The Role of Surgery in Primary Thyroid Lymphoma: Experience in the Last 10 Years of a Specialized Unit

Primary Thyroid Lymphoma (PTL) is an uncommon disease, although its incidence is of 5%. Ultrasound and Fine Needle Aspiration Cytology (FNAC) usually do not provide the diagnosis. Surgery is one of the treatment options because it enables histological diagnosis and can also relieve compression symptoms in patients with rapid growth cervical mass. We present 7 cases of PTL diagnosed in the last 10 years in our unit. Five were female (71.4%) and 2 were male (28.6%). The mean age was 64.2 (range: 40 - 81);4 patients (57.1%) had associated Hashimoto’s Thyroiditis (HT). One patient (14.2%) had concomitant Graves disease. 5 cases presented with compressive symptoms and cervical mass. Ultrasound was not diagnostic in any case. FNAC was diagnostic only in one patient (14.3%). Five patients underwent total thyroidectomy (71.4%). All the cases were diagnosed with lymphoma postoperatively. Two interventions consisted of left hemithyroidectomies (28.6%). No complications appeared. 5 patients (71.4%) were classified as Mucosa-Associated Lymphoid Tissue (MALT) lymphoma. We also observed 1 Follicular grade I lymphoma and 1 Burkitt case. When the extension study was done, 1 patient was at stage IIIE (14%), 2 at IIE (28.5%) and 4 at IE (57.14%). Rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) and Iphosphamide, ethoposide and high dose Cytarabine (IVAC) were the treatment scheme when chemotherapy was used (in three cases). Two cases were treated only with total thyroidectomy, and 2 with total thyroidectomy and rituximab, and the latter was MALT. Complete Remission (CR) was achieved in all patients in the first year. All are still alive and in CR. In our experience, PTL diagnose can be challenging before surgery. Although surgery is not the gold standard for treatment, when it is done, it should be curative in MALT lymphomas confined to the thyroid.

Progressively Enlarging Goiter:Case Reports of Primary Thyroid Lymphoma and Literature Review

Primary thyroid lymphoma(PTL)is an exceptionally rare and highly aggressive potentially curable malignant disease.We report three typical cases of PTL referred to our hospital.All three cases had long history of Hashimoto’s thyroiditis,and presented with progressively enlarging neck mass.The first two cases were confirmed by surgical biopsy to be diffuse large B cell lymphoma,and received radiotherapy combined with chemotherapy,or received only chemotherapy.The third case was confirmed by core needle biopsy to be mucosa-associated lymphoid tissue lymphoma,and received radiotherapy.In summary,confirmation of PTL diagnosis is essential for further clinical decisions.Core biopsy should be one of the most important methods to make the diagnosis of PTL,while the use of fine needle aspiration cytology alone is still limited in diagnosing PTL.

Pathology Verified Concomitant Papillary Thyroid Carcinoma in the Sonographically Suspected Thyroid Lymphoma:A Case Report

PAPILLARY thyroid carcinoma （PTC） is the most common thyroid cancer and consists of nearly 80% of all cases of thyroid cancer.1 It is asso- ciated with the lowest level of malignancy and an excellent prognosis. Primary thyroid lymphoma （PTL） is a lymphomatous process which develops in the thyroid without involvement of primary lymphoid organs or distant metastases at diagnosis.2 It is a rare malignancy that accounts for 1%-5% of all thyroid malignancies and less than 2% of all extranodal lymphomas. The incidence of PTL is one or two cases per million.2＇ 3 It occurs frequently in elder woman, with a peak incidence in the sixth decade of life.

