Advances in the Diagnosis and Treatment of Appendiceal Mucinous Neoplasms

Primary appendiceal neoplasms represent a relatively low percentage of all gastrointestinal cancers. A subset of these neoplasms, those of epithelial origin, are characterised by the production of a considerable amount of mucus, which is referred to as appendiceal mucinous neoplasms (AMN). Appendiceal mucinous neoplasms (AMN) have a low incidence, are easily misdiagnosed, depend on postoperative examination for confirmation of the diagnosis, are prone to form a “diagnosis”, and have a high incidence of the disease. Furthermore, they are prone to form peritoneal pseudomyxoma peritonei (PMP), are controversial in surgical decision-making, are prone to recurring after surgery alone, and are tricky to manage clinically. In this paper, we review the pathological characteristics, diagnosis and treatment of appendiceal mucinous tumours in the light of recent literature reports, with a view to providing certain references for the clinical diagnosis and treatment of this disease. .

Asymptomatic low-grade appendiceal mucinous neoplasm:A case report

BACKGROUND Low-grade appendiceal neoplasms(LAMN)are characterized by low incidence and atypical clinical presentations,often leading to misdiagnosis as acute or chronic appendicitis before surgery.The primary diagnostic tool for LAMN is abdominal computed tomography(CT)imaging.Surgical resection remains the cornerstone of LAMN management,necessitating en bloc tumor excision to minimize the risk of iatrogenic rupture.Laparoscopy,known for its minimal invasiveness,reduced postoperative discomfort,and expedited recovery,is a safe and reliable approach for LAMN treatment.Despite the possibility of pseudomyxoma peritonei development,appendectomy and partial appendectomy generally result in negative tumor margins and favorable outcomes,which can be attributed to the disease’s slow growth and lower malignancy.CASE SUMMARY A 71-year-old male patient was admitted to our hospital with a pelvic spaceoccupying lesion detected 1 mo prior.Physical examination showed a soft abdomen without tenderness or rebound and no palpable masses.No shifting dullness was noted,and digital rectal examination revealed no palpable mass.Enteroscopy revealed a raised,smooth-surfaced mass measuring 3.0 cm in the cecum.Abdominal contrast-enhanced CT showed a markedly thickened and dilated appendix with visible cystic shadows.Laparoscopic surgery was performed and revealed a significantly dilated appendix,leading to laparoscopic resection of the appendix and part of the cecum.Post-surgical pathologic analysis confirmed LAMN.The patient received symptomatic and supportive post-operative care and was discharged on postoperative day 4 without complications such as abdominal bleeding,intestinal obstruction,or incision infection.No tumor recurrence was observed during a 7-mo follow-up period.CONCLUSION LAMN is a rare disease that lacks specific clinical manifestations.Abdominal CT plays a crucial role in diagnosing LAMN,and laparoscopic surgery is a safe and effective diagnostic and therapeutic approach.

Diagnosis and treatment of biliary mucinous cystic neoplasms: A single-center experience

Background: Biliary mucinous cystic neoplasms(BMCNs) are rare hepatobiliary cystic tumors, which can be divided into noninvasive and invasive types. This study aimed to investigate the diagnosis, treatment, and prognosis of BMCNs in a large single center. Methods: We analyzed 49 patients with BMCNs confirmed by postoperative pathology at the First Afflliated Hospital, Zhejiang University School of Medicine between January 2007 and December 2021. Results: Among the 49 patients, 37 were female(75.5%), and the average age was 57.04 years. Common symptoms included abdominal discomfort, jaundice and fever, while 22 patients(44.9%) had no symptoms. Serum carbohydrate antigen(CA) 19-9 and CA125 concentrations were elevated in 34.8% and 19.6% of patients, respectively. Forty-eight patients had tumors in the intrahepatic bile ducts and only one had a tumor in the extrahepatic bile duct. Forty-eight patients with noninvasive intrahepatic BMCNs were further analyzed in terms of pathological features: 34(70.8%) had low-grade intraepithelial neoplasms(LGINs), and 14(29.2%) had high-grade intraepithelial neoplasms(HGINs). The potential immunohistochemical markers of BMCNs were cytokeratin(CK) 19, CK7, estrogen receptor and progesterone receptor. Follow-up data for 37 patients with intrahepatic BMCNs were obtained. The median overall survival(OS) of BMCNs was not reached. The longest survival time was 137 months.The 5-and 10-year OS rates were 100% and 85.4%, respectively. The 5-and 10-year recurrence-free survival(RFS) rates were 93.9% and 80.2%, respectively. Conclusions: BMCNs are rare cystic neoplasms that commonly occur in middle-aged females. BMCNs can only be diagnosed and classified by postoperative pathology, as there are no specific clinical presentations, serological indicators or imaging modalities for preoperative diagnosis. Complete surgical resection is necessary for BMCNs, and the postoperative prognosis is favorable.

