Targeted gene sequencing and bioinformatics analysis of patients with gallbladder neuroendocrine carcinoma:A case report

BACKGROUND Gallbladder neuroendocrine carcinoma(NEC)represents a subtype of gallbladder malignancies characterized by a low incidence,aggressive nature,and poor prognosis.Despite its clinical severity,the genetic alterations,mechanisms,and signaling pathways underlying gallbladder NEC remain unclear.CASE SUMMARY This case study presents a rare instance of primary gallbladder NEC in a 73-year-old female patient,who underwent a radical cholecystectomy with hepatic hilar lymphadenectomy and resection of liver segments IV-B and V.Targeted gene sequencing and bioinformatics analysis tools,including STRING,GeneMANIA,Metascape,TRRUST,Sangerbox,cBioPortal and GSCA,were used to analyze the biological functions and features of mutated genes in gallbladder NEC.Twelve mutations(APC,ARID2,IFNA6,KEAP1,RB1,SMAD4,TP53,BTK,GATA1,GNAS,and PRDM3)were identified,and the tumor mutation burden was determined to be 9.52 muts/Mb via targeted gene sequencing.A protein-protein interaction network showed significant interactions among the twelve mutated genes.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were used to assess mutation functions and pathways.The results revealed 40 tumor-related pathways.A key regulatory factor for gallbladder NEC-related genes was identified,and its biological functions and features were compared with those of gallbladder carcinoma.CONCLUSION Gallbladder NEC requires standardized treatment.Comparisons with other gallbladder carcinomas revealed clinical phenotypes,molecular alterations,functional characteristics,and enriched pathways.

Early adenocarcinoma mixed with a neuroendocrine carcinoma component arising in the gastroesophageal junction: A case report

BACKGROUND Early adenocarcinoma mixed with a neuroendocrine carcinoma(NEC)component arising in the gastroesophageal junctional(GEJ)region is rare and even rarer in young patients.Here,we report such a case in a 29-year-old Chinese man.CASE SUMMARY This patient presented to our hospital with a 3-mo history of dysphagia and regurgitation.Upper endoscopy revealed an elevated nodule in the distal esophagus 1.6 cm above the GEJ line,without Barrett’s esophagus or involvement of the gastric cardia.The nodule was completely resected by endoscopic submu-cosal dissection(ESD).Pathological examination confirmed diagnosis of intra-mucosal adenocarcinoma mixed with an NEC component,measuring 1.5 cm.Immunohistochemically,both adenocarcinoma and NEC components were positive for P53 with a Ki67 index of 90%;NEC was positive for synaptophysin and chromogranin.Next-generation sequencing of 196 genes demonstrated a novel germline mutation of the ERCC3 gene in the DNA repair pathway and a germline mutation of the RNF43 gene,a common gastric cancer driver gene,in addition to pathogenic somatic mutations in P53 and CHEK2 genes.The patient was alive without evidence of the disease 36 mo after ESD.CONCLUSION Early adenocarcinoma with an NEC component arising in the distal esophageal side of the GEJ region showed evidence of gastric origin.

Critical considerations for the management of gastrointestinal mixed neuroendocrine non-neuroendocrine neoplasms and pure neuroendocrine carcinomas

Mixed neuroendocrine non-neuroendocrine neoplasms constitute rare tumors that are located mainly in the gastrointestinal(GI)tract and have high degrees of malignancy,and the frequency of these tumors has been increasing.They consist of a neuroendocrine neoplastic component with another component of adenocarcinoma usually and have a dismal prognosis.The rare GI pure neuroendocrine carcinoma is highly aggressive and requires complex and extensive management since a genetic distinction exists between it and GI non-neuroendocrine neoplasms,which are generally slow-growing lesions.The most common GI-mixed neuroendocrine non-neuroendocrine neoplasms are colorectal,followed by gastric,mainly in the gastroesophageal junction.Current imaging modalities of nuclear medicine and radiology play important roles in the accuracy of diagnosis.Liquid biopsy may contribute to early detection and timely diagnosis.Ultrasonography,either endoscopic or abdominal,is a technique that contributes to a diagnosis;additionally,contrast-enhanced ultrasonography is very helpful in followup appointments.Histopathology establishes a definite diagnosis and stage by evaluating the cell differentiation grade and the cell proliferation index Ki67.The genetic profile can be valuable in diagnosis and gene therapy.Surgical resection with wide lymphadenectomy,whenever possible,and adjuvant chemotherapy constitute the main therapeutic management strategies.Targeted therapy and immunotherapy achieve encouraging results.