Coexistence of papillary thyroid microcarcinoma and mucosa-associated lymphoid tissue lymphoma in a context of Hashimoto's thyroiditis

Papillary thyroid cancer(PTC)represents 80%-85%of thyroid cancer and its prevalence has been rising in the last decades.Primary thyroid lymphoma(PTL)accounts for 3%of extranodal lymphomas and about 5%of thyroid malignancies,having a prevalence of one or two cases per million people.Mucosa-Associated Lymphoid Tissue lymphoma represents approximately30%of PTL.Both entities have an indolent course and a very good prognosis.Diagnosis is made by ultrasound and fine needle aspiration(FNA)or surgery specimen pathology.They have also been associated with Hashimoto’s thyroiditis(HT),but pathogenesis and its links remains to be known.Treatment remains controversial and surgery is generally accepted in cases of disease limited to thyroid,as the present.Patients with thyroid nodules should be observed and followed.If there is an enlargement by ultrasound or clinical symptoms,FNA should be performed promptly.Patients with HT deserve additional surveillance,since this condition is associated with both PTC and PTL.In this case,the management with surgery and radioactive iodine ablation therapy was effective for both entities.Patients with thyroid nodules should be properly evaluated with ultrasound and thyroid function tests.If there is an enlargement of the neck,reported by symptoms or ultrasound,it requires further investigation.HT is associated to both PTC and PTL so if the enlargement of the nodules is on this context additional tests such as FNA should be performed.In this case,the patient was managed with surgery and radioactive iodine ablation therapy and it was effective for both entities.

Dignosis and Treatment of Primary Malignant Lymphoma of the Thyroid Gland

Primary malignant lymphoma of the thyroid gland is a rare disease comprising about 1%–3% of the thyroid malignancies, and this uncommon lymphoma represent less than 1% of all non-Hodgkinlymphomas (NHL). According to the modified Ann-Arbor-Classification primary thyroid lymphoma by definition is a lymphoma that is restricted to the thyroid gland (stage I E ) or involves the thyroid gland and supradiaphragmatic predominantly adjacent thyroid lymph nodes (stage II E ). Primary thyroid lymphoma is a heterogenous disease encompassing a wide variety of lymphoma entities. The diagnosis and treatment of this lymphoma are emphasis of this article. Key words thyroid gland - lymphoma - diagnosis - treatment

Thyroid lymphoma: A case report and literature review

Thyroid lymphoma is an unusual pathology. Different subtypes of lymphoma can present as primary thyroid lymphoma. This review illustrates via imaging, findings and treatment the need for accurate diagnosis and timely treatment. Patients and methods: patient's chart, pathological findings and radiological images were reviewed in a retrospective analysis. Over several days, this 80 years old woman developed airway obstruction and rapid enlargement of her thyroid secondary to diffuse large B-cell lymphoma. She rapidly responded to her oncological protocol. Primary thyroid lymphoma is a rare disease. It is an important diagnosis to consider in patients presenting with rapidly enlarging neck masses. It is a treatable condition with fairly favorable overall survival even with the most aggressive histological subtypes.

Primary Thyroid Non-Hodgkin’s Lymphoma

Primary non-Hodgkin’s lymphoma of the thyroid gland was rarely described. We report the case of a 44-year-old man admitted for an anterior neck swelling, hoarseness and dyspnea. The chest radiograph showed a trachea deviation. He had no clinical, biological or radiological sign of other lymphoma locations. Ultrasound examination of the neck revealed a bilateral heterogeneous thyroid lesion. Cytology revealed lymphoid cells having high nuclear-cytoplasmic ratio with multiple and irregular nucleoli. An urgent thyroid surgery consisting of total thyroidectomy had been performed since the presence of compressive signs due to the tumor. The histopathological examination of a biopsy from the thyroid tissue confirmed a high-grade non-Hodgkin’s lymphoma. Then, L-thyroxin substitution therapy, chemotherapy and radiotherapy were initiated. A prolonged remission was noted.

