Clinicopathologic significance of gastric adenocarcinoma with neuroendocrine features

MANEC TUMOR OF RECTUM. A RARE CASE SERIES OF 3 PATIENTS AND A LITERATURE REVIEW

The term Mixed Adeno-Neuro-Endocrine Carcinoma (MANEC) was introduced in 2010 by the WHO Classification of Tumors of the Digestive System. It refers to a neoplasm with dual epithelial and neuroendocrine differentiation, each component representing at least 30% of the tumor. It is an uncommon tumor accounting for < 3% of all colon and rectum malignancies. We report three cases of this extremely rare MANEC of the rectum. All three cases presented with hematochezia, variable constipation, and abdominal pain. They were diagnosed and staged appropriately with colonoscopy, biopsy with immunohistochemistry, and imaging. They underwent an anterior resection with circular stapled anastomoses. Because of the low incidence of this histotype, we reviewed the clinical presentation, diagnostic characteristics, and treatment of MANEC of the colon and rectum.

Gastric Mixed Adenoneuroendocrine Carcinoma with Revised Diagnosis after Retrospective Pathologic Review

Gastric mixed adenoneuroendocrine carcinoma (MANEC) is an entity defined by World Health Organization in 2010, which is composed of adenocarcinoma and neuroendocrine neoplasm. This is a very rare type of tumor in the stomach, which is estimated to be one to two per one million people per year on gastrointestinal track. In general, as MANEC often shows a poor prognosis, early diagnosis of the disease is important for achieving a favorable outcome. However, due to its rarity and histological heterogeneity, it is hard to suspect this disease initially, and sometimes this tumor is misdiagnosed as adenocarcinoma. The present case was a 76-year-old man who was initially diagnosed with gastric tubular adenocarcinoma without distant metastasis. Only 1 month after a curative surgery, multiple liver metastases were newly detected. Retrospective pathologic review resulted in a revised diagnosis as a gastric MANEC, and the patient underwent palliative systemic chemotherapy to achieve partial response.

[Mixed Neuroendocrine-non-neuroendocrine Neoplasm of the Stomach that is Distributed in Depth on the Same Tumor: Inconsistent with the Definition of Mixed Adenoneuroendocrine Carcinoma in the 2010 World Health Organization Classification of Tumors of the Digestive System]

A mixed adenoneuroendocrine carcinoma (MANEC) of the stomach is a rare disease entity that was first defined by the World Health Organization (WHO) classification (2010) for tumors of the digestive system. According to the WHO classification (2010), MANEC is referred to as a tumor with both neuroendocrine and non-neuroendocrine neoplasms; each component of the tumor should be at least 30%. On the other hand, this cut-off value lacks clinical evidence and does not explain the characteristics and heterogeneity of this tumor. A 66-year-old male diagnosed with early gastric cancer (EGC) at a community hospital was referred to the Kosin University Gospel Hospital for further evaluation of gastric cancer. Esophagogastroduodenoscopy and EUS performed at the Kosin University Gospel Hospital revealed a sub-mucosal tumor-like component. In addition, a re-biopsy revealed a neuroendorine tumor at different depths of the same tumor. The final pathologic-diagnosis through surgery revealed a mixed neuroendocrine- non-neuroendocrine neoplasm, which is inconsistent with the definition of MANEC. Clinicians should consider EUS when a tumor has atypical endoscopic findings, even if EGC has already been diagnosed.

Mixed adenoneuroendocrine carcinoma of the liver: A rare case report

A 55-year-old woman presented with chest and back pain of unknown cause. Contrast-enhanced computed tomography revealed two low-density tumors, sized 4.6 and 4.4 cm, in the hepatic caudate and left inner lobes, respectively. There are multiple enlarged lymph nodes around the abdominal aorta, hepatogastric ligament and gastrosplenic ligament. At the same time, there were multiple enlarged lymph nodes between the portal vein and the vena cava. Upper gastrointestinal endoscopy revealed chronic non-atrophic gastritis and esophagitis (grade B). Endoscopic examination of the lower digestive tract revealed polyps of the colon, diagnosed as tubular adenomas following biopsy and histopathological examination. The patient underwent left three hepatic resection (including left inner lobe, left outer lobe and right anterior lobe resection), abdominal lymph node dissection, right liver tumor radiofrequency ablation, hepatic caudate lobe resection, intestinal adhesion release, vena cava formation, portal vein repair and hilar cholangioplasty. The pathological examination of the resected specimens revealed intrahepatic bile duct carcinoma and hepatic parenchymal neuroendocrine tumor (NET). In addition, liver solid portions consisted of tumor cells with characteristic salt-and-pepper nuclei. Immunohistochemical examination revealed expression of the neuroendocrine marker synaptophysin in this solid component, confirming the diagnosis of NET. Furthermore, the MIB-1 proliferation index of the NET was higher compared with that of the adenocarcinoma, and lymph node invasion by the NET component was detected, indicating a neuroendocrine carcinoma (NEC, or NET G3). The diagnosis of mixed adenoneuroendocrine carcinoma of the liver was confirmed based on the World Health Organization 2010 criteria. Taking into consideration the patient's poor general condition, only symptomatic supportive treatment was administered postoperatively, without chemotherapy. Contrast-enhanced computed tomography at 45 days postoperatively revealed disease progression, with metastases in the liver stump, abdominal lymph nodes, spine and pelvis. The patient remained on symptomatic supportive treatment and succumbed to disease progression 3 months after surgery.

