La rotura espontánea del injerto renal es una complicación rara pero que puede ser catastrófica pudiendo comprometer la vida del paciente y la viabilidad del injerto. Se puede producir por múltiples causas como rechazo agudo, trombosis del injerto, infecciones, obstrucción ureteral o trauma desapercibido durante cirugía o biopsia renal. El tratamiento tradicional ha sido la nefrectomía pero en casos seleccionados es posible realizar de forma segura un manejo conservador para reparar la laceración y al mismo tiempo realizar tratamiento de la posible causa. Se presenta el caso de una paciente que presentó rotura espontánea del injerto renal asociada a rechazo.Spontaneous renal allograft rupture is a rare, but life threatening, complication of kidney transplantation and it may compromise the graft function and patient survival. Several causes have been proposed such as, acute rejections, graft thrombosis, infectious diseases, graft occlusion, ureteral occlusion, and trauma due to a surgical procedure or kidney biopsy. Graft nephrectomy is considered the standard treatment, but in selected cases conservative management is possible by repairing the rupture, and at the same time treat the cause. A report is presented on a patient who received a deceased-donor kidney transplant and experienced spontaneous allograft rupture due to acute rejection.

Mutations in the mitochondrial genome have been fibrosis, sclerosis of some glomeruli and arteriolosclerosis. Immunofluorescence was negative. In all three found to be responsible for several neuromuscular and cases, electron microscopy showed various mitochoncardiac diseases. Mitochondrial genome alterations drial lesions in many of the distal tubular epithelial cells can, however, present as renal tubular dysfunction (Figure 1): an increased thickness of the internal mem[1,2]. Recently, aberrant mitochondria and mitochonbranes; a distended empty core (Figures 2 and 4), also drial DNA (mtDNA) deletion were diagnosed ultraseen by light microscopy (Figure 6 ); or dense inclusions structurally in a renal biopsy specimen from a patient (Figures 2 and 3) enveloped occasionally by irregular with chronic tubulointerstitial nephropathy (TIN) [3]. or concentric cristae (Figure 3). Additionally, some We demonstrate the renal biopsy findings in a family epithelial cells were filled so densely with aberrant with three affected individuals presenting with chronic mitochondria that they resembled oncocytes (Figure 5). progressive TIN, distorted mitochondria, and mtDNA mtDNA from the blood of these patients was anapoint mutation. The disease, and the mutation lysed, and an A to G mutation was detected in position appeared to have been maternally inherited. 5656 [4]. We interprete the mutation as a probable Renal biopsies were performed on a 12-year-old boy, causative factor of the aberrant mitochondria and his 11-year-old sister, and a 17-year-old maternal male renal disease. The formation of oncocyte-like cells may cousin (biopsied 15 years earlier). They all had probe connected with the mtDNA mutation as renal gressively impaired renal function. Two other maternal tumours composed of oncocytes are characterised by relatives are known to have died earlier because of an altered restriction pattern of the mtDNA [5]. The chronic renal failure, but renal biopsy was not carried arteriolar lesions in our patients in childhood may be out on these patients. Detailed renal functional explained by the suggestion that premature arteridata were available from the siblings: decreased GFR o( lo)sclerosis can result from a mtDNA mutation [6 ]. (creatinine clearance: boy: 38 ml/min/1.73 m2, girl: These illustrations provide a detailed ultrastructural 30 ml/min/1.73 m2); increased renal sodium loss (fracdocumentation of mitochondrial TIN and emphasise the tionated Na excretion: 1.38%, 1.25% [normal: <1], need to pay careful attention to mitochondrial changes UNa/UK: 8.19, 4.79, normal: 1.5±1); serum Na 117 in tubules in patients with idiopathic chronic TIN. mM/l, 122 mM/l; decreased urinary concentrating Acknowledgements. The study was supported in part by grants from capacity (DDAVP-test: 690 mosm/l, 620 mosm/l OTKA (T-016525 to B.I. and T-025010 to S.T.) and from ETT [normal: >1000]); elevated PTH level: 89 pg/ml, (588/1996–06 to B.I. and 673/1996–06 to S.T.). 100 pg/ml (normal: 10–60 pg/ml ); and aminoaciduria (beta-aminoisobutyric acid: 36.2 mMol/mM/creat, References 23.9. mMol/mM/creat [normal: 0–13]). Extrarenal fea-

In two nephrology centres between 1983 and 1993 among 1545 kidney biopsies 34 cases of thin basement membrane nephropathy have been diagnosed. All patients had a varying degree of microscopic dysmorph haematuria, occasional slight proteinuria--except two nephrotic children; and normal blood pressure with one exception. 5 children and 7 adults experienced repeated bouts of macroscopic haematuria mainly after exercise or upper respiratory tract infection, one child after tonsillectomy. All patients had normal renal function and retained it during the follow-up period (mean 61 months, 3 months to 22 years), except a 46 year old patient, who was found to have the joint occurrence of light chain gammopathy and hypertension. Seven patients had positive family history for microscopic haematuria, in four family members of three patients renal biopsy disclosed mesangioproliferative glomerulonephritis with thin GBM segments. As a cut off value for thin basement membrane nephropathy we considered 264 nm. The morphometric analysis of the electron micrographs revealed a mean thickness of 210 nm. No differences in basement membrane thickness were measured regarding gender, age or the presence of macroscopic haematuria. The thin basement membrane is considered to be the pathological basis and predisposing alteration leading to haematuria.