Clinical Outcomes of 67 Patients Treated with Chemoradiotherapy for Primary Thyroid Non-Hodgkin’s Lymphoma in Osaka Medical College

Background: The reports of clinical outcomes of patients treated with chemoradiotherapy for primary thyroid non-Hodgkin’s lymphoma are rare. We report our results of chemoradiotherapy for primary thyroid non-Hodgkin’s lymphoma. Materials and Methods: The subjects were 67 patients with thyroid non-Hodgkin’s lymphoma among 269 patients with malignant lymphoma who received radiotherapy in our hospital during a period between May 1990 and June 2005. The patients included 16 men and 51 women, with a mean age of 66.2 ± 10.7 years (30 - 84 years). The disease stage was stage I in 42 patients, stage II in 24, and unclear in 1. The histologic type was B-cell lymphoma in 66 patients, MALT in 9, diffuse type in 52, follicular type in 5, and diffuse and follicular type in 1. CHOP chemotherapy regimen for malignant lymphoma patients was as follows. Intravenous drip infusion of cyclophosphamide 750 mg/m2, (drip) infusion of doxorubicin 50 mg/m2, and intravenous injection of vincristine 1.4 mg/m2 were administered on day 1, followed by 5 consecutive days of oral prednisolone 100 mg/m2. This regimen was repeated every 3 weeks (21 days) in 6 to 8 courses. Modified CHOP chemotherapy regimen was as follows. Intravenous drip infusion of cyclophosphamide 600 mg/m2, intravenous (drip) infusion of doxorubicin 40 mg/m2, intravenous infusion of vindesine 3 mg/m2, and intravenous drip infusion of prednisolone 60 mg/body were administered on day 1, and intravenous prednisolone was changed to oral prednisolone with the dose tapered gradually. After completing one course of this regimen, two courses of radiotherapy (a total of 36 Gy) were performed, followed by 6 courses of the chemotherapy regimen at lower doses (80% of the initial doses) repeated once a month. Results: Results of chemoradiotherapy in all patients were excellent. The 15-year survival rate was over 80%. Although there were no significant differences in the results of chemoradiotherapy among different histologic types of thyroid malignant lymphoma, the survival rate was 100% for MALT type, as compared with poor results for diffuse large type or diffuse mixed type. The analysis of the results of chemoradiotherapy according to the stage of malignant thyroid lymphomas revealed that therapeutic results were significantly better in stage I than in stage II. Conclusion: The CHOP chemoradiotherapy regimen and modified CHOP chemoradiotherapy regimen were excellent for primary thyroid non-Hodgkin’s lymphoma.

Complete response in anaplastic lymphoma kinase–rearranged oncocytic thyroid cancer:A case report and review of literature

BACKGROUND Oncocytic carcinoma of the thyroid is a rare disease,characterized by a poor prognosis and low response rate to radioiodine therapy.Crizotinib is a specific anaplastic lymphoma kinase(ALK)inhibitor,which was initially developed in non-small cell lung cancer.Other solid tumors harboring a translocation in ALK have been described,such as renal carcinoma,thyroid,colorectal,ovarian cancers,and spitzoid melanoma.The research of ALK rearrangements in thyroid tumor is a promising therapeutic track,and treatments need to be explored.CASE SUMMARY We report the case of a 76-year-old woman with a history of multinodular goiter,who was hospitalized for impairment of her general condition.She was diagnosed with metastatic oncocytic thyroid cancer.Synchrone metastases were found:Multiple mediastinal lymphadenopathies,lytic bone lesions and bilateral mammary lumps.Fluorescence in situ hybridization analysis revealed an ALK rearrangement in 61%of cells.No other mutation was found.A tumor board discussion based on molecular characteristics of the tumor suggested initiating a daily treatment by crizotinib,a specific ALK inhibitor.A positron emission tomography scan performed 4 mo after the initiation of crizotinib showed a complete metabolic response.CONCLUSION This case highlights an unexpected efficacy of crizotinib in an ALK-rearranged thyroid tumor,and the need of further assessments.

