Influence of primary tumor location and resection on survival in metastatic colorectal cancer

BACKGROUND Patients with right sided colorectal cancer are known to have a poorer prognosis than patients with left sided colorectal cancer, whatever the cancer stage. To this day, primary tumor resection(PTR) is still controversial in a metastatic, non resectable setting.AIM To explore the survival impact of PTR in patients with metastatic colorectal cancer(mCRC) depending on PTL.METHODS We retrospectively collected data from all consecutive patients treated for mCRC at the Centre Georges Francois Leclerc Hospital. Univariate and multivariate Cox proportional hazard regression models were used to assess the influence of PTR on survival. We then evaluated the association between PTL and overall survival among patients who previously underwent or did not undergo PTR. A propensity score was performed to match cohorts.RESULTS Four hundred and sixty-six patients were included. A total of 153(32.8%) patients had unresected synchronous mCRC and 313(67.2%) patients had resected synchronous mCRC. The number of patients with right colic cancer, left colic cancer and rectal cancer was respectively 174(37.3%), 203(43.6%) and 89(19.1%). In the multivariate analysis only PTL, PTR, resection of hepatic and or pulmonary metastases and the use of oxaliplatin, EGFR inhibitors or bevacizumab throughout treatment were associated to higher overall survival rates. Survival evaluation depending on PTR and PTL found that PTR improved the prognosis of both left and right sided mCRC. Results were confirmed by using a weighted propensity score.CONCLUSION In mCRC, PTR seems to confer a higher survival rate to patients whatever the PTL.

Primary tumor resection in colorectal cancer with unresectable synchronous metastases: A review

At the time of diagnosis, 25% of patients with colorectal cancer(CRC) present with synchronous metastases, which are unresectable in the majority of patients. Whether primary tumor resection(PTR) followed by chemotherapy or immediate chemotherapy without PTR is the best therapeutic option in patients with asymptomatic CRC and unresectable metastases is a major issue, although unanswered to date. The aim of this study was to review all published data on whether PTR should be performed in patients with CRC and unresectable synchronous metastases. All aspects of the management of CRC were taken into account, es-pecially prognostic factors in patients with CRC and un-resectable metastases. The impact of PTR on survival and quality of life were reviewed, in addition to the characteristics of patients that could benefit from PTR and the possible underlying mechanisms. The risks of both approaches are reported. As no randomized study has been performed to date, we finally discussed how a therapeutic strategy's trial should be designed to pro-vide answer to this issue.

Colorectal adenocarcinoma patients with M1a diseases gain more clinical benefits from palliative primary tumor resection than those with M1b diseases: A propensity score matching analysis

BACKGROUND Surgical resection is regarded as the only potentially curative treatment option for patients with metastatic colorectal cancer(CRC).The National Comprehensive Cancer Network clinical practice guidelines do not recommend palliative surgery unless there is a risk of severe symptoms.However,accumulating evidence has shown that palliative surgery is associated with more favorable outcomes for patients with metastatic CRC.AIM To investigate the separate role of palliative primary tumor resection for patients with stage IVA(M1a diseases)and stage IVB(M1b diseases)colorectal adenocarcinoma(CRA).METHODS CRA patients diagnosed from 2010 to 2015 with definite M1a and M1b categories according to the 8th edition of American Joint Committee on Cancer staging system were selected from the Surveillance Epidemiology and End Results(SEER)database.To minimize potential selection bias,the data were adjusted by propensity score matching(PSM).Baseline characteristics,including gender,year of diagnosis,age,marital status,primary site,surgical information,race,grade,chemotherapy,and radiotherapy,were recorded and analyzed.Univariate and multivariate analyses were performed to explore the separate role of palliative surgery for patients with M1a and M1b diseases.RESULTS A total of 19680 patients with metastatic CRA were collected from the SEER database,including 10399 cases of M1a diseases and 9281 cases of M1b diseases.Common independent prognostic factors for both M1a and M1b patients included year of diagnosis,age,race,marital status,primary site,grade,surgery,and chemotherapy.After PSM adjustment,3732 and 3568 matched patients in the M1a and M1b groups were included,respectively.Patients receiving palliative primary tumor resection had longer survival time than those without surgery(P<0.001).For patients with M1a diseases,palliative resection could increase the median survival time by 9 mo;for patients with M1b diseases,palliative resection could prolong the median survival time by 7 mo.For M1a diseases,patients with lung metastasis had more clinical benefit from palliative resection than those with liver metastasis(15 mo for lung metastasis vs 8 mo for liver metastasis,P<0.001).CONCLUSION CRA patients with M1a diseases gain more clinical benefits from palliative primary tumor resection than those with M1b diseases.Those patients with M1a(lung metastasis)have superior long-term outcomes after palliative primary tumor resection.

