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S M Bonsib

Publications and source records attributed to S M Bonsib.

At least 19 recordsLinked to original sources
PubMed1999

The Banff 97 working classification of renal allograft pathology.

BACKGROUND: Standardization of renal allograft biopsy interpretation is necessary to guide therapy and to establish an objective end point for clinical trials. This manuscript describes a classification, Banff 97, developed by investigators using the Banff Schema and the Collaborative Clinical Trials in Transplantation (CCTT) modification for diagnosis of renal allograft pathology. METHODS: Banff 97 grew from an international consensus discussion begun at Banff and continued via the Internet. This schema developed from (a) analysis of data using the Banff classification, (b) publication of and experience with the CCTT modification, (c) international conferences, and (d) data from recent studies on impact of vasculitis on transplant outcome. RESULTS: Semiquantitative lesion scoring continues to focus on tubulitis and arteritis but includes a minimum threshold for interstitial inflammation. Banff 97 defines "types" of acute/active rejection. Type I is tubulointerstitial rejection without arteritis. Type II is vascular rejection with intimal arteritis, and type III is severe rejection with transmural arterial changes. Biopsies with only mild inflammation are graded as "borderline/suspicious for rejection." Chronic/sclerosing allograft changes are graded based on severity of tubular atrophy and interstitial fibrosis. Antibody-mediated rejection, hyperacute or accelerated acute in presentation, is also categorized, as are other significant allograft findings. CONCLUSIONS: The Banff 97 working classification refines earlier schemas and represents input from two classifications most widely used in clinical rejection trials and in clinical practice worldwide. Major changes include the following: rejection with vasculitis is separated from tubulointerstitial rejection; severe rejection requires transmural changes in arteries; "borderline" rejection can only be interpreted in a clinical context; antibody-mediated rejection is further defined, and lesion scoring focuses on most severely involved structures. Criteria for specimen adequacy have also been modified. Banff 97 represents a significant refinement of allograft assessment, developed via international consensus discussions.

Acute Disease↗
PubMed1998

Oncocytic adrenocortical neoplasms: a report of seven cases and review of the literature.

Oncocytic neoplasms of the adrenal gland are rare. We describe the clinicopathologic and immunohistochemical findings of seven oncocytic adrenocortical neoplasms, five oncocytomas, and two oncocytic neoplasms of uncertain malignant potential. Three tumors were studied using electron microscopy. These neoplasms occurred in five women and two men (median age, 55 years) with no clinical evidence that the neoplasms were functional. The size of the neoplasms varied from 5.0 cm to 13.5 cm. Histologically, each neoplasm was composed exclusively of oncocytes. The oncocytomas had very low or absent mitotic activity and no evidence of necrosis. The two oncocytic neoplasms of uncertain malignant potential had increased mitotic activity and necrosis but no evidence of invasion or metastases. Nuclear atypia, either focal or generalized, was found in all neoplasms. Immunohistochemical studies performed using fixed, paraffin-embedded sections showed strong reactivity with the mitochondrial antibody mES-13 in all neoplasms. Four of five oncocytomas and one oncocytic neoplasm of uncertain malignant potential expressed keratin, predominantly keratin 18, as shown using the CAM 5.2 and AE3 antibodies. Two neuroendocrine-associated markers, neuron specific enolase and synaptophysin, were positive in seven and five neoplasms, respectively. However, all neoplasms were negative for the other neuroendocrine markers tested, including chromogranin A, tyrosine hydroxylase, and dopamine beta-hydroxylase, as well as for epithelial membrane antigen, S100, and p53. Using the MIB-1 (Ki-67) antibody, proliferative activity was increased in both oncocytic neoplasms of uncertain malignant potential. All six patients with available clinical follow-up data are alive without evidence disease, although the follow-up interval is relatively short (< 2 years) for the two patients with oncocytic neoplasms of uncertain malignant potential. We conclude that oncocytic adrenocortical neoplasms are nonfunctional tumors that can become large before they are detected by radiologic studies. The majority of neoplasms are benign and should not be misdiagnosed as carcinoma.

