Systematic review of risk factors,prognosis,and management of colorectal signet-ring cell carcinoma

BACKGROUND Colorectal signet-ring cell carcinoma(CSRCC)is a rare clinical entity which accounts for approximately 1%of all colorectal cancers.Although multiple studies concerning this specific topic have been published in the past decades,the pathogenesis,associated risk factors,and potential implications on treatment are still poorly understood.Besides the low incidence,historically confusing histological criteria have resulted in confusing data.Nevertheless,the rising incidence of CSRCC along with relatively young age at presentation and associated dismal prognosis,highlight the actual interest to synthesize the known literature regarding CSRCC.AIM To provide an updated overview of risk factors,prognosis,and management of CSRCC.METHODS A literature search in the MEDLINE/PubMed database was conducted with the following search terms used:‘Signet ring cell carcinoma’and‘colorectal’.Studies in English language,published after January 1980,were included.Studies included in the qualitative synthesis were evaluated for content concerning epidemiology,risk factors,and clinical,diagnostic,histological,and molecular features,as well as metastatic pattern and therapeutic management.If possible,presented data was extracted in order to present a more detailed overview of the literature.RESULTS In total,67 articles were included for qualitative analysis,of which 54 were eligible for detailed data extraction.CSRCC has a reported incidence between 0.1%-2.4%and frequently presents with advanced disease stage at the time of diagnosis.CSRCC is associated with an impaired overall survival(5-year OS:0%-46%)and a worse stagecorrected outcome compared to mucinous and not otherwise specified adenocarcinoma.The systematic use of exploratory laparoscopy to determine the presence of peritoneal metastases has been advised.Surgery is the mainstay of treatment,although the rates of curative resection in CSRCC(21%-82%)are lower compared to those in other histological types.In case of peritoneal metastasis,cytoreductive surgery with hyperthermic intraperitoneal chemotherapy should only be proposed in selected patients.CONCLUSION CSRCC is a rare clinical entity most often characterized by young age and advanced disease at presentation.As such,diagnostic modalities and therapeutic approach should be tailored accordingly.

Early gastric composite tumor comprising signet-ring cell carcinoma and mucosa-associated lymphoid tissue lymphoma:A case report

BACKGROUND Composite tumors are neoplasms comprising two distinct,yet intermingling,cell populations.This paper reports a rare phenomenon where early gastric signet-ring cell carcinoma(SRCC)and gastric mucosa-associated lymphoid tissue(MALT)lymphoma coexist within the same lesion.CASE SUMMARY A 40-year-old woman presented to the West China Hospital for examination,which revealed a whitish,shallow,and uneven mucosal lesion in the stomach.The lesion was diagnosed as a poorly differentiated adenocarcinoma,including SRCC with atypical lymphoid hyperplasia associated with Helicobacter pylori infection,based on histopathological examination of the biopsy specimen.The lesion was excised using segmental gastrectomy.However,histological exami-nation of the surgical specimen confirmed that it was a poorly differentiated gastric adenocarcinoma with features of SRCC and MALT lymphoma.These two entities were stage I and coexisted in the same lesion.CONCLUSION It is uncommon for gastric SRCC and MALT lymphoma to coexist without distinct borders.Surgical resection is effective for these lesions.

Immunosuppressive tumor microenvironment in gastric signet-ring cell carcinoma

Gastric signet-ring cell carcinoma(GSRCC)is a subtype of gastric cancer with distinct phenotype and high risk of peritoneal metastasis.Studies have shown that early GSRCC has a good prognosis,while advanced GSRCC is insensitive to radiotherapy,chemotherapy or immune checkpoint blockade therapy.With technological advancement of single-cell RNA sequencing analysis and cytometry by time of flight mass cytometry,more detailed atlas of tumor microenvironment(TME)in GSRCC and its association with prognosis could be investigated extensively.Recently,two single-cell RNA sequencing studies revealed that GSRCC harbored a unique TME,manifested as highly immunosuppressive,leading to high immune escape.The TME of advanced GSRCC was enriched for immunosuppressive factors,including the loss of CXCL13+-cluster of differentiation 8+-Tex cells and declined clonal crosstalk among populations of T and B cells.In addition,GSRCC was mainly infiltrated by follicular B cells.The increased proportion of SRCC was accompanied by a decrease in mucosaassociated lymphoid tissue-derived B cells and a significant increase in follicular B cells,which may be one of the reasons for the poor prognosis of GSRCC.By understanding the relationship between immunosuppressive TME and poor prognosis in GSRCC and the underlying mechanism,more effective immunotherapy strategies and improved treatment outcomes of GSRCC can be anticipated.

