Phospholipase A2 receptor-negative membranous nephropathy presenting as a rare renal manifestation of IgG4-related disease.

IgG4-related disease is a fibroinflammatory condition characterized by dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells affecting multiple organs. Though the most common renal manifestation of IgG4-related disease is tubulointerstitial nephritis, it can rarely present as secondary membranous nephropathy. We present a case of a 75-year-old male with phospholipase A2 receptor-negative membranous nephropathy as an atypical manifestation of IgG4-related disease. The patient presented with nephrotic syndrome and was found to have elevated serum IgG4 levels and IgG4-positive plasma cells in the kidney biopsy. He was successfully treated with corticosteroids and rituximab, resulting in significant improvement in proteinuria and normalization of IgG4 levels. This case highlights the importance of considering IgG4-related disease in patients with phospholipase A2 receptor-negative membranous nephropathy, especially in those with a history of other organ involvement. Early recognition and treatment of IgG4-related disease are crucial to prevent progressive kidney damage and improve patient outcomes.

Filariasis-Associated Secondary Membranous Nephropathy: A Rare Presentation.

Parasitic infections like filariasis are uncommon causes of secondary membranous nephropathy (MN) which requires serological tests to detect circulating Wuchereria bancrofti antigens for its diagnosis or the identification of microfilariae in the capillary lumen on kidney biopsy. The immunochromatographic card tests is simple, non invasive and has high sensitivity and specificity. We report a case of 30 year old lady who presented to us with nephrotic syndrome which on kidney biopsy showed features of membranous nephropathy with negative staining for Anti PLA2R, THSD7A and exostosin. A thorough workup was done to find out any secondary cause of MN where she was found positive with filiarial antibody test. Hence, a diagnosis of secondary membranous pattern nephropathy was considered for which she was treated with diethylcarbamazine (DEC) and other supportive medications which on follow up showed marked resolution of proteinuria.

Diagnosis and treatment of secondary nephrotic syndrome with rash as the first symptom: a case report.

BACKGROUND: Membranous nephropathy (MN) is a common type of nephrotic syndrome (NS) in adults, accounting for about 20-30% of cases. Although secondary to specific factors, the coexistence of MN and mantle cell lymphoma (MCL) has been scarcely reported in clinical literature. CASE PRESENTATION: A 59-year-old Chinese male was admitted to the hospital with a generalized pruritic rash with bilateral lower extremity edema, which did not improve significantly after symptomatic treatment. He had undergone renal biopsy, and the diagnosis was thought to be secondary MN (SMN), therefore, we did a lymph node biopsy on the patient and found that MN was complicated with MCL. Soon after, the patient was admitted to the hematology department for a BR chemotherapy regimen (composed of bendamustine 90 mg/m2 BSA (body surface area), rituximab 375 mg/m2 BSA and dexamethasone 5 mg), and during the post-treatment follow-up, both his symptoms and renal function improved. CONCLUSIONS: The mechanism underlying the combination of SMN and MCL remains elusive and exceedingly rare, consequently often overlooked in clinical practice. This case serves to offer valuable clinical insights for diagnosis and treatment, while emphasizing the pivotal role of renal pathology in clinical assessment.

The Association of Lower Levels of Baseline Proteinuria With Earlier Remission in Primary Membranous Nephropathy.

Aim To study the clinical profile and course and to assess the outcome of patients with biopsy-proven primary membranous nephropathy (MN). Methods This study was carried out in a tertiary care hospital between December 2017 and December 2021 on four-year retrospective biopsy-proven patients with membranous nephropathy (MN). Urinary proteins, serum albumin, and serum creatinine were the baseline investigations that were performed. Special tests were done whenever necessary. Patients were treated with a modified Ponticelli (MP) regimen whenever needed. Patients were followed up after treatment administration for a minimum of a year. Results The study was done in 48 biopsy-proven MN patients. Thirty-six patients had primary MN with a mean age of 47+/-11.7 years. The male-female ratio was 2.6:1. Hypertension was present in 39% (14 patients), microscopic hematuria in 28% (10 patients), and acute kidney injury in 22% (8 patients). The mean 24-hour urinary protein was 11.2+/-2.9 g/day. PLA2R was positive in 78% (28 patients) of primary MN patients. Spontaneous remission was noted in 13.8% (5 patients) who were treated conservatively. Spontaneous remission was associated with lower baseline proteinuria (p<0.001), higher baseline serum albumin (p<0.001), and PLA2R negativity (p=0.04). Complete or partial treatment response was noted in 74.2% (23 patients). Treatment remission was associated with lower baseline proteinuria (p=0.018). Secondary membranous nephropathy (secondary MN) was diagnosed in 12 patients. Eleven were class V lupus nephritis, all women, and one male person living with HIV/AIDS (PLHA). Conclusions The majority of our primary MN patients were PLA2R positive on renal biopsy. Statistically significant factors associated with spontaneous remission were lower proteinuria, higher serum albumin at baseline, and PLA2R negativity. Treatment response was associated with lower proteinuria at presentation. The most common cause of secondary MN was lupus nephritis.

