A randomized, non-comparative phase 2 study of neoadjuvant immune-checkpoint blockade in retroperitoneal dedifferentiated liposarcoma and extremity/truncal undifferentiated pleomorphic sarcoma

Based on the demonstrated clinical activity of immune-checkpoint blockade (ICB) in advanced dedifferentiated liposarcoma (DDLPS) and undifferentiated pleomorphic sarcoma (UPS), we conducted a randomized, non-comparative phase 2 trial ( NCT03307616 ) of neoadjuvant nivolumab or nivolumab/ipilimumab in patients with resectable retroperitoneal DDLPS (n = 17) and extremity/truncal UPS (+ concurrent nivolumab/radiation therapy; n = 10). The primary end point of pathologic response (percent hyalinization) was a median of 8.8% in DDLPS and 89% in UPS. Secondary end points were the changes in immune infiltrate, radiographic response, 12- and 24-month relapse-free survival and overall survival. Lower densities of regulatory T cells before treatment were associated with a major pathologic response (hyalinization > 30%). Tumor infiltration by B cells was increased following neoadjuvant treatment and was associated with overall survival in DDLPS. B cell infiltration was associated with higher densities of regulatory T cells before treatment, which was lost upon ICB treatment. Our data demonstrate that neoadjuvant ICB is associated with complex immune changes within the tumor microenvironment in DDLPS and UPS and that neoadjuvant ICB with concurrent radiotherapy has significant efficacy in UPS.

Neuroblastoma and opsoclonus-myoclonus-ataxia syndrome--clinical and pathological characteristics

INTRODUCTION

Opsoclonus-myoclonus-ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome in childhood.

MATERIALS AND METHODS

We reviewed the literature and reported on clinical and pathological characteristics of four children with OMA and peripheral neuroblastic tumours. In two of the children the onset of neurological symptoms was connected with a vaccination and in one with viral infection. The suprarenal gland was the primary localization of the tumour in 3 of the children and in one the tumour was located in the retroperitoneal area. All cases were in stage II or III of the disease, with no metastases or MYCN amplification. The group included two ganglioneuroblastomas, one ganglioneuroma and one differentiating neuroblastoma. The tumours were characterized by the presence of lymphocytic infiltrations with lymphadenoplasia. Immunohistochemical analysis of inflammatory infiltrations revealed mixed type populations of lymphocytes with prevalence of the cytotoxic type (CD8 and CD56-positive cells). The participation of dendritic cells and macrophages was also detected. All patients were treated by surgery alone or with adjuvant chemotherapy with a positive outcome. In 3 cases persistent neurological disorders were observed with exacerbations during infections.

CONCLUSION

In some patients the onset of OMA is related to vaccination or infection. Children with OMA and neuroblastoma despite a good oncological prognosis often present permanent neurological and developmental deficits. The inflammatory infiltrations within the tumours are combined, with predominant participation of cytotoxic cells.

Autoantibody production from a thymoma and a follicular dendritic cell sarcoma associated with paraneoplastic pemphigus

BACKGROUND

Paraneoplastic pemphigus (PNP) is an autoimmune mucocutaneous disease. We previously reported that B cells in a Castleman tumour associated with PNP produced autoantibodies. However, it is uncertain whether the production of autoantibodies from the associated tumour is a common mechanism in PNP.

OBJECTIVES

To investigate autoantibody production in a thymoma and a follicular dendritic cell sarcoma that were excised from two patients with PNP.

METHODS

Tumour cells were cultured, and their surface markers were identified. Indirect immunofluorescence, immunoblotting and enzyme-linked immunosorbent assay (ELISA) using culture media from the tumours were used to detect PNP autoantibodies.

RESULTS

B cells with markers (CD22+, surface membrane IgG+ and surface membrane IgM+) of mature B lymphocytes constituted a proportion of cultured tumour cells in both tumours. Western blot showed that the medium from both the thymoma and the follicular dendritic cell sarcoma cells recognized 190-kDa periplakin and 210-kDa envoplakin bands of human epithelial proteins as well as recombinant linker regions of periplakin, envoplakin, desmoplakin and bullous pemphigoid antigen 1. ELISA was positive for antidesmoglein 3 antibody.