Neuroendocrine carcinoma of the common hepatic duct coexisting with distal cholangiocarcinoma:A case report and review of literature

BACKGROUND Neuroendocrine carcinoma(NEC)of the extrahepatic bile duct is very rare,and the treatment and prognosis are unclear.Herein,we report the case of a middleaged female with primary large cell NEC(LCNEC)of the common hepatic duct combined with distal cholangiocarcinoma(dCCA).Additionally,after a review of the relevant literature,we summarize and compare mixed neuroendocrine-nonneuroendocrine neoplasm(MiNEN)and pure NEC to provide a reference for selecting the appropriate treatment and predicting the prognosis of this rare disease.CASE SUMMARY A 62-year-old female presented to the hospital due to recurrent abdominal pain for 2 months.Physical examination showed mild tenderness in the upper abdomen and a positive Courvoisier sign.Blood tests showed elevated liver transaminase and carbohydrate antigen 199 levels.Imaging examination revealed node dissection was performed,and hepatic duct tumours were unexpectedly found during surgery.Pathology suggested poorly differentiated LCNEC(approximately 0.5 cm×0.5 cm×0.4 cm),Ki-67(50%),synaptophysin+,and chromogranin A+.dCCA pathology suggested moderately differentiated adenocarcinoma.The patient eventually developed lymph node metastasis in the liver,bone,peritoneum,and abdominal cavity and died 24 months after surgery.Gene sequencing methods were used to compare gene mutations in the two primary bile duct tumours.CONCLUSION The prognosis of MiNEN and pure NEC alone is different,and the selection of treatment options needs to be differentiated.

Three-in-one incidence of hepatocellular carcinoma,cholangiocellular carcinoma,and neuroendocrine carcinoma:A case report

BACKGROUND Primary hepatic neuroendocrine carcinoma(NEC)is rare,and a combination with hepatocellular carcinoma(HCC)and cholangiocarcinoma(CCA)is extremely rare.To date,only four combination cases have been reported.The present paper describes the fifth patient.CASE SUMMARY A 32-year-old Chinese man with chronic hepatitis B was hospitalized for persistent upper abdominal pain.Abdominal computed tomography(CT)examination revealed a liver mass.The tumor was located in the 7th and 8th segments of the liver,and CT and magnetic resonance imaging findings were consistent with the diagnosis of HCC.Laboratory examinations revealed the following:Alanine aminotransferase,243 U/L;aspartate aminotransferase,167 U/L;alpha-fetoprotein,4519μg/L.Laparoscopic right lobe hepatectomy was performed on the liver mass.Postoperative pathology showed low differentiation HCC plus medium and low differentiation CCA combined with NEC.One month after the surgery,the patient suffered from epigastric pain again.Liver metastasis was detected by CT,and tumor transcatheter arterial chemoembolization was performed.Unfortunately,the liver tumor was progressively increased and enlarged,and after 1 mo,the patient died of liver failure.CONCLUSION This is a rare case,wherein the tumor is highly aggressive,grows rapidly,and metastasizes in a short period.Imaging and laboratory tests can easily misdiagnose or miss such cases;thus,the final diagnosis relies on pathology.

