Mixed adenoneuroendocrine carcinoma of the ampulla: Two case reports

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: Three case reports and a literature review

Mixed adenoneuroendocrine carcinoma is defined as a tumor with a mixture of adenocarcinoma components and neuroendocrine neoplasm components. Each of these two components of mixed adenoneuroendocrine carcinoma accounts for at least 30% of all tumors. Mixed adenoneuroendocrine carcinoma might be located in the ampulla of Vater, a very rare location compared to other organs. Thus, its treatment and prognosis plans have not been established yet. We report three cases of mixed adenoneuroendocrine carcinoma occurring in the ampulla of Vater. Each patient had a different clinical course. In general, difficulty in preoperative diagnosis, risk of early recurrence, and poor disease course were main hallmarks of mixed adenoneuroendocrine carcinoma arising from the ampulla of Vater. However, one patient in this case report survived although she did not receive adjuvant chemotherapy due to her old age. Therefore, it is important to establish a careful treatment strategy for mixed adenoneuroendocrine carcinoma arising from the ampulla of Vater.

Management and outcomes of mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A systematic review and pooled analysis of 56 patients

BACKGROUND

Tumors of mixed neuroendocrine and nonneuroendocrine histology are classified as collision, combined, or amphicrine and can occur in most organs, including the hepato-pancreato-biliary tract. Given the rarity of mixed adenoneuroendocrine carcinoma (MANEC) of the ampulla of Vater, the patient characteristics, management, and outcomes remain unclear. We sought to systematically review the worldwide literature on ampullary MANECs.

METHODS

Eligible studies were identified through a systematic search of the MEDLINE (via PubMed), Scopus, and Cochrane Library databases (end-of-search-date: January 5th, 2022), according to the PRISMA 2020 statement.

RESULTS

A total of 39 studies reporting on 56 patients with ampullary MANEC were included. The median age was 63.0 (interquartile range [IQR]: 51.0-69.0) years and 55.6% were male (n = 25/45). Most had combined tumors (64.4%; n = 29/45), followed by collision (24.4%; n = 11/45), and amphicrine tumors (11.1%; n = 5/45). More than half had lymph node metastasis (56.8%; n = 25/44), yet only 7.9% had distant metastasis (n = 3/38). Tumor resection (i.e., mostly pancreaticoduodenectomy) was performed in 96.3% (n = 52/54), followed by adjuvant chemotherapy in 61.8% (n = 21/34). Nearly half experienced disease recurrence (47.2%; n = 17/36) over a median follow-up of 12.0 (IQR: 3.0-16.0) months, and 42.1% (n = 16/38) died over a median follow-up of 12.0 (IQR: 4.0-18.0) months. The most common cause of death was disease progression/recurrence in 81.3% (n = 13/16).

CONCLUSION

Early diagnosis and management of ampullary MANEC is challenging yet crucial to improve outcomes since many patients are diagnosed at an advanced disease stage and have unfavorable outcomes. Multicenter granular data are warranted to further understand and improve outcomes in these patients.

Ampullary Large-Cell Neuroendocrine Carcinoma, a Diagnostic Challenge of a Rare Aggressive Neoplasm: A Case Report and Literature Review

Ampullary large-cell neuroendocrine carcinomas (LCNECs) are extremely rare, and available data are limited on case reports. They present with jaundice, non-specific abdominal pain, or weight loss, imitating adenocarcinoma. Their incidence increases due to the improved diagnostic techniques. However, preoperative diagnosis remains challenging. We report the case of a 70-year-old man with a history of metabolic syndrome, cholecystectomy, and right hemicolectomy, presenting with jaundice. Laboratory results showed increased liver biochemistry indicators and elevated CA 19-9. Esophagogastroduodenoscopy revealed an ulcerative tumor on the ampulla of Vater, and the biopsy revealed neuroendocrine carcinoma. Although computed tomography (CT) detected enlarged regional lymph nodes, the positron emission tomography (PET) showed a hyperactive lesion only in this area. Pylorus-preserving pancreatoduodenectomy with R0 resection was performed. Pathologic evaluation of the 3.1 × 1.9 cm tumor revealed an LCNEC with immunohistochemical positivity at Synaptophysin, EMA, CD56, and cytokeratin CK8/18. The Ki-67 index was 45%. Two out of the nine dissected lymph nodes were occupied by the neoplasm. The patient was discharged home free of symptoms, and adjuvant chemotherapy with carboplatin + etoposide was initiated. A comprehensive review of the reported cases showed that the preoperative biopsy result was different from the final diagnosis in few cases, regarding the subtypes. Conventional radiology cannot identify small masses, and other methods, such as endoscopy, magnetic resonance cholangiopancreatography (MRCP), and FDG-PET scan, might aid the diagnosis. Diagnosis is based on histology and immunohistochemical markers of the surgical specimens. The treatment of choice is pancreatoduodenectomy, followed by adjuvant chemotherapy. However, recurrence is frequent, and the prognosis remains poor.