Rare presentation of small bowel adenocarcinoma with neuroendocrine differentiation in the jejunum: A case report and summary of diagnostic and management options

Cancer of the small bowel (SB) is rare. The most common SB malignancy is neuroendocrine, followed by adenocarcinoma. SB adenocarcinoma with overlapping neuroendocrine differentiation (NED) is very uncommon. The present case report discusses the case of a young African American female who presented with high-grade SB perforation and underwent urgent surgical repair. Histology of the tumor revealed jejunal adenocarcinoma with NED. To the best of our knowledge, this type of tumor has not yet been reported in the jejunum. Referring patients that present with insidious and nonspecific abdominal discomfort for imaging studies that are more sensitive to the SB could potentially identify tumors earlier, prevent the development of emergent gastrointestinal complications and offer a chance for cure. An overview of diagnostic tools for SB evaluation was provided.

Prognostic Threshold of Neuroendocrine Differentiation in Gastric Carcinoma: a Clinicopathological Study of 945 Cases

Purpose

The significance of neuroendocrine differentiation (NED) in gastric carcinoma (GC) is controversial, leading to ambiguous concepts in traditional classifications. This study aimed to determine the prognostic threshold of meaningful NED in GC and clarify its unclear features in existing classifications.

Materials and Methods

Immunohistochemical staining for synaptophysin, chromogranin A, and neural cell adhesion molecule was performed for 945 GC specimens. Survival analysis was performed using the log-rank test and univariate/multivariate models with percentages of NED (P_NED) and demographic and clinicopathological parameters.

Results

In total, 275 (29.1%) cases were immunoreactive to at least 1 neuroendocrine (NE) marker. GC-NED was more common in the upper third of the stomach. P_NED, and Borrmann's classification and tumor, lymph node, metastasis stages were independent prognostic factors. The cutoff P_NED was 10%, beyond which patients had significantly worse outcomes, although the risk did not increase with higher P_NED. Tumors with ≥10% NED tended to manifest as Borrmann type III lesion with mixed/diffuse morphology and poorer histological differentiation; the NE components in this population mainly grew in insulae/nests, which differed from the predominant growth pattern (glandular/acinar) in GC with <10% NED.

Conclusions

GC with ≥10% NED should be classified as a distinct subtype because of its worse prognosis, and more attention should be paid to the necessity of additional therapeutics for NE components.

Gastric Endocrine Carcinoma: A New Look at a Rare Tumor From Cases in Japan

Objective:

We evaluated the clinicopathologic factors associated with gastric neuroendocrine carcinoma (NEC) in patients who underwent surgical resection. Gastric NEC is rare, accounting for only about 0.6% of all malignant gastric tumors. Neither its pathogenesis nor its treatment has been fully established.

Methods:

We assessed 10 patients with gastric NEC who underwent surgical resection in our hospital between September 2007 and June 2019.

Results:

The patients consisted of 9 men and 1 woman, aged 63 to 78 years. The tumors were localized in the upper region (n = 5), middle region (n = 3), and lower region (n = 2). The macroscopic types were evaluated as 0-IIc (n = 3), 1 (n = 3), 2 (n = 1), 3 (n = 2), and 4 (n = 1). The stages were ascertained as IA (n = 3), IIB (n = 3), IIIA (n = 2), IIIB (n = 1), and IIIC (n = 1). Radical resection was performed in all the patients. After surgery, relapse-free survival was achieved in 6 patients. The mean postoperative survival time was 63.5 months. On immunostaining, 6 patients were positive for CD56, and all were positive synaptophysin and chromogranin A. Of the 10 patients, standard-type adenocarcinoma was concomitantly present in 6.

