and Hounsfield unit values of all PanNETs during each phase on CT were measured by one radiologist. We compared the CT features between pathological tumor grades using Fisher's exact test for nominal scales and Mann-Whitney U test for ordinal scales or continuous variables. Additionally, we evaluated the performances of the CT findings and their combinations to diagnose G2 tumors.

RESULTS

G2 tumors showed significantly larger in tumor size than G1 tumors (p=0.029). All 4 tumors with hepatic metastases were G2. Non-hyperattenuation compared with pancreatic parenchyma during portal venous phase (PVP) was significantly associated with G2 (p=0.016). The accuracy for G2 diagnosis of tumor size (≥20mm), M grade (M1), and tumor conspicuity (non-hyperattenuation during PVP) were 71%, 61%, and 71%, respectively, while the accuracy of their combination was 82%.

CONCLUSION

Contrast-enhanced CT features (tumor size, M grade, and tumor conspicuity during PVP) can predict the pathological tumor grades of PanNETs.

p27 Loss Is Associated with Poor Prognosis in Gastroenteropancreatic Neuroendocrine Tumors

Purpose

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) represent a heterogeneous disease group originating from the neuroendocrine cells. Identification of prognostic markers, related to neuroendocrine tissue-selective tumorigenesis, is necessary to find therapeutic targets.

Materials and Methods

A total of 327 patients with GEP-NETs were included in this study; there were 49 gastric, 29 duodenal, 49 pancreatic, 12 hepatobiliary, 33 appendiceal, 5 proximal colon, and 150 distal colon cases. We performed immunostaining with the tissue microarray method for menin, p27, and p18.

Results

We observed negative staining for menin, p27, and p18 in 34%, 21%, and 56% of GEP-NETs, respectively. The loss of p27, but not menin, was positively correlated with the grade of Ki-67. Menin–/p27–, menin–/p27+, menin+/p27–, and menin+/p27+ phenotype groups included 13%, 22%, 8%, and 57% of patients, respectively. A dichotomized comparison showed that menin– or p27– tumors were significantly associated with foregut and midgut localizations, high World Health Organization (WHO) grade, lymph node metastasis, and more advanced stage as compared to menin+/p27+ patients. Kaplan-Meier analysis for the overall survival showed that p27 loss was significantly associated with decreased survival. Multivariate analysis showed that p27 loss is an independent factor for poor overall survival.

Conclusion

Our results revealed that the loss of p27 is associated with poor prognosis and the menin-p27 pathway is important in the tumorigenesis of GEP-NETs.

Spectrum of Gastroenteropancreatic NENs in Routine Histological Examinations of Bioptic and Surgical Specimen: A Study of 161 Cases Collected from 17 Departments of Pathology in the Czech Republic

Objective. To characterize GEP-NENs in routine biopsies and surgical specimen in the Czech Republic and to evaluate how WHO Classification (2010) is acceptable in diagnostic practice. Methods. Paraffin-embedded blocks and bioptic reports were collected from 17 departments of pathology. Histologic slides were stained with H&E and immunohistologically for CgA, synaptophysin, and Ki-67. Results. Out of 28 gastric NENs, there were 22 NETs, G1, 5 NETs, G2, and 1 NEC. Ten duodenal NENs were NETs, G1. Among 27 NENs of jejunum and ileum, 23 were NETs, G1, 2 NETs, G2, and 1 NEC and 1 mixed adenoneuroendocrine carcinoma (MANEC). Among 42 appendiceal “incidentalomas”, 39 were NETs G1, 2 goblet cell carcinoids, and 1 MANEC. Out of 34 large intestinal NENs, 30 were NETs, G1, 3 NETs, G2, and 1 NEC. One small intestinal and 6 large bowel neoplasms were reclassified as poorly differentiated adenocarcinomas. In 12 pancreatic NENs, there were 7 NETs, G1, 3 NETs, G2, and 2 NECs. Conclusions. Our study demonstrates differences in GEP-NENs frequency in sites of origin in our region, comparing to other countries. Regarding routine bioptic diagnostics, we gave evidence that the WHO 2010 classification of NENs is fully acceptable for exact categorisation of tumours.