The nail-patella syndrome is a hereditary disorder showing an autosomal dominant trait. It is characterized by a series of skeletal disorders and nephropathy. The skeletal defects and the renal involvement might occur separately. The usual clinical presenting syndromes of the nephropathy are asymptomatic proteinuria, microscopic haematuria and sometimes nephrotic syndrome. In a considerable proportion of patients renal failure develops. We summarise the clinico-pathological features of the disease presenting in two children and in a young man. The two children showed heavy microscopic occasionally, macroscopic haematuria, asymptomatic proteinuria and the adult patient had nephrotic syndrome. Nail-patella abnormalities were observed in one child without the involvement of family members. Except for the mother of the other child no urine abnormalities could be demonstrated in the patient's families. The kidney biopsy revealed the characteristic signs of the nail-patella syndrome in different extent: bundles of collagen fibrils in the glomerular basement membrane (GBM). Segmental and thinning of the GBM also occurred in the two children. This defect predisposes to the clinically dominant micro- and macroscopic haematuria. These children's reual function remained stable during the follow-up period of 4-7 years. In the GBM of the third patient small subepithelial electron dense deposits-corresponding to stage I. membranous glomerulonephritis- and extensive collagen deposition was found. After two years follow-up persistent nephrotic syndrome and gradual decline in renal function could be observed.

Arteriolosclerosis frequently occurs in IgA nephritis (IgAN), and it is the hallmark of benign nephrosclerosis (BNS). The quantitative ultrastructure of juxtaglomerular arterioles is not known in these disorders. We examined afferent and efferent arterioles in renal biopsies from 25 adult patients with IgAN (hypertension at biopsy: 14 patients) and 9 patients with BNS. Six agematched living renal transplant donors acted as controls. A systematic independent sample of profiles was obtained in thin sections taken at predetermined levels. The thickness of the media (myomedial cells plus the matrix) and the thickness of the medial matrix were estimated stereologically. From these estimates, the matrix/myomedia ratio was calculated. In IgAN with normotension or hypertension, the afferent media and its compartments did not exhibit significant thickening compared with the controls, whereas in BNS the afferent media and its layers were markedly and significantly thickened. The efferent media in IgAN and BNS displayed mild and significant thickening, with significant thickening of the matrix in BNS and IgAN with normotension. The matrix/myomedia ratio was not altered significantly in any group. The results indicate that the afferent arterioles are not the main sites of IgAN-related arteriolosclerosis, that arteriolosclerosis in IgAN and arteriolosclerosis in BNS are different lesions, and that increased efferent arteriolar thickness, demonstrated here for the first time in IgAN and BNS, might be a manifestation of angiotensin II-mediated autoregulatory efferent vasoconstriction exerted to maintain the glomerular filtration pressure.

The correlation of B mode and Doppler sonographic parameters and diagnoses established by histological examination of graft biopsies, nephrectomies and clinical data are discussed. 48 histological samples from 36 patients were reevaluated. The maximum interval between sonography and histology was 36 hours. The Banff classification criteria were used during histological examinations. Doppler examination evaluation was based on the resistance index (RI). Reproducibility was controlled by means of intra- and interobserver variability in 10 patients. RI values higher than 75% were regarded as abnormal. On the basis of these observations and the literature data specific sonographic features can be detected in renal artery occlusion and renal vein thrombosis. In pyelonephritis, dilatation of the collecting system was frequent. No morphological changes were detected in cyclosporin-A nephrotoxicity and the Doppler signs were not characteristic for this disease. No differentiation was found between acute rejection and acute tubular necrosis. The noninvasive duplex sonographic examinations can provide very important information regarding the flow situation of a transplanted kidney. In some cases a definitive diagnosis can be achieved, but in other cases biopsy is the method of choice.

The case of a 33-year-old man is presented, who acutely developed disturbance of consciousness, symptoms of raised intracranial pressure and unilateral neurological signs. The underlying lesion was a hemorrhagic tumor located in the left lateral ventricle. On histological examination, the surgically resected mass proved to be a central neurocytoma, a benign neuroectodermal neoplasia. Difficulties in differential diagnosis by imaging technics and histopathology render this unusual lesion worth publishing. To the best of our knowledge, no similar report on this recently described rare entity has been published in Hungary.

