Retrospective analysis of the clinicopathological characteristics of gastrointestinal neuroendocrine neoplasms

Mixed adenoneuroendocrine carcinoma originating from the appendix and colorectum: a comparative analysis of a large population-based database

PURPOSE

As a rare gastrointestinal neoplasm, the demographic, clinicopathological, and prognostic characteristics of mixed adenoneuroendocrine carcinoma (MANEC) remain unclear. The purpose of this study was to evaluate its biological features, survival outcome, and prognostic factors.

METHODS

From the Surveillance, Epidemiology, and End Results (SEER) database, we retrospectively reviewed clinicopathological and survival data of 513 patients who were histopathologically diagnosed with MANEC of the appendix and colorectum bettween 2004 and 2015. The clinicopathological features and survival outcomes of MANEC located at different anatomical locations were compared, and predictive factors for cancer-specific survival (CSS) and overall survival (OS) were assessed.

RESULTS

In terms of anatomical distribution of MANEC, the appendix (64.5%, 331/513) was more frequently involved, followed by colon (28.1%, 144/513) and rectum (7.4%, 38/513). The MANEC at different anatomical locations had a distinct clinicopathological characteristic, and colorectal MANEC was significantly associated with more aggressive biological features. The survival outcomes of appendiceal MANEC were significantly better than that of colorectal MANEC (3-year CSS rate 73.8% vs 59.4%, P = 0.010; 3-year OS 69.2% vs 48.3%, P < 0.001). In addition, hemicolectomy had a better survival benefit than appendicectomy for patients with appendiceal MANEC, regardless of lymph node metastasis (P < 0.05). Tumor location, histology grade III, tumor size > 2 cm, T3-T4 stage, lymph node metastasis, and distant metastasis were independent prognostic factors for patients with MANEC.

CONCLUSIONS

Tumor location had an important prognostic significance for MANEC. As an uncommon clinical entity, colorectal MANEC had more aggressive biological features and worse prognosis than its appendiceal counterpart. The standard surgical procedure and clinical management strategy for MANEC need to be established.

Survival Analysis in Gastrointestinal Neuroendocrine Carcinoma With Bone Metastasis at Diagnosis

Purpose

Gastrointestinal neuroendocrine carcinoma (NEC) with bone metastasis is rarely reported. The purpose of this study is to explore the prognosis and risk factors of such patients.

Patients and Methods

We retrospectively reviewed patients diagnosed as gastrointestinal NECs with bone metastasis at diagnosis from 2010 to 2016 by using the Surveillance, Epidemiology and End Results (SEER) database. Predictors of overall survival (OS) and cancer-specific survival (CSS) were analyzed by univariable and multivariable Cox analyses. Kaplan–Meier plots were constructed to show the correlation between independent predictors and survival.

Results

A total of 330 gastrointestinal NEC patients with bone metastasis at diagnosis were included for analysis. Over half of patients were male and older than 60 years old. The most common primary site of gastrointestinal NEC with bone metastasis was the pancreas. The prognosis of gastrointestinal NEC with bone metastasis (3-year OS and CSS rates: 16.7 and 17.0%) was very poor. On Cox multivariable analysis, age over 60 years old, no surgery, and lung metastasis were independent predictors of decreased OS and CSS.

Conclusions

We identified three independent factors associated with prognosis among gastrointestinal NEC patients with bone metastasis, namely age, surgery, and lung metastasis. For younger gastrointestinal NEC patients with bone metastasis, surgical resection of primary tumors as well as actively treating lung metastasis might be useful for prolonging survival.

Rectal mixed adenoneuroendocrine carcinoma: Case report

RATIONALE

Colorectal mixed neuroendocrine-nonneuroendocrine neoplasms constitute a rare group of gastrointestinal tumors composed by both neuroendocrine and nonneuroendocrine components. Nondiagnostic macroscopic features, specific histological features, and poor awareness of the disease are responsible for the underestimated incidence and conflicting data available. Due to lack of randomized clinical trials and validated clinical guidelines, diagnostic and therapeutic approach are based on the standard of care for pure colorectal neuroendocrine carcinomas or adenocarcinomas.

PATIENT CONCERNS

A 76-year-old caucasian male, without relevant medical or familial history, presented a positive faecal occult blood test during colorectal cancer screening.

DIAGNOSIS

Total colonoscopy identified a rectal lesion with biopsy showing a moderate rectal adenocarcinoma staged as cT2N0M0.