Mixed neuroendocrine and adenocarcinoma of gastrointestinal tract:A complex diagnosis and therapeutic challenge

In this editorial we comment on the manuscript describing a case of adenocarcinoma mixed with a neuroendocrine carcinoma of the gastroesophageal junction.Mixed neuroendocrine and non-neuroendocrine neoplasms of the gastrointestinal system are rare heterogeneous group of tumors characterized by a high malignant potential,rapid growth,and poor prognosis.Due to the rarity of these cancers,the standard therapy is poorly defined.The diagnosis of these tumors is based on combination of morphological features,immunohistochemical and neuroendocrine and epithelial cell markers.Both endocrine and epithelial cell components can act independently of each other and thus,careful grading of each component separately is required.These cancers are aggressive in nature and the potential of each component has paramount importance in the choice of treatment and response.Regardless of the organ of origin,these tumors portend poor prognosis with increased proportion of neuroendocrine component.Multidisciplinary services and strategies are required for the management of these mixed malignancies to provide the best oncological outcomes.The etiopathogenesis of these mixed tumors remains obscure but poses interesting question.We briefly discuss a few salient points in this editorial.

Molecular features of gastroenteropancreatic neuroendocrine carcinoma: A comparative analysis with lung neuroendocrine carcinoma and digestive adenocarcinomas

Objective: There is an ongoing debate about whether the management of gastroenteropancreatic(GEP)neuroendocrine carcinoma(NEC) should follow the guidelines of small-cell lung cancer(SCLC). We aim to identify the genetic differences of GEPNEC and its counterpart.Methods: We recruited GEPNEC patients as the main cohort, with lung NEC and digestive adenocarcinomas as comparative cohorts. All patients undergone next-generation sequencing(NGS). Different gene alterations were compared and analyzed between GEPNEC and lung NEC(LNEC), GEPNEC and adenocarcinoma to yield the remarkable genes.Results: We recruited 257 patients, including 99 GEPNEC, 57 LNEC, and 101 digestive adenocarcinomas.Among the mutations, KRAS, RB1, TERT, IL7R, and CTNNB1 were found to have different gene alterations between GEPNEC and LNEC samples. Specific genes for each site were revealed: gastric NEC(TERT amplification),colorectal NEC(KRAS mutation), and bile tract NEC(ARID1A mutation). The gene disparities between small-cell NEC(SCNEC) and large-cell NEC(LCNEC) were KEAP1 and CDH1. Digestive adenocarcinoma was also compared with GEPNEC and suggested RB1, APC, and KRAS as significant genes. The TP53/RB1 mutation pattern was associated with first-line effectiveness. Putative targetable genes and biomarkers in GEPNEC were identified in22.2% of the patients, and they had longer progression-free survival(PFS) upon targetable treatment [12.5 months vs. 3.0 months, HR=0.40(0.21-0.75), P=0.006].Conclusions: This work demonstrated striking gene distinctions in GEPNEC compared with LNEC and adenocarcinoma and their clinical utility.

Clinical analysis of 12 cases of ovarian neuroendocrine carcinoma

BACKGROUND Neuroendocrine neoplasms of the female genital tract are rare.AIM To enhance our clinical understanding of neuroendocrine carcinoma(NEC)of the ovary.METHODS A retrospective review was conducted on 12 patients diagnosed with NEC of the ovary,analyzing clinicopathological characteristics,treatment modalities,and survival status.RESULTS The median age at diagnosis was 34.5 years(range:20 to 62 years).Among the 12 cases,9 were small cell carcinoma of the ovary and 3 were large cell NEC.Five cases were stage I tumors,one case was stage IV,and six cases were stage III.Eleven patients underwent surgery as part of their treatment.All patients received adjuvant chemotherapy.Among the 12 patients,one patient received radiotherapy,and one patient with a BRCA2 mutation was administered PARP inhibitor maintenance after chemotherapy.The median progression-free survival was 13 months,and the median overall survival was 19.5 months.Four cases remained disease-free,while eight cases experienced tumor recurrence,including three cases that resulted in death due to disease recurrence.CONCLUSION NEC of the ovary is a rare condition that is more common in women of childbearing age and is associated with aggressive behavior and poor clinical outcomes.Surgical resection remains the mainstay of treatment,with some patients benefiting from adjuvant chemoradiation therapy.