Waist subcutaneous soft tissue metastasis of rectal mucinous adenocarcinoma: A case report

BACKGROUND Rectal mucinous adenocarcinoma(MAC)is a rare pathological type of rectal can-cer with unique pathological features and a poor prognosis.It is difficult to diag-nose and treat early because of the lack of specific manifestations in some aspects of the disease.The common metastatic organs of rectal cancer are the liver and lung;however,rectal carcinoma with metastasis to subcutaneous soft tissue is a rare finding.CASE SUMMARY In this report,the clinical data,diagnosis and treatment process,and postope-rative pathological features of a patient with left waist subcutaneous soft tissue masses were retrospectively analyzed.The patient underwent surgical treatment after admission and recovered well after surgery.The final pathological diagnosis was rectal MAC with left waist subcutaneous soft tissue metastasis.CONCLUSION Subcutaneous soft tissue metastasis of rectal MAC is rare,and it can suggest that the tumor is disseminated,and it can appear even earlier than the primary ma-lignant tumor,which is occult and leads to a missed diagnosis and misdiagnosis clinically.When a subcutaneous soft tissue mass of unknown origin appears in a patient with rectal cancer,a ma-lignant tumor should be considered.

The Influence of Aerial Exposure on Sea Anemones Aulactinia veratra Mucin Genes Expression Using the RNA Sequencing

Mucin genes are the main component of mucus. The sea anemone species, Aulactinia veratra (Phylum Cnidaria) contains different types of mucin genes. In the intertidal zone, A. veratra is found to be exposed to air during the low tide and produces large quantities of mucus as an external covering. The relation between low tide and mucus secretion is still unclear, and what is the role of mucin during arial exposure is not yet investigated. This study hypothesised that the mucin genes in A. veratra would have significantly high expression in response to aerial exposure. Therefore, the aim of current study was to examine and analyses the response of A. veratra mucins in response to an experiment involving three hours of aerial exposure. To achieve this, aim the RNA-sequencing and bioinformatics analyses were used to examine the expression profile of A. veratra mucin genes in response to aerial exposure. The generated results have shown that, Mucin4-like and mucin5B-like were up-regulated in response to the three hours of aerial exposure in A. veratra. This finding shows a significant role of mucin5B-like and mucin4-like genes in response to air stress at low tide. The data generated from this study could be used in conjunction with future mucin gene studies of sea anemones and other cnidarians to compare A. veratra mucin gene expression results across time, and to extend our understanding of mucin stress response in this phylum.

Establishment of a cholangiocarcinoma risk evaluation model based on mucin expression levels

BACKGROUND Cholangiocarcinoma(CCA)is a highly malignant cancer,characterized by frequent mucin overexpression.MUC1 has been identified as a critical oncogene in the progression of CCA.However,the comprehensive understanding of how the mucin family influences CCA progression and prognosis is still incomplete.AIM To investigate the functions of mucins on the progression of CCA and to establish a risk evaluation formula for stratifying CCA patients.METHODS Single-cell RNA sequencing data from 14 CCA samples were employed for elucidating the roles of mucins,complemented by bioinformatic analyses.Subse-quent validations were conducted through spatial transcriptomics and immuno-histochemistry.The construction of a risk evaluation model utilized the least absolute shrinkage and selection operator regression algorithm,which was further confirmed by independent cohorts and diverse data types.RESULTS CCA tumor cells with elevated levels of MUC1 and MUC4 showed activated nucleotide metabolic pathways and increased invasiveness.MUC5AC-high cells were found to promote CCA progression through WNT signaling.MUC5B-high cells exhibited robust cellular oxidation activities,leading to resistance against antitumoral treatments.MUC13-high cells were observed to secret chemokines,recruiting and transforming macrophages into the M2-polarized state,thereby suppressing antitumor immunity.MUC16-high cells were found to promote tumor progression through interleukin-1/nuclear factor kappa-light-chain-enhancer of activated B cells signaling upon interaction with neutrophils.Utilizing the expression levels of these mucins,a risk factor evaluation formula for CCA was developed and validated across multiple cohorts.CCA samples with higher risk factors exhibited stronger metastatic potential,chemotherapy resistance,and poorer prognosis.CONCLUSION Our study elucidates the functional mechanisms through which mucins contribute to CCA development,and provides tools for risk stratification in CCA.