Anti-Neuron-Derived Neurotrophic Factor Antibodies in Secondary Membranous Nephropathy Caused by Syphilis: A Case Report.

We present the case of a 61-year-old man who developed nephrotic syndrome as a result of syphilis-associated secondary membranous nephropathy (MN). The patient showed nephrotic syndrome remission following antibiotic treatment for syphilis alone. Pathologically, the target antigen of immune complexes accumulated on glomerular basement membranes (GBM) in secondary MN caused by syphilis has been reported to be neuron-derived neurotrophic factor (NDNF). His renal histopathology was consistent with secondary MN caused by syphilis, with a full-house pattern on immunofluorescence microscopy, in addition to NDNF deposits that colocalized with IgG deposits granularly on the GBM. However, to date, there is no serological evidence for the involvement of NDNF in the GBM. In the present study, we found that anti-NDNF autoantibodies in the acute-phase serum disappeared in the convalescent-phase serum of a patient who recovered from syphilis and nephrotic syndrome after antibiotic therapy alone. This result supports the hypothesis that treatment of syphilis with antibiotics suppresses NDNF's antigenicity. In summary, we found new serological evidence emphasizing that NDNF is an etiological antigen in secondary MN caused by syphilis.

[Renal manifestations of syphilis]. / Manifestations rénales de la syphilis.

Syphilis is an acquired or congenital systemic pathology, currently on the rise in Europe. The clinical manifestations of syphilis are not very specific and variable over time. In this case report, we describe two renal presentations of syphilis in patients followed in a Pre-Exposure Prophylaxis (PrEP) program for the prevention of HIV infection. The specificity of the renal involvement of syphilis, the diagnostic and the therapeutic management will be discussed in this article.

La syphilis est une pathologie systémique acquise ou congénitale, actuellement en recrudescence en Europe. Les manifestations cliniques de la syphilis sont souvent peu spécifiques et variables au cours du temps. Nous décrivons ici deux présentations rénales de la syphilis survenues chez des patients suivis dans un programme de Pre-Exposure Prophylaxis (PrEP) de prévention contre l'infection VIH. La spécificité de l'atteinte rénale de la syphilis, la mise au point diagnostique et la prise en charge thérapeutique seront discutées dans cet article.

A Diagnostic and Therapeutic Dilemma Concerning Exostosin 1/Exostosin 2-associated Lupus-like Membranous Nephropathy with Positive Antinuclear Antibody in an Elderly Man with Various Immune Abnormalities.

Exostosin 1 (EXT1) and exostosin 2 (EXT2)-associated membranous nephropathy (MN) may be associated with active autoimmune disease. We encountered an elderly man who presented with EXT1/EXT2-associated lupus-like MN with full house immune deposits, monoclonal gammopathy of uncertain significance and Sjögren's syndrome. The patient exhibited various other immune abnormalities. Although he did not fulfill the criteria of clinical systemic lupus erythematosus (SLE), he met a stand-alone renal criterion of the Systemic Lupus International Collaborating Clinics (SLICC) 2012. Whether or not a stand-alone renal criterion with EXT1/EXT2 positivity, as in the present patient, can efficiently guide decisions regarding the diagnosis and treatment of SLE remains a clinical dilemma.

Case report: A surgically treated case of diaphragmatic clear cell carcinoma without relation to endometriosis.