INTERVENTIONS

Anterior resection of the rectum with right ileostomy followed by local radiotherapy with radio-sensitising chemotherapy and adjuvant chemotherapy with capecitabine 1000 mg bid plus oxaliplatin 130 mg/m2. Due to chronic nodular pulmonary aspergillosis and chemotherapy induced immunosuppression patient was on 400 mg/daily of oral voriconazole.

OUTCOMES

Overall survival of 15 months after progression under first line treatment and under palliative chemotherapy with platinum plus etoposide regimen.

LESSONS

The reported case illustrates the challenge associated to the management of mixed neuroendocrine-nonneuroendocrine carcinomas due to lack of validated guidelines and scientific evidence. From diagnosis and staging to treatment, all steps must be tailored to individual clinical and histological features.

Clinicopathological characteristics and prognosis of 77 cases with type 3 gastric neuroendocrine tumours

BACKGROUND

For the rarity of type 3 gastric neuroendocrine tumours (g-NETs), their clinicopathological characteristics and prognosis are not well illustrated.

AIM

To describe the clinicopathological features and outcome of type 3 g-NETs in the Chinese population.

METHODS

Based on the 2019 WHO pathological classification, the clinicopathological characteristics and prognosis of patients with type 3 g-NETs in China were retrospectively analysed.

RESULTS

A total of 77 patients (55.8% of females) with type 3 g-NETs were analysed, with a median age of 48 years (range: 28-79 years). The tumours were mainly located in the gastric fundus/body (83.1%) and were mostly solitary (83.1%), with a median size of 1.5 cm (0.8-3.5 cm). Of these, there were 37 G1 tumours (48.1%), 31 G2 (40.3%), and 9 G3 (11.7%). Ten (13.0%) and 24 (31.2%) patients had lymph node and distant metastasis, respectively. In addition, type 3 g-NETs were heterogeneous. Compared with G1 NETs, G2 NETs had a higher lymph node metastasis rate, and G3 NETs had a higher distant metastasis rate. G1 and G2 NETs with stage I/II disease (33/68) received endoscopic treatment, and no tumour recurrence or tumour-related death was observed within a median follow-up time of 36 mo. Grade and distant metastasis were identified to be independent risk factors for prognosis in multivariable analysis.

CONCLUSION

Type 3 g-NETs are obviously heterogeneous, and the updated WHO 2019 pathological classification may be used to effectively evaluate their biological behaviors and prognosis. Also, endoscopic treatment should be considered for small (< 2 cm), low grade, superficial tumours.

Clinical implications of mismatch repair deficiency screening in patients with mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN)

INTRODUCTION

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) are rare tumors, mainly encountered in the gastroenteropancreatic tract. Based on the limited available data, MiNEN is usually a highly aggressive neoplasm combining a high-grade neuroendocrine and a non-neuroendocrine component, associated with a poor prognostic outlook. Deficient DNA mismatch repair (MMR) results in microsatellite instability, which is a useful screening marker for identifying patients with Lynch syndrome and a prognostic factor for chemotherapeutic interventions. Little information on MMR status in MiNEN is available in published studies. Therefore, the purpose of this study was to explore the status and putative role of MMR on MiNEN.

METHODS

We investigated the MMR status in 44 cases and characterized their clinicopathological features and prognoses. Immunohistochemistry was performed for four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2).

RESULTS

Mean age at diagnosis was 61 years, and 75% of the patients were male. Lymph node metastases were observed in 14 (35.9%) patients. The most common tumor localizations were gastric (28 patients, 63.6%). Lack of immunohistochemical expression of MMR proteins was shown in 38.6% of cases. The common deletion rates of one or more proteins were 29.4% (5/17) for MLH1/PMS2 and 23.5% (4/17) for MLH1. Correlation between clinicopathological parameters showed that MMR deficiency was significantly associated with early TNM stage and better prognoses in patients with MiNEN.

CONCLUSION

MiNENs showed frequent losses of MMR protein expression, which contributes to the knowledge of the pathological and clinical aspects of MiNEN tumors.

Gastrointestinal mixed adenoneuroendocrine carcinoma: a population level analysis of epidemiological trends

Background

The rise in incidence and mortality of gastrointestinal mixed adenoneuroendocrine carcinoma (MANEC) has not been well focused. The aim of our study was to examine epidemiological trends in incidence and incidence-based (IB) mortality of gastrointestinal MANEC at a population level.

