Adenoma, adenocarcinoma and mixed carcinoid-adenocarcinoma arising in a small lesion of the colon

Mixed adenoneuroendocrine carcinoma of the colon and rectum

Mixed adenoneuroendocrine carcinoma (MANEC) are rare cancers of the gastrointestinal (GI) and pancreatobiliary tract. They are characterized by the presence of a combination of epithelial and neuroendocrine elements, where each component represents at least 30% of the tumour. Review of literature and consolidation of clinicopathological data. Sixty-one cases of colorectal MANEC have been reported in literature and one seen in this centre. The median age of the patients affected was 61.9 ± 12.4 years (20-94 years). Male to female ratio is 1.0:1.2. Presentations were similar to other colorectal malignancies. 58.0% of colorectal MANECs were found in the right colon, 8.1% cases in the transverse, 16.1% in the left colon, 16.1% in the rectum. These tumours appeared invasiveness 79.1% were T3-T4. Over 90% of cases were presented with metastatic disease. The majority of patient underwent surgical resection of the primary cancer (96.6%). Of these, 10 operations (17.9%) were emergency operations due to obstruction, perforation, or bleeding. Three patients received first line palliative care. In eight cases (13.8%), patients underwent adjuvant chemotherapy. The median overall survival after diagnosis was 10 ± 2.4 months (95% CI: 5.37-14.64 months). MANECs are rare but aggressive colorectal cancers. Surgical resection of localized disease with adjuvant chemotherapy appears to significantly improve survival in small case series. Further understanding through the sharing of experiences is required.

Management of MANEC of the colon and rectum: A comprehensive review of the literature

Mixed adeno-neuroendocrine carcinoma (MANEC) is a rare pathological diagnosis recently acknowledged by the World Health Organization in 2010. MANEC is a neoplasm characterized by significant histological heterogeneity and is characterized by the simultaneous presence of both adenocarcinomatous and neuroendocrine differentiation; their definition includes each component found in at least 30% of the tumor. Colorectal MANEC constitutes an uncommon type of malignant tumor. The true prevalence of colorectal MANEC has not been precisely defined and published studies are limited to case reports and small case series. The aim of the present review was to accumulate the existing evidence on colorectal MANEC with special attention to the clinicopathological characteristics, management and survival rates of patients diagnosed with this malignancy. A total of 20 studies (16 case reports and 4 retrospective cohorts) reported outcomes for patients with colorectal MANEC and were finally considered eligible for analysis. The results of the present study show that patients with early stage MANEC have more favorable survival compared to those diagnosed in advanced stages. Due to its neuroendocrine nature, which is characterized by rapid progression, MANEC is diagnosed in advanced stages in the majority of cases and thus potentially explains the poor survival rates. Because of its aggressive nature and high recurrence rate, adjuvant chemotherapy constitutes a critical part of the treatment and significantly improves survival. Further larger studies are needed in order to establish guidelines for the treatment of these rare lesions.

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.

Mixed Adenoneuroendocrine Carcinoma of the Gastroesophageal Junction: A Rare Find

Neoplastic lesions that demonstrate neuroendocrine features are rare. However, esophageal tumors containing both adenocarcinomatous and neuroendocrine components are exceedingly rare. Mixed adenoneuroendocrine carcinomas (MANECs) are gastrointestinal tumors with both adenocarcinomatous and neuroendocrine differentiation. They have a tendency for early metastases but clinically manifest relatively late. Imaging studies are often nonspecific with regard to tumor type, and a histopathologic study of biopsy material is required for definitive diagnosis. The overall prognosis is poor. The current report describes a rare case of gastroesophageal MANEC tumor, with approximately 60% neuroendocrine and 40% adenocarcinomatous components. Since there is a dearth of concrete management guidelines for MANECs, we present possible management options to add to the existing literature.

Mixed Adenoneuroendocrine Carcinoma Causing Colonic Intussusception

Colonic intussusception is a rare cause of intestinal obstruction in adults and is caused by a malignant lesion in about 70% of cases. Early diagnosis and treatment are essential. We present a 64-year-old male patient with right colonic intussusception caused by a mixed adenoneuroendocrine carcinoma (MANEC), presenting as a giant pedunculated polyp (54 mm of largest diameter). The patient underwent right colectomy with primary anastomosis and adjuvant chemotherapy. The diagnosis of intussusception of the colon in adults is difficult because of its rarity and nonspecific clinical presentation. In this case, the cause was a rare histological type malignant tumor (MANEC).