Signet-ring cell carcinoma of the transverse colon in a 10-year-old girl:A case report

BACKGROUND Signet-ring cell carcinoma(SRCC)is a rare subtype of colorectal cancer.The incidence of primary colonic SRCC is relatively rare in pediatric patients,with a limited number of reported cases currently available.The prognosis for this specific tumor type is unfavorable,and the preoperative diagnosis presents challenges,potentially leading to misdiagnosis.This case report describes the diagnosis of primary SRCC in the colon of a 10-year-old girl.CASE SUMMARY The patient was admitted to the hospital due to abdominal pain and vomiting.A computed tomography scan revealed an irregular mass with soft tissue density in her transverse colon,showing uneven density and multiple calcifications.The patient underwent surgical resection of the affected bowel and lymph node dissection,which was confirmed by pathological examination to be SRCC infiltrating both nerves and the entire intestinal wall.Additionally,tumor thrombus formation was observed in blood vessels and lymphatic vessels,multiple cancerous nodules were found in the omentum,and metastasis to 18 of 26 mesenteric lymph nodes examined.Immunohistochemistry for mismatch repair gene protein demonstrated microsatellite stability.No mutations in KRAS,NRAS,BRAF,or PIK3CA genes were detected through molecular pathology analysis.After surgery,she received standard chemotherapy for 8 cycles without tumor progression or other abnormalities during a 12-month follow-up period CONCLUSION Primary colonic SRCC is a rare malignant tumor with atypical clinical symptoms,and timely identification and intervention are crucial for improving the prognosis.

Colon signet-ring cell carcinoma with chylous ascites caused by immunosuppressants following liver transplantation:A case report

BACKGROUND Chylous ascites is caused by disruption of the lymphatic system,which is characterized by the accumulation of a turbid fluid containing high levels of triglycerides within the abdominal cavity.The two most common causes are cirrhosis and tuberculosis,and colon signer ring cell carcinoma(SRCC)due to the use of immunosuppressants is extremely rare in cirrhotic patients after liver transplantation,making it prone to misdiagnosis and missed diagnosis.CASE SUMMARY A 52-year-old man who underwent liver transplantation and was administered with immunosuppressants for 8 months was admitted with a 3-month history of progressive abdominal distention.Initially,based on lymphoscintigraphy and lymphangiography,lymphatic obstruction was considered,and cystellar chyli decompression with band lysis and external membrane stripping of the lymphatic duct was performed.However,his abdominal distention was persistent without resolution.Abdominal paracentesis revealed allogenic cells in the ascites,and immunohistochemistry analysis revealed adenocarcinoma cells with phenotypic features suggestive of a gastrointestinal origin.Gastrointestinal endoscopy was performed,and biopsy showed atypical signet ring cells in the ileocecal valve.The patient eventually died after a three-month follow-up due to progression of the tumor.CONCLUSION Colon SRCC,caused by immunosuppressants,is an unusual but un-neglected cause of chylous ascites.

Prediction of lymph node metastasis in early gastric signet-ring cell carcinoma:A real-world retrospective cohort study

BACKGROUND Signet-ring cell carcinoma(SRCC)was previously thought to have a worse prognosis than other differentiated gastric cancer(GC),however,recent studies have shown that the prognosis of SRCC is related to pathological type.We hypothesize that patients with SRCC and with different SRCC pathological components have different probability of lymph node metastasis(LNM).AIM To establish models to predict LNM in early GC(EGC),including early gastric SRCC.METHODS Clinical data from EGC patients who had undergone gastrectomy at the First Affiliated Hospital of Nanjing Medical University from January 2012 to March 2022 were reviewed.The patients were divided into three groups based on type:Pure SRCC,mixed SRCC,and non-signet ring cell carcinoma(NSRC).The risk factors were identified through statistical tests using SPSS 23.0,R,and EmpowerStats software.RESULTS A total of 1922 subjects with EGC were enrolled in this study,and included 249 SRCC patients and 1673 NSRC patients,while 278 of the patients(14.46%)presented with LNM.Multivariable analysis showed that gender,tumor size,depth of invasion,lymphovascular invasion,ulceration,and histological subtype were independent risk factors for LNM in EGC.Establishment and analysis using prediction models of EGC showed that the artificial neural network model was better than the logistic regression model in terms of sensitivity and accuracy(98.0%vs 58.1%,P=0.034;88.4%vs 86.8%,P<0.001,respectively).Among the 249 SRCC patients,LNM was more common in mixed(35.06%)rather than in pure SRCC(8.42%,P<0.001).The area under the ROC curve of the logistic regression model for LNM in SRCC was 0.760(95%CI:0.682-0.843),while the area under the operating characteristic curve of the internal validation set was 0.734(95%CI:0.643-0.826).The subgroups analysis of pure types showed that LNM was more common in patients with a tumor size>2 cm(OR=5.422,P=0.038).CONCLUSION A validated prediction model was developed to recognize the risk of LNM in EGC and early gastric SRCC,which can aid in pre-surgical decision making of the best method of treatment for patients.