Mixed neuroendocrine-nonneuroendocrine neoplasm of the ampulla: Four case reports

BACKGROUND

Mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN) is a rare tumor that occurs in the gastrointestinal tract and pancreas, usually composed of adenocarcinoma and neuroendocrine carcinoma. MiNEN occurring in ampulla is even rarer. We report 4 cases of MiNEN in ampulla, combined with literature review to summarize the clinical features and treatment of the disease, in order to improve the understanding of the disease.

CASE SUMMARY

A retrospective analysis was performed in 4 cases of MiNEN of the ampulla diagnosed by pathology from 2014 to 2021. The 4 patients were all male, aged 67-81 years (average 72.25 years). Among them, 2 patients had jaundice, 1 patient had abdominal pain, and 1 patient had jaundice with abdominal pain as the first symptom. All 4 patients underwent enhanced CT or MRI, which all indicated that the tumors were located in the ampulla. Two patients underwent duodenoscopy, and a biopsy revealed ampullary adenocarcinoma. All 4 patients underwent radical pancreaticoduodenectomy. Four cases were followed up: One patient developed severe complications after the operation, his condition deteriorated, and he survived for 1 mo. In the other 3 patients, tumor recurrence was observed during follow-up, and 2 of them survived for 29 mo and 22 mo respectively. One case survived and is still being followed up.

CONCLUSION

MiNEN of the ampulla are extremely rare, lacking typical clinical symptoms and imaging features, and are usually diagnosed after postoperative histopathological and immunohistochemical examinations. The main treatment is radical surgical resection, which can be combined with chemotherapy. The best method of diagnosis and treatment needs further research.

Surgical resection of mixed neuroendocrine-non-neuroendocrine neoplasm in the biliary system: a report of two cases

BACKGROUND

Mixed neuroendocrine-non-neuroendocrine neoplasm (MINEN) is a rare disease and there is scarce literature on its diagnosis, treatment, and prognosis. We encountered two unusual cases of MINEN in the biliary tract, one in the ampulla of Vater and the other in the distal bile duct. In this report, we describe the clinical course of these two cases in detail.

CASE PRESENTATION

Case 1: A 69-year-old woman presented with a chief complaint of epigastric pain. When endoscopic sphincterotomy and retrograde biliary drainage were performed for gallstone pancreatitis, an ulcerated lesion was found in the ampulla of the Vater. Based on the biopsy results, the lesion was diagnosed as the ampulla of Vater carcinoma and subtotal stomach-preserving pancreatoduodenectomy (SSPPD) was performed. Postoperative histopathological examination revealed the coexistence of adenocarcinoma and neuroendocrine carcinoma components, consistent with the diagnosis of MINEN. In addition, lymph node metastasis was found on the dorsal side of the pancreas and the metastatic component was adenocarcinoma. Adjuvant chemotherapy with etoposide and cisplatin was administered for 6 months, and presently the patient is alive without recurrence 64 months after surgery. Case 2: A 79-year-old man presented with a chief complaint of anorexia. Cholangiography showed severe stenosis of the distal bile duct. A biopsy was conducted from the stenotic lesion and it revealed the lesion to be adenocarcinoma. A diagnosis of distal bile duct carcinoma was made, and SSPPD was performed. Histopathological examination revealed the coexistence of adenocarcinoma and neuroendocrine carcinoma components, and the tumor was confirmed as MINEN of the distal bile duct. No adjuvant chemotherapy was administered due to the poor performance status. 7 months later, the patient was found to have a liver metastasis.

CONCLUSION

We experienced two valuable cases of biliary MINEN. To identify better treatments, it is important to consider the diversity of individual cases and to continue sharing a variety of cases with different presentations.