Pulmonary collision tumor consisting of adenocarcinoma and typical carcinoid--a case report and review of literature

Collision tumors are rare in nature. We report a case of a 70-year-old woman who was found to have a new mass in the right lung. Right upper and middle lobectomies with a mediastinal lymph node sampling were performed. Pathological examination of the mass revealed a collision tumor composed of micropapillary adenocarcinoma and typical carcinoid. The neoplastic cells were not intimately admixed with one another. To the best of our knowledge, this case is the first report in the English medical literature of a primary pulmonary collision tumor consisting of micropapillary adenocarcinoma and typical carcinoid.

A case of very well-differentiated adenocarcinoma with carcinoid tumor in the ascending colon

Malignant tumors with mixed glandular and neuroendocrine characteristics with at least 30% of each component are classified as mixed adenoneuroendocrine carcinoma (MANEC) by the World Health Organization 2010 classification. We report here a case of very well-differentiated adenocarcinoma accompanied by carcinoid tumor, categorized as MANEC. A 41-year-old Japanese man was clinically diagnosed with ascending colon cancer and underwent right hemicolectomy. Using an immunohistologic technique, the pathologic diagnosis was very well-differentiated adenocarcinoma accompanied by carcinoid tumor and marked eosinophil infiltration, which was categorized as MANEC. By immunohistochemical analysis, tumor cells of the carcinoid component exhibited very low proliferation activity. Our case was thought to be MANEC without high malignant potential. MANEC as per the World Health Organization 2010 classification seems to include tumors with diverse grades of malignancy, and it might need to have subclassifications according to the malignancy potential of the tumor cells.

Low-grade neuroendocrine tumors arising in intestinal adenomas: evidence for alterations in the adenomatous polyposis coli/β-catenin pathway

Low-grade neuroendocrine tumors (NETs) arising in intestinal adenomas are rare. They are occasionally observed in patients with familial adenomatous polyposis (FAP), suggesting a role for the adenomatous polyposis coli/β-catenin pathway. We identified 25 composite adenoma/low-grade NETs from colorectum (21) and duodenum (4) and evaluated their clinicopathological features, survival, and nuclear β-catenin expression by immunohistochemistry. β-catenin staining was scored as % positivity × intensity (weak, 1; moderate, 2; and strong, 3), for a total possible score of 300. Control groups included 1781 adenomas without NET, 63 composite adenoma/high-grade neuroendocrine carcinomas (NECs), and 32 sporadic NETs. Among 25 adenoma/low-grade NETs, 4 (16%) occurred in patients with FAP. Size of the NET component ranged from 0.01 to 0.9 cm (mean, 0.32 cm). Most (84%) arose in "advanced" adenomas (size >1 cm, villous architecture [72%], or high-grade dysplasia [56%]). In contrast, villous architecture and high-grade dysplasia were present in only 14% (P < .001) and 7% (P < .001), respectively, of adenomas without NET. Overall survival with adenoma/low-grade NET was significantly higher than adenoma/high-grade NEC but significantly lower than sporadic NET (P < .001). Higher β-catenin expression was seen in adenoma/low-grade NETs (mean score, 231) compared with sporadic NETs (mean score, 48; P < .0001) and adenoma/high-grade NEC (mean score, 173; P = .04). In summary, composite adenoma/low-grade NETs most commonly occur with advanced polyps, but the NET component itself is generally small and indolent. In contrast to sporadic NETs, the occurrence of these lesions in FAP and their high levels of nuclear β-catenin expression support a pathogenic role for the adenomatous polyposis coli/β-catenin pathway.

Colorectal neuroendocrine carcinomas and adenocarcinomas share oncogenic pathways. A clinico-pathologic study of 12 cases

OBJECTIVE

Neuroendocrine carcinomas (NECs) are rare neoplasms with an increasing incidence. Oncogenetic pathways of colorectal NEC are still poorly understood, and no treatment standards are available for these rare tumors.

METHODS

We analyzed retrospectively the clinical records and histology of 12 patients with colorectal NEC. KRAS and BRAF mutations were investigated after the dissection of exoendocrine and neuroendocrine components. ALK alterations and EML4-ALK transcripts were detected by in-situ hybridization and determination of fusion transcripts, respectively.