Update on diagnosis and treatment of early signet-ring cell gastric carcinoma: A literature review

Gastric signet-ring cell gastric carcinoma(GSRC)is an unfavorable subtype of gastric cancer(GC)that presents with greater invasiveness and poorer prognosis in advanced stage than other types of GC.However,GSRC in early stage is often considered an indicator of less lymph node metastasis and more satisfying clinical outcome compared to poorly differentiated GC.Therefore,the detection and diagnosis of GSRC at early stage undoubtedly play a crucial role in the management of GSRC patients.In recent years,technological advancement in endoscopy including narrow-band imaging and magnifying endoscopy has significantly improved the accuracy and sensitivity of the diagnosis under endoscopy for GSRC patients.Researches have confirmed that early stage GSRC that meets the expanded criteria of endoscopic resection showed comparable outcomes to surgery after receiving endoscopic submucosal dissection(ESD),indicating that ESD could be considered standard treatment for GSRC after thorough selection and evaluation.This article summarizes the current knowledge and updates pertaining to the endoscopic diagnosis and treatment of early stage signet-ring cell gastric carcinoma.

Clinicopathological and prognostic differences between mucinous gastric carcinoma and signet-ring cell carcinoma

Objective： To analyze the differences in clinicopathologic characteristics and prognosis between mucinous gastric carcinoma （MGC） and signet-ring cell carcinoma （SRCC）. Methods： Clinicopathologic and prognostic data of 1,637 patients with histologically confirmed MGC or SRCC who received surgical operations in the Department of Gastroenterological Surgery, Beijing Cancer Hospital between December 2004 and December 2009 were retrospectively collected and analyzed. The clinicopathological features were analyzed statistically using Z2 test. Survival was analyzed using the Kaplan- Meier method and multivariate analysis of Cox proportional hazards regression model （backward, stepwise）. Results： A total of 181 patients with gastric cancer （74 MGC, 107 SRCC） were included. MGC, when compared with SRCC, was featured by senile patients, stage III and I~, upper third stomach, large tumor size, positive lymph node metastasis, and positive lymphatic vascular invasion （P〈0.05）. The overall 5-year survival rate showed no difference between the two groups （48.8% vs. 44.8%, P〉0.05）. However, the survival rate for MGC patients was significant lower than that for SRCC patients when compared among the age 〈60 years, negative distant metastasis, and tumor localized at upper third stomach （P〈0.05）. Multivariate Cox proportional hazards models revealed that distant metastasis was a significant independent prognostic indicator in MGC group, and lymph node metastasis and distant metastasis was significant independent prognostic indicators in SRCC group. Conclusions： While compared with SRCC, MGC is associated with a more aggressive tumor biologic behavior. There is no statistically significant difference in distant metastasis, an independent prognostic indicator for both MGC and SRCC, which might be the reason for no significant difference of the overall survival rate between the patients with MGC and SRCC.

Signet-ring cell carcinoma of ampulla of Vater:Contrast-enhanced ultrasound findings

Signet-ring cell carcinoma(SRCC) of ampulla of Vater is extremely uncommon,and less than 15 cases have been reported so far in literature.It mainly occurs in elderly people(median age 57 years).We report a rare case of SRCC of the ampulla of Vater in a 38-year-old woman who presented with a small tumor at the Vater,discovered by the contrast-enhanced ultrasound(CEUS).Histopathological examination showed prominent signet-ring features.We also describe the imaging features of SRCC of ampulla of Vater in CEUS.