CONCLUSIONS

The presence and localization in tumours of B-lymphocyte clones against proteins of the plakin family and desmoglein 3 in skin may not be confined to PNP with Castleman disease, but is possibly a common mechanism in PNP associated with various tumours.

Results of a Phase I study utilizing monocyte-derived dendritic cells pulsed with tumor RNA in children with Stage 4 neuroblastoma

BACKGROUND

A Phase I study of 11 pediatric patients with newly diagnosed, Stage 4 neuroblastoma was conducted using monocyte-derived dendritic cells (DC) pulsed with tumor RNA to produce antitumor vaccines (DC(RNA)).

METHODS

Patients received two courses of induction with carboplatin followed by standard chemotherapy, surgery, radiation, high-dose therapy, stem cell rescue, and DC(RNA) vaccine therapy.

RESULTS

The results showed that this method for producing and administering DC(RNA) from a single leukapheresis product was both feasible and safe in this pediatric neuroblastoma population. Two courses of carboplatin maintained lymphocyte counts at normal levels. However, immune function 6 weeks after high-dose chemotherapy and stem cell rescue and prior to receiving DC(RNA) was impaired in all patients tested. There was an alteration in the ratio of CD4-positive and CD80-positive T cells. CD4-positive cell numbers were below normal, whereas CD8-positive cell numbers were above normal for all patients. In addition, CD19-positive cell numbers were below normal for all but one patient. It was found that humoral responses to recall antigens (diphtheria and tetanus) and cellular responses to mitogen and recall antigens were below normal in most patients. Despite this, two of three patients tested showed a tumor-specific humoral immune response to DC(RNA). Among the patients who had measurable disease at the time of DC(RNA) vaccine, none showed any objective tumor response.

CONCLUSIONS

DC(RNA) vaccines were both safe and feasible in children with Stage 4 neuroblastoma. Humoral responses to tumor were detected, although remained immunosuppressed at the time of administration, limiting efficacy.

A functioning-desensitization paraganglioma which caused hemodynamic instability during tumoral resection: report of a case

Paragangliomas are uncommon tumors arising from the neuroendocrine elements of the paraganglia. Their successful management is associated with many problems. We herein present the findings of a 22-year-old man in whom a paraganglioma was incidentally found and in which the clinical and previous operative behavior was functioning desensitization. As a result, preoperative medication was not performed; however, during the tumor resection the patient demonstrated hemodynamic instability.

The ultrastructural and immunohistochemical heterogeneity of CD-30-positive neoplasms: so-called anaplastic large cell Ki-1 lymphomas

Anaplastic large cell lymphoma (ALCL), also referred to as Ki-1 lymphomas, was first recognized as an entity with characteristic light microscopic appearance in 1985. This tumor is composed of variably cohesive cells, often with large, markedly atypical, and multinucleated cellular forms. The recognition of ALCL resulted from the development of a monoclonal antibody in Kiel, Germany, named Ki-1, which was initially believed to be a putative marker for Reed-Sternberg cells. This antibody was later found to be specific against the epitope CD-30. Attempts to create strict criteria to preserve this neoplasm as a specific entity have undergone evolution. However, it is now clear that included in this group are a variety of pleomorphic neoplasms with CD-30 immunoreactivity. Some of these neoplasms are nonlymphoid and show marked heterogeneity in their immunohistochemical and ultrastructural profiles. This article aims to highlight the ultrastructural spectrum of neoplasms exhibiting CD-30 positivity that are within the spectrum of ALCL. It remains to be determined if there are subgroups of these CD-30-positive neoplasms that can be segregated on the basis of ultrastructural and immunohistochemical criteria with corresponding clinical correlates that may impact on their management, treatment, and prognosis. We review here the heterogeneity of CD-30-positive neoplasms (so-called anaplastic large cell Ki-1 lymphomas).

Lymphoma and methyldopa therapy

I describe a patient who developed a drug associated lymphoma with methyldopa attributable to hypersensitive reaction. Several forms of immunologic changes have been observed with methyldopa therapy. In general, they have been considered to be hypersensitive changes from the common development of hemolytic anemia, lupus, retroperitoned fibrosis, thrombocytopenia, and hepatitis.