Mixed neuroendocrine nonneuroendocrine neoplasms of the pancreas: a case report and literature review of pancreatic mixed neuroendocrine nonneuroendocrine neoplasm

A 36-year-old woman underwent left lateral hepatic lobectomy and tumor enucleation of the pancreatic head due to the diagnosis of mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs). Her past medical history revealed an ill-defined mass in the pancreatic uncinate (approximately 1 cm in size) and liver nodules in segment II, suggesting a pancreatic neuroendocrine tumor (pNET) and liver metastases. After the operation, pathological examination showed that the lesion in the pancreas was MiNEN. The neuroendocrine component consisted of grade 1 (G1) NETs, and the nonneuroendocrine part was well-differentiated adenocarcinoma. Additionally, in hepatic lesions, the type of pancreaticobiliary duct in moderately differentiated adenocarcinoma indicated the source of tumor cells. We present the following case in accordance with the CARE reporting checklist. MiNENs of the pancreas are extremely rare and heterogeneous malignancies. Owing to the rarity of pancreatic MiNEN, no structured guidelines on preoperative diagnostics, therapy and follow-up exist thus far. Thus, problems in differential diagnosis and appropriate therapy may arise when treating suspected MiNEN patients. We performed a rigorous search on pancreatic MiNEN via PubMed and Web of Science. In total, 167 studies were identified, and 28 cases in 15 studies about pancreatic MiNEN were assessed. All the available information was listed and fully discussed.

The clinical profiles, management, and prognostic factors of biliary mixed neuroendocrine nonneuroendocrine neoplasms: A systematic review of the literature

BACKGROUND

Mixed neuroendocrine nonneuroendocrine neoplasms (MiNENs) originating from the biliary system (gallbladder, biliary tract, or ampulla of Vater) are extremely rare and have not been discussed in detail or systematically. We aimed to present the demographics, clinicopathological characteristics, management, and prognostic factors of biliary MiNENs.

METHODS

A systematic search of electronic biomedical databases (Web of Science, PUBMED, and Embase) was performed to identify eligible studies. Survival was analyzed with the Kaplan-Meier method. Log-rank tests were used to evaluate the differences between groups, and the effects of various clinical and histopathological features on prognosis were analyzed by univariate and multivariate Cox regression.

RESULTS

Fifty-three publications (patients, n = 67) were included. The median overall survival time was 21.0 months. Fifty-one patients (76.1%) underwent radical surgery and median survival for 41 months (P < .001). Twenty-two patients who received adjuvant radiochemotherapy treatment after radical surgery had a median survival for 43 months (P = .076). Radical resection (P < .001), Ki-67 index (P = .011), tumor stage (P < .001), neuroendocrine (NEC) grade (P = .011), and non-NEC grade (P = .017) were independent statistically significant prognostic factors according to univariate analysis; radical resection (P = .010) and small morphological subtype (P = .036) were independent statistically significant prognostic factors associated with higher overall survival according to multivariate analysis, and radical resection (P = .005) and age < 65 years (P = .026) were associated with higher recurrence free survival time.

CONCLUSION

Radical resection is essential for long-term survival. Aggressive multimodality therapy with adjuvant radiochemotherapy and biotherapy may improve survival of biliary MiNENs. Further randomized controlled trials are needed to determine the standard treatment.

Mixed Neuroendocrine Non-Neuroendocrine Neoplasms: A Systematic Review of a Controversial and Underestimated Diagnosis

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) represent a rare diagnosis of the gastro-entero-pancreatic tract. Evidence from the current literature regarding their epidemiology, biology, and management is of variable quality and conflicting. Based on available data, the MiNEN has an aggressive biological behaviour, mostly driven by its (often high-grade) neuroendocrine component, and a dismal prognosis. In most cases, the non-neuroendocrine component is of adenocarcinoma histology. Due to limitations in diagnostic methods and poor awareness within the scientific community, the incidence of MiNENs may be underestimated. In the absence of data from clinical trials, MiNENs are commonly treated according to the standard of care for pure neuroendocrine carcinomas or adenocarcinomas from the same sites of origin, based on the assumption of a biological similarity to their pure counterparts. However, little is known about the molecular aberrations of MiNENs, and their pathogenesis remains controversial; molecular/genetic studies conducted so far point towards a common monoclonal origin of the two components. In addition, mutations in tumour-associated genes, including TP53, BRAF, and KRAS, and microsatellite instability have emerged as potential drivers of MiNENs. This systematic review (91 full manuscripts or abstracts in English language) summarises the current reported literature on clinical, pathological, survival, and molecular/genetic data on MiNENs.

Signet Ring Cell Carcinoma of the Ampulla of Vater With Focal Neuroendocrine Differentiation of the Amphicrine Type: Report of a Case With Long-Term Survival

Carcinoma of the ampulla of Vater is an uncommon neoplasm and represents 0.5% of all gastrointestinal malignancies, being less common than carcinoma of the pancreas and bile ducts. The most common ampullary tumor is the adenocarcinoma with tubular growth pattern. Signet ring cell carcinoma is extremely rare. In this article, we report a case of signet ring cell carcinoma of the ampulla of Vater showing focal neuroendocrine amphicrine differentiation and intestinal phenotype, which occurred in a 49-year-old male who is still alive 7 years after surgery, without evidence of recurrence. This long-term survival might be attributed not only to the early stage of the disease but also to the neuroendocrine differentiation and the absence of genetic alterations.