LINE-1 family member GCRG123 gene is up-regulated in human gastric signet-ring cell carcinoma

AIM： To analyze the expression profiles of a human gastriccancer-related gene, GCRG123, in human gastric signetring cell carcinoma tissues, and to perform bioinformatics analysis on GCRG123.METHODS： In situ hybridization was used to explore the GCRG123 expression pattern in paraffin-embedded gastric tissues, including 15 cases of signet-ring cell carcinoma, 15 of intestinal-type adenocarcinoma, and 15 of normal gastric mucosa. Northern blotting was used to analyze the differences in GCRG123 expression between stomach signet-ring cell carcinoma and intestinal-type adenocarcinoma tissues. Online software, including BLAST, Multalin and BLAT, were applied for bioinformatics analysis. National Center for Biotechnology Information （NCBI） and the University of California Santa Cruz （UCSC） databases were used for the analyses.RESULTS： The in situ hybridization signal appeared as blue precipitates restricted to the cytoplasm. Ten out of 15 cases of gastric signet ring cell carcinoma, normal gastric mucosal epithelium and pyloric glands showed high GCRG123 expression. Low GCRG123 expression was observed in gastric intestinal-type adenocarcinoma and normal gastric glands. Northern blotting revealed that GCRG123 was up-regulated in signet-ring cell carcinoma tissue but down-regulated in intestinal-type adenocarcinoma tissue. BLAST and Multalin analyses revealed that the GCRG123 sequence had 92% similarity with the ORF2 sequence of human long interspersed nuclear element retrotransposons （LINE-1, L1）. BLAT analysis indicated that GCRG123 mapped to all chromosomes. GCRG123 was found to integrate in the intron-17 and -23 of Rb, 5＇ flanking region of IL-2 and clotting factor Ⅸ genes.CONCLUSION： GCRG123, an active member of the Lt family, was up-regulated in human gastric signet-ring cell carcinoma.

Primary signet-ring cell carcinoma of the colon at early stage: A case report and a review of the literature

A 67-year-old man, who had undergone surgery to resect multiple gastric cancers 4 years ago, visited our hospital for surveillance colonoscopy. Colonoscopy revealed a discolored, 7-mm in diameter, flat-elevated lesion with central depression in the transverse colon near the splenic flexure. Although the findings of endoscopy and barium enema were suggestive of submucosal invasion, the patient chose to undergo endoscopic mucosal resection. Pathological examination of the resected specimen revealed signet-ring cell carcinoma and a positive surgical margin. A second operation was performed, and no residual tumor or metastasis to lymph nodes was found in the resected specimens. Primary colorectal cancers composed of signet-ring cell carcinoma detected and treated at an early stage are extremely rare. We present a case and review the literature.

Edema of limbs as the primary symptom of gastric signet-ring cell carcinoma:A case report and literature review

BACKGROUND Metastatic skin cancers are relatively rare dermatological malignancies.They usually present as nodules,erythematous lesions,scar-like lesions or other lesion types.Signet-ring cell carcinoma(SRCC)is an uncommon histological type of gastric cancer that usually behaves aggressively and has a poor prognosis.Skin metastasis may be the first sign of clinically silent visceral cancer or recurrence of an internal malignancy.CASE SUMMARY Herein we report on the case of a 55-year-old man with edema of a lower extremity as the primary symptom which progressed from local to generalized pitting edema in the year following skin involvement.Pathological evidence from gastroscopic specimens and subcutaneous tissue biopsy showed typical signetring cells and gland-like structures.Consistently,immunohistochemical analysis revealed positive pan-cytokeratin expression in tumor cells.A diagnosis of gastric SRCC with skin metastasis was established.Moreover,lymphoscintigraphy showed an obvious accumulation of radiotracer on the anterior and posterior sides of the right leg which indicated lymphedema.We reviewed the relevant literature on subcutaneous metastases of gastric SRCC.CONCLUSION This rare case emphasizes the importance of physical examination as it may help elucidate the etiology of edema.

Gastric signet-ring cell carcinoma with paraneoplastic eosinophilia: A case report and literature review

We report the case of a 40-year-old female Chinese patient with gastric signet-ring cell carcinoma that was first diagnosed because of paraneoplastic eosinophilia.The patient’s eosinophil count reduced markedly to normal levels within 24 h after radical gastrectomy and Billroth II anastomosis.The patient recovered well after the surgery and no abnormalities were found during the regular follow-ups.Paraneoplastic eosinophilia is an unusual manifestation that usually remains asymptomatic;moreover,cases of solid malignant tumors with eosinophilia are uncommon.To our knowledge,this is the first reported case of paraneoplastic eosinophilia in a patient with gastric carcinoma.We considered eosinophilia as a manifestation of a paraneoplastic syndrome,which can be the first clinical manifestation of a malignancy.