Methods

The incidence and IB mortality of gastrointestinal MANEC as well as data on affected patients from 2000 to 2016 were obtained from the Surveillance, Epidemiology, and End Results database. Trends in incidence and IB mortality were assessed using Joinpoint regression. The Kaplan–Meier method and log-rank test were used for survival analysis. Cox proportional hazards regression was used to identify independent predictors of mortality.

Results

581 patients diagnosed with gastrointestinal MANEC were enrolled. Gastrointestinal MANEC incidence was 0.23 cases per 1,000,000 individuals in 2000 and 1.16 cases per 1,000,000 individuals in 2016, with an annual percent change (APC) of 8.0% (95% CI 5.7–10.3%, P < 0.05). IB mortality also showed a sustained increase (APC 12.9%, 95% CI 9.0–16.8%, P < 0.05). In Cox regression analysis, age at diagnosis, tumor grade and stage, lymph node metastasis, surgery, and tumor size were independently associated with mortality. Median survival was 75 months (95% CI 60–128 months). Median survival of appendiceal MANEC was significantly longer than that of cecal MANEC (115 vs. 31 months; P < 0.001).

Conclusions

We found a sustained and rapid increase both in incidence and IB mortality of gastrointestinal MANEC, manifesting that there has been no significant improvement in patient outcomes, nor progress in prevention and treatment. Additional resources should be devoted to gastrointestinal MANEC research.

Paired Box 5 (PAX5) Expression in Poorly Differentiated Neuroendocrine Carcinoma of the Gastrointestinal and Pancreatobiliary Tract: Diagnostic and Potentially Therapeutic Implications

Paired Box 5 (PAX5), a well-established B-cell marker, is preferentially expressed in small cell lung carcinoma and regulates the transcription of c-Met, offering a potential for therapeutic target. Its expression in poorly differentiated neuroendocrine carcinoma (PDNEC) of the digestive system has not been systemically evaluated. Archived pathology materials from 38 PDNEC in the gastrointestinal (GI) and pancreatobiliary (PB) tract were reviewed. Representative tumor sections were subject to immunohistochemical stain for PAX5, c-Met, and CD20. The extent of the staining [focal (<10%), patchy (10% to 50%), and diffuse (>50%)] and intensity (1+ to 3+) was evaluated. In total, 38 cases of well-differentiated neuroendocrine tumors from GI/PB tract served as controls. Nuclear PAX5 staining was observed in 16 (42%) cases in total, in 46% (11/24) of large cell neuroendocrine carcinoma, 67% (4/6) of small cell neuroendocrine carcinoma, and 13% (1/8) of mixed adenoneuroendocrine carcinoma, with diffuse (8), patchy (4), or focal (4) staining. The intensity was 3+ (2), 2+ (6), and 1+ (8). PAX5 expression was common in ampullary (4/5) and gastroesophageal junctional/esophageal (5/9) PDNEC. Two (5%) of 38 well-differentiated neuroendocrine tumors were positive for PAX5. Three PAX5 positive PDNEC showed weak cytoplasmic c-Met immunolabeling. CD20 was negative in all tumors. Our data show that PAX5 is commonly expressed in PDNEC of the GI/PB tract including small cell neuroendocrine carcinoma. This observation warrants a cautious approach when interpreting small biopsy of poorly differentiated neoplasms, especially when lymphoma is considered in the differentials. Further study of PAX5/c-Met signaling pathway and its potential therapeutic value in GI/PB PDNEC is warranted.

A Neuroendocrine Tumor of Unknown Primary Origin that Responded to Treatment Based on Tumor Grade Progression

The standard chemotherapies for neuroendocrine tumors (NETs) are somatostatin analog (SSA) and targeted-agents for NET G1/G2 and platinum-based chemotherapy for neuroendocrine carcinoma (NEC), classified according to the WHO criteria of 2010. We report a case of NET, in which tumors were successfully treated with platinum-containing chemotherapy after remarkable progression with SSA. A 46-year-old man with multiple lymph nodes and liver metastases of unknown primary origin was diagnosed with NET G2 based on the examination of a biopsy specimen. His tumors were stable with SSA for a year, but rapidly became enlarged. A second biopsy revealed NEC. He received cisplatin plus etoposide, and his tumors showed a marked reduction in size.