Adenoma, Oxyphilic↗
PubMed1998

Extensively cystic renal neoplasms: cystic nephroma, cystic partially differentiated nephroblastoma, multilocular cystic renal cell carcinoma, and cystic hamartoma of renal pelvis.

Predominantly cystic renal neoplasms have been the source of diagnostic confusion and controversy. In this review, the authors analyze the clinical and pathological features of four entities that consistently exhibit a diffusely cystic growth pattern, are strikingly similar in their gross appearances, and are not separable by preoperative imaging studies. Based on the literature, this review concludes that tumors in young children that have been classified as cystic nephroma and cystic partially differentiated nephroblastoma likely represent a single entity, and all should be considered highly cystic Wilms' tumors with little or no capacity for invasion or metastasis and diagnosed as cystic partially differentiated nephroblastoma. Conversely, cystic nephroma in adults has no discernible connection with Wilms' tumor or nephrogenic rests and should be considered a benign composite neoplasm of stroma and epithelium of unknown histogenesis, which may rarely become malignant with secondary development of a sarcoma. Multilocular cystic renal cell carcinoma appears to be unrelated to cystic nephroma and if the following criteria are met, it appears to be a neoplasm with an intrinsically cystic growth pattern, and no, or at most little, malignant potential: (1) an expansile mass is surrounded by a fibrous wall, (2) the interior of the tumor entirely is composed of cysts and septa with no expansile solid nodules, and (3) the septa contain aggregates of epithelial cells with clear cytoplasm. Cystic hamartoma of the renal pelvis is a rare, complex tumor composed of stroma with a prominent smooth muscle component and a variety of epithelial elements.

Adenocarcinoma, Clear Cell↗
PubMed1998

Fetal obstructive uropathy without renal dysplasia: a study of the renal findings in 13 cases presenting with megacystis.

PURPOSE: Metanephric maldevelopment is a frequent sequela of fetal urinary tract obstruction, particularly when maternal oligohydramnios and massive lower urinary tract dilatation are present. The kidneys in 13 subjects at an estimated 15 to 39 weeks of gestation with distal urinary tract obstruction presenting with severe megacystis not associated with renal dysplasia were examined to discover other manifestations of impaired renal development. MATERIALS AND METHODS: Complete autopsy specimens in 13 cases of severe megacystis in which 1 and 2 kidneys in 3 and 10, respectively, were free of dysplastic features were examined to determine whether there were abnormalities in the cortex and medulla that indicated impaired renal development. RESULTS: The kidneys in 9 cases had various abnormalities indicative of perturbed renal development, such as the premature disappearance and phenotypic alteration of nephrogenic zone cells, a decreased number of nephron generations and medullary collecting duct abnormalities. In 4 cases the kidneys had developed normally. CONCLUSIONS: The majority of subjects with urinary obstruction but nondysplastic kidneys had significant renal abnormalities that would have limited future functional capacity. However, abnormal development is not inevitable even in severe fetal obstruction, suggesting that select cases may benefit from fetal intervention.

Fetal Death↗
PubMed1997

Renal maldevelopment: a pediatric renal biopsy study.

We reviewed 18 pediatric open renal biopsies performed because of renal insufficiency in patients with renal or renal and lower urinary tract (LUT) anomalies. Nine patients had LUT anomalies, 6 had small kidneys, and 3 had normal-sized, enlarged polycystic, and ectopic kidneys, respectively. Patients with LUT anomalies underwent biopsy at an earlier age and had a higher incidence of extrarenal anomalies. Seventeen biopsy specimens were abnormal: 15 showed focal forms of renal dysplasia, and 1 biopsy each showed glomerulocystic kidney disease and dominant polycystic kidney disease. The specimens with dysplasia also contained normal-looking nephrons, whose numbers were particularly striking in patients with a normal LUT. The biopsy specimen from the ectopic kidney was normal. Progressive renal disease developed in 12 of 17 patients with follow-up. All of them had either bilateral uncorrectable LUT abnormalities or bilateral small kidneys. This study demonstrates that renal biopsies in patients with renal insufficiency and gross abnormalities in kidneys or the LUT will often show evidence of parenchymal maldevelopment, principally focal forms of renal dysplasia Although normal nephrons are also present, and might even predominate, progressive disease should be anticipated in the presence of bilateral involvement because of the underlying developmental abnormality coupled with complications related to LUT disease and deficiency in renal mass.