Signet-ring cell carcinoma of the stomach: Impact on prognosis and specific therapeutic challenge

While the incidence of gastric cancer has decreased worldwide in recent decades,the incidence of signetring cell carcinoma(SRCC) is rising. SRCC has a specific epidemiology and oncogenesis and has two forms: early gastric cancer,which can be resected endoscopically in some cases and which has a better outcome than non-SRCC,and advanced gastric cancer,which is generally thought to have a worse prognosis and lower chemosensitivity than non-SRCC. However,the prognosis of SRCC and its chemosensitivity with specific regimens are still controversial as SRCC is not specifically identified in most studies and its poor prognosis may be due to its more advanced stage. It therefore remains unclear if a specific therapeutic strategy is justified,as the benefit of perioperative chemotherapy and the value of taxanebased chemotherapy are unclear. In this review we analyze recent data on the epidemiology,oncogenesis,prognosis and specific therapeutic strategies in both early and advanced SRCC of the stomach and in hereditary diffuse gastric cancer.

Gastric adenocarcinoma of fundic gland type with signet-ring cell carcinoma component: A case report and review of the literature

A depressed lesion was found at a gastric angle of 76-yearold Japanese woman by esophagogastroduodenoscopy. Four years prior, she was diagnosed with a Helicobacter pylori infection but no eradication was performed. The pathological diagnosis of biopsy specimens was signet-ring cell carcinoma. Endoscopic submucosal dissection(ESD) was performed. Histopathological examination of the ESD specimen revealed proliferation of well-differentiated tubular adenocarcinoma mimicking fundic gland cells at the deep layer of the lamina propria mucosae. These tumor cells expressed focally pepsinogen-Ⅰ, diffusely MUC6, and scattered H^+/K^+ ATPase according to immunohistochemistry. Therefore, we diagnosed this tumor as gastric adenocarcinoma of fundic gland type(GA-FG). Adjacent to the GA-FG, proliferation of signet-ring cell carcinoma which diffusely expressed MUC 2 and MUC 5AC was observed. Intestinal metaplasia was focally observed in the surrounding mucosa of the signet-ring cell carcinoma. To the best of our knowledge, this is the first case report of GA-FG with a signet-ring cell carcinoma component. The origin of signet-ring cell carcinoma, i.e., whether it accidentally arose from a non-neoplastic mucosa and coexisted with the GA-FG or dedifferentiated from the GA-FG is unclear at present. We expect the accumulation of similar cases and further analysis to clarify this issue.

Signet-ring cell carcinoma arising from a fundic gland polyp in the stomach

Fundic gland polyps(FGPs)are currently the most common type of gastric polyps and are usually benign.However,although rare,gastric adenocarcinoma of FGP has been recently proposed as a new variant of gastric adenocarcinoma.Here we report the first case of a49-year-old woman with focal signet ring cell carcinoma that arose from an FGP of the stomach.The tumor was completely excised by endoscopic snare polypectomy.FGPs should therefore be evaluated for malignant changes although they occur rarely,if the FGP has an erosive or irregular surface.

Synchronous occurrence of carcinoid, signet-ring cell carcinoma and heterotopic pancreatic tissue in stomach: A case report and literature review

We presented an unusual case with coexistence of carcinoid, signet-ring cell carcinoma （SRC） and heterotopic pancreatic tissue in stomach. Gastroscopic examination of this 63-year-old male patient showed multiple protrusions in gastric corpus near the greater curvature, identified by subsequent biopsy as carcinoid, Distal subtotal gastrectomy was performed, Histological and immunohistochemical examinations showed a carcinoid tumor in gastric corpus near the greater curvature, an intramucosal SRC at the lesser curvature of corpus and heterotopic pancreatic tissue in muscularis propria of the antrum at the lesser curvature with hyperplasia of peripheral endocrine cells producing multiple pancreatic hormones, We reviewed the literatures on clinicopathological characteristics and the differential diagnosis of the above three abnormalities, and concluded that the carcinoid in corpus near the greater curvature and SRC in the lesser curvature are independent lesions; the loci of endocrine cells in the muscularis propria and serosa are hyperplastic lesions from the heterotopic pancreatic tissue, rather than dissemination of carcinoid in corpus.