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.

Clinicopathological features and prognosis of gastric mixed adenoneuroendocrine carcinoma

Gastric mixed adenoneuroendocrine carcinomas (MANECs) are rare malignant tumors. This study aimed to investigate the clinicopathological features, diagnosis, prognosis, and treatment outcome in gastric MANECs patients. Clinicopathological data and the archived slides of 40 cases of MANEC patients were retrospectively reviewed. Immunohistochemistry (IHC) staining was performed to detect expression of synaptophysin (Syn), chromogranin A (CgA), CD56, CKpan, CK7, CK8/18, carcinoembryonic antigen (CEA), CK5/6, P40 and Ki-67. Hematoxylin and eosin staining demonstrated exocrine and neuroendocrine components, each accounting for at least 30% of the whole lesion. Exocrine components diffusely expressed epithelial markers CKpan, CK7, CK8/18, and CEA and endocrine components widely expressed at least one of the markers Syn, CgA, and CD56. Ki-67 index and mitosis determined the endocrine component grade as G3. Thirty-three of 40 patients were successfully followed up for 3 to 105 months with median survival of 12 months. Survival analysis showed a significant difference in prognosis with regard to patient's age, disease stage, tumor relapse status, and distant metastasis status. In conclusion, patient's age, disease stage, tumor relapse status, and distant metastasis status are important contributors to poor prognosis. Old patients with advanced stage, recurrence, or metastasis to the liver, pancreas or other distant organs show a poor prognosis.

Cytological features of mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A case report with immunocytochemical analyses

Mixed adenoneuroendocrine carcinoma (MANEC) is defined as a tumor that has morphologically recognizable both adenocarcinoma and neuroendocrine carcinoma components comprising at least 30% of either components. MANEC occurring in the ampulla of Vater is extremely rare, and only 16 cases have been reported in the English language literature. In the present report, we describe the first case of MANEC of the ampulla of Vater with immunocytochemical analyses. An 82-year-old Japanese male was incidentally found to have a tumorous lesion in the ampulla of Vater. Endoscopic ultrasound-fine needle aspiration (EUS-FNA) of the tumor was performed. The Papanicolaou smear demonstrated the presence of different three components. The most dominant component was cohesive clusters of small round cells with round to oval nuclei with powdery chromatin and scant cytoplasm, which corresponded to small cell carcinoma. The second component was an adenocarcinoma, which was composed of irregularly overlapping clusters of tall columnar cells with large round to oval nuclei containing conspicuous nucleoli. The third component was an adenoma, which was comprised of flat cohesive clusters of columnar cells without atypia. Immunocytochemical analyses demonstrated that synaptophysin was expressed in the small round cells, and cdx-2 was expressed in all three components. Accordingly, a cytodiagnosis of MANEC with adenoma component was made. Preoperative diagnosis of ampullary MANEC is difficult. However, this report clearly demonstrates three different components in the EUS-FNA cytological specimen. Therefore, we suggest that cytological examination is a useful method for diagnosis of MANEC of the ampulla of Vater.

Mixed adenoneuroendocrine carcinoma of the esophagogastric junction: A case report and review of the literature

Mixed adenoneuroendocrine carcinoma (MANEC) simultaneously contains two kinds of carcinoma components, namely, neuroendocrine carcinoma (NEC) and adenocarcinoma, each of which accounts for more than 30% of total carcinoma components. The incidence rate of MANEC cases is relatively lower, and the MANEC cases that occur at the esophagogastric junction are extremely rare, with merely three cases reported in the literature. The histological patterns provide the basis for diagnosis of MANEC. However, in case of poor tumor differentiation, a diagnosis of MANEC depends on immunohistochemical staining. The vast majority of MANEC cases are determined by the postoperative pathologic diagnosis based on large samples. The histological origin of MANEC has not been made clear, and there are disputes over its biological behavior and prognosis. At present, there has been no specific therapy for MANEC, while operative treatment-based comprehensive therapy still plays a dominant role. This case suggests that histological patterns act as the basis for diagnosis of MANEC; However, in case of poor tumor differentiation, the confirmed diagnosis of MANEC relies on immunohistochemical staining.