IgG lambda type of monoclonal gammopathy and thin basement membrane nephropathy were established in a middle-aged man examined because of persistent haematuria, lambda light-chain proteinuria and moderately diminished renal function. A 10% level of plasmocytosis was verified by bone-marrow aspiration. The more than 6-year follow-up showed the gammopathy to be benign. The thin basement membrane nephropathy was verified by electronmicroscopic analysis of renal tissue obtained by percutaneous renal biopsy: lamina densa of the glomerular capillaries thinned to 30-100 nm. In spite of the usually good outcome of thin basement membrane nephropathy, in this case it was accompanied by glomerular sclerosis, subsequent destruction of nephrons, hypertensive vascular alterations and a clinical deterioration of the renal function after 4 years. A rebiopsy excluded the possible complications (amyloidosis, non-amyloid immunoglobulin nephropathy, cylinder nephropathy, etc) of light-chain proteinuria.

A case of ceruminous adenocarcinoma is reported. The tumor destroyed the right pyramid, widely invaded the base of the skull and caused death shortly after the diagnosis. Distant metastases were not found by autopsy. The tumour cells reacted with epithelial markers and with the antibody against S-100 protein. Heparan sulphate proteoglycan seemed to be a good marker for detecting basement membrane ruptures and concomitant tumour invasion. Among the lectins BS-I and PNA gave the strongest reactions in the stroma. This is the first immunohistochemical and lectin histochemical report on ceruminous adenocarcinoma.

Following 689 percutaneous renal biopsies, membranous glomerulonephritis was proved in 68 patients. In 16 (23.5%) an underlying primary disease was verified, and thus the glomerulonephritis the secondary form. The primary disease was SLE in 5 cases, diabetes mellitus in 5 cases, rheumatoid arthritis in 3 cases, chronic active hepatitis in 2 cases, an ulcerative colitis and eosinophilic angiolymphoid hyperplasia in 1 patient. As initial sign, nephrotic syndrome emerged in 87.5% of the 16 cases. Microscopic haematuria was observed in half of the patients, as was hypertension, while acute renal failure presented in only 1 case. Histologically, in 13 cases the predominance of early glomerular alterations was characteristic, while in 9 cases the picture proved to be equivocal and accompanied by some degree of interstitial alterations. During combined treatment, remission was achieved in 75%. Two patients with SLE died, but not as a consequence of renal failure. Transient side-effects of the treatment were registered in 5 cases. The principal pathogenetic and clinical differences between the individual secondary nephritis forms, and the difficulty of their differentiation from the idiopathic cases, even on repeated examination, are emphasized. In 3 patients the possibility of secondary renal processes was suggested by the histological picture, and this was proved by the detailed clinical findings.

Composition of the extracellular matrix (ECM) was studied in transplant vasculopathy occurring in rejected renal allografts using the immunoperoxidase technique with antisera against laminin, and collagen types I, III and IV. In acute transplant vasculopathy the loose ECM network of the intima showed intense immunostaining for laminin and type IV collagen. Type III collagen was detected in the advanced acute cellular intimal proliferations, while early acute lesions did not show immunreactions. Type I collagen was not seen in significant amount. In contrast to these findings in chronic transplant vasculopathy associated with intimal fibrosis the ECM was largely composed of interstitial collagen types III and I, while staining for the basement membrane type ECM components were markedly reduced. Degradation of the matrix components with variable composition was noted in foci of mononuclear infiltrates occurring inside the fibrotic intima. These results indicate that the ECM shows a compositional change in transplant vasculopathy which is associated with the age of the lesion.

The recent demonstration of the endothelial fenestration at the juxtaglomerular part of the afferent arteriole facing mesangial and granular cells and finger-like protrusions of urinary space into the region of the lacis in experimental animals like the rat, the mouse, and Tupaia belangeri led us to propose the hypothesis of a "short loop" feedback mechanism. To establish whether a further species possesses these morphological features, the JGA region was examined in the human kidney. Tissue was obtained by needle biopsy from patients and conventional electron-microscopical procedures including serial sections were utilized to reevaluate the morphology of JGA. Both the endothelial fenestration in the wall of the afferent arteriole and protrusions with filtration slits of urinary space into the lacis, were observed with remarkable heterogeneity. The occurrence of these features of JGA in such diverse mammalian species as rat, mouse, Tupaia, and man suggests that these structures may be involved in regulatory process and the proposed "short loop" feedback mechanism may be a general phenomenon.

Arteries were investigated ultrastructurally in material from 40 needle and wedge biopsies of renal allografts, and immunohistochemically in another 10 cases with signs of chronic obliterative transplantation arteriopathy. In the early biopsies, but even in the control kidneys, thin extensions of the smooth muscle cells of the media were observed, which were in direct contact with the endothelial cells through the lamina elastica interna. These extensions may contain receptors mediating endothelial noxae to the smooth muscle cells thus initiating their proliferation, migration to the intima presumably begins in the early post-transplant period and continues until the lumen is occluded. Concomitantly, inflammatory cells (mainly macrophages, with a smaller number of CD4 and CD8-positive T lymphocytes) invade the intima. The proliferating myointimal cells, possibly having become HLA-DR-positive, may behave as antigen-presenting cells, enhancing the anti-graft immune response further, and aggravating the arterial injury.