PRIMARY TUMORS OF THE SMALL INTESTINE (ANALYSIS OF 102 PATIENTS)

Primary tumors of the small intestine are uncommon and a correct preoperative diagnosis is extremely difficult. From 1964 to 1983, 102 cases of this disease were detected surgically at our hospital. In order to investigate the problems involved in diagnosis and treatment, a comprehensive analysis of small intestinal tumors is made in this paper.

Clinical analysis of multiple primary gastrointestinal malignant tumors:A 10-year case review of a single-center

BACKGROUND Multiple primary malignant tumors(MPMTs)was first described by Billroth as early as 1889,with the first report published by Warren and Gates in 1932.Since then,numerous cases have been reported.A literature review of 1104269 patients with cancer revealed that the incidence of MPMTs ranged from 0.73 to 11.7%.In recent years,however,there has been a significant upward trend in the incidence of this phenomenon,which may be associated with many different factors,including the advancement of modern diagnostic procedures facilitating the examination and diagnosis of more MPMTs,increased exposure to chemotherapy and radiotherapy that exacerbate the risk of new malignant tumors in patients with cancer,and prolonged survival of patients with cancer allowing sufficient time for the development of new primary cancers.AIM To analyze the incidence,clinical features,treatment factors,prevalence,and prognosis of patients with MPMTs in the gastrointestinal tract treated in a single center.Additionally,we analyzed the different tumor combinations,time interval between the occurrence of tumors,and staging.METHODS This retrospective cohort study analyzed 8059 patients with pathologically confirmed gastrointestinal malignant tumors treated at the Gansu Province Hospital in Lanzhou,Gansu,China between June 2011 and June 2020.Of these,85 patients had MPMTs.The clinical features,treatment factors,prevalence,and prognosis of this latter cohort were analyzed.RESULTS The incidence of MPMTs in patients with gastrointestinal malignant tumors was 1.05%(85/8059),including 83 double primary malignant tumors and two triple primary malignant tumors of which 57(67.06%)were synchronous MPMTs(SMPMTs)and 28(32.94%)were metachronous MPMTs(MMPMTs).The most frequent associations were found between the rectum colon cancers within the SMPMT category and the gastric-colon cancers within the MMPMT category.For the MMPMTs,the median interval was 53 months.The overall 1-,3-and 5-year survival rates from diagnosis of the first primary cancer were 91.36%,65.41%,and 45.97%,respectively;those from diagnosis of the second primary cancer were 67.90%,29.90%,and 17.37%,respectively.CONCLUSION MPMTs in the gastrointestinal tract have a high incidence and poor prognosis.Thus,it is necessary to perform both gastroscopy and colonoscopy in patients with gastrointestinal tumors.Multidisciplinary comprehensive diagnosis and treatment may improve the diagnosis rate and treatment efficiency of MPMTs.

Self-adaptive non-covalent albumin-binding near-infrared probe conjugates enabling precise sentinel lymph node metastasis illumination and primary tumor imaging

Tumor sentinel lymph node(SLN)metastasis plays a vital role in tumor staging and therapeutic decision-making process.However,precise diagnosis of primary tumors and lymphatic metastases is still hindered by low imaging resolution and poor photostability of fluorescent probes.Herein,we report three novel IR820-fatty acid(FA)conjugates(IR-OA,IR-LA,and IR-PA)for precise lymphatic metastasis illumination and primary tumor diagnosis.The IR-FA conjugates are able to non-covalently bound to albumin in vivo,and the fluorescence quantum yield is significantly enhanced after incubation with bovine serum albumin(BSA)in vitro.Moreover,the BSA-IR-FA conjugates display large Stokes shift(>120 nm),dramatically improving in vivo imaging resolution.Among them,IR-PA demonstrates distinct advantage over IR-OA,IR-LA,and IR-maleimide(MAL)(fluorescent probe previously reported by our group)in terms of fluorescence quantum yield,photostability,and imaging resolution.As a result,IR-PA exhibits satisfactory imaging results with high fluorescence intensity and imaging resolution in sentinel lymph node metastasis illumination and primary tumor location.Our findings provide a self-adaptive albumin-binding near-infrared probe conjugate for accurate diagnosis of primary tumors and lymphatic metastases.