B7-1 expression decreases tumorigenicity and induces partial systemic immunity to murine neuroblastoma deficient in major histocompatibility complex and costimulatory molecules

Neuroblastoma may escape an immune attack by virtue of its low expression of surface accessory molecules essential in the antitumor response. Murine neuroblastoma, neuro-2a, was transduced with the retroviral vector LB7-1SN to examine the influence of B7-1 expression on the immune response directed against a low major histocompatibility class (MHC) I and class II negative, B7-2, and ICAM-1 negative tumor. Using a retroperitoneal model for implantation of neuroblastoma in its natural site, we demonstrated that expression of B7-1 by neuro-2a reduces its tumorigenicity. Coinjection of B7-1-positive and -negative cells improved survival compared with mice receiving B7-1-negative cells alone. This was dependent on the ratio of B7-1+ to B7-1- neuro-2a cells injected. CD8+ and not CD4+ T-cell depletion significantly increased tumor-induced mortality in syngeneic A/J mice, indicating that B7-1 decreases tumorigenicity primarily by direct constimulation of CD8+ T cells. Rejection of N-2a/B7-1 tumors or preimmunization with irradiated N-2a/B7-1 cells die not increase protection to challenge with unmodified neuro-2a cells over mice vaccinated with N-2a/neo. Furthermore, cytotoxic T lymphocyte (CTL) precursor frequencies were not significantly higher after in vivo priming and in vitro stimulation with irradiated N-2a/B7-1 compared with N-2a/neo, indicating that B7-1 costimulation by the tumor, in the absence of adequate antigen presentation by MHC molecules, may limit the generation of effective CTLs.

Retroperitoneal Ewing's sarcoma

We report a case of extraskeletal Ewing's sarcoma arising in the retroperitoneal cavity. The tumor was excised en bloc with the left kidney and infiltrated portion of the left ureter. Histological diagnosis was confirmed by both electron micrography and immunohistochemical staining using a newly developed mouse monoclonal antibody 5C11, which specifically reacts with Ewing's sarcoma. An adjuvant chemotherapy T-11 regimen has been successfully preventing the recurrence.

Retroperitoneal inoculation of murine neuroblastoma results in a reliable model for evaluation of the antitumor immune response

To more closely mimic the natural site of human neuroblastoma and the original spontaneous arising paraspinal murine tumor, the authors developed a new model system in which murine neuroblastoma cells (neuro-2a) are implanted directly into the retroperitoneal space. This method of administration resulted in an aggressive and reproducible neuroblastoma model, with death occurring at a median of 20.3 days after tumor implantation using 1 x 10(6) neuro-2a cells, compared with the intraperitoneal (median, 31 days) and subcutaneous routes (median, 35.1 days) (P < .001). Adoptive transfer of single cell suspensions from livers, spleens, and bone marrows of mice with retroperitoneal tumors into healthy hosts resulted in tumor growth, confirming the presence of metastatic foci in these organs. The retroperitoneal murine neuroblastoma model was used to assess the importance of natural killer (NK) and T cells in regulating the growth of neuro-2a in vivo. T cells played an equally protective role as NK cells; depletion of either T or NK populations significantly decreased survival as compared with undepleted mice. Elimination of both NK and T cells further accelerated mortality of neuro-2a-bearing mice as compared to those depleted of either T or NK populations. The retroperitoneal murine model is a highly relevant in vivo system for preclinical studies of new therapeutic approaches for neuroblastoma.

Interleukin-2 gene transfer into murine neuroblastoma decreases tumorigenicity and enhances systemic immunity causing regression of preestablished retroperitoneal tumors