Primary large cell neuroendocrine carcinoma of the bladder:A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)of the bladder is a rare nonurothelial tumor of the bladder.The treatment of LCNEC of the bladder is different from that of urothelial carcinoma(UC);therefore,early and accurate diagnosis is particularly important.As LCNEC of the bladder is rare and its clinical symptoms and radiographic features are similar to those of urothelial tumors,the clinical diagnosis of the disease remains challenging.CASE SUMMARY We report a 72-year-old female patient who presented with gross hematuria for 3 mo.A solitary tumor located in the anterior wall of the bladder was found by cystoscopy.Pathological examination after biopsy suggested UC of the bladder in the absence of immunohistochemical assessment.The patient underwent partial cystectomy and was finally diagnosed with LCNEC(pT2bN0M0)based on the results of postoperative immunohistochemical examination.During the 10-mo follow-up,no signs of tumor recurrence or metastasis were found.CONCLUSION Immunohistochemical examination is essential for diagnosing LCNEC of the bladder.Accurate diagnosis and multidisciplinary treatment in the early stage of the disease are crucial for improving the prognosis.

Small Cell Neuroendocrine Carcinoma of the Vulva: Case Report and Literature Review

Background: Neuroendocrine neoplasms are those that develop from a neuroendocrine cell. They most commonly affect the lungs, gastrointestinal tract, and pancreas, being rare conditions in the female genital tract. When present, these neoplasms often manifest with nonspecific signs and symptoms such as pain, itching, swelling, single-focus lesions, bleeding, and enlargement of inguinal lymph nodes, in addition to the presence of progressively enlarging vulvar nodules. Consequently, the diagnostic investigation involves histopathological examination and confirmation through immunohistochemistry. Objective: To present a comprehensive understanding of this rarely studied pathology. The primary objective is to provide valuable insights that could aid in the future development of universally applicable treatment guidelines. Case Presentation: A 57-year-old female, with no prior comorbidities, menopause at 36, who presented with a left vulvar nodule accompanied by intense pain and swelling, later diagnosed with small cell neuroendocrine carcinoma in the vulva. Conclusion: This case report highlights the importance of enhancing our knowledge regarding small cell neuroendocrine carcinoma in the vulva, given its scarcity in medical literature. The information presented here underscores the need for standardized diagnostic and treatment approaches, paving the way for future consensus on managing this uncommon but challenging neoplasm.

Large-cell neuroendocrine carcinoma of the bladder:A case report

BACKGROUND Bladder neuroendocrine tumors are few and exhibit a high degree of aggressiveness.The bladder is characterized by four distinct forms of neuroendocrine tumors.Among them,large-cell neuroendocrine carcinoma is the least prevalent,but has the highest level of aggressiveness.The 5-year survival rate for large-cell neuroendocrine carcinoma of the bladder is exceedingly poor.To date,only a few dozen cases have been reported.CASE SUMMARY Here,we report the case of a 65-year-old man with large-cell neuroendocrine carcinoma of the bladder.The patient presented to the Department of Urology at our hospital due to the presence of painless hematuria without any identifiable etiology.During hospitalization,abdominal computed tomography revealed the presence of an irregular mass on the right anterior wall of the bladder.A cystoscopic non-radical resection of the bladder lesion was performed.The postoperative pathological examination revealed large-cell neuroendocrine bladder cancer.Previous reports on cases of large-cell neuroendocrine carcinoma cases were retrieved from PubMed,and the present paper discusses the currently recognized best diagnostic and treatment options for large-cell neuroendocrine carcinoma based on the latest research progress.CONCLUSION Large-cell neuroendocrine carcinoma of the bladder is an uncommon malignancy with a highly unfavorable prognosis.Despite ongoing efforts to prolong patient survival through multidisciplinary therapy,the prognosis remains unfavorable.Large-cell neuroendocrine carcinoma continues to be a subject of uncertainty.