Biopsy↗
PubMed1996

Angiotensin II receptor antagonists in the prevention of radiation nephropathy.

Angiotensin-converting enzyme (ACE) inhibitors can be used to prevent the development of radiation nephropathy. Current studies were designed to determine whether blocking the angiotensin II (AII) receptor, rather than preventing the creation of AII, would be effective in the prophylaxis of radiation nephropathy. Rats received 17 Gy total-body irradiation (TBI) in six fractions followed by syngeneic bone marrow transplantation (BMT). Prior to TBI the rats were randomized to groups receiving an ACE inhibitor (captopril), an AII type 1 (AT1) receptor antagonist (L-158,809) or no treatment. Renal function was assessed over 40 weeks, and a subset of animals were sacrificed for histopathology at 33 weeks. Renal function deteriorated progressively in animals receiving TBI alone, leading to renal failure by 34 weeks. Renal function was significantly better in animals receiving either captopril or L-158,809, and none of these animals had progressed to renal failure by 43 weeks. Analysis of both renal function and histopathology shows that the AII receptor antagonist is more effective than the ACE inhibitor in the prophylaxis of BMT nephropathy. This indicates that a reduction of activation of the AT1 receptor by AII, by itself, is sufficient for the prophylaxis of radiation nephropathy.

Angiotensin Receptor Antagonists↗
PubMed1996

HMB-45 reactivity in renal leiomyomas and leiomyosarcomas.

Ten renal smooth muscle tumors (seven leiomyomas, three leiomyosarcomas) and an unusual smooth muscle-invested renal cell carcinoma were studied for HMB-45 reactivity. All leiomyomas strongly expressed at least one, and most expressed three, smooth muscle markers (desmin, MSA, SMSA) and were negative for two cytokeratin markers (BDK, AE1). Six of seven leiomyomas and the smooth muscle investment of a renal carcinoma contained a population of cells strongly positive for HMB-45. A total of 15 blocks from the 6 HMB-45-positive leiomyomas were studied, and no adipocytes or abnormal vessels suggestive of angiomyolipoma were identified. The six HMB-45-positive leiomyomas seemed to arise from the renal capsule, whereas a seventh leiomyoma, which was negative for HMB-45, seemed to arise from the renal pelvis. Three leiomyosarcomas were also studied, which strongly expressed at least one smooth muscle marker and contained myofilaments at electron microscopic examination. No cytokeratin reactivity and no HMB-45-positive cells were detected in these leiomyosarcomas nor in the normal renal capsule adjacent to leiomyomas. This study showed that HMB-45-positive cells are detectable in a population of cells in some smooth muscle tumors, particularly in those that appear to arise from the renal capsule.

Actins↗
PubMed1995

Papillary renal tumors. Morphologic, cytochemical, and genotypic features.