Murine neuroblastoma, neuro-2a, was transduced with the retroviral vector LIL-2SN in order to examine the influence of localized interleukin (IL)-2 production on the immune response against a low major histocompatibility complex (MHC) class I, class II-negative, and intercellular adhesion molecule (ICAM)-1-negative tumor. Two neomycin-resistant (neo R) clones, N-2a/IL-2/L (2.5 +/- 0.4 U/ml/10(6) cells/24 h) and N-2a/IL-2/H (44.6 +/- 8.8 U/ml), were studied as representative low and high IL-2 producers, respectively. Using a recently developed retroperitoneal (r.p.) model for implantation of neuroblastoma in its natural site, we demonstrated that production of IL-2 by neuro-2a reduces its tumorigenicity in a dose-dependent fashion. T-cell, but not natural killer (NK) cell, depletion significantly increased tumor induced mortality in syngeneic A/J mice. Mice genetically devoid of T-cells (C.B-17 scid/scid) also experienced a significant increase in mortality rates. This indicates that the antitumor effect of locally secreted IL-2 is mediated primarily through activation of T-cells. Immunization of mice with irradiated N-2a/IL-2/H cells resulted in protection when challenged at a later date with unmodified neuro-2a cells. Depletion of CD8+, but not CD4+, T-cells prior to vaccination abrogated the protective effect, indicating that the priming phase of the immune response is CD8+ T-cell dependent. Mice with established r.p. tumors were vaccinated with N-2a/IL-2/H, which significantly prolonged their survival compared to unimmunized controls and to mice immunized with non-IL-2-producing neuro-2a cells. Because of the similarities of this model with the human tumor, our studies indicate that IL-2-transduced neuroblastoma cells may be effective in generating systemic immunity leading to eradication of minimal residual disease.

[A case of retroperitoneal teratoma showing high level of CA19-9]

We report a case retroperitoneal mature teratoma showing an abnormally high CA19-9 (carbohydrate antigen 19-9) serum level in a 30-year-old woman. She was hospitalized for an episode of left upper abdominal pain. High CA19-9 tissue level and immunohistochemical findings were found in removed tissue. This case is the third report of a CA19-9-producing teratoma and literature was reviewed and discussed.

An inducible cell line (Natasha), from a neuroblastoma patient with circulating HSR-positive blasts, expressing neurohormones

A cell line, established from a neuroblastoma patient, expresses NCAM and L1 cell adhesion molecules. Two chromosomal abnormalities were present in bone marrow (10%) and cell line (82%) metaphases: (i) a homogeneously staining region (HSR) at the distal part of chromosome 14, and (ii) an insertion of unidentified dark G-banding material in 1 p36. The identification in the patient of chr 14-HSR-positive tumour cells, before the in vitro adaptation, suggests a direct HSR formation without preceding double minutes (dms; or a very early in vivo dms----HSR transformation). N-myc was amplified in the HSR. Cells expressed proopiomelanocortin and corticotropin releasing factor mRNAs. Untreated cells were relatively differentiated; nevertheless they dramatically responded to retinoic acid, forming extensive neurites, growth-cones, cell-cell and cell-neurite junctions. Neurofilaments and synaptic figures containing many dense core granules were identified. This differentiation was irreversible. This cell line is therefore useful for the study of differentiation and in particular for the involvement of neurohormones in the differentiation process.

Melanocyte-marker-HMB-45 is regularly expressed in angiomyolipoma of the kidney

HMB-45 (melanocytic cell-specific monoclonal antibody) immunoreactivity was investigated in 10 cases of angiomyolipoma (AML) (1 with massive regional lymph node involvement) of the kidney and detected in all of them. No HMB-45 immunoreactivity was found in other tumors of the region which can occasionally be confused with AML, such as renal cell carcinoma, Wilms' tumor, and retroperitoneal sarcoma (leiomyosarcoma and liposarcoma). These findings indicate that HMB-45 is not a melanocyte-restricted marker and suggest that its expression might be useful in distinguishing AML from other tumors of the kidney and retroperitoneum.

Fine needle aspiration diagnosis of intraabdominal and retroperitoneal lymphomas by a morphologic and immunocytochemical approach

We reviewed 238 fine needle aspiration biopsies (FNA) of intraabdominal or retroperitoneal (IA/RP) masses in 192 patients with known or suspected lymphoma. A limited battery of immunocytochemical stains, including kappa (k) and lambda (l) light chains and Leu-4, was performed in 104 aspirates. On hundred twenty-eight of the FNA were diagnostic of or consistent with lymphoma, and three were diagnostic of carcinoma. Twenty-eight were considered negative for malignancy and 79 were suspicious for lymphoma or were nondiagnostic. For 135 of the FNA, a histologic biopsy specimen was available for comparison purposes. Overall, only one false-positive result was seen in a specimen lacking immunocytochemical data. The sensitivity of FNA lymphoma diagnosis was 66%. False-negative results due to sampling error were not uncommon, giving a predictive value of a negative result as 42%. The classification of the lymphomas by FNA was identical to that of the surgical biopsy in 86% of specimens and concurrently discrepant in 6%. We conclude that the routine performance of immunocytochemical studies on FNA of IA/RP masses is a feasible and valuable technique. Whereas suboptimal sensitivity and sampling error may make a negative diagnosis unreliable, lymphoma marker studies (combined with morphology) allow for an accurate and confident diagnosis and subclassification of lymphoma in the majority of cases.