Textbook Outcome as a measure of surgical quality assessment and prognosis in gastric neuroendocrine carcinoma:A large multicenter sample analysis

Objective:Quality assurance is crucial for oncological surgical treatment assessment.For rare diseases,singlequality indicators are not enough.We aim to develop a comprehensive and reproducible measurement,called the"Textbook Outcome"(TO),to assess the quality of surgical treatment and prognosis of gastric neuroendocrine carcinoma(G-NEC)patients.Methods:Data from patients with primary diagnosed G-NEC included in 24 high-volume Chinese hospitals from October 2005 to September 2018 were analyzed.TO included receiving a curative resection,≥15 lymph nodes examined,no severe postoperative complications,hospital stay≤21 d,and no hospital readmission≤30 d after discharge.Hospital variation in TO was analyzed using a case mix-adjusted funnel plot.Prognostic factors of survival and risk factors for non-Textbook Outcome(non-TO)were analyzed using Cox and logistic models,respectively.Results:TO was achieved in 56.6%of 860 G-NEC patients.TO patients had better overall survival(OS),disease-free survival(DFS),and recurrence-free survival(RFS)than non-TO patients(P<0.05).Moreover,TO patients accounted for 60.3%of patients without recurrence.Multivariate Cox analysis revealed non-TO as an independent risk factor for OS,DFS,and RFS of G-NEC patients(P<0.05).Increasing TO rates were associated with improved OS for G-NEC patients,but not hospital volume.Multivariate logistic regression revealed that nonlower tumors,open surgery,and>200 mL blood loss were independent risk factors for non-TO patients(P<0.05).Conclusions:TO is strongly associated with multicenter surgical quality and prognosis for G-NEC patients.Factors predicting non-TO are identified,which may help guide strategies to optimize G-NEC outcomes.

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 (7th 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.

Neuroendocrine carcinomas arising in ulcerative colitis:Coincidences or possible correlations?

Patients with inflammatory bowel disease （IBD） are at increased risk of colorectal malignancies. Adenocarcinoma is the commonest type of colorectal neoplasm associated with ulcerative colitis （UC） and Crohn＇s disease, but other types of epithelial and non-epithelial tumors have also been described in inflamed bowel. With regards to non-epithelial malignancies, lymphomas and sarcomas represent the largest group of tumors reported in association with IBD, especially in immunosuppressed patients. Carcinoids and in particular neuroendocrine neoplasms other than carcinoids （NENs） are rare tumors and are infrequently described in the setting of IBD. Thus, this association requires further investigation. We report two cases of neoplasms arising in mild left-sided UC with immuno- histochemical staining for neuroendocrine markers： a large cell and a small cell neuroendocrine carcinoma of the rectum. The two patients were different in age （35 years vs 77 years） and disease duration （11 years vs 27 years）, and both had never received immunosuppressant drugs. Although the patients underwent regular endoscopic and histological follow-up, the two neoplasms were locally advanced at diagnosis. One of the two patients developed multiple liver metastases and died 15 mo after diagnosis. These findings confirm the aggressiveness and the poor prognosis of NENs compared to colorectal adenocarcinoma. While carcinoids seem to be coincidentally associated with IBD, NENs may also arise in this setting. In fact, long-standing inflammation could be directly responsible for the development of pancellular dysplasia involving epithelial, goblet, Paneth and neuroendocrine cells. It has yet to be established which IBD patients have a higher risk of developing NENs.

Collision carcinoma of the rectum involving neuroendocrine carcinoma and adenocarcinoma:A case report

BACKGROUND Collision carcinoma is a rare histological pattern,and includes two or more different types of tumors coexisting in the same organ as one neoplasm.Different to the combined type,the two adjacent tumors of collision carcinoma are histologically distinct.Collision carcinoma may occur from any origin or organ,including the cecum,liver,cervix,thyroid,stomach,kidney,and esophagus.In the rectum,adenocarcinoma is the most common pathological type,the combined type is rare,and collision tumors are even rarer.To date,only a limited number of collision carcinoma cases originating from the rectum have been reported.Due to the scarcity of rectal collision carcinoma,more cases need to be reported to fully understand the clinico-pathological features and biological behavior of the tumor.CASE SUMMARY Here we report a 40-year-old female who presented with the chief complaints of persistent changes in bowel habits and hematochezia for 10 d.She underwent Miles'operation which revealed a collision carcinoma of the rectum,showing a“side by side”pattern,composed of a high grade neuroendocrine carcinoma,(small cell carcinoma)and moderately differentiated adenocarcinoma,based on its clinico-pathological features and biological behavior.The patient remained disease-free at 12 mo follow-up.We also focused on the related literature and expert opinion.CONCLUSION Collision carcinoma is a rare tumor with ambiguous biological behavior.Greater attention should be paid to its clinico-pathologic diagnosis.Regular and adequate follow-up is essential to help rule out metastasis and assess the prognosis.