INTRODUCTION AND IMPORTANCE: Diaphragmatic tumor is a rare neoplastic disease. Only three reports have revealed diaphragmatic primary clear cell carcinoma. On the other hand, secondary membranous nephropathy is sometimes triggered by the carcinoma. We describe a case of primary diaphragmatic clear cell carcinoma without relation to endometriosis or ovarian malignancies, and secondary membranous nephropathy was triggered by diaphragmatic primary clear cell carcinoma. CASE PRESENTATION: A 67-year-old woman was found to have membranous nephropathy due to examination for renal dysfunction. A rare diaphragmatic tumor was identified on CT scan for rule out secondary membranous nephropathy. She had underwent resection of the right diaphragm tumor and reconstruction with expanded polyterafluoroethylene (e-PTFE). CLINICAL DISCUSSION: Pathological examination revealed the presence of clear cells with papillary arrangement and no findings of the endometriosis. Immunohistochemistry revealed that the tumor was positive for CK7, p53, and HNF-1-beta. And there had been no evidence of ovarian malignancies. A diagnosed of clear cell carcinoma of the right diaphragm without relation to endometriosis or ovarian malignancies was made. After resection of the tumor, it was revealed that her renal function was improvement. CONCLUSION: This is the first report of diaphragmatic clear cell carcinoma without relation to endometriosis or ovarian malignancies that caused secondary membranous nephropathy. One year after the resection of the tumor, she is being followed up and has shown no signs of recurrence.

The Clinicopathologic Spectrum of Membranous Nephropathy with Lupus-Like Features.

INTRODUCTION: The pathologic features of membranous lupus nephritis (MLN) are occasionally encountered in secondary membranous nephropathy (sMN) without overt clinical evidence of systemic lupus erythematosus. Moreover, some sMN with lupus-like features (lupus-like membranous nephropathy [LL-MN]) have a clinical presentation more typical of primary membranous nephropathy (pMN). Based on the confounding clinical and pathologic presentation, it is unclear how to categorize and treat these patients. METHODS: We performed immunohistochemical staining for recently discovered target antigens associated with MN -NELL-1, THSD7A, and EXT1/2 and compared the clinicopathologic presentation of patients with LL-MN to those with pMN and MLN. RESULTS: From 2015 to 2020, there were 21 patients with MLN and 99 with MN, of which 59% were diagnosed pMN and 41% sMN. 44% of sMN patients showed lupus-like features (LL-fx). All LL-MN patients were negative for PLA2R and NELL1, but 12% were positive for EXT1/2. 50% of LL-MN patients had an identifiable systemic disease, of which 56% were autoimmune disease (AD) and 44% infection. Compared to pMN, LL-MN had a higher incidence of underlying AD (p = 0.02). Within pMN, 24% also had LL-fx (LL-pMN), and all but 1 were PLA2R- (78%) or NELL1-positive (15%). Only 5% of pMN patients had an AD, 66% of which showed LL-fx. Most idiopathic LL-MN were treated and behaved clinically similarly to pMN. There were no differences in outcome in terms of progression toward end-stage renal disease or mortality between LL-MN versus pMN and MLN. CONCLUSION: LL-MN appears to have a significant association with underlying AD and has a subset showing EXT1/2 positivity, whereas most LL-pMN and idiopathic LL-MN likely represent an atypical pathologic presentation of pMN.

Syphilis-Related Nephropathy: A Rare Manifestation of a Re-emerging Disease.

Syphilis is a curable sexually transmitted infection caused by the spirochete Treponema pallidum. Its clinical manifestations are variable as it has a remarkable aptitude to imitate a spectrum of clinical pictures. This phenomenon has bestowed upon it the epithet "the great imitator" within the medical literature. The escalating global prevalence of syphilis cases underscores the importance of shedding light on its rare manifestations. Syphilitic nephropathy is an uncommon manifestation of secondary syphilis. Here, we report two cases of syphilis-related nephropathy, the first presented as a nephrotic syndrome, and the second as a nephritic syndrome. Both cases had a favorable outcome after treatment of syphilis with benzathine penicillin G.

Favorable outcome in PLA2R positive HBV-associated membranous nephropathy.