Elevated CA 125 serum levels and epithelial ovarian cancer metastatic to retroperitoneal lymph nodes

Elevations in CA 125 levels have been reported in approximately 80% of patients with epithelial ovarian cancer. Studies demonstrate that elevations of CA 125 at the time of second-look procedures correlate with the presence of tumor in 100% of cases. Two cases are reported with elevated CA 125 in which clinical examination and noninvasive studies with CAT scans failed to demonstrate tumor. In both cases laparotomy was performed because of the elevation of CA 125. Although intraabdominal exploration did not reveal the source of the CA 125 elevation, extensive retroperitoneal dissection demonstrated microscopic tumor in retrocaval lymph nodes in both cases. The ability to monitor patients with CA 125 is demonstrated and the importance of elevated antigen levels emphasized. Benign conditions associated with falsely positive CA 125 are discussed.

Retroperitoneal mass presentations of B-immunoblastic sarcoma

A clinicopathologic analysis of nine patients with B-immunoblastic sarcoma (B-IBS) presenting as a bulky lymph node-based retroperitoneal mass is reported. The histologic and immunologic findings, similar to those reported in B-IBS presenting in various other nodal and extranodal sites, support the recognition of this aggressive large cell non-Hodgkin's lymphoma (NHL) as a distinct pathologic entity. The patients, with a mean age of 60.5 years, presented for evaluation of abdominal pain and a palpable abdominal mass. Four patients were Stage II or IIE, one Stage III, and four Stage IV; eight of nine had B symptoms. Chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin [CHOP-B] or cyclophosphamide, doxorubicin, vincristine, methotrexate with leucovorin rescue, cytarabine [ACOMLA]) yielded significant palliation in five patients (mean survival, 12.3 months); three untreated patients and one receiving radiation treatment (XRT) died within 1 month from diagnosis. There was a striking predilection for pleuropulmonary involvement in disseminating disease. The initial blood lymphocyte count correlated significantly with survival (correlation coefficient, 0.84). The one durable complete remission (CR) was obtained in a patient who received substantial surgical debulking before chemotherapy.

Retroperitoneal mass presentations of B-immunoblastic sarcoma

A clinicopathologic analysis of nine patients with B-immunoblastic sarcoma (B-IBS) presenting as a bulky lymph node-based retroperitoneal mass is reported. The histologic and immunologic findings, similar to those reported in B-IBS presenting in various other nodal and extranodal sites, support the recognition of this aggressive large cell non-Hodgkin's lymphoma (NHL) as a distinct pathologic entity. The patients, with a mean age of 60.5 years, presented for evaluation of abdominal pain and a palpable abdominal mass. Four patients were Stage II or IIE, one Stage III, and four Stage IV; eight of nine had B symptoms. Chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin [CHOP-B] or cyclophosphamide, doxorubicin, vincristine, methotrexate with leucovorin rescue, cytarabine [ACOMLA]) yielded significant palliation in five patients (mean survival, 12.3 months); three untreated patients and one receiving radiation treatment (XRT) died within 1 month from diagnosis. There was a striking predilection for pleuropulmonary involvement in disseminating disease. The initial blood lymphocyte count correlated significantly with survival (correlation coefficient, 0.84). The one durable complete remission (CR) was obtained in a patient who received substantial surgical debulking before chemotherapy.

Non-seminomatous germ cell tumors of the testis. Analysis of CEA production in primary tumors and in retroperitoneal lymph node metastases after PVB chemotherapy

In the present investigation we compared CEA immunoperoxidase staining in testicular tumors (before PVB chemotherapy) and retroperitoneal tumors (after PVB chemotherapy) with CEA levels in the cyst fluid of retroperitoneal mature teratoma and in the patients' serum. CEA had no value as a serum tumor marker since serum CEA elevations were not associated with tumor activity. Only one elevated CEA level after chemotherapy was associated with bleomycin pneumonitis. Despite normal serum levels, CEA was localized immunohistochemically in yolk sac tumor and mature teratoma in the primary tumors and in retroperitoneal mature teratoma following PVB chemotherapy. The presence of CEA in cells lining cystic mature teratoma was associated with high CEA levels in the cyst fluid.