Long-term control with chemoradiation of initially metastatic mixed adenoneuroendocrine carcinoma of the rectum: a case report

BACKGROUND

Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarcinomatous and neuroendocrine components. They can originate in any organ but are more common in the rectum. Due to their rarity, current treatment recommendations for mixed adenoneuroendocrine carcinoma are based on limited data and follow general guidelines for the management of adenocarcinomas and neuroendocrine neoplasms. Uncertainty regarding the efficacy of the available local and systemic treatment strategies is a compounding issue. Even those patients with locally limited disease have a relatively short life expectancy. In this report, we describe a case of deep rectal mixed adenoneuroendocrine carcinoma with long survival after chemoradiation.

CASE PRESENTATION

A 48-year-old Caucasian woman was diagnosed with a grade 3 rectal adenocarcinoma combined with a poorly differentiated large cell neuroendocrine carcinoma component and synchronous metastases (cT3cN1cM1) in both lobes of the liver in 2012. She received concomitant chemoradiotherapy followed by four additional cycles of cisplatin plus irinotecan. Initial treatment induced complete remission of the rectal tumor and liver metastases. Consequently, it was not necessary to surgically resect the primary tumor or any of the metastases. Three months after the end of treatment, one metastasis in the first segment of the liver showed regrowth, and stereotactic body radiotherapy of the metastasis and chemotherapy resulted in a clinical complete response. The patient has been recurrence-free for more than 5 years.

CONCLUSIONS

Extended long-term control of a poorly differentiated metastatic (stage IV) mixed adenoneuroendocrine carcinoma is rare. The multimodal first- and second-line regimens of radiotherapy and chemotherapy described in this case report represent a new therapeutic approach. Encouraged by the results in this case, we compiled a review of the literature on mixed adenoneuroendocrine carcinoma.

Utility of CT in differentiating liver metastases of well-differentiated gastroenteropancreatic neuroendocrine neoplasms from poorly-differentiated neuroendocrine neoplasms

Objective

To determine the capability of dynamic enhanced computed tomography (CT) to differentiate liver metastases (LMs) of well-differentiated from poorly-differentiated gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs).

Methods

Patients with LMs of GEP-NENs who underwent dynamic enhanced CT examination in Peking University Cancer Hospital from January 2009 to October 2015 were included and data were retrospectively analyzed. We assessed the qualitative and quantitative CT features to identify the significant differentiating CT features of LMs of poorly-differentiated GEP-NENs from those of well-differentiated GEP-NENs using univariate analysis and a multivariate logistic regression model.

Results

The study included 22 patients with LMs of well-differentiated GEP-NENs and 32 patients with LMs of poorly-differentiated GEP-NENs. Univariate analysis revealed statistically significant differences between the LMs of well- and poorly-differentiated GEP-NENs in terms of feeding arteries (36.4% vs. 75.0%, χ²=8.061, P=0.005), intratumoral neovascularity (18.2% vs. 59.4%, χ²=9.047, P=0.003), lymphadenopathy (27.3% vs. 81.2%, χ²=15.733, P<0.001), tumor-to-aortic ratio in the hepatic arterial and portal venous phase (T-A/AP: 0.297±0.080vs. 0.251±0.059, t=2.437, P=0.018; T-A/PVP: 0.639±0.138 vs. 0.529±0.117, t=3.163, P=0.003) and tumor-to-liver ratio in the hepatic arterial phase (T-L/AP: 1.108±0.267 vs. 0.907±0.240, t=2.882, P=0.006). The LMs of poorly-differentiated GEP-NENs showed more feeding arteries, more intratumoral neovascularity, more lymphadenopathy and a lower tumor-to-aortic ratio. Multivariate analysis suggested that intratumoral neovascularity [P=0.015, OR=0.108, 95% confidence interval (95% CI), 0.018-0.646], lymphadenopathy (P=0.001, OR=0.055, 95% CI, 0.009-0.323) and T-A/PVP (P=0.004, OR=5.3E-5, 95% CI, 0.000-0.044) were independent factors for differentiating LMs of poorly-differentiated from well-differentiated GEP-NENs.

Conclusions

Dynamic enhanced CT features (intratumoral neovascularity, lymphadenopathy and T-A/PVP) are useful in the pathological classification of LMs of GEP-NENs.