INTRODUCTION: Over half of the patients with hepatitis B virus associated membranous nephropathy (HBV-MN) were found to be phospholipase A2 receptor (PLA2R) positive. Whether MN is really secondary to hepatitis B or just coincidence of hepatitis and PLA2R positive idiopathic MN (IMN) remains controversial. METHODS: We retrospectively studied seven PLA2R positive HBV-MN patients with complete data in Huashan Hospital from 2009 to 2016 and compared them with PLA2R positive idiopathic MN patients. RESULTS: Proteinuria and renal function of these 7 HBV-MN patients were similar to that of IMN patients. However, 5 of them were female and half showed hypocomplementemia, while in IMN group only 32.4% were female and 20% had hypocomplementemia, and the level of hematuria was 94.5/µL in HBV-MN patients and 64.9 /µL in IMN patients, though there was no statistically significant difference. Renal biopsies revealed significantly increased mesangial eletron-deposits in HBV-MN patients. All 7 patients received antiviral therapy, and one patient received immunosuppresants due to severe nephrotic syndrome with acute myocardial infarction and elevated serum creatinine. Compared with IMN group, the prevalence of remission without immunosuppressive therapy of HBV-MN patients was higher (85.7% vs. 43.7%), while the percentage of patients receiving immunosuppresants was lower (14.3% vs. 47.9%) (P=0.048). CONCLUSION: Compared with IMN patients, PLA2R positive HBV-MN patients had a more favorable prognosis after antiviral therapy, indicating a secondary form of MN. For these patients, antiviral treatment is recommended and long observation time should be provided before use of immunosuppressive treatment.

Secondary Membranous Nephropathy Due to Benign Tumors in 2 Young Women: A Case Report.

Membranous nephropathy (MN) is one of the most common causes of adult-onset nephrotic syndrome. We describe the cases of 2 young women in their 20s presenting with nephrotic syndrome due to antiphospholipase A2 receptor (anti-PLA2R)-negative MN, that was found to be associated with benign tumors. Both women had no extrarenal symptoms of a connective tissue disease, infection, or malignancy. They both had been previously healthy and were not receiving treatment with any drugs. Both had MN on kidney biopsy. Biopsies were negative for PLA2R antigen, and their serum did not demonstrate the presence of anti-PLA2R antibodies. Both were investigated for a secondary cause on the basis of negative anti-PLA2R serology and biopsy features supportive of secondary MN and were found to have benign tumors on radioimaging: a uterine leiomyoma and mesenteric fibromatosis, respectively. In both instances, the nephrotic syndrome remitted following resection of the tumors. To our knowledge, uterine leiomyoma and mesenteric fibromatosis have not previously been described in association with MN. These cases highlight the importance of pursuing a secondary cause of MN in patients without anti-PLA2R antibodies in serum or PLA2R antigen on kidney biopsy.

Is de novo membranous nephropathy suggestive of alloimmunity in renal transplantation? A case report.

BACKGROUND: Post-transplant nephrotic syndrome (PTNS) in a renal allograft carries a 48% to 77% risk of graft failure at 5 years if proteinuria persists. PTNS can be due to either recurrence of native renal disease or de novo glomerular disease. Its prognosis depends upon the underlying pathophysiology. We describe a case of post-transplant membranous nephropathy (MN) that developed 3 mo after kidney transplant. The patient was properly evaluated for pathophysiology, which helped in the management of the case. CASE SUMMARY: This 22-year-old patient had chronic pyelonephritis. He received a living donor kidney, and human leukocyte antigen-DR (HLA-DR) mismatching was zero. PTNS was discovered at the follow-up visit 3 mo after the transplant. Graft histopathology was suggestive of MN. In the past antibody-mediated rejection (ABMR) might have been misinterpreted as de novo MN due to the lack of technologies available to make an accurate diagnosis. Some researchers have observed that HLA-DR is present on podocytes causing an anti-DR antibody deposition and development of de novo MN. They also reported poor prognosis in their series. Here, we excluded the secondary causes of MN. Immunohistochemistry was suggestive of IgG1 deposits that favoured the diagnosis of de novo MN. The patient responded well to an increase in the dose of tacrolimus and angiotensin converting enzyme inhibitor. CONCLUSION: Exposure of hidden antigens on the podocytes in allografts may have led to subepithelial antibody deposition causing de novo MN.

Renal manifestations of syphilis.

Syphilis is a sexually transmitted disease caused by spirochaete Treponema pallidum. The incidence of syphilis is rising across the globe. It has been described in the literature as a great imitator due to the vast range of clinical manifestations that can occur in the disease. Renal manifestations are rare but a feature of secondary syphilis. It can cause glomerulopathies, tubular pathology and vasculitic lesions in the kidney. Membranous nephropathy is the most commonly reported glomerular lesion associated with syphilis. With two recent cases of secondary membranous nephropathy due to syphilis, it is timely to review the current state of knowledge, and discuss the different renal manifestation of syphilis, its pathology and treatment options.