Conclusions:

Some patients with surgically resected gastric NEC survived over a long period, suggesting the usefulness of radical resection. In future studies, the pathogenesis of gastric NEC should be fully clarified, and therapeutic strategies must be further developed.

Gastric adenocarcinoma is concurrent with metastatic neuroendocrine cancer treated with nivolumab and chemotherapy: A case report

Gastric adenocarcinoma concurrent with metastatic neuroendocrine cancer (NEC) is rare. In the present case report, a 39-year-old male was first pathologically diagnosed by gastric endoscopy as having a highly differentiated adenocarcinoma. Next, positron emission tomography-computed tomography examination and bone marrow biopsy confirmed extensive metastasis. Subsequently, the patient underwent 6 cycles of immunotherapy (nivolumab, 160 mg) and 5 cycles of chemotherapy based on the XELOX regimen (oxaliplatin + capecitabine). Following this, the patient received the final cycles of nivolumab and XELOX; however, the patient then succumbed. Further biopsy of the metastatic collarbone lymph nodes indicated NEC. Overall, the progression-free survival was ~3.5 months, and overall survival (OS) was ~6 months. The case presented the possibility of concurrent gastric adenocarcinoma and NEC in the clinic. In addition, the efficacy of a combined regimen such as immunotherapy and chemotherapy for such disorders still requires further validation in the future.

Mixed adenoneuroendocrine carcinoma in the stomach: a case report with a literature review

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare disease that was first defined in the 2010 World Health Organization classification of endocrine tumors. We present the case of a 65-year-old man with an ulcerative depressed lesion measuring 3 cm in diameter and found in the lower gastric body. It was diagnosed as a MANEC, and we performed subtotal gastrectomy with D2 lymph node dissection. The patient is still alive, and no recurrence was observed at a 12-month follow-up. Most MANECs tend to have a poor prognosis. Curative resection, including an adequate lymph node dissection, should be considered, and intense follow-up is needed.

Mixed adenoneuroendocrine carcinoma (MANEC) of the gastroesophageal junction: a case report and review of the literature

Esophageal cancer is the fourth most common neoplasm of the gastrointestinal tract. It is responsible for 1.7% of all deaths related with cancer. The two main types of esophageal cancer are squamous cell carcinoma and adenocarcinoma. Other types of esophageal cancer are uncommon. We present a 57-year-old man admitted to the hospital with nausea and vomiting due to a high-grade malignant mixed adenoneuroendocrine carcinoma of the gastroesophageal junction. The patient underwent Ivor-Lewis esophagectomy and adyuvant chemoradiotherapy. At 8-month follow-up he was alive without evidence of recurrence.

Cervical Carcinoma With Divergent Neuroendocrine and Gastrointestinal Differentiation

Neuroendocrine carcinomas of the uterine cervix are rare tumors with aggressive behavior. They comprise <4% of cervical carcinomas. They may coexist with both adenocarcinoma and squamous cell carcinoma of cervix. Signet ring carcinoma of cervix is a rarer entity and less than 20 cases have been described in the literature. We present a case of a 34-year-old female who presented with systemic thrombosis, splenic mass and a cervical mass which on biopsy showed divergent differentiation of primitive large cell neuroendocrine carcinoma with signet ring cells. The cervical tumor was positive for human papilloma virus 16/18 by in situ hybridization, confirming cervical origin of the tumor. This unusual presentation and morphology needs to be recognized and appropriately evaluated when patients present with tumors of unknown origin in metastatic sites.

Comparison of relapse-free survival in gastric neuroendocrine carcinoma (WHO grade 3) and gastric carcinoma

BACKGROUND

We compared relapse-free survival (RFS) in gastric neuroendocrine carcinoma (WHO grade 3) and gastric carcinoma (GC). This is one of very few studies that compare the prognosis of poorly differentiated neuroendocrine carcinoma (WHO grade 3, G3 NEC) with that of GC.

METHODS

Between 1996 and 2014, 63 patients were diagnosed with G3 NEC of the stomach and 56 with gastric neuroendocrine tumors (NETs) with GC at Asan Medical Center in Seoul, Korea. We also randomly selected 762 patients diagnosed with GC between 1999 and 2008.