Primary Cardiac Tumors Operated on in Côte d’Ivoire: They Are Almost All Myxomas

Objective: Through this surgical series, we present the epidemiological and anatomical-clinical aspects and the surgical results concerning patients operated on for a primary cardiac tumor at the Abidjan Heart Institute. Materials and Method: This is a retrospective descriptive study covering the period of January 1982 to December 2022, based on the medical records of patients operated on for a primary cardiac tumor at the Abidjan Heart Institute. Results: Twenty-seven (27) patients underwent surgery for a primary cardiac tumor, including 14 women and 13 men with a mean age of 41.5 years (range 19 - 76 years). The main circumstances of discovery were exertional dyspnea, palpitation and syncope or pseudo-syncope. The main site was the septal wall of the left atrium. The diagnosis of myxoma was confirmed by pathological examination of the surgical specimen in 96.3% (n = 24) of the patients and it was a malignant large cell immunoblastic lymphoma of the myocardium in 3.7% (n = 1) of the patients. The mean largest diameter was 46.1 mm. The postoperative course was marked by an ischaemic stroke (n = 1);recurrence of a left atrial myxoma 5 years after the first tumor removal (n = 1). Two cases of death were noted, one due to the evolution of immunoblastic large cell lymphoma and the other due to an extracorporeal circulation accident. Conclusion: Almost all primary cardiac tumors operated on in Abidjan are myxomas. The circumstances of the discovery of these cardiac tumors are multiple and varied but dominated by exertional dyspnea, palpitation and syncope. Whatever their histological type, primary cardiac tumors are serious affections, in view of the haemodynamic and rhythmic disorders they cause.

Heterochronous multiple primary prostate cancer and lymphoma:A case report

BACKGROUND Multiple primary malignant tumors(MPMTs)are rare type of cancer,especially when solid tumors are the first and lymphoma is the second primary malignancy.We report a patient with heterochronous MPMTs consisting of prostate cancer and rectal diffuse large B-cell lymphoma(DLBCL).CASE SUMMARY We report a 77-year-old male patient diagnosed with prostate cancer who was treated with radiation therapy and one year of endocrine therapy with bicalutamide(50 mg per day)and an extended-release implant of goserelin(1/28 d).Seven years later,rectal DLBCL with lung metastases was found.CONCLUSION Although rare,the possibility of prostate cancer combined with a double primary cancer of DLBCL can provide a deeper understanding.

Elevated preoperative CA125 is associated with poor survival in patients with metastatic colorectal cancer undergoing primary tumor resection:a retrospective cohort study

Background The impact of the preoperative carbohydrate antigen 125(CA125)level on the survival of metastatic colorectal cancer(CRC)patients undergoing primary tumor resection(PTR)remains uncertain.The aim of this study was to assess the prognostic value in overall survival(OS)and cancer-specific survival(CSS)between patients with and without an elevated preoperative CA125 level.Methods All metastatic CRC patients receiving PTR between 2007 and 2017 at the Sixth Affiliated Hospital of Sun Yat-sen University(Guangzhou,China)were retrospectively included.OS and CSS rates were compared between patients with and without elevated preoperative CA125 levels.Results Among 326 patients examined,46(14.1%)exhibited elevated preoperative CA125 levels and the remaining 280(85.9%)had normal preoperative CA125 levels.Patients with elevated preoperative CA125 levels had lower body mass index,lower preoperative albumin level,lower proportion of preoperative chemotherapy,higher carcinoembryonic antigen and carbohydrate antigen 19–9(CA19–9)levels,poorer differentiation,and more malignant histopathological type than patients with normal preoperative CA125 levels.In addition,patients with elevated preoperative CA125 levels exhibited more advanced pathological T and N stages,more peritoneal metastasis,and more vessel invasion than patients with normal preoperative CA125 levels.Moreover,the primary tumor was more likely to be located at the colon rather than at the rectum in patients with elevated CA125 levels.Both OS and CSS rates in patients with elevated preoperative CA125 levels were significantly lower than those in patients with normal preoperative CA125 levels.Multivariate Cox regression analysis revealed that an elevated preoperative CA125 level was significantly associated with poor prognosis in metastatic CRC patients undergoing PTR.The hazard ratio(HR)in OS was 2.36(95%confidence interval[CI],1.67–3.33,P<0.001)and the HR in CSS was 2.50(95%CI,1.77–3.55,P<0.001).The survival analysis stratified by peritoneal metastasis also demonstrated that patients with elevated preoperative CA125 levels had lower OS and CSS rates regardless of peritoneal metastasis.Conclusion Based on an analysis of metastatic CRC patients undergoing PTR,an elevated preoperative CA125 level was associated with poor prognosis,which should be taken into consideration in clinical practice.