Solitary acral persistent papular mucinosis nodule:A case report and summary of eight Korean cases

BACKGROUND Acral persistent papular mucinosis(APPM)is a rare idiopathic subtype of localized lichen myxedematosus.To date,there have been 40 APPM cases reported worldwide;however,only 7 cases have been reported in the Korean literature.CASE SUMMARY A 70-year-old man was referred to our hospital with a solitary pinkish nodule on the dorsum of his right hand.Despite the absence of symptoms,the patient wanted to know the exact diagnosis;thus,a biopsy was performed.Histopathological examination of a biopsy specimen obtained from the nodule on the dorsum of his hand revealed orthokeratotic hyperkeratosis with patchy parakeratosis,prominent hypergranulosis,and diffuse dissecting mucinous deposition between collagen bundles,along with some bland-looking spindle cells throughout the dermis.The nodule was histologically diagnosed as an APPM,and an intralesional triamcinolone injection(2.5 mg/mL)was started every 2 wk.After three sessions of treatment,the patient showed marked improvements.CONCLUSION To the best of our knowledge,this is the first case of a Korean APPM presenting as a solitary nodule that showed a marked response to triamcinolone intralesional injection.Since it is a rare disease,we report this case to contribute to future research on the pathogenesis and treatment of APPM.

Evaluation of appendiceal mucinous neoplasms by curved lineararray echoendoscope:A preliminary study

BACKGROUND Preoperative diagnosis of appendiceal mucinous neoplasms is challenging,and there are few reports regarding the endosonographic characteristics of these neoplasms.AIM To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound(EUS)by curved linear-array echoendoscope.METHODS A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed.The EUS characteristics and patients’clinical data were reviewed.RESULTS Twenty-two patients were included in the study.The linear-array echoendoscope successfully reached the ileocecal region in every patient.In the endoscopic view,we could observe the protrusion in the appendiceal orifice in all patients.A volcano sign was observed in two patients,and an atypical volcano sign was seen in two patients.EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries.No wall nodules were observed,but an onion-peeling sign was observed in 17 cases.CONCLUSION Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS.Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.

Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas:A case report

BACKGROUND Intraductal papillary mucinous neoplasm(IPMN)is a rare pancreatic tumor and has the potential to become malignant.Surgery is the most effective treatment at present,but there is no consensus on the site of resection.Heterotopic pancreas occurs in the gastrointestinal tract,especially the stomach and duodenum but is asymptomatic and rare.We report a case of ectopic pancreas with IPMN located in the jejunum.CASE SUMMARY A 56-year-old male patient suffered from severe pain,nausea and vomiting due to a traffic accident and sought emergency treatment at our hospital.Contrast-enhanced computed tomography of the whole abdomen suggested splenic congestion,which was considered to be splenic rupture.Emergency laparotomy was performed,and the ruptured spleen was removed during the operation.Unexpectedly,a cauliflower-like mass of about 2.5 cm×2.5 cm in size was incidentally found about 80 cm from the ligament of Treitz during the operation.A partial small bowel resection was performed,and postoperative pathology confirmed the small bowel mass as heterotopic pancreas with low-grade IPMN.CONCLUSION Ectopic pancreas occurs in the jejunum and is pathologically confirmed as IPMN after surgical resection.