Two patients with rare mixed adenoneuroendocrine carcinomas of the rectum

Mixed adenoneuroendocrine carcinomas of the gastrointestinal tract are until today poorly understood and thus very challenging for interdisciplinary therapy. We herewith report the first case series of patients with a primary mixed adenoneuroendocrine carcinoma of the rectum. Both cases were initially diagnosed as adenocarcinoma and only secondarily with mixed adenoneuroendocrine carcinoma and had a poor outcome due to a rapid tumor progression and resistance to chemotherapy. A 65-year-old female presented with local tumor recurrence and hepatopulmonary metastasis 1 year after primary surgery for adenocarcinoma of the rectum and consecutive radiochemotherapy regimen. Fluorouracil (5-FU) was followed by bevacizumab- and capecitabine-based chemotherapy but had to be discontinued due to side effects and progressive disease. Progressive local pain syndrome accompanied by recurrent bleeding episodes led to a local tumor-debulking operation. Afterward, mixed adenoneuroendocrine carcinoma as the underlying diagnosis in the final histopathological examination was detected. The patient died 3 months after the operation in the context of a fulminant tumor progress. A 63-year-old male patient underwent neoadjuvant radiochemotherapy and laparoscopic rectum resection. After 5 months, postoperative oxaliplatin/capecitabine-based adjuvant chemotherapy was switched to carboplatin/etopsid due to a progressive polyneuropathy and biopsy-proven pulmonary metastasis. The patient then had to be switched to local radiation of cerebral metastases and Topotecan due to cerebral bleeding episodes but died 18 months after the initial diagnosis. In conclusion of our case series, mixed adenoneuroendocrine carcinomas of the rectum should be considered as a rare but aggressive tumor entity. An early and detailed histopathological diagnosis is required in order to establish an individual interdisciplinary treatment concept.

Extremely Long Survival under Combined Immunotherapy in a Metastatic Functional Neuroendocrine Neoplasia Patient

Treatment and prognosis of neuroendocrine neoplasia depends on tumor size, stage, grade, resectability, and extent of distant metastasis. In most cases a multimodality approach including surgical, locally invasive procedures, peptide-guided radioreceptor therapy (PRRT), and medical therapies represent the mainstay of treatment in advanced disease. In the reported case, a 68-year-old man was diagnosed in 2010 with an initially functional (histamine) neuroendocrine tumor of gastric type III, G2, stage IVB, cT4cN1cM1 (hepatic, peritoneal, nodal, osseous), including a hepatic tumor load of 25%. Intensive multimodality approaches including combined immunotherapy (vaccination and PD-1/CTLA-4 blockade) led to a survival of 8 years until now with a high quality of life and minimal residual disease (only a single, small paragastric recurrence) despite the dedifferentiation of the tumor into a neuroendocrine carcinoma G3 (Ki-67 of 80%) including a nonfunctional stage.

Sex comb on midleg like-2 is a novel specific marker for the diagnosis of gastroenteropancreatic neuroendocrine tumors

Sex comb on midleg like-2 (SCML2) is a polycomb-group protein that encodes transcriptional repressors essential for appropriate development in the fly and in mammals. On the basis of previous findings, the present study aimed to explore the possibility of developing SCML2 into a new diagnostic marker for gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A total of 64 paired GEP-NET tissues and adjacent non-tumorous tissues were obtained from patients who had undergone surgical resection between January 2009 and January 2014, and the expression of SCML2 and two neuroendocrine markers, namely synaptophysin (Syn) and chromogranin A (CgA), in the tissues was assessed by immunohistochemistry. Strong SCML2 staining was observed predominantly in the cell nuclei of GEP-NET tissues, and the overall expression rate and staining intensity of SCML2 were higher than those of Syn or CgA, respectively. Spearman rank correlation analysis demonstrated that SCML2 was not correlated with either Syn or CgA, while the combined detection of SCML2 with Syn or with CgA increased the diagnostic sensitivity to 100%. SCML2 expression in GEP-NETs was associated with several clinicopathological parameters, such as histological type, tumor grade, depth of invasion and clinical stage. Kaplan-Meier survival curves revealed that patients with higher SCML2 expression had lower survival rates than those with lower expression levels, while Cox proportional hazards regression analysis revealed that SCML2 was not an independent prognostic factor for GEP-NET patients. Therefore, SCML2 may have potential as a specific marker for joint use with other markers to improve the diagnostic efficiency of GEP-NETs.

Systematic review of resecting primary tumor in MNETs patients with unresectable liver metastases

BACKGROUND

Treatment for midgut neuroendocrine tumor patients with unresectable liver metastasis has long been a controversial issue. This system review aims to summarize existing evidence concerning the value of primary tumor resection in this group of patients.