Absence of enhancement in a lesion does not preclude primary central nervous system T-cell lymphoma:A case report

BACKGROUND Primary central nervous system lymphoma(PCNSL)is a non-Hodgkin lymphoma that originates in the central nervous system(CNS)and is exclusively limited to the CNS.Although most PCNSLs are diffuse large B-cell lymphomas,primary CNS T-cell lymphomas(PCNSTLs)are rare.PCNSTLs typically demonstrate some degree of enhancement on contrast-enhanced magnetic resonance imaging(MRI).To the best of our knowledge,non-enhancing PCNSTL has not been reported previously.CASE SUMMARY A 69-year-old male presented to the neurology department with complaints of mild cognitive impairment and gradual onset of left lower leg weakness over a span of two weeks.Initial MRI showed asymmetric T2-hyperintense lesions within the brain.No enhancement was observed on the contrast-enhanced T1 image.The initial diagnosis was neuro-Behçet’s disease.Despite high-dose steroid therapy,no alterations in the lesions were identified on initial MRI.The patient’s symptoms deteriorated further.An MRI performed one month after the initial scan revealed an increased lesion extent.Subsequently,brain biopsy confirmed the diagnosis of PCNSTL.The patient underwent definitive combined chemoradiotherapy.However,the patient developed bacteremia and died of septic shock approximately three months after diagnosis.CONCLUSION The absence of enhancement in the lesion did not rule out PCNSTL.A biopsy approach is advisable for pathological confirmation.

Marginal zone lymphoma with severe rashes: A case report

BACKGROUND Marginal zone lymphoma(MZL)is an indolent subtype of non-Hodgkin lymphoma(NHL),which is rare clinically with severe rashes as the initial symptom.CASE SUMMARY This study reports a case of MZL with generalized skin rashes accompanied by pruritus and purulent discharge.First-line treatment with rituximab combined with zanubrutinib had poor effects.However,after switching to obinutuzumab combined with zanubrutinib,the case was alleviated,and the rashes disappeared.CONCLUSION For patients with advanced stage MZL not benefiting from type I anti-CD20 monoclonal antibody(mAb)combination therapy,switching to a type II anti-CD20 mAb combination regimen may be considered.This approach may provide a new perspective in the treatment of MZL.

Transformed gastric mucosa-associated lymphoid tissue lymphoma originating in the colon and developing metachronously after Helicobacter pylori eradication:A case report

BACKGROUND Helicobacter pylori(H.pylori)eradication treatment for primary gastric mucosaassociated lymphoid tissue(MALT)lymphoma has already been established.However,t(11;18)(q21;q21)/API2-MALT1 translocation-positive lesions are a type of primary gastric MALT lymphoma in which a response to eradication treatment is difficult to achieve.In addition,trisomy 18 may be associated with diffuse large B-cell lymphoma(DLBCL)transformation of gastric MALT lymphoma.CASE SUMMARY A 66-year-old man was diagnosed with MALT lymphoma in the ascending colon by colonoscopy and biopsy.Two years later,esophagogastroduodenoscopy revealed chronic atrophic gastritis that was positive for H.pylori,and eradication treatment was administered.Two years and nine months later(at the age of 70),a new ulcerative lesion suggestive of MALT lymphoma appeared in the gastric body,and six months later,a similar lesion was also found in the fundus.One year later(4 years and 3 months after H.pylori eradication),at the age of 72,the lesion in the gastric body had become deeper and had propagated.A biopsy revealed a pathological diagnosis of DLBCL.Both MALT lymphoma lesions in the ascending colon and DLBCL lesions in the stomach were positive for the t(11;18)(q21;q21)/API2-MALT1 translocation,and trisomy 18q21 was also detected.After 6 courses of R-CHOP(rituximab,cyclophosphamide,doxorubicin,vincristine and prednisone)chemotherapy,all of the above lesions disappeared[complete remission(CR)],and CR has been maintained for more than 3 years.In addition,both the colonic and gastric lesions were proven to have the same clonality.CONCLUSION Because the patient had a MALT1 translocation with trisomy 18q21,it was thought that this gastric MALT lymphoma developed independently of H.pylori infection and progressed.