Comparison of clinicopathological characteristics and survival outcomes between gallbladder mucinous adenocarcinoma and gallbladder adenocarcinoma:A propensity score-matched study

BACKGROUND Gallbladder mucinous adenocarcinoma(GBMAC)is a rare subtype of gallbladder adenocarcinoma(GBAC),with limited knowledge of its survival outcomes from small case series and single-center retrospective analysis.AIM To compare the clinicopathological characteristics of GBMAC with typical GBAC and its prognostic factors to gain insights into this field.METHODS This study was conducted using data from the Surveillance,Epidemiology,and End Results database,including cases of GBMAC and typical GBAC diagnosed from 2010 to 2017.The Pearson chi-square test or Fisher exact test was used to examine the differences in clinicopathological features between these two cohorts.In addition,propensity score matching(PSM)analysis was performed to balance the selection biases.Univariate and multivariate Cox hazards regression analyses were performed to determine independent prognostic factors for cancer-speci
c survival(CSS)and overall survival(OS).The Kaplan–Meier curves and log-rank tests were used to assess the OS and CSS of GBMAC and typical GBAC patients.RESULTS The clinicopathological and demographic characteristics of GBMAC were different from typical GBAC.They included a larger proportion of patients with unmarried status,advanced American Joint Committee on Cancer(AJCC)stage,higher T stage,higher N1 stage rate and lower N0 and N2 stage rates(P<0.05).Multivariate analyses demonstrated that surgery[OS:Hazard ratio(HR)=2.27,P=0.0037;CSS:HR=2.05,P=0.0151],chemotherapy(OS:HR=6.41,P<0.001;CSS:HR=5.24,P<0.001)and advanced AJCC stage(OS:Stage IV:HR=28.99,P=0.0046;CSS:Stage III:HR=12.31,P=0.015;stage IV:HR=32.69,P=0.0015)were independent prognostic indicators for OS and CSS of GBMAC patients.Furthermore,after PSM analysis,there was no significant difference between GBMAC and matched typical GBAC patients regarding OS(P=0.82)and CSS(P=0.69).CONCLUSION The biological behaviors of GBMAC are aggressive and significantly different from that of typical GBAC.However,they show similar survival prognoses.Surgery,chemotherapy,and lower AJCC stage were associated with better survival outcomes.Further research is needed in the future to verify these results.

Reoperation for heterochronic intraductal papillary mucinous neoplasm of the pancreas after bile duct neoplasm resection:A case report

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB)and intraductal papillary mucinous neoplasm(IPMN)of the pancreas have similar pathological manifestations.However,they often develop separately and it is rare for both to occur together.Patients presenting with heterochronic IPMN after IPNB are prone to be misdiagnosed with tumor recurrence.CASE SUMMARY A 67-year-old male patient was admitted 8.5 years after IPNB carcinoma and 4 years after the discovery of a pancreatic tumor.A left hepatic bile duct tumor with distal bile duct dilatation was found 8.5 years ago by the computed tomography;therefore,a left hepatectomy was performed.The postoperative pathological diagnosis was malignant IPNB with negative cutting edge and pathological stage T1N0M0.Magnetic resonance imaging 4 years ago showed cystic lesions in the pancreatic head with pancreatic duct dilatation,and carcinoembryonic antigen continued to increase.Positron emission tomography showed a maximum standard uptake value of 11.8 in the soft tissue mass in the pancreatic head,and a malignant tumor was considered.Radical pancreatoduodenectomy was performed.Postoperative pathological diagnosis was pancreatic head IPMN with negative cutting edge,pancreaticobiliary type,stage T3N0M0.He was discharged 15 d after the operation.Follow-up for 6 mo showed no tumor recurrence,and quality of life was good.CONCLUSION IPNB and IPMN are precancerous lesions with similar pathological characteristics and require active surgery and long-term follow-up.

Synchronous manifestation of colorectal cancer and intraductal papillary mucinous neoplasms

High rates of extrapancreatic malignancies,in particular colorectal cancer(CRC),have been detected in patients with intraductal papillary mucinous neoplasm(IPMN).So far,there is no distinct explanation in the literature for the development of secondary or synchronous malignancies in patients with IPMN.In the past few years,some data related to common genetic alterations in IPMN and other affiliated cancers have been published.This review elucidated the association between IPMN and CRC,shedding light on the most relevant genetic alterations that may explain the possible relationship between these entities.In keeping with our findings,we suggested that once the diagnosis of IPMN is made,special consideration of CRC should be undertaken.Presently,there are no specific guidelines regarding colorectal screening programs for patients with IPMN.We recommend that patients with IPMNs are at high-risk for CRC,and a more rigorous colorectal surveillance program should be implemented.