Collision tumor of hepatocellular carcinoma and neuroendocrine carcinoma involving the liver: Case report and review of the literature

Primary hepatic neuroendocrine carcinoma(NEC) with concurrent occurrence of hepatocellular carcinoma(HCC) of the liver is very rare. Only 8 cases have been reported in the literature. Concurrent occurrence of HCC and NEC in the liver is classified as combined type or collision type by histological distributional patterns; only 2 cases have been reported. Herein, we report a case of collision type concurrent occurrence of HCC and NEC, in which primary hepatic NEC was in only a small portion of the nodule, which is different from the 2 previously reported cases. A 72-year-old male with chronic hepatitis C was admitted to our hospital for a hepatic mass detected by liver computed tomography(CT) at another clinic. Because the nodule was in hepatic segment 3 and had proper radiologic findings for diagnosis of HCC, including enhancement in the arterial phase and wash-out in the portal and delay phases, the patient was treated with laparoscopic left lateral sectionectomy. The pathology demonstrated that the nodule was 2.5 cm and was moderately differentiated HCC. However, a 3 mm-sized focal neuroendocrine carcinoma was also detected on the capsule of the nodule. The tumor was concluded to be a collision type with HCC and primary hepatic NEC. After the surgery, for follow-up, the patient underwent a liver CT every 3 mo. Five multiple nodules were found in the right hepatic lobe on the follow-up liver CT 6 mo post-operatively. As the features of the nodules in the liver CT and MRI were different from that of HCC, a liver biopsy was performed. Intrahepatic recurrent NEC was proven after the liver biopsy, which showed the same pathologic features with the specimen obtained 6 mo ago. Palliative chemotherapy with a combination of etoposide and cisplatin has been administered for 4 months, showing partial response.

Pure large cell neuroendocrine carcinoma originating from the endometrium: A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)of the endometrium is an uncommon and highly aggressive tumor that has not been comprehensively characterized.We report a case of pure endometrial LCNEC and review the current literature of similar cases to raise awareness of the histological features,treatment,and prognosis of this tumor.CASE SUMMARY We report the case of a 73-year-old woman who presented with irregular postmenopausal vaginal bleeding.Ultrasonography showed an enlarged uterus and a 5.1 cm×3.3 cm area of medium and low echogenicity in the uterine cavity.Biopsy by dilatation and curettage suggested poorly differentiated carcinoma.Magnetic resonance imaging revealed a heterogeneously enhanced uterine tumor with diffuse infiltration of the posterior wall of the uterine myometrium and enlarged pelvic lymph nodes.The patient underwent a hysterectomy and bilateral adnexal resection.Gross observation revealed an ill-defined white solid mass of the posterior wall of the uterus infiltrating into the serosa with multiple solid nodules on the serous surface.Microscopically,the tumor cells showed neuroendocrine morphology(organoid nesting).Immunohistochemistry revealed the tumor cells were diffusely positive for the neuroendocrine markers CD56,chromogranin A,and synaptophysin.Thus,the tumor was diagnosed as stage IIIC endometrial LCNEC.CONCLUSION Pathologic findings and immunohistochemistry are essential in making a diagnosis of endometrial LCNEC.