Extramedullary IgM plasmacytoma presenting in skin

An IgM-secreting extramedullary plasmacytoma with macroglobulinemia presented itself in the skin. Reactions of the plasmacytoid cells in dermal nodules to erythrocyte-antibody-complement complexes suggested that the neoplastic cells differentiated in situ. Large numbers of plasmacytoid neoplastic cells co-mingled with alpha naphthyl acetate esterase-positive histiocytes in a random and "territorial" distribution, which suggested a functional relationship between them. The subject of extramedullary cutaneous plasmacytoma is reviewed and discussed.

Assessment of serial carcinoembryonic antigen (CEA) assays in postoperative detection of recurrent colorectal cancer

Monthly serial postoperative CEA determinations, three-monthly system review plus physical examination, and a battery of six-monthly laboratory and radiologic tests were compared in order to evaluate each in detection of recurrent colorectal cancer. Twelve of the 33 patients studied prospectively developed recurrent disease. In this study CEA was found not to be a substitute for careful clinical follow-up, but if used in a serial manner it was a useful adjunct for detection of early recurrent cancer, especially intra-hepatic and retroperitoneal disease recurring in patients with elevated pretreatment CEA levels. The other laboratory and radiologic tests employed were often useful to confirm progressing disease, but they did not reveal any first evidence of recurrent disease.

Assessment of serial carcinoembryonic antigen (CEA) assays in postoperative detection of recurrent colorectal cancer

Monthly serial postoperative CEA determinations, three-monthly system review plus physical examination, and a battery of six-monthly laboratory and radiologic tests were compared in order to evaluate each in detection of recurrent colorectal cancer. Twelve of the 33 patients studied prospectively developed recurrent disease. In this study CEA was found not to be a substitute for careful clinical follow-up, but if used in a serial manner it was a useful adjunct for detection of early recurrent cancer, especially intra-hepatic and retroperitoneal disease recurring in patients with elevated pretreatment CEA levels. The other laboratory and radiologic tests employed were often useful to confirm progressing disease, but they did not reveal any first evidence of recurrent disease.

Increase in E-rosettes after transfer factor (TF) treatment: fractionation of TF

The effect of transfer factor (TF) on E-rosettes (ER) was studied in vivo in a patient with Hodgkin's disease. Transfer factor was given in doses of 10 units/sq m intramuscularly. The ER forming cells and the ER scores were determined. The ER score method took into account the number of erythrocytes in each rosette. The increase in ER score was maximum at 24 hours and it declined during the following one to two weeks. It was suggested that TF may have to be given more frequently than indicated by the persistence of skin reactivity. TF was fractionated with high pressure liquid chromatography. Fraction 2 increased ER in a patient with Schwannoma. Non-specificity of TF was also discussed.

Immunohistochemical study of glomerular lesions in retroperitoneal lymphomas

An immunohistochemical study was performed on the kidneys of 10 subjects with retroperitoneal lymphomas. Kidneys were first examined by light microscopy and six kidneys were further studied by immunofluorescence. Light microscopic evidence of damage found in 6 of 10 subjects was characterized by thickening of the basement membrane of glomerular capillaries and an increase in the mesangial matrix. In the areas of light microscopically visible damage, deposits of Schiff-positive material and argyrophilic material were present. No significant changes were found in the tubules. Four of the six kidneys which showed damage by light microscopy showed further evidence of histologic change in areas of glomerular damage when examined using the direct immunofluorescence technic. In 2 subjects, diffuse deposits of IgG and beta1C-beta1A globulin in basement membranes and the mesangial region were prominent, while in the remaining 2 subjects IgG and beta1C-beta1A globulin were localized as linear and/or beaded deposits, both inside and outside the basement membranes. Only focal deposits of these conjugates were seen in the mesangium. No localization of IgA, IgM, rabbit antihuman fibrin or fibrinogen was noted in any of the cases. The tubules yielded negative reactions for the localization of any of the conjugates. The results of this study seem to support the concept that, in some cases of retroperitoneal lymphomas, clinical and renal functional disturbances may be explained on the basis of an immunologic injury to the basement membranes of the glomeruli.