Gefitinib improves severe bronchorrhea and prolongs the survival of a patient with lung invasive mucinous adenocarcinoma:A case report

BACKGROUND Lung invasive mucinous adenocarcinoma(LIMA),formerly referred to as mucinous bronchioloalveolar carcinoma,is a rare disease that usually presents as bilateral lung infiltration,is unsuitable for surgery and radiotherapy,and shows poor response to conventional chemotherapy.CASE SUMMARY We report a 56-year-old Chinese man with a history of smoking and epidermal growth factor receptor mutation-positivity who was initially misdiagnosed as severe pneumonia,but was ultimately diagnosed as a case of invasive mucinous adenocarcinoma of the lung by computed tomography-guided percutaneous lung biopsy.Bronchorrhea and dyspnea were improved within 24 h after initiation of gefitinib therapy and the radiographic signs of bilateral lung consolidation showed visible improvement within 30 d.After more than 11 months of treatment,there is no evidence of recurrence or severe adverse events.CONCLUSION Although the precise mechanism of the antitumor effects of gefitinib are not clear,our experience indicates an important role of the drug in LIMA and provides a reference for the diagnosis and treatment of this disease.

Dissimilar survival and clinicopathological characteristics of mucinous adenocarcinoma located in pancreatic head and body/tail

BACKGROUND Growing evidence shows that pancreatic tumors in different anatomical locations have different characteristics,which have a significant impact on prognosis.However,no study has reported the differences between pancreatic mucinous adenocarcinoma(PMAC)in the head vs the body/tail of the pancreas.AIM To investigate the differences in survival and clinicopathological characteristics between PMAC in the head and body/tail of pancreas.METHODS A total of 2058 PMAC patients from the Surveillance,Epidemiology,and End Results database diagnosed between 1992 and 2017 were retrospectively reviewed.We divided the patients who met the inclusion criteria into pancreatic head group(PHG)and pancreatic body/tail group(PBTG).The relationship between two groups and risk of invasive factors was identified using logistic regression analysis.Kaplan-Meier analysis and Cox regression analysis were conducted to compare the overall survival(OS)and cancer-specific survival(CSS)of two patient groups.RESULTS In total,271 PMAC patients were included in the study.The 1-year,3-year,and 5-year OS rates of these patients were 51.6%,23.5%,and 13.6%,respectively.The 1-year,3-year,and 5-year CSS rates were 53.2%,26.2%,and 17.4%,respectively.The median OS of PHG patients was longer than that of PBTG patients(18 vs 7.5 mo,P<0.001).Compared to PHG patients,PBTG patients had a greater risk of metastases[odds ratio(OR)=2.747,95%confidence interval(CI):1.628-4.636,P<0.001]and higher staging(OR=3.204,95%CI:1.895-5.415,P<0.001).Survival analysis revealed that age<65 years,male sex,low grade(G1-G2),low stage,systemic therapy,and PMAC located at the pancreatic head led to longer OS and CSS(all P<0.05).The location of PMAC was an independent prognostic factor for CSS[hazard ratio(HR)=0.7,95%CI:0.52-0.94,P=0.017].Further analysis demonstrated that OS and CSS of PHG were significantly better than PBTG in advanced stage(stage III-IV).CONCLUSION Compared to the pancreatic body/tail,PMAC located in the pancreatic head has better survival and favorable clinicopathological characteristics.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm(IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucinproducing cells arising in the main duct(MD) and/or branch ducts(BD) of the pancreas.Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity.IPMN lacks ovarian-type stroma,unlike mucinous cystic neoplasm,and is defined as a grossly visible entity(≥ 5 mm),unlike pancreatic intraepithelial neoplasm.With the use of high-resolution imaging techniques,very small IPMNs are increasingly being identified.Most IPMNs are solitary and located in the pancreatic head,although 20%-40% are multifocal.Macroscopic classification in MD type,BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications.Based on cytoarchitectural atypia,IPMN is classified into low-grade,intermediategrade and high-grade dysplasia.Based on histological features and mucin(MUC) immunophenotype,IPMNs are classified into gastric,intestinal,pancreatobiliary and oncocytic types.These different phenotypes can be observed together,with the IPMN classified according to the predominant type.Two pathways have been suggested:gastric phenotype corresponds to less aggressive uncommitted cells(MUC1-,MUC2-,MUC5 AC +,MUC6 +) with the capacity to evolve to intestinal phenotype(intestinal pathway)(MUC1-,MUC2 +,MUC5 AC +,MUC6- or weak +) or pancreatobiliary /oncocytic phenotypes(pyloropancreatic pathway)(MUC1 +,MUC 2-,MUC5 AC +,MUC 6 +) becoming more aggressive.Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises(about 40% of IPMNs),except in some cases of minimal invasion.The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer.Once resected,they must be extensively sampled or,much better,submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Malignancy risk factors and prognostic variables of pancreatic mucinous cystic neoplasms in Chinese patients