Case Report: Membranous Nephropathy Secondary to Cobalamin C Disease.

BACKGROUND: Mutation of MMACHC causes inherited cobalamin C disease with methylmalonic academia (MMA) and homocysteinemia. Renal complications may also be present in patients with this deficiency. However, membranous nephropathy secondary to cobalamin C disease has not been reported to date. CASE PRESENTATION: We encountered a 17-year-old female patient with a trans-compound mutation of MMACHC who presented with membranous nephropathy, MMA, homocysteinemia, and hyperuricemia. The mutations of c.80A>G (chr1:45966084) and c.482G>A (chr1:45974520) (predicting p.Gln27Arg and p.Arg161Gln missense changes at the amino acid level) had been inherited from her father and mother, respectively. Hydroxocobalamin, betaine, and L-carnitine were administered. The patient achieved complete remission of the membranous nephropathy and resolution of the MMA, homocysteinemia, and hyperuricemia. CONCLUSION: Membranous nephropathy secondary to cobalamin C disease is reversible with timely intervention.

The role of serum levels of anti-phospholipase A2 receptor antibodies in the diagnosis of primary membranous nephropathy.

INTRODUCTION: Primary membranous nephropathy (PMN) is one of the most common causes of nephrotic syndrome in adults. The disease process is probably initiated by the binding of circulating autoantibodies to target podocyte antigens. In 2009, Beck et al. found that phospholipase A2 receptor (PLA2R1) was expressed on human podocytes in patients with PMN. Recent evidence suggests that PLA2R1 autoantibodies play an important role in the diagnosis of PMN. AIM: The aim of the present study was to compare the serum levels of anti-PLA2R1 in patients with PMN, second MN (SMN), other nephropathies (ON), and healthy controls (HC). MATERIALS AND METHODS: The study included 52 patients with PMN, 12 patients with SMN, 49 patients with ON, and 50 healthy controls. The serum concentration of anti-PLA2R1 was determined with ELISA kit (Anti-PLA2R ELISA, IgG, EUROIMMUN, Lübeck, Germany) using MR-96A microplate Reader (MINDRAY). Statistical analysis was performed with SPSS v.22.0. RESULTS: There was significant difference in the serum anti-PLA2R1 concentrations between patient groups and HC (p<0.0001). Compared to HC, the median anti-PLA2R1 level in the PMN group was significantly higher (4.8 RU/ml vs. 34.9 RU/ml, p=0.001), in the ON group it was lower (2.1 RU/ml, p=0.002) and did not differ in patients with SMN (2.9 RU/ml, p=0.193). The anti-PLA2R1 serum levels were significantly higher in the PMN group than in the SMN (p=0.015) and ON (p<0.001) groups. CONCLUSIONS: Our results showed that anti-PLA2R1 is significantly increased in patients with PMN. We can conclude that the anti-PLA2R1 serum concentration may be used as a beneficial biomarker for distinguishing PMN from other membranous nephropathies.

Membranous Nephropathy with Proteinase 3-ANCA-associated Vasculitis Successfully Treated with Rituximab.

Membranous nephropathy (MN) with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (ANCA-GN) is seen infrequently. Previous reports of patients with ANCA-GN with MN showed that the most frequent ANCA subtype was myeloperoxidase-ANCA. We herein present a 73-year-old woman with scleritis, hematuria, proteinuria, and positive serum proteinase 3 (PR3)-ANCA. She underwent a renal biopsy and was diagnosed with MN and ANCA-GN. Immunofluorescence staining for PR3 colocalized with IgG along the glomerular basement membrane were observed. Oral prednisolone and intravenous rituximab therapy immediately improved her symptoms and urinalysis abnormalities. PR3-ANCA may be involved in the pathogenesis of MN via the formation of immune complexes.

Secondary Membranous Nephropathy. A Narrative Review.