BACKGROUND: Papillary renal tumors lack alterations of chromosome 3 and show trisomy of chromosomes 7 and 17, genotypic features distinct from nonpapillary carcinomas. METHODS: The authors examined 39 papillary renal neoplasms to identify morphologic features allowing distinction of high grade from low grade tumors. Twenty-nine papillary tumors and 13 nonpapillary tumors were examined for the presence of trisomy of chromosome 7 using fluorescence in situ hybridization. Data recorded included tumor size, stage, grade, architectural pattern, and the presence of glycogen, foam cells, and iron. RESULTS: Nineteen tumors were classified as low grade and 20 as high grade. The high grade tumors more often formed tall papillae with solid and tubular areas and had more intracellular glycogen, whereas the low grade tumors were more often trabecular. There was no significant difference in tumor size or iron deposition. High grade tumors were of higher stage. Foam cells more commonly were noted in low grade tumors. Sixty-seven percent of low grade, 43% of high grade, and none of the nonpapillary tumors showed trisomy of chromosome 7. Metastases developed only in patients with high grade papillary tumors (10/19, 7 within 2 years of diagnosis), all of whom died of disease. CONCLUSIONS: Papillary renal carcinomas with high nuclear grade are more likely to behave in an aggressive fashion, whereas those with low nuclear grade may be associated with longer disease free survival. Furthermore, trisomy of chromosome 7 can be identified by fluorescence in situ hybridization and is useful in differentiating true papillary from nonpapillary renal neoplasms.

Carcinoma, Papillary↗
PubMed1995

Radiation-induced changes in glomerular and tubular cell kinetics and morphology following irradiation of a single kidney in the pig.

PURPOSE: Radiation-induced changes in glomerular and tubular cell kinetics and morphology following irradiation of a single pig kidney were assessed. METHODS AND MATERIALS: The right kidney of 13 adult female Large White pigs was irradiated with a single dose of 9.8 Gy gamma rays. Animals were serially killed between 2 and 24 weeks postirradiation (PI); 1 h prior to postmortem each pig received 500 mg bromodeoxyuridine (BrdUrd). At postmortem, both kidneys were removed and tissue taken to prepare cell suspensions. The labeling index (LI) of these suspensions was measured using flow cytometry; in vivo BrdUrd incorporation in glomerular and tubular cells was determined immunohistochemically. The kidneys were also assessed histologically. RESULTS: Irradiation of the right kidney alone resulted in a significant increase in renal cell LI in both the irradiated and the contralateral unirradiated kidney within 2 weeks of irradiation; peak values of 1.57 +/- 0.32% and 1.04 +/- 0.13%, respectively, were seen 4 weeks PI, significantly greater (P < 0.001) than the preirradiation value of 0.18 +/- 0.01%. The LI values then declined with time, but remained greater than those seen prior to irradiation. A similar pattern of response was determined from counts of labeled glomerular and tubular cells identified immunohistochemically. The increase in labeled glomerular cells was seen 2 weeks PI, whereas that for the tubular cells did not occur until 4 weeks PI. The irradiated kidney exhibited diffuse, progressive glomerular alterations. In contrast, tubular damage was focal; the irradiated kidney also exhibited a prominent vasculopathy, involving arteriolar and peripheral interlobular artery thickening. The contralateral unirradiated kidney appeared unchanged. CONCLUSION: These findings confirm the hypothesis that the morphologic and kinetic responses observed after irradiation of a single kidney are similar to those observed after irradiation of both kidneys. Renal irradiation results in significant alterations in glomerular and tubular cell proliferation and morphology within 2-4 weeks of irradiation; glomerular changes appear predominant.

Animals↗
PubMed1995

Radiation nephropathy: a review.

The marked radiosensitivity of renal tissue represents a limitation on the total radiotherapeutic dose that safely can be applied to treatment volumes that include the kidneys. Radiation nephropathy is characterized by a progressive reduction in renal hemodynamics associated with a severe anemia. The latter is often normochromic normocytic in character, but can progress to a microangiopathic hemolytic anemia. The pathogenic mechanisms responsible for the development of radiation nephropathy remain ill-defined. Experimental studies which allow serial determinations of functional, morphologic, and cell kinetic radiation-induced changes indicate that primarily glomerular but also tubular alterations occur in the primary stages of radiation nephropathy. Glomerular capillary endothelial cell loss is seen within several weeks of irradiation. Remaining endothelial cells exhibit increased permeability leading to a subendothelial transudate. Mesangiolysis also is observed. In contrast, podocytes appear to be relatively unaffected at this stage. The endothelial changes appear to resolve, but the mesangial lesions progress, with hypercellularity and/or hypertrophy, increased mesangial matrix, mesangial sclerosis, and ultimately, glomerulosclerosis. These mesangial changes are similar to those observed in other chronic glomerulopathies. Dietary protein restriction, corticosteroids, and ACE-inhibitors all can reduce the severity of experimental radiation nephropathy.