Clinical study of chemotherapy-related cognitive impairment in patients with non-Hodgkin lymphoma

BACKGROUND Chemotherapy for malignant tumors can cause brain changes and cognitive impairment,leading to chemotherapy-induced cognitive impairment(CICI).Current research on CICI has focused on breast cancer and Hodgkin’s lymphoma.Whether patients with non-Hodgkin’s lymphoma(NHL)undergoing chemo-therapy have cognitive impairment has not been fully investigated.therapy have cognitive impairment has not been fully investigated.AIM To investigate whether NHL patients undergoing chemotherapy had cognitive impairments.METHODS The study included 100 NHL patients who were required to complete a compre-hensive psychological scale including the Brief Psychiatric Examination Scale(MMSE)at two time points:before chemotherapy and within 2 wk of two chemo-therapy courses.A language proficiency test(VFT),Symbol Number Pattern Test(SDMT),Clock Drawing Test(CDT),Abbreviated Daily Cognition Scale(ECog-12),Prospective and Retrospective Memory Questionnaire,and Karnofsky Perfor-mance Status were used to assess cognitive changes before and after chemo-therapy.RESULTS The VFT scores for before treatment(BT)and after treatment(AT)groups were 45.20±15.62,and 42.30±17.53,respectively(t-2.16,P<0.05).The CDT scores were 8(3.5-9.25)for BT and 7(2.5-9)for AT groups(Z-2.1,P<0.05).Retrospective memory scores were 13.5(9-17)for BT and 15(13-18)for AT(Z-3.7,P<0.01).The prospective memory scores were 12.63±3.61 for BT and 14.43±4.32 for AT groups(t-4.97,P<0.01).The ECog-12 scores were 1.71(1.25-2.08)for BT and 1.79(1.42-2.08)for AT groups(Z-2.84,P<0.01).The SDMT and MMSE values did not show a significant difference between BT and AT groups.CONCLUSION Compared to the AT group,the BT group showed impaired language,memory,and subjective cognition,but objec-tive cognition and execution were not significantly affected.

Rare primary gastric peripheral T-cell lymphoma not otherwise specified:A case report

BACKGROUND Gastrointestinal lymphoma typically arises in the stomach,small bowel,or colorectum and is usually a B-cell lymphoma.However,primary T-cell lymp-homas originating in the stomach are particularly rare.Gastric peripheral T-cell lymphoma-not otherwise specified(PTCL-NOS)is an extremely rare subtype.CASE SUMMARY We report a 63-year-old male presenting with epigastric pain.Esophagogastro-duodenoscopy revealed a large ulcerative lesion in the gastric cardia.Biopsy and immunohistochemical profiling confirmed PTCL-NOS.Imaging indicated stage II disease involving the stomach and intra-abdominal lymph nodes.The patient is planned to undergo cyclophosphamide,doxorubicin,vincristine,and prednisone or cyclophosphamide,doxorubicin,vincristine,prednisone,and etoposide chemo-therapy.CONCLUSION This case highlights the necessity of considering PTCL-NOS in differential diag-noses of gastric lesions.Comprehensive histopathological and immunohistoche-mical analysis is crucial for accurate diagnosis and guiding treatment.

Advances in the application of auxiliary imaging techniques in parathyroid diseases

Hypoparathyroidism is one of the main complications after total thyroidectomy,severely affecting patients’quality of life.How to effectively protect parathyroid function after surgery and reduce the incidence of hypoparathyroidism has always been a key research area in thyroid surgery.Therefore,precise localization of parathyroid glands during surgery,effective imaging,and accurate surgical resection have become hot topics of concern for thyroid surgeons.In response to this clinical phenomenon,this study compared several different imaging methods for parathyroid surgery,including nanocarbon,indocyanine green,near-infrared imaging techniques,and technetium-99m methoxyisobutylisonitrile combined with gamma probe imaging technology.The advantages and disadvantages of each method were analyzed,providing scientific recommendations for future parathyroid imaging.In recent years,some related basic and clinical research has also been conducted in thyroid surgery.This article reviewed relevant literature and provided an overview of the practical application progress of various imaging techniques in parathyroid surgery.