Poorly cohesive cells gastric carcinoma including signet-ring cell cancer:Updated review of definition,classification and therapeutic management

While the incidence of gastric cancer(GC)in general has decreased worldwide in recent decades,the incidence of diffuse cancer historically comprising poorly cohesive cells-GC(PCC-GC)and including signet ring cell cancer is rising.Literature concerning PCC-GC is scarce and unclear,mostly due to a large variety of historically used definitions and classifications.Compared to other histological subtypes of GC,PCC-GC is nevertheless characterized by a distinct set of epidemiological,histological and clinical features which require a specific diagnostic and therapeutic approach.The aim of this review was to provide an update on the definition,classification and therapeutic strategies of PCC-GC.We focus on the updated histological definition of PCC-GC,along with its implications on future treatment strategies and study design.Also,specific considerations in the diagnostic management are discussed.Finally,the impact of some recent developments in the therapeutic management of GC in general such as the recently validated taxane-based regimens(5-Fluorouracil,leucovorin,oxaliplatin and docetaxel),the use of hyperthermic intraperitoneal chemotherapy as well as pressurized intraperitoneal aerosol chemotherapy and targeted therapy have been reviewed in depth for their relative importance for PCC-GC in particular.

Signet-ring cell carcinoma of breast presenting with genital tract metastasis

Objective: To analyze the clinicopathologic features of breast signet-ring cell carcinoma (SRCC) presenting with genital tract metastasis. Methods: A 54-year-old woman presented with metrorrhagia was described and the immunostaining was performed. Results: Histologically, signet ring cells (SRCs) scattered in the stroma of endometrium and cervix, bilateral fallopian tubes, ovaries and left breast. Immunohistochemistry of these SRCs showed strong reactive for cytokertin 7, CEA, GCDFP-15, and weak reactive for CA125 and negative for cytokertin 20. All these information confirmed the breast origin of SRCC. Conclusion: Primary breast SRCC is extremely rare with metrorrhagia as its first symptom. Gynecologist and pathologist should be aware of this possibility when metrorrhagia is the only symptom. Immunohistochemistry can help differentiate the origin of SRCC.

Primary signet-ring cell carcinoma of the extrahepatic bile duct:A case report

BACKGROUND Signet ring cell carcinoma(SRCC)is a specific type of mucinous secretory adenocarcinoma,which contains abundant mucus in the cytoplasm and pushes the nucleus to one side of the cell membrane,forming a round or oval,and the nuclear deviations give the cells a signet ring-like appearance.SRCC often originates in the gastrointestinal tract,especially in the stomach.However,primary SRCC of the extrahepatic bile duct is extremely rare.Therefore,little is known about its epidemiology,treatment,and prognosis.CASE SUMMARY An 82-year-old female was admitted with abdominal pain,jaundice,and skin pruritus for 2 mo.She had no specific family history.Physical examination presented normal vital signs,icteric sclera,visible jaundice,and mild tenderness in the right upper abdominal quadrant.Tumor-related cell markers were within normal values.Contrast-enhanced computed tomography revealed a thickened wall of the common bile duct,strengthened with intrahepatic bile duct dilation and multiple round-like lesions in the liver.In addition,the lymph nodes in the hepatic hilum area,the pancreatic head area,and around the abdominal aorta were enlarged.Thus,a preoperative diagnosis of cholangiocarcinoma was established.To alleviate jaundice and prolong the overall survival,percutaneous transhepatic cholangiopancreatic drainage(PTCD)was performed.During the operation,segmental stenosis of the extrahepatic bile duct and a vine-like expansion of the intrahepatic bile duct was observed.Furthermore,a biliary biopsy was performed under fluoroscopy to determine the nature and origin of the lesion.The pathological diagnosis of the biopsy was SRCC.Finally,a diagnosis of primary SRCC of extrahepatic bile duct with distant lymph node metastasis and multiple liver metastases was made based on the radiographic,PTCD,and pathological characteristics.The tumor was diagnosed as T3N1M1 stage IV.Despite our aggressive approach,the patient died of liver failure after 1 mo.CONCLUSION This is the only case report on primary SRCC of the extrahepatic bile duct with distant organ metastasis to date.