Animals↗
PubMed1994

Necrotizing medullary lesions in patients with ANCA associated renal disease.

One hundred and five renal specimens from patients with antineutrophil cytoplasmic antibody and antiglomerular basement membrane antibody-associated diseases were reviewed for necrotizing lesions involving the renal medulla. Necrotizing medullary lesions were identified in eight of 56 cases in which medullary tissue was present. All eight were in patients with antineutrophil cytoplasmic antibody (ANCA) associated disease (seven, C-ANCA; one P-ANCA). Four types of medullary lesions were identified; necrotizing capillaritis (seven cases), necrotizing arteriolitis (two cases), pathergic granulomas (three cases) and papillary tip necrosis (one case). Both medullary arteriolitis and medullary peritubular capillaritis developed without corresponding cortical arteriolitis or cortical peritubular capillaritis. Although necrotizing glomerulonephritis was present in seven of eight patients, its activity did not parallel the severity of the medullary lesions. We conclude that several forms of necrotizing medullary vascular lesions may develop in ANCA-associated disease and that there is discordance between state of activity and types of vessel affected between cortical and medullary vascular compartments.

Adolescent↗
PubMed1994

Immunocytochemical analysis of band 3 protein in renal cell carcinoma, nephroblastoma, and oncocytoma.

Band 3 protein is an anion-exchange protein that in the human kidney is restricted to a subpopulation of collecting duct-intercalated cells; however, it is absent in the metanephric-derived cells of the nephron. We have studied band 3 protein expression in a series of 60 renal tumors that included 10 oncocytomas, 42 renal cell carcinomas, and eight nephroblastomas by using frozen tumors and a monoclonal antibody. We detected band 3 protein expression in nine of 10 oncocytomas but not in any renal cell carcinomas or nephroblastomas. This finding confirms that band 3 protein is a specific marker for oncocytoma and therefore may have a potential diagnostic application. It also supports the contention that renal cell carcinoma and oncocytoma are histogenically unrelated; the former is metanephric blastema derived and the latter is ampullary bud derived.

Adenoma, Oxyphilic↗
PubMed1993

Coexistent anti-neutrophil cytoplasmic antibody and antiglomerular basement membrane antibody associated disease = report of six cases.

From a series of 95 patients biopsied for rapidly progressive glomerulonephritis, twelve patients were identified with anti-glomerular basement membrane-mediated renal disease who were also tested for antineutrophil cytoplasmic antibody (ANCA). Six patients had both anti-glomerular basement membrane and ANCA antibodies. Three of the latter six patients had significant extrarenal disease, including severe hemoptysis, while the remaining three patients had only renal disease. The three patients with extrarenal disease had either a myeloperoxidase-positive perinuclear-ANCA (two patients) or a proteinase-3-positive cytoplasmic-ANCA (one patient). Two patients with renal disease alone had a myeloperoxidase-negative and proteinase-3-negative perinuclear-ANCA, and one patient had a proteinase-positive cytoplasmic-ANCA. Renal biopsy in all six patients showed a severe necrotizing and crescentic glomerulonephritis involving 94 to 100% of glomeruli. Renal arteritis was also noted in one perinuclear-ANCA patient. Despite aggressive therapy with steroids, cyclophosphamide, and plasma exchange, two of the six double-antibody patients died and four are on dialysis. We conclude that ANCA is commonly present in anti-glomerular basement membrane-associated disease and believe that this observation may have implications in the serologic evaluation of ANCA- and anti-glomerular basement membrane-positive patients.

Adult↗
PubMed1993

Occurrence of melanin in pheochromocytoma.