RESULTS

8 cohort studies were identified for qualitative analysis. None of them strictly met with the inclusion criteria and meta-analysis was impossible. There was a tendency towards better overall survival for the primary tumor resected group in all 8 studies, in which 6 demonstrated significant difference. Progression free survival to liver disease was prolonged and less patients died of liver failure in the resected group.

METHODS

MEDLINE, EMBASE and CENTRAL were searched until 2016/7/4 for relevant studies, with primary outcome being overall survival, and secondary outcome being progression free survival, cause of death and symptom relief.

CONCLUSIONS

Current evidence supports resection of primary tumor for midgut neuroendocrine tumor patients with liver metastases, but randomized controlled trials are required to reach a final conclusion.

A Case Report: Gastric Mixed Neuroendocrine-Nonneuroendocrine Neoplasm with Aggressive Neuroendocrine Component

Mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) is defined as mixed epithelial neoplasms composed of both neuroendocrine and nonneuroendocrine components with variable proportions for each component. Neuroendocrine component can show morphological features including well- or poorly differentiated neuroendocrine neoplasms and nonneuroendocrine component can present different tumor types depending on the site of origin. Recently, studies of tumors have shown that MiNENs are not as rare as our traditional belief, due to the wide application for immunohistochemistry. However, our knowledge of MiNENs is still limited. There is no universal consensus about nomenclature, classification, and guideline of treatment. Hereby, we would like to present a case report of gastric MiNEN with aggressive neuroendocrine component to contribute a small part towards common understanding of gastric MiNENs.

The correlation and clinical implication of VEGF-C expression in microvascular density and lymph node metastasis of gastric carcinoma

As the most common malignant tumor, gastric cancer had persistently high occurrence and mortality rate worldwide. Unfavorable treating outcome occur due to distal metastasis, making the inhibition of angiogenesis and managing tumor metastasis being crucial factors for affecting prognosis. Vascular endothelial growth factor-C (VEGF-C) is one important angiogenesis factor and mainly facilitates proliferation and differentiation of vascular endothelial cells in angiogenesis. It has been indicated in development and occurrence in gastric cancer, while its expression and correlation with microvascular density (MVD)/lymph node metastasis are still unclear. A total of 52 gastric tumor and 25 normal tissue samples were recruited for quantifying mRNA and protein expression of VEGF-C by real-time PCR and Western blotting. MVD and lymph tube density were quantified for further analysis of the correlation between VEGF-C and pathological parameters including clinical stage and lymph node metastasis. Both mRNA and protein levels of VEGF-C were significantly elevated in gastric tissues (p<0.05). In lymph node metastasis cases, VEGF-C was further potentiated compared to non-metastatic group (p<0.05). VEGF-C expression was positively correlated with MVD, lymph tube density and clinical stage (p<0.05) but not with age, sex or differentiation grade. VEGF-C expression is closely correlated with lymph node metastasis of gastric cancer. It may participate in the progression of gastric cancer via facilitating angiogenesis and lymph node metastasis, thus can be used in predicting prognosis of patients with gastric carcinoma.

Gastric neuroendocrine tumor treated with endoscopic submucosal dissection

A case of a 59-year-old male patient with gastric neuroendocrine tumor which was misdiagnosed as adenocarcinoma, is presented. Herein, primary diagnosis was made due to the similarity of endoscopic pictures of both diseases and dues to the inappropriate interpretation of a small biopsy sample. The patient was qualified for endoscopic submucosal dissection. Microscopic examination of whole lesion, supplemented by immmunohistochemical reactions (chromogranin A, synaptophysin, cytokeratins 7 and 20, Ki67) revealed gastric neuroendocrine tumor (NET) G2.

The lesson learnt is that to provide effective treatment to the patient, it is necessary to use all available methods to make a proper diagnosis and to distinguish the suspected disease from others with similar features.

Clinicopathological and Prognostic Evaluations of Mixed Adenoneuroendocrine Carcinoma of the Colon and Rectum: A Case-Matched Study

BACKGROUND

Mixed adenoneuroendocrine carcinoma of the colon and rectum is a very rare type of tumor.

OBJECTIVE

The aim of the present study was to evaluate the clinicopathological characteristics and prognosis of mixed adenoneuroendocrine carcinomas of the colon and rectum.

DESIGN

This was a retrospective case-matched analysis (from March 2007 to December 2013).