Collision tumor of squamous cell carcinoma and neuroendocrine carcinoma in the head and neck:A case report

BACKGROUND There are many disputes about the definition,diagnosis,therapy,and prognosis of collision tumors.CASE SUMMARY We describe a rare patient with a collision tumor consisting of neuroendocrine carcinoma(NEC)and squamous cell carcinoma(SCC)in the nasal cavity and paranasal sinus.She received operation,concurrent chemoradiotherapy,and then two cycles of palliative chemotherapy.Follow-up at 12 mo after diagnosis showed that this patient experienced a complete response with no signs of recurrence or metastasis.A literature review of previous 26 cases diagnosed with collision tumor of NEC and SCC in the head and neck was also undertaken.CONCLUSION It is challenging to manage collision tumors because there are two morphologically and etiologically distinct tumors.Well-designed multimodality therapy including surgery and chemoradiotherapy might lead to a long survival in these patients.

Silent advanced large cell neuroendocrine carcinoma with synchronous adenocarcinoma of the colon:A case report

BACKGROUND Large cell neuroendocrine carcinoma(LCNEC)accounts for about 0.25%of colorectal cancer patients.Furthermore,synchronous LCNEC and adenocarcinoma coexistence in the colon is very rare.LCNEC are usually aggressive and have a poor prognosis.Usually,colorectal LCNEC patients complain of abdominal symptoms such as pain,diarrhea or hematochezia because it is often diagnosed as an advanced disease that accompanies metastatic lesions.CASE SUMMARY We describe a case of relatively asymptomatic synchronous LCNEC and colon adenocarcinoma.A 62-year-old male patient visited our hospital due to anemia detected by a local health check-up.He did not complain of melena,hematochezia or abdominal pain.Physical examination was unremarkable and his abdomen was soft,nontender and nondistended with no palpable mass.Laboratory tests revealed anemia with hemoglobin 5.1 g/dL.Colonoscopy revealed an ulcerofungating lesion in the ascending colon and about a 1.5 cm-sized large sessile polyp in the sigmoid colon.Endoscopic biopsy of the ascending colon lesion revealed the ulcerofungating mass that was LCNEC and endoscopic mucosal resection at the sigmoid colon lesion showed a large polypoid lesion that was adenocarcinoma.Multiple liver,lung,bone and lymph nodes metastasis was found on chest/abdominal computed tomography and positron emission tomography.The patient was diagnosed with advanced colorectal LCNEC with liver,lung,bone and lymph node metastasis(stage IV)and synchronous colonic adenocarcinoma metastasis.In this case,no specific symptom except anemia was observed despite the multiple metastases.The patient refused systemic chemotherapy and was discharged after transfusion.CONCLUSION We report a case of silent LCNEC of the colon despite the advanced state and synchronous adenocarcinoma.

Neuroendocrine carcinoma of the endometrium concomitant with Lynch syndrome:A case report

BACKGROUND Large-cell neuroendocrine carcinoma(NEC)is an uncommon type of tumor that can occur in the endometrium.This aggressive cancer requires definitive management.Here,we describe the clinical characteristics and treatment of a postmenopausal woman with large cell NEC of the endometrium.CASE SUMMARY A 55-year-old Asian female presented with a 1-year history of postmenopausal vaginal bleeding.Transvaginal ultrasound revealed a thickened endometrium(30.2 mm)and a hypervascular tumor.Computed tomography revealed that the tumor had invaded more than half of the myometrium and spread to the pelvic lymph nodes.The tumor marker,carcinoembryonic antigen,was elevated(3.65 ng/mL).Endocervical biopsy revealed high-grade endometrial carcinoma.She underwent radical hysterectomy,bilateral salpingo-oophorectomy,omentectomy,and bilateral pelvic and para-aortic lymph node dissection.Pathological examination revealed mixed neuroendocrine and endometrioid adenocarcinoma,pT2N0M0,grade 3,and International Federation of Gynecology and Obstetrics stage 2.Immunohistochemistry showed moderate estrogen and progesterone receptor expressions(20%and 1%,respectively),focal CD56 expression(NEC marker),positive staining for vimentin,p53(wild type),and ki67(90%),and loss of expression of PMS2(Lynch syndrome marker).The patient received five cycles of cisplatin and etoposide after surgery.No recurrence was noted after 5 mo.CONCLUSION We report the characteristics and successful management of a rare case of large cell endometrial NEC concomitant with Lynch syndrome.