Melanin or a melanin-like pigment was observed in six of 19 pheochromocytomas. The intracellular pigment was Fontana-positive, bleach-labile dark brown to black material and distinct from coincidental hemosiderin and lipochrome. Ultrastructural components of the pigmented tumors include melanosomes and premelanosomes. Two patients with pigmented tumors had associated von Hippel-Lindau syndrome, and one had neurofibromatosis. The occurrence of melanin and melanosomes in pheochromocytoma has not been previously reported in the English literature. It is probably a reflection of the neural crest origin of this neoplasm.

Adrenal Gland Neoplasms↗
PubMed1992

Renal artery stenosis modifies glomerular injury in antineutrophil cytoplasmic antibody-associated disease.

A 68-year-old man presented with renal failure, heart failure, gastrointestinal bleeding, and a pulmonary infiltrate. Serologic evaluation revealed a perinuclear antineutrophil cytoplasmic antibody (ANCA) at a titer of 1:1280, which on immunoblot and enzyme immunoassay showed antimyeloperoxidase specificity. Autopsy showed microscopic polyarteritis based on the presence of necrotizing alveolitis and crescentic glomerulonephritis. The extent and activity of the glomerular disease was modified by a right renal artery stenosis (RAS). Twenty percent of glomeruli on the right and 82% glomeruli on the left contained crescentic lesions. Furthermore, predominantly active lesions were associated with renal artery stenosis, while the contralateral kidney contained mostly organized crescents. This observation suggests that hemodynamic factors or its sequelae can influence the onset and severity of ANCA-associated disease.

Aged↗
PubMed1991

Renal oncocytoma: diagnostic utility of cytokeratin-containing globular filamentous bodies.

Sixty-six renal cortical epithelial tumors were classified by light and electron microscopy into 18 oncocytomas and 48 renal carcinomas, and their pattern of cytokeratin and vimentin reactivity was evaluated by immunoperoxidase using paraffin-embedded tissue. We found by electron microscopy that most oncocytomas (11 of 15) contain globular filamentous bodies that consist of a complex of intermediate filaments and organelles. These structures were found to correlate on immunohistochemistry with a discrete punctate cytoplasmic pattern of cytokeratin reactivity, provided the antibody preparation contained specificity for cytokeratins 8 and 18. A similar punctate finding was not observed in four oncocytomas nor in the 48 renal carcinomas. Although 11 oncocytomas failed to express vimentin, seven tumors showed focal reactivity restricted to rare individual cells in areas of sclerosis (five tumors) or in cell clusters bordering central scars (two tumors). We conclude that many oncocytomas contain a potentially diagnostically useful punctate pattern of cytokeratin reactivity and that focal vimentin reactively may be observed in otherwise typical oncocytomas, restricted to tumor cells appearing to be undergoing atrophy.

Adenoma↗
PubMed1991

Immunocytochemical characterization of a monoclonal antibody directed against mitochondria reactive in paraffin-embedded sections.

The monoclonal antibody mES 13 was previously produced against bacterially expressed BALB ras p21 and was reported to have both membrane and cytoplasmic reactivity in formalin-fixed, paraffin-embedded tissue sections. In the current study, the cytoplasmic reactivity of mES 13 is investigated and demonstrated to be mitochondrial. Immunoelectron microscopic studies showed specific labeling of mitochondria without labeling of other organelles. In normal tissues, the antibody strongly labeled tissues known to have large amounts of mitochondria such as renal tubules, hepatocytes, and myocardium. The pattern of reactivity of tumors generally mimicked that of normal tissues, with carcinomas and melanomas usually showing stronger staining than sarcomas and lymphomas. Two granular cell tumors were negative. Among renal neoplasms, mES 13 strongly labeled renal oncocytomas and granular cell renal cell carcinomas and showed weaker staining of clear cell and chromophobe cell tumors. The mES 13 antibody should be useful in the characterization and diagnosis of tumors in which oncocytoma is in the differential diagnosis, especially when only paraffin-embedded tissue is available for study.

Adenoma↗