Current Understanding of Papillary Thyroid Carcinoma

The term thyroid neoplasm incorporates tumors that originate from follicular cells and those that arise from parafollicular cells (C cells). Differentiated thyroid cancer, which originates from follicular cells, includes papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), oncocytic cell carcinoma (Hürthle), poorly differentiated carcinoma, and anaplastic thyroid carcinoma (ATC). PTC tends to have an indolent clinical course with low morbidity and mortality. However, this entity has a broad range of biological and clinical behavior that can result in disease recurrence and death, depending on patient and tumor characteristics and the initial treatment approach. PTC is the most common form of well-differentiated thyroid cancer (WDTC) and based on the most recent statistics, accounts for approximately 89.4% of all thyroid malignancies. PTC appears as an irregular solid or cystic nodule in normal thyroid parenchyma. PTC has the propensity for lymphatic invasion, but it is less likely to have hematogenous spread. Around 11% of patients with PTC present with distant metastases outside the neck and mediastinum. This manuscript with review the current understanding of the epidemiology, pathology, molecular characteristics, prognostic factors, and dynamic risk stratification of PTC centered on an evidence-based and personalized approach.

Molecular Diagnosis of Thyroid Nodules and Its Future Implications for the Management of Thyroid Cancer

Molecular testing in thyroid nodules and thyroid cancer is rapidly evolving;care must be used when incorporating molecular testing for thyroid nodules into clinical practice. A clear appreciation of the goals and restraints of molecular testing must be integrated into how physicians use and explain molecular testing to patients. Molecular tests can help rule in cancer for indeterminate thyroid nodules with very specific mutations for thyroid cancer, such as BRAF and RET/PTC, and can help reduce the rates of completion thyroidectomies in this era of de-escalation of the management of thyroid disease. The positive predictive value (PPV) of malignant cytology (Bethesda VI) is 98%;and even though molecular testing improves specificity and PPV, it falls short of this ideal for other mutations. We present a detailed evaluation of the current state of molecular testing and their clinical relevance in the setting of diagnostic utility and their impact on surgical decision-making. By recapitulating the clinical impact of these tests and some of the related drawbacks, we hope to provide adequate up to date information of the appropriate utilization of these tools in the management of indeterminate or suspicious thyroid nodules and highlight future directions on their utilization for the management of thyroid cancer.

MicroRNAs in thyroid cancer with focus on medullary thyroid carcinoma:potential therapeutic targets and diagnostic/prognostic markers and web based tools

This review aimed to describe the inculpation of microRNAs(miRNAs)in thyroid cancer(TC)and its subtypes,mainly medullary thyroid carcinoma(MTC),and to outline web-based tools and databases for bioinformatics analysis of miRNAs in TC.Additionally,the capacity of miRNAs to serve as therapeutic targets and biomarkers in TC management will be discussed.This review is based on a literature search of relevant articles on the role of miRNAs in TC and its subtypes,mainly MTC.Additionally,web-based tools and databases for bioinformatics analysis of miRNAs in TC were identified and described.MiRNAs can perform as oncomiRs or antioncoges,relying on the target mRNAs they regulate.MiRNA replacement therapy using miRNA mimics or antimiRs that aim to suppress the function of certain miRNAs can be applied to correct miRNAs aberrantly expressed in diseases,particularly in cancer.MiRNAs are involved in the modulation of fundamental pathways related to cancer,resembling cell cycle checkpoints and DNA repair pathways.MiRNAs are also rather stable and can reliably be detected in different types of biological materials,rendering them favorable diagnosis and prognosis biomarkers as well.MiRNAs have emerged as promising tools for evaluating medical outcomes in TC and as possible therapeutic targets.The contribution of miRNAs in thyroid cancer,particularly MTC,is an active area of research,and the utility of web applications and databases for the biological data analysis of miRNAs in TC is becoming increasingly important.