Ampullary Mixed Adenoneuroendocrine Carcinoma: Surprise Histology, Familiar Management

INTRODUCTION

Mixed adenoneuroendocrine carcinoma (MANEC) has recently been defined by the World Health Organization in 2010. These are rare tumors and MANECs of ampullary region are even rarer. Only 19 cases have been reported in literature. We present 3 cases; the largest series, second case of amphicrine tumor and first case associated with chronic pancreatitis.

METHODS

Retrospective review of 3 patients who were diagnosed to have ampullary MANEC.

RESULTS

All 3 patients were diagnosed preoperatively as neuroendocrine carcinoma and underwent margin negative pancreaticoduodenectomy. The histopathology revealed MANECs of small cell, mixed type in 2 patients and large cell, amphicrine type in 1 patient. The neuroendocrine component was grade 3 in all, the tumor was T3 in 2 and T2 in 1 and all had nodal metastases. Two patients received adjuvant chemotherapy and 2 of them had recurrence at 13 and 16 months. The median survival was 15 months.

CONCLUSION

Ampullary MANECs are rare tumors. They are diagnosed on histopathologic examination of the resected specimen. Clinical presentation, management, and prognosis is similar to ampullary adenocarcinoma in literature.

A case of mixed adenoneuroendocrine carcinoma of the pancreas: Immunohistochemical analysis for histogenesis

RATIONALE

Tumors with multiple histological features, such as adenocarcinomas and neuroendocrine carcinomas, were included as a new category of neuroendocrine carcinomas in the 2010 World Health Organization classification. We recently experienced a rare case of a pancreatic carcinoma with both adenocarcinoma and neuroendocrine carcinoma components, a so-called mixed adenoneuroendocrine carcinoma.

PATIENT CONCERNS AND DIAGNOSIS

A 66-year-old man was referred to our hospital with obstructive jaundice. Contrast-enhanced computed tomography images indicated a tumor located at the pancreatic head measuring 3.0 × 2.5 cm in diameter and invading the common bile duct. Cytological examination of the bile juice obtained by endoscopic retrograde cholangiopancreatography revealed adenocarcinoma cells. Pancreaticoduodenectomy was performed safely as radical resection.

INTERVENTIONS

Microscopically, the resected tumor consisted of tightly intermingled adenocarcinoma and neuroendocrine carcinoma components. On the immunohistochemical examination, p53 was ubiquitously positive in both components, whereas chromogranin A, synaptophysin and neuron-specific enolase, neuroendocrine markers, were limited to the neuroendocrine carcinoma component.

OUTCOMES

Thus, such features of both adenocarcinoma and neuroendocrine carcinoma observed microscopically and immunohistochemically seemed to indicate a composite tumor.

LESSONS

The findings of this case suggest that adenocarcinoma and neuroendocrine carcinoma may be derived from a single cancer stem cell.

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.

Common Hepatic Duct Mixed Adenoneuroendocrine Carcinoma Masquerading as Cholangiocarcinoma

Bile duct mixed adenoneuroendocrine carcinoma (MANEC) is a rare entity. It is defined as having mixed elements of both neuroendocrine tumors (NET) and an adenocarcinoma element, the lesser component forming at least 30% of the tumor. It is a subtype of neuroendocrine carcinoma (NEC) showing both gland-forming epithelial tumor cells and neuroendocrine cells. It is generally misdiagnosed as cholangiocarcinoma on imaging studies. The preoperative pathological workup from the endoscopic retrograde cholangiography brush cytology usually misses the NET/NEC component since it often lies deeper in the tumor. However, it is reported that it is the NEC component that defines the prognosis of the tumor; hence, it is vital to identify the NEC component. We present a rare case of common hepatic duct (CHD) MANEC that was preoperatively misdiagnosed as cholangiocarcinoma.

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A case report

Mixed adenoneuroendocrine carcinomas (MANECs) are rare biphasic tumour types, which are morphologically recognisable as both gland-forming and neuroendocrine neoplasms. Within the gastrointestinal tract, MANECs occur predominantly in the stomach or colorectum. The present study described a case of a MANEC originating from the ampullary region. The patient presented with widespread metastatic disease. Biopsy samples obtained from the ampullary primary tumour disclosed a complex lesion with adenocarcinoma and neuroendocrine small cell carcinoma components, positive for the intestinal transcription factor caudal type homeobox-2 and for neuroendocrine markers, including chromogranin A, synaptophysin, cluster of differentiation 56/neural cell adhesion molecule. By contrast, biopsy samples obtained from metastatic tissue revealed pure neuroendocrine carcinoma. As exemplified by this true mixed tumour, tumour heterogeneity evolves as the major challenge in oncology today, with potentially severe implications for the choice of chemotherapy. The assessment of metastatic sites may render valuable diagnostic information that is crucial for clinical decision-making and patient management.