RESULTS

Patients with G3 NEC tumors that invaded the muscularis propria or shallower had poorer RFS than those with GC of the same type, while G3 NEC that invaded the subserosa or deeper had similar RFS to GC of that type. Patients diagnosed with G3 NEC with N0 or N2 had poorer RFS than the corresponding patients with GC, while those who had G3 NEC with N1 or N3 had similar RFS to the corresponding patients with GC. G3 NEC patients had poorer RFS than well-differentiated, moderately differentiated and poorly differentiated GC patients, while G3 NEC patients had similar RFS to that of those with signet ring cell carcinoma (SRC). In addition, patients with G3 NEC of stages I or IIa had poorer RFS than those with corresponding GC, while G3 NEC stage IIb or greater had similar RFS to the corresponding GC.

CONCLUSIONS

Non-advanced G3 NEC showed poorer RFS than GC excluding SRC, while advanced G3 NEC has a similar RFS to that of GC without SRC. Therefore, we recommend that patients with non-advanced G3 NEC of the stomach be given a more aggressive treatment and surveillance than those with non-advanced GC excluding SRC.

Coexisting tubular adenoma with a neuroendocrine carcinoma of colon allowing early surgical intervention and implicating a shared stem cell origin

High-grade colonic neuroendocrine carcinomas (NECs) are uncommon but extremely aggressive. Their co-existence with tubular adenoma (TA) has rarely been reported. We present a 68-year-old man who was found on routine colonoscopy to have multiple colorectal TAs and an ulcerated lesion in the ascending colon. Microscopically, a poorly-differentiated invasive carcinoma juxtaposed with a TA was identified. Differential diagnosis included a poorly-differentiated adenocarcinoma, medullary carcinoma, high-grade NEC and lymphoma. The immunohistochemical profile showed positive staining for keratins, synaptophysin and chromogranin but negative for LCA, CDX2, CK7, CK20, TTF-1 and PSA, supporting the NEC diagnosis. Upon subsequent laparoscopic right hemicolectomy, the tumor was identified as a 3.0 cm umbilicated and ulcerated mass with an adjacent TA. Both TA and NEC showed positive staining for β-catenin indicating a shared colonic origin. The mitotic counts (77/10 high power fields) and a high proliferation rate (75% by Ki-67) corroborated a high-grade stratification. Mutational analysis indicated a wild-type BRAF and KRAS with mismatch repair proficiency. The AJCC (7^th edition) pathologic stage is pT3, pN0, pMx. The patient received adjuvant chemotherapy with cisplatin/etoposides for three cycles and will be followed up for a year to detect recurrence. In conclusion, the co-existence of TA with high grade-NEC in our case allowed early identification and intervention of the otherwise asymptomatic but aggressive tumor. In addition, the finding of a high-grade NEC within a large TA in this case suggests a link between the two lesions and could represent a shared stem cell origin.

Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: report of two cases

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation, each component representing at least 30% of the tumor. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. Our first case was diagnosed in a 74-years-old female as a polypoid lesion of the cecum with direct invasion in the transverse colon, without lymph node metastases. The second case was diagnosed in the stomach of a 46-years-old male as a polypoid tumor of the antral region that invaded the pancreas and presented metastases in 22 regional lymph nodes. The metastatic tissue was represented by the glandular component. In both cases, the tumor consisted of a moderately-differentiated tubular adenocarcinoma (with mucinous component in Case 1) intermingled with neuroendocrine carcinoma. Ki67 index was lower than 20% in Case 1, respectively higher than 20% in Case 2. The neuroendocrine component was marked by synaptophysin and neuron specific enolase, being negative for Keratins 7/20. The neuroendocrine component represented 60% in Case 1, and 40% in Case 2, respectively. The glandular components were marked by carcinoembryonic antigen, maspin and keratin 20/7 (Case 1/2). Both cases were proved to be microsatellite stable. Independently by the localization and tumor stage, MANECs appear to be highly malignant tumors, with high risk for distant metastases. The aggressiveness seems to depend on the endocrine component, independent of its proportion. The neuroendocrine component could be a dedifferentiated adenocarcinoma with a neuroendocrine phenotype.

Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: report of two cases

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation, each component representing at least 30% of the tumor. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. Our first case was diagnosed in a 74-years-old female as a polypoid lesion of the cecum with direct invasion in the transverse colon, without lymph node metastases. The second case was diagnosed in the stomach of a 46-years-old male as a polypoid tumor of the antral region that invaded the pancreas and presented metastases in 22 regional lymph nodes. The metastatic tissue was represented by the glandular component. In both cases, the tumor consisted of a moderately-differentiated tubular adenocarcinoma (with mucinous component in Case 1) intermingled with neuroendocrine carcinoma. Ki67 index was lower than 20% in Case 1, respectively higher than 20% in Case 2. The neuroendocrine component was marked by synaptophysin and neuron specific enolase, being negative for Keratins 7/20. The neuroendocrine component represented 60% in Case 1, and 40% in Case 2, respectively. The glandular components were marked by carcinoembryonic antigen, maspin and keratin 20/7 (Case 1/2). Both cases were proved to be microsatellite stable. Independently by the localization and tumor stage, MANECs appear to be highly malignant tumors, with high risk for distant metastases. The aggressiveness seems to depend on the endocrine component, independent of its proportion. The neuroendocrine component could be a dedifferentiated adenocarcinoma with a neuroendocrine phenotype.

Prognostic significance of neuroendocrine components in gastric carcinomas

BACKGROUND

Gastric neuroendocrine carcinomas (NECs) and mixed adenoneuroendocrine carcinomas (MANECs) are aggressive tumours but the prognostic significance of a neuroendocrine component in <30% of the tumour remains unclear. Here, the implication of neuroendocrine components in gastric carcinomas was assessed according to proportion.

METHODS

Surgically resected primary gastric carcinomas with neuroendocrine morphology (NEM; n=88) from 2000 to 2012 at Asan Medical Center were retrospectively reviewed. Neuroendocrine differentiation (NED) was defined as immunopositivity for one of three neuroendocrine markers (synaptophysin, chromogranin or CD56) within the NEM area. To validate the prognostic significance of NED, these cases were compared with 650 randomly selected gastric adenocarcinomas without NEM from the same time period.

RESULTS

Gastric carcinomas with NEM were reclassified as NEC (⩾70% NED, n=47), MANEC (30-70% NED, n=10), gastric carcinoma with 10-30% NED (GCNED, n=8) and carcinoma with <10% NED (n=23). The survival rates of patients with ⩾10% NED were significantly poorer than those with <10% NED but no survival difference was observed between NEC and MANEC. In univariate analyses, older age (⩾60years), larger tumour size (⩾4cm), advanced stage group, ⩾10% NED and lymphovascular or perineural invasion were indicative of a poor prognosis. Stage group and ⩾10% NED remained as independent prognostic factors by multivariate analysis.

CONCLUSIONS

A minor proportion (10-30%) of NED should not be overlooked in gastric carcinomas with NEM. NED should be carefully evaluated to predict patient outcomes and plan optimal additional therapies.

Mixed adenoneuroendocrine gastric carcinoma: a case report and review of the literature

We present a rare case of a gastric mixed adenoneuroendocrine tumor and review the related English literature. A 77-year-old Caucasian woman was admitted to our department with nausea, anorexia, weight loss, and anemia. Esophagogastroduodenoscopy showed a large (>7 cm) ulcerative mass in the greater curvature of the stomach. Biopsy showed the presence of an adenocarcinoma with moderate differentiation. The patient underwent D2 subtotal gastrectomy. Histopathological analysis revealed a diagnosis of mixed gastric adenoneuroendocrine carcinoma. The post-operative course was uneventful, and at the 6-month follow-up, the patient was alive without evidence of recurrence. Our review of the English literature suggested that such cases are most often reported from eastern countries. Multimodal treatment should be the aim for these patients because of the neuroendocrine component of the tumor.

Classification, clinicopathologic features and treatment of gastric neuroendocrine tumors

Gastric neuroendocrine tumors (GNETs) are rare lesions characterized by hypergastrinemia that arise from enterochromaffin-like cells of the stomach. GNETs consist of a heterogeneous group of neoplasms comprising tumor types of varying pathogenesis, histomorphologic characteristics, and biological behavior. A classification system has been proposed that distinguishes four types of GNETs; the clinicopathological features of the tumor, its prognosis, and the patient’s survival strictly depend on this classification. Thus, correct management of patients with GNETs can only be proposed when the tumor has been classified by an accurate pathological and clinical evaluation of the patient. Recently developed cancer therapies such as inhibition of angiogenesis or molecular targeting of growth factor receptors have been used to treat GNETs, but the only definitive therapy is the complete resection of the tumor. Here we review the literature on GNETs, and summarize the classification, clinicopathological features (especially prognosis), clinical presentations and current practice of management of GNETs. We also present the latest findings on new gene markers for GNETs, and discuss the effective drugs developed for the diagnosis, prognosis and treatment of GNETs.