RESULTS

At the time of diagnosis, the mean age of the patients was 60 years (40-79) and 10 patients had synchronous metastases. A transient response occurred in two patients and one patient treated with cisplatin-etoposide or fluoropyrimidine-oxaliplatin, respectively. Tumor progression-related death occurred in 11 of 12 patients. Ten tumors contained an exocrine component, accounting for 5-70% of the tumor, and the other two contained an amphicrine component. BRAF/KRAS mutations were found in six of 10 tumors, corresponding to BRAF(V600E) (n=2) or KRAS(G12D) (n=2), KRAS(G12V) or KRAS(G13D). DNA was obtained from both exocrine and endocrine components in seven cases, and the BRAF/KRAS status was identical in all cases. Split of the ALK locus was detected in a minority of tumor cells in two of eight cases, but EML4-ALK transcripts were absent.

CONCLUSION

The association of an exocrine component in all cases and the similar profile of BRAF/KRAS mutations indicate that colorectal NEC may correspond to a high-grade transformation of colorectal carcinoma. New chemotherapy regimens using targeted therapies should be assessed in these tumors.

Mixed Adenoneuroendocrine Carcinomas (MANECs) of the Gastrointestinal Tract: An Update

The systematic application of immunohistochemical techniques to the study of tumors has led to the recognition that neuroendocrine cells occur rather frequently in exocrine neoplasms of the gut. It is now well known that there is a wide spectrum of combinations of exocrine and neuroendocrine components, ranging from adenomas or carcinomas with interspersed neuroendocrine cells at one extreme to classical neuroendocrine tumors with a focal exocrine component at the other. In addition, both exocrine and neuroendocrine components can have different morphological features ranging, for the former, from adenomas to adenocarcinomas with different degrees of differentiation and, for the latter, from well differentiated to poorly differentiated neuroendocrine tumors. However, although this range of combinations of neuroendocrine and exocrine components is frequently observed in routine practice, mixed exocrine-neuroendocrine carcinomas, now renamed as mixed adenoneuroendocrine carcinomas (MANECs), are rare; these are, by definition, neoplasms in which each component represents at least 30% of the lesion. Gastrointestinal MANECs can be stratified in different prognostic categories according to the grade of malignancy of each component. The present paper is an overview of the main clinicopathological, morphological, immunohistochemical and molecular features of this specific rare tumor type.

Synchronous epithelial and neuroendocrine cancers of the pancreas: case series of a rare occurrence

The presence of neuroendocrine cells in adenocarcinomas is not an unusual finding and is well described in gastrointestinal tract cancers, eg, colorectal cancer and gastric cancer. Genetic analysis of such tumors has suggested a common multipotent progenitor stem cell origin. The prognostic significance of neuroendocrine cells in adenocarcinoma cells is unclear. There is a scant literature on synchronous pancreas ductal adenocarcinoma and pancreas neuroendocrine tumors. We report 2 cases with a purpose of discussing management strategies, prognosis, and potential etiologies of this rare presentation.

Perforated mixed carcinoid-adenocarcinoma in transverse colon and at gastroenterostomy site: case report

Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm.

Colonic carcinoid tumors: a clinicopathologic study of 23 patients from a single institution