BACKGROUND Pancreatic mucinous cystic neoplasms(MCNs)represent one of the precursor lesions of pancreatic ductal adenocarcinoma,and their detection has been facilitated by advances in preoperative imaging.Due primarily to the rarity of MCNs,however,there is limited knowledge regarding the prognostic variables and high-risk factors for malignant transformation.A more comprehensive and nuanced approach is necessary to fill this gap and provide a basis for improved treatment decisions and patient outcomes.AIM To investigate the high-risk factors associated with malignant MCNs and to explore the prognostic factors of MCN with associated invasive carcinoma(MCNAIC).METHODS All cases of resected MCNs from a single high-volume institution between January 2012 and January 2022 were retrospectively reviewed.Only cases with ovarian-type stroma verified by progesterone receptor staining were included.Preoperative features,histological findings and postoperative course were documented.Multivariate logistic regression was employed to investigate variables related to malignancy.Survival analysis was performed using the Kaplan-Meier curve,and the prognostic factors were assessed to evaluate the postoperative course of patients with MCN-AIC.RESULTS Among the 48 patients,36 had benign MCNs,and 12 had malignant MCNs(1 high-grade atypical hyperplasia and 11 MCN-AIC).Age,tumour size,presence of solid components or mural nodules and pancreatic duct dilatation were identified as independent risk factors associated with malignancy.The follow-up period ranged from 12 mo to 120 mo,with a median overall survival of 58.2 mo.Only three patients with MCN-AIC died,and the 5-year survival rate was 70.1%.All 11 cases of MCN-AIC were stage I,and extracapsular invasion was identified as a prognostic factor for poorer outcomes.CONCLUSION The risk factors independently associated with malignant transformation of MCNs included age,tumour size,presence of solid components or mural nodules,and pancreatic duct dilatation.Our study also revealed that encapsulated invasion was a favourable prognostic factor in MCN-AIC patients.

Malignant transformation of pulmonary bronchiolar adenoma into mucinous adenocarcinoma:A case report

BACKGROUND Bronchiolar adenoma(BA)and ciliated muconodular papillary tumor are rare tumors that have bilayered cell proliferation and continuous expression of p40 and CK5/6 in the basal cell layer.Diagnosis is difficult because of the limited knowledge of these tumors and their morphological similarities to malignant tumors,including invasive mucinous adenocarcinoma,especially based on the histopathology of intraoperative frozen sections.These tumors are now considered to be benign neoplasms,with malignant transformation reported in only a few cases.CASE SUMMARY A 57-year-old woman presented with a 17.0 mm×7.0 mm nodule in the lower lobe of the left lung.Hematoxylin-eosin staining and immunohistochemistry of a surgical specimen were performed.The tumor consisted of a BA area and a mucinous adenocarcinoma(MA)area.In the BA area,the tumor had a bilayered structure of luminal cells and basal cells.The basal cells were positive for CK5/6 and p40,but the MA area was negative for these biomarkers.The Ki-67 proliferation index was low(1%-2%).The patient was diagnosed with BA accompanied by MA,and had a favorable outcome.CONCLUSION The present study indicated that BA may be carcinogenic,and suggests that clinicians should be aware of its potential for malignant transformation.