Membranous nephropathy (MN) is a common cause of proteinuria and nephrotic syndrome all over the world. It can be subdivided into primary and secondary forms. Primary form is an autoimmune disease clinically characterized by nephrotic syndrome and slow progression. It accounts for ~70% cases of MN. In the remaining cases MN may be secondary to well-defined causes, including infections, drugs, cancer, or autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), urticarial vasculitis, sarcoidosis, thyroiditis, Sjogren syndrome, systemic sclerosis, or ankylosing spondylitis. The clinical presentation is similar in primary and secondary MN. However, the outcome may be different, being often related to that of the original disease in secondary MN. Also, the treatment may be different, being targeted to the etiologic cause in secondary MN. Thus, the differential diagnosis between primary and secondary MN is critical and should be based not only on history and clinical features of the patient but also on immunofluorescence and electron microscopy analysis of renal biopsy as well as on the research of circulating antibodies. The identification of the pathologic events underlying a secondary MN is of paramount importance, since the eradication of the etiologic factors may be followed by remission or definitive cure of MN. In this review we report the main diseases and drugs responsible of secondary MN, the outcome and the pathogenesis of renal disease in different settings and the possible treatments.

Association of SNPs in PLA2R1 with idiopathic and secondary membranous nephropathy in two Chinese cohorts.

Objectives: Specific single-nucleotide polymorphisms (SNPs) in the M-type phospholipase A2 receptor-1 (PLA2R1) are associated with increased risk of idiopathic membranous nephropathy (IMN) in European populations. We hypothesized links between IMN and SMN with these SNPs in two Chinese cohorts.Methods: A cohort of 166 IMN patients and 144 controls from southern China (Group A) and a cohort of 212 IMN patients, 118 SMN patients, and 162 controls from northwestern China (Group B) were recruited. SNPs within PLA2R1 (rs3749119, rs3749117, rs35771982, rs3828323, and rs4664308) were identified and the frequencies of genotypes and alleles were determined for the different groups.Results: Relative to controls, IMN patients had a greater prevalence of rs35771982, rs3749117, and rs4664308 in Group A (OR = 1.61, 95% CI = 1.13-2.31, P = 0.011; OR = 1.62 (1.15-2.29), P = 0.006 and OR = 1.17 (1.06-1.28), P = 0.001, respectively) and in Group B (OR = 1.58 (1.13-2.22), P = 0.009; OR = 1.68 (1.22-2.33), P = 0.002 and OR = 1.15 (1.06-1.25), P < 0.001, respectively). Genotype and allele distributions of rs4664308 differed significantly between SMN patients and controls in Group B (OR = 1.58 (1.10-2.26), P = 0.012). Genotype and allele distribution of rs35771982 and rs4664308 differed significantly between PLA2R-Ab(+) and PLA2R-Ab(-) IMN patients in Group B (OR = 1.59 (1.09-2.31), P = 0.018 and OR = 1.15 (1.03-1.29), P = 0.005, respectively).Conclusion: This study of two cohorts from different regions of China indicate that specific PLA2R1 polymorphisms are associated with IMN and SMN.

Duodenal Schwannoma as a Rare Association With Membranous Nephropathy: A Case Report.

Membranous nephropathy (MN) associated with malignancies is a well-known entity. However, its association with benign neoplasm is not broadly recognized. A 69-year-old man with recurrent nephrotic syndrome presented with pedal edema and proteinuria of 5 months' duration. Laboratory results showed hypoalbuminemia and hyperlipidemia. Proteinuria was estimated to be protein excretion of 3.5g/d. Studies were negative for viral hepatitis, syphilis, human immunodeficiency virus, autoimmune diseases, and paraproteinemia. Kidney biopsy disclosed MN with negative phospholipase A2 receptor (PLA2R) staining, favoring a secondary form of MN. Computed tomography detected a 7.6-cm duodenal schwannoma. Elective surgical resection was performed. Pathologic study showed that THSD7A (thrombospondin type 1 domain-containing 7A) was positive in both glomeruli and schwannoma. Commonly, secondary MN is related to underlying conditions, including lupus, hepatitis, and neoplasm, and can be medication induced. The risk for developing a concomitant neoplasm among patients with PLA2R-negative MN is up to 12 times higher than in the general population. Most of these neoplasms are malignancies, and the presence of autoantibodies directed at similar tissue targets is hypothesized as the potential mechanism. In our case, THSD7A may be the autoantibody that has linked the schwannoma and the development of MN. Although benign tumors rarely produce renal manifestations, effective treatment may lead to resolution of nephrotic syndrome.