Prognostic value of primary tumor surgery in seminoma patients with distant metastasis at diagnosis:a population-based study

The aims of this study were to determine the prog no stic value of primary tumor surgery and identify optimal can didates for such surgery among patients with semi noma and dista nt metastasis at diag no sis.We ide ntified 521 patients with seminoma and distant metastasis at diagnosis between 2004 and 2014 from the Surveillanee,Epidemiology,and End Results database.Among these patients,434 had undergone surgery,whereas 87 had not.The prognostic value of primary tumor surgery was assessed by Kaplan-Meier methods,log-rank analyses,and multivariate Cox's proportional hazards model.Survival curves and forest plots were also plotted.Survival analysis indicated that patients who underwent surgery had a better 5-year overall survival and cancer-specific survival tha n those who did not.Multivariate analyses dem on strated that primary tumor surgery is an in depende nt prog no stic factor for overall survival and cancer-specific survival,along with age at diagnosis,Mstage,and marital status.In addition,primary tumor surgery still had con siderable prog no stic value in the subgroup of patie nts with lymph node metastasis.Further,forest plots demonstrated that patie nts with Mia stage,N1 or N2-3 stage,and a youn ger age at diagnosis(<60 years)may ben efit from primary tumor surgery.In con elusion,our findings indicate that primary tumor surgery is correlated with improved survival in patients with seminoma and distant metastasis.Furthermore,primary tumor surgery is an independent prognostic indicator for patients with seminoma and distant metastasis.

Primary tumors of the heart: the great masqueraders

To the Editor： The recent case report of primary cardiac hemangioendothelioma prompted me to write this letter-to-the-editor for 5 reasons.

High incidence combination of multiple primary malignant tumors of the digestive system

BACKGROUND Clinical reports of multiple primary malignant tumors(MPMTs)in the digestive system are increasing.In China,although the survival rate of patients with MPMTs is increasing,the quality of life is very low.Many patients have reached the advanced stage when the second primary tumor is found,resulting in no early intervention and treatment.This is due to the misunderstanding of MPMTs by clinicians,who treat such tumors as metastases.Therefore,before a patient has a second primary tumor,doctors should understand some common combinations of digestive system MPMTs to provide clinical guidance to the patient.AIM To explore the high incidence combination of digestive system MPMTs under heterochronism and synchronization.METHODS A total of 1902 patients with MPMTs at Peking Union Medical College Hospital were analyzed retrospectively.They were divided into metachronous MPMT and synchronous MPMT groups,and then the high incidence combinations of the first primary cancer and the second primary cancer in metachronous cancer and synchronous cancer were sorted.Sex and age differences between metachronous and synchronous tumors were tested by the chi square test and t test,respectively.A P value<0.05 was considered as statistically significant,and SPSS version 26.0(SPSS Inc.,Chicago,Illinois,United States)was used for statistical analysis.RESULTS Among the 1902 patients with MPMTs confirmed by pathology,1811(95.2%)cases were secondary primary cancers,89(4.7%)cases were tertiary primary cancers,and 2(0.1%)cases were quaternary primary cancers.Most(88.2%)of the secondary primary cancers were identified as metachronous multiple primary cancers six months after diagnosis of the first primary cancer.The top ten most common MPMTs in the first primary cancer group ranged from high to low as follows:Breast cancer,thyroid cancer,nonuterine cancer,lung cancer,colon cancer,kidney cancer,uterine cancer,bladder cancer,rectal cancer,and gastric cancer.The highest incidence rate of the first primary cancer in male metachronous cancer was lung cancer(11.6%),the highest incidence rate of the second primary cancer was still lung cancer(24.9%),the highest incidence rate of the first primary cancer in female metachronous cancer was breast cancer(32.7%),and the highest incidence rate of the second primary cancer was lung cancer(20.8%).Among them,breast cancer,nonuterine cancer and uterine cancer were female-specific malignant tumor types,and thyroid cancer also accounted for 79.6%of female patients.The top five metachronous cancer combinations,independent of female-specific malignant tumor types and thyroid cancer,were colon cancer and lung cancer(26 cases),kidney cancer and lung cancer(25 cases),rectal cancer and lung cancer(20 cases),gastric cancer and lung cancer(17 cases),and bladder cancer and lung cancer(17 cases).The most common synchronous cancer combination was colon cancer and rectal cancer(15 cases).CONCLUSION Screening for lung cancer should be performed six months after the detection of colon cancer while rectal cancer screening should be performed within six months.