Non-retroareolar male mucinous breast cancer without gynecomastia development in an elderly man:A case report

BACKGROUND Male breast cancer(MBC)is an extremely rare condition and accounts for less than 1%of all breast cancers,and malignant tumors occur in less than 1%of the affected men.Mucinous breast cancer is extremely rare and accounts for 2%of all invasive breast cancers.Generally,MBC is accompanied by a retroareolar mass.CASE SUMMARY Herein,we report a case of male mucinous breast carcinoma(MMBC)without gynecomastia development and with mass localization outside the common retroareolar region,wherein the mass was a painless nodule in the right breast of a 64-year-old man.We also discuss the clinical and pathological characteristics of this unusual tumor.The excised breast specimen showed pure mucinous carcinoma.The patient had strong expression of estrogen and progesterone receptors,a low Ki-67 proliferation index of the tumor cells,and negative pathological axillary lymph nodes.The patient underwent modified radical mastectomy and axillary lymph node dissection,followed by tamoxifen hormone therapy.CONCLUSION To the best of our knowledge,this is the first case report of MMBC in the nonretroareolar region of the nipple without gynecomastia development.Mucinous tumors are easily missed during diagnosis,and the incidence of axillary lymph node metastases of chest mucinous tumors has increased.

Local recurrence after successful endoscopic submucosal dissection for rectal mucinous mucosal adenocarcinoma:A case report

BACKGROUND Mucinous adenocarcinoma of the colorectum is a rare histological subtype characterized by an abundant mucinous component.Mucinous tumors are frequently diagnosed at an advanced stage,which indicates an aggressive subtype.However,few case reports have been published,and little information is available concerning genetic alterations in mucinous adenocarcinoma.CASE SUMMARY A 76-year-old man underwent en bloc endoscopic submucosal dissection(ESD)for the management of a type 0-Is+IIa lesion.Histological examination revealed an intramucosal mucinous adenocarcinoma with signet-ring cell carcinoma and well-to-moderately differentiated tubular adenocarcinoma.Three years after the ESD,local recurrence was detected by an endoscopic examination,revealing a new 0-Is+IIa lesion with a phenotype similar to the previously resected lesion.Re-ESD was chosen for the management of the recurrent tumor,and the histological examination showed positive tumor infiltration at the vertical margin.Additional surgical resection was performed for the curative treatment.Genetic analysis showed pathogenic alterations in RNF43 and TP53 in the adenoma and an additional SMAD4 alteration in the carcinoma.CONCLUSION This mucinous mucosal adenocarcinoma case was suggested to have an aggressive phenotype and a careful and close follow-up are required.

Epidemiologic characteristics and risk factors associated with overall survival for patients with mucinous colorectal cancer:A population-based study

BACKGROUND Mucinous adenocarcinoma(MC)has attracted much attention as a distinct histologic subtype of colorectal cancer in recent years.However,data about its epidemiologic and prognostic characteristics are limited.Therefore,patient data extracted from the National Cancer Institute’s Surveillance,Epidemiology,and End Results Program were collected to analyze the epidemiologic and clinicopathological characteristics of MC.AIM To determine the epidemiologic and clinicopathological characteristics of MC.METHODS The incidence trend of MC was calculated through the Joinpoint Regression Program.Cox regression analyses were performed to identify prognostic factors associated with overall survival(OS).A nomogram was established to predict the survival probability of individual patients with MC.RESULTS We found that rates of MC decreased from 4.50/100000 in 2000 to 1.54/100000 in 2018.Rates of MCs in patients aged≤50 years decreased 2.27%/year during 2000-2018.The incidence of appendiceal MCs increased from 0.14/100000 in 2000 to 0.24/100000 in 2018,while the incidence in other anatomic subsites continued to decrease.On multivariable Cox analyses,age,race,tumor site,T stage,N stage,M stage,surgery,and chemotherapy were associated with OS.A nomogram was developed based on these factors,and the area under the curve for 1-year,3-year,and 5-year OS in the training cohort was 0.778,0.778,and 0.768,respectively.CONCLUSION Our results demonstrated that MC incidence decreased in almost all anatomic subgroups except for the appendix.A nomogram predicting the survival probability of patients with MCs showed good performance.