CONTEXT: Colonic carcinoids, excluding those arising in the appendix, have proved to be extremely rare. Due to their rarity, the characteristics and behavior of this unusual malignancy remain unclear. OBJECTIVE: To review the clinicopathologic features of patients operated on carcinoid tumors of the colon. METHODS: Twenty-three patients (12 males and 11 females) were operated on colonic carcinoids. The mean age of the patients was 63.0 ± 12.9 years (42 to 85 years). The clinical and histopathological data of patients who were pathologically diagnosed as having carcinoid tumors and submitted to surgical treatment over a 30-year period (1977-2007) were gathered. Actuarial patient survival was estimated using the Kaplan-Meier method, with carcinoid-specific death as the outcome. RESULTS: The mean time elapsed between onset of symptoms and surgical treatment was 8.3 months (1.5 to 20 months). The most frequent symptoms or signs encountered were abdominal pain followed by anorexia or weight loss, diarrhea, abdominal tenderness, palpable abdominal mass, and rectal bleeding. No carcinoid syndrome was noted. The lesion was located in the cecum in 16 (69.6%) patients, in the sigmoid in 3 patients (13.0%), in the ascending colon in 3 patients (13.0%), and in the transverse colon in one patient (4.3%). Twenty-one (91.3%) patients were operated on curative intent. Spreading of the disease to the liver and peritoneum was found in two (8.7%) patients who submitted to intestinal bypass. The mean size of the largest mass was 3.7 ± 1.2 cm (1.5 to 6.2 cm). There were multiple (two or more) lesions in three cases (13.0%). In the resected cases, the lymph nodes were compromised in 10 patients (47.6%) and disease-free in 11 (52.4%). Venous invasion and neural infiltration were both present in five (23.8%) patients. The tumors had penetrated the muscularis propria in all resected cases. Four (17.4%) patients had a second non-carcinoid primary tumor. Three (13.0%) patients died due to postoperative complications and five (21.7%) patients died from metachronous metastases or local recurrence. Fifteen patients (65.2%) remain alive without evidence of active disease. The mean follow-up period was 12 years (1.2 to 18 years), whereas the mean global survival was 50.7 ± 34.2 months and the crude survival rate at 5 years was 62.7%. CONCLUSIONS: Carcinoid tumors of the colon are frequently right-sided and may be clinically occult until an advanced stage is reached. Based on the relatively poor survival rates reported, it is recommended that, in addition to standard surgical resection, vigorous surveillance for metastatic disease must be performed, particularly during the first 2 years after surgery. In addition, these patients require evaluation of the entire gastrointestinal tract for evidence of coexisting malignancy, along with an extended period of follow-up, because tumor recurrences after 5 years are not uncommon.

Goblet cell carcinoids and other mixed neuroendocrine/nonneuroendocrine neoplasms

Within the spectrum of neuroendocrine tumors arising in different organs, intermediate and controversial entities exist displaying a coexistence of neuroendocrine and nonneuroendocrine cell populations, and that are grouped under terms such as "goblet cell carcinoid", "mixed endocrine-exocrine carcinoma", "combined carcinomas", or "adenocarcinoma with neuroendocrine differentiation". These tumors may display variable amounts of the two components, potentially ranging from 1 to 99%, and variable structural patterns, ranging from single scattered neuroendocrine cells to a well-defined neuroendocrine tumor cell component organized in typical organoid, trabecular, or solid growth patterns. Although variably included in the site-specific World Health Organization classification schemes, clear definitions and diagnostic features are still missing, as well as a definite knowledge of their biological properties and histogenesis. In the present report, the main characteristics of tumors showing mixed neuroendocrine and nonneuroendocrine features will be described, using morphological patterns and site of origin as schematic guidelines. Moreover, molecular and clinical aspects, which might help to understand their possible histogenesis and biological behavior, will be reviewed.

[Mixed endocrine tumors]

Mixed endocrine tumors are tumors composed of at least two distinct tumor populations, one of which is endocrine. Because of their rarity and unusual presentation, endocrine mixed tumors raise many problems of diagnosis, management and therapy. Three main types of endocrine mixed tumors are recognized: The existence of these various types has been confirmed by recent molecular studies, even if the same studies have also shown that the histogenesis of a mixed endocrine tumor cannot be predicted from its histological features. Composite tumors are the less rare mixed tumors. The recent WHO classification recommends to restrict the term of composite endocrine tumor to the epithelial tumors containing at least 30% of obviously tumoral endocrine cells; some authors recommend to use higher thresholds, of at least 50%, in order to avoid overdiagnosis. The endocrine component is usually well differentiated, easily identified by its suggestive histological features; the endocrine nature of tumor cells is confirmed by the immunodetection of specific endocrine and neuro-endocrine markers (such as chromogranin A and synaptophysin). In some cases, the endocrine component is poorly differentiated: the demonstration of neuro-endocrine markers is necessary to confirm the diagnosis. Mixed tumors can occur in every anatomical site; they are more frequent in organs containing endocrine cells in the normal state (especially the digestive tract and the pancreas), but they can also be observed in organs devoid of endocrine cells (such as the mammary gland). The management of mixed endocrine tumors must take into account the more aggressive component. Mixed tumors containing a well differentiated endocrine component and an adenocarcinomatous component are to be treated like adenocarcinomas. Mixed tumors containing a poorly differentiated endocrine component must be considered as poorly differentiated endocrine carcinomas.