Clinical characteristics and outcome of primary hepatic neuroendocrine tumors after comprehensive therapy

BACKGROUND Primary hepatic neuroendocrine tumors(PHNETs),a group of neuroendocrine neoplasms,are extremely rare.There are only few case reports about PHNETs in the literature.The lack of large samples and multicenter research results in poor diagnostic and therapeutic approaches.AIM To discuss the clinical characteristics,diagnosis,and treatment of PHNETs and risk factors related to survival.METHODS We retrospectively analyzed the clinical data,imaging features,immunohistochemistry data,and treatment efficacy of 40 patients who were pathologically diagnosed with PHNETs and admitted to The First Affiliated Hospital of Zhengzhou University from January 1,2014 to November 15,2019.Finally,survival analysis was performed to identify the risk factors for survival.RESULTS The main symptoms and signs included intermittent abdominal pain(19 patients,47.5%)and bloating(8 patients,20.0%).The positive rates of tested tumor markers were recorded as follows:Carbohydrate antigen 19-9(CA19-9)(6 patients,15.0%),CA72-4(3 patients,7.5%),carcinoembryonic antigen(7 patients,17.5%),and alpha-fetoprotein(6 patients,15.0%).Immunohistochemical staining results showed positivity for Syn in 38(97.4%)of 39 patients,for chromogranin A in 17(65.4%)of 26 patients,for CD56 in 35(94.6%)of 37 patients,for AE1/AE3 in 28(87.5%)of 32 patients,and for Ki-67 in all 40(100.0%)patients.The overall survival rate was significantly related to the tumor grade,AE1/AE3,and Ki-67.tumor number,tumor size,metastasis,and treatment)and overall survival.CONCLUSION Higher grade,negative AE1/AE3,and higher Ki-67 are associated with a worse survival rate.Kinds of treatment and other parameters have no significant influence on overall survival.

Surgical resection of adrenal metastasis from primary liver tumors:a report of two cases

BACKGROUND:Although the treatment of extrahepatic metastases from primary liver tumors is essentially palliative,solitary metastasis from such tumors offers a possibility of cure by surgical resection.The adrenal gland is an uncommon site for metastasis from primary liver tumors. METHOD:We report two cases of adrenalectomy for solitary adrenal metastasis:one from intrahepatic cholangiocarcinoma and the other from hepatocellular carcinoma. RESULTS:The patient with intrahepatic cholangiocar- cinoma had a synchronous adrenal metastasis and underwent simultaneous liver resection and adrenalectomy. However,he developed recurrent disease 17 months following surgery for which he is presently on palliative chemotherapy.The other patient underwent adrenalectomy for adrenal metastasis 3 months following liver transplantation for hepatocellular carcinoma.He is presently alive and disease-free 27 months after adrenalectomy. CONCLUSION:Carefully selected patients with solitary metastasis from primary liver tumors may be considered for resection.

Gastrointestinal stromal tumors and second primary malignancies before and after the introduction of imatinib mesylate

Gastrointestinal stromal tumor （GIST） is the most common mesenchymal malignancy of the gastrointestinal tract.GISTs may coexist with different types of cancer,either synchronous or metachronous （1）.Most GISTs develop in a sporadic fashion,but familial occurrence,such as neurofibromatosis and Carney-triad,has also been reported （2）.The overall frequency of second tumors in different series varied from 4.5% to 33%.The most frequent types of GIST-associated cancers were gastrointestinal carcinomas （47%）,lymphoma/leukemia （7%）,carcinomas of prostate （9%）,breast （7%）,kidney （6%）,lung （5%）,female genital tract （5%）,carcinoid tumors （3%）,soft tissue and bone sarcomas （3%）,malignant melanoma （2%） and seminoma （1%） （1,3-5）.