SETTINGS

This study was conducted at Yokosuka Kyosai Hospital.

PATIENTS

One thousand three hundred six consecutive patients with a preoperative diagnosis of colorectal cancer and who underwent tumor resection were enrolled in the present study. Each patient diagnosed with mixed adenoneuroendocrine carcinoma was 1:2 matched with 2 counterparts who had been diagnosed with adenocarcinoma.

INTERVENTION

Immunohistochemical staining for neuroendocrine markers (chromogranin A, synaptophysin, and CD56) was performed. Cases in which the neuroendocrine component accounted for >30% of the tumor were diagnosed as mixed adenoneuroendocrine carcinomas.

RESULTS

Among 1306 patients, 42 patients (3.2%) were diagnosed with mixed adenoneuroendocrine carcinoma and were compared with 84 patients with adenocarcinoma who had been randomly case matched. The average Ki-67-labeling index value was 78.0% (range, 30.0%-99.0%). Chromogranin A, synaptophysin, and CD56 positivity were observed in 42.9% (18/42), 81.0% (34/42), and 33.3% (14/42) of the tumors. Both the disease-free survival and overall survival were significantly worse for mixed adenoneuroendocrine carcinoma than for adenocarcinoma. Ten patients underwent treatment with oxaliplatin-based chemotherapy. The response rate was 40.0%; the median progression-free survival and overall survival were 6.3 months and 18.1 months.

LIMITATIONS

This was a retrospective single-institution study that included a limited number of cases. The treatment regimens used included different types of oxaliplatin-based chemotherapy.

CONCLUSION

Mixed adenoneuroendocrine carcinoma of the colon and rectum has a poor prognosis after curative resection and should be distinguished from adenocarcinoma.

A Previously Undescribed Presentation of Mixed Adenoneuroendocrine Carcinoma

We report a case of mixed adenoneuroendocrine carcinoma (MANEC) of stomach with tubular adenoma and well-differentiated neuroendocrine tumor (WD-NET) in the primary tumor in the stomach giving rise to biphenotypic regional nodal metastases. A 35-year-old woman with abdominal pain was found to have a 1.8-cm gastric lesion, diagnosed as WD-NET (intermediate grade) on the biopsy. The resection specimen contained residual WD-NET; there was also a gastric adenoma adjacent to the NET and nodal metastasis with both adeno- and neuroendocrine components. The tumor was classified as MANEC. Of note, the entire gastric tissue was submitted and multiple deeper levels of the adenomatous lesion were examined; no adenocarcinoma was present in the primary lesion. While association of gastric adenoma with neuroendocrine neoplasm is rare, presence of biphenotypic metastasis originating from such a lesion is highly unusual and to the best of our knowledge has not been reported.

CEA Level, Radical Surgery, CD56 and CgA Expression Are Prognostic Factors for Patients With Locoregional Gastrin-Independent GNET

Gastrin-independent gastric neuroendocrine tumors (GNETs) are highly malignant. Radical resections and lymphadenectomy are considered to be the only possible curative treatment for these tumors. However, the prognosis of gastrin-independent GNETs is not well defined. In this study, we identified prognostic factors of locoregional gastrin-independent GNETs.All patients diagnosed with locoregional gastrin-independent GNETs between 2000 and 2014 were included in this retrospective study. Clinical characteristics, blood tests, pathological characteristics, treatments, and follow-up data of the patients were collected and analyzed.Of the 66 patients diagnosed with locoregional gastrin-independent GNETs, 57 (86.4%) received radical resections, 7 (10.6%) with palliative resection, 1 (1.5%) with gastrojejunostomy, and 1 (1.5%) with exploration surgeries. The median survival time for these patients was 19.0 months (interquartile range, 11.0-38.0). The 1-, 3-, and 5-year survival rates were 72%, 34%, and 28%, respectively. Multivariate analysis indicated that carcinoembryonic antigen (CEA) level (P = 0.04), radical resection (P = 0.04), and positive Cluster of Differentiation 56 (CD56) expression (P = 0.016) were significant prognostic factors on overall survival rate. Further univariate and multivariate analysis of 57 patients who received radical resections found that CgA expression (P = 0.35) and CEA level (P = 0.33) are independent prognostic factors.Gastrin-independent GNETs had poor prognosis. Serum CEA level, radical surgery, CD56 and CgA expression are markers to evaluate the survival of patients with locoregional gastrin-independent GNETs.