Primary pancreatic peripheral T-cell lymphoma:A case report

BACKGROUND Primary pancreatic lymphoma(PPL)is an exceedingly rare tumor with limited mention in scientific literature.The clinical manifestations of PPL are often nonspecific,making it challenging to distinguish this disease from other panc-reatic-related diseases.Chemotherapy remains the primary treatment for these individuals.CASE SUMMARY In this case study,we present the clinical details of a 62-year-old woman who initially presented with vomiting,abdominal pain,and dorsal pain.On further evaluation through positron emission tomography-computed tomography,the patient was considered to have a pancreatic head mass.However,subsequent endoscopic ultrasonography-guided fine needle aspiration(EUS-FNA)revealed that the patient had pancreatic peripheral T-cell lymphoma,not otherwise specified(PTCL-NOS).There was a substantial decrease in the size of the pancreatic mass after the patient underwent a cycle of chemotherapy comprised of brentuximab vedotin,decitabine,and oxaliplatin(brentuximab vedotin and Gemox).The patient had significant improvement in radiological findings at the end of the first cycle.CONCLUSION Primary pancreatic PTCL-NOS is a malignant and heterogeneous lymphoma,in which the clinical manifestations are often nonspecific.It is difficult to diagnose,and the prognosis is poor.Imaging can only be used for auxiliary diagnosis of other diseases.With the help of immunostaining,EUS-FNA could be used to aid in the diagnosis of PPL.After a clear diagnosis,chemotherapy is still the first-line treatment for such patients,and surgical resection is not recommended.A large number of recent studies have shown that the CD30 antibody drug has potential as a therapy for several types of lymphoma.However,identifying new CD30-targeted therapies for different types of lymphoma is urgently needed.In the future,further research on antitumor therapy should be carried out to improve the survival prognosis of such patients.

Primary lymphomas of the genitourinary tract:A population-based study

Objective:We performed a population-based analysis focusing on primary extranodal lymphoma of either testis,kidney,bladder or prostate(PGUL).Methods:We identified all cases of localized testis,renal,bladder and prostate primary lymphomas(PL)versus primary testis,kidney,bladder and prostate cancers within the Surveillance,Epidemiology,and End Results database(1998e2015).Estimated annual proportion change methodology(EAPC),multivariable logistic regression models,cumulative incidence plots and multivariable competing risks regression models were used.Results:The rates of testis-PL,renal-PL,bladder-PL and prostate-PL were 3.04%,0.22%,0.18%and 0.01%,respectively.Patients with PGUL were older and more frequently Caucasian.Annual rates significantly decreased for renal-PL(EAPC:5.6%;pZ0.004)and prostate-PL(EAPC:3.6%;pZ0.03).In multivariable logistic regression models,older ager independently predicted testis-PL(odds ratio[OR]:16.4;p<0.001)and renal-PL(OR:3.5;p<0.001),while female gender independently predicted bladder-PL(OR:5.5;p<0.001).In surgically treated patients,cumulative incidence plots showed significantly higher 10-year cancer-specific mortality(CSM)rates for testis-PL,renal-PL and prostate-PL versus their primary genitourinary tumors.In multivariable competing risks regression models,only testis-PL(hazard ratio[HR]:16.7;p<0.001)and renal-PL(HR:2.52;p<0.001)independently predicted higher CSM rates.Conclusion:PGUL rates are extremely low and on the decrease in kidney and prostate but stable in testis and bladder.Relative to primary genitourinary tumors,PGUL are associated with worse CSM for testis-PL and renal-PL but not for bladder-PL and prostate-PL,even after adjustment for other-cause mortality.