Rare neonatal malignant primary orbital tumors: Three case reports

BACKGROUND Aggressive malignant primary orbital tumors are extremely rare in newborns.The current cases further clarify the clinical features of malignant primary orbital tumors in neonates.CASE SUMMARY At the time of presentation at the Seventh Center of People’s Liberation Army General(PLAG)Hospital,the children were 1-,2-and 5-mo-old,respectively,and included 2 boys and 1 girl.All three cases had unilateral proptosis at birth,and underwent mass excision and histopathologic examination.A peripheral primary neuroectodermal tumor,an aggressive infantile fibromatosis and an embryonic rhabdomyosarcoma were diagnosed,respectively.The first case underwent routine chemotherapy following surgery but died within three months due to worsening condition as the tumor spread throughout the body.The other two children were treated by surgery,and at the follow-up visits 6 mo and 1 year after surgery,respectively,the wound was completed healed,and they had normal growth and development without radiotherapy or chemotherapy.A review of highly uncommon orbital tumors in newborns is also provided.CONCLUSION Malignant primary tumors should be considered in the presence of unilateral proptosis in newborns.

A Rare Case of a Primary Cardiac Tumor Presenting as Fatal Ventricular Tachycardia

Primary cardiac tumors are extremely uncommon.Here,we report the case of a patient with a primary left ventricular interstitial tumor presenting with hemodynamically unstable ventricular tachycardia.In response to hemodynamically unstable ventricular tachycardia,an implantable cardioverter-defibrillator was inserted.One month after defibrillator implantation,the patient developed episodes of high ventricular tachycardia that could not be effectively terminated by catheter radiofrequency ablation,thus further confirming that the ventricular tachycardia was induced by the left ventricular interstitial tumor.The patient is doing well on medical therapy to date.

Clinicopathological significance and prognostic value of claudin10 expression in primary malignant tumors of digestive system:A metaanalysis

Objective:To investigate the correlation between claudin10 expression and clinicopathological characteristics and prognosis of primary malignant tumors of digestive system.Methods:We searched the PubMed,Web of Science,Ovid MEDLINE,CNKI,CQVIP,and WanFang Data databases.The data between claudin10 expression and clinical characteristics as well as survival outcome were extracted.RevMan 5.3 and Stata 15.1 software were employed for metaanalysis.Results:A total of 6 studies containing 512 patients with primary malignant tumors of digestive system were analyzed.The analysis showed that high expression of claudin10 was more common in cancer tissue than in normal tissue[OR=3.22,95%CI(2.26,4.60),P<0.01],and was associated with increasing tumor size[OR=6.21,95%CI(2.44,15.83),P<0.01],high differentiation[OR=0.56,95%CI(0.32,0.99),P=0.05],positive lymph node metastasis[OR=3.41,95%CI(1.09,10.65),P=0.03].The expression of claudin10 was not associated with sex[OR=1.62,95%CI(0.91,2.90),P=0.10],age[OR=1.72,95%CI(0.97,3.07),P=0.06],distant metastasis[OR=4.51,95%CI(0.55,36.70),P=0.16],or prognosis[HR=1.99,95%CI(0.93,4.23),P=0.08].Conclusion:The expression of claudin10 is correlated with the clinicopathological features of primary malignant tumors of digestive system and is a potential tumor marker.

Primary primitive neuroectodermal tumor in the pericardium-a focus on imaging findings:A case report

BACKGROUND Primitive neuroectodermal tumors(PNETs)are rare,sporadic malignant tumors of the peripheral nervous system,bone,or soft tissues.However,to the best of our knowledge,only three cases of PNET in the pericardium have been reported in the English literature,and their magnetic resonance imaging findings have not previously been described.CASE SUMMARY A 3-year-old boy was hospitalized with a 1-wk history of recurrent vomiting and weakness.Detailed history-taking revealed no evidence of heart disease.Computed tomography demonstrated a soft tissue mass in the left pericardial cavity with heterogeneous contrast enhancement.The border between the mass and the heart was poorly defined.Thoracotomy revealed a mass invading the left ventricle,with a high risk of bleeding.The mass was considered inoperable.A biopsy was performed,and the histological and immunohistochemical findings confirmed the diagnosis of primary PNET of the pericardium.The patient received four cycles of standard chemotherapy.Chest magnetic resonance imaging 3 mo after the initiation of chemotherapy revealed that the tumor in the pericardium still existed,but its volume had slightly decreased.The patient was lost to follow-up,and the final outcome was therefore unknown.CONCLUSION Medical imaging plays an important role in defining the pericardial origin of PNET and understanding its characteristics.Magnetic resonance imaging can provide more information on the tumor than computed tomography and may thus aid therapeutic planning.