Renal oncocytoma in transplant patients: report of 2 cases

We report on 2 cases of renal oncocytoma occurring in a liver transplant patient and in a kidney allograft recipient, respectively, during the posttransplant period. This neoplasm has never been reported in transplant patients; its relationship with long-term immunosuppressive therapy is questioned.

[Primary bladder signet ring cell adenocarcinoma. Apropos of 1 case. Review of the literature]

The authors report a new case of signet ring cell carcinoma of bladder whose characteristic findings are the parietal infiltration and the rapidly fatal course. Based on a review of the literature, they define the histological features of this very rare tumour (less than 20 documented cases have been reported). The pluripotent behaviour of urothelial cells appears to be the essential element in the histogenesis of this tumour type, which is very similar to gastric linitis plastica.

Evolution of untreated mild rejection in heart transplant recipients

To elucidate whether mild rejection requires treatment, we retrospectively examined the spontaneous natural history of this histologic feature without an increase of immunosuppression. During a 4-year period, 55 heart transplantations were performed in 54 patients on whom 958 endomyocardial biopsies were performed. Among these biopsies, 162 specimens showed features of mild rejection. We studied the results of subsequent biopsies performed 7 to 10 days later, without any change in immunosuppression. These revealed regression of lesions to minimal rejection in 51 cases (31%), the same histologic feature in 82 cases (51%), or progression to moderate or severe rejection in 29 cases (18%). In 82% of these cases, therefore, no aggravation of histologic feature was observed. We separated the cases in which current-study biopsies showed mild rejection into three groups according to the result of the most recent biopsy, that is, minimal, mild, or moderate-severe rejection. The percentage of good outcome was not modified by the nature of the previous biopsy specimen: 84%, if minimal rejection was preceding the study biopsy; 82%, in the cases of mild rejection; and 77%, for moderate or severe rejection. We did not find significant differences in this evolution between patients with fewer or more than two moderate or severe acute rejections in the first 4-month period after heart transplantation (respectively, 15% or 24% progression to moderate or severe acute rejection after nontreated mild rejection).(ABSTRACT TRUNCATED AT 250 WORDS)

Phenotyping of 76 human bladder tumors with a panel of monoclonal antibodies: correlation between pathology, surface immunofluorescence and DNA content

Phenotyping of 76 bladder tumors (11 grade I, 33 grade II and 32 grade III) has been carried out by flow cytometry on cell suspensions with simultaneous determination of DNA content and surface immunofluorescence using G4 and 5 new monoclonal antibodies (10D1, 7C12, 6D1, 3C6 and 12F6) directed against bladder tumor cells. Ten normal bladder samples were used as control. Antibodies 6D1 and 12F6 were specific for tumor cells whereas the others also labelled umbrella cells. Cells from grade I tumors were labelled with 10D1, 6D1, 7C12 and 12F6 antibodies, and cells of grade II tumors with 7C12 and to a lesser degree with 12F6 but not with 10D1 and 6D1. Grade III tumor cells were specifically labelled with antibodies 3C6 and G4. Reactivity of antibodies with tissue sections was well correlated with cytometry results, except for the antibody 3C6. Finally, most of the cells stained by 3C6 and G4 were shown to have a DNA index greater than 1.0. In conclusion cells of low grade tumors can be identified with 10D1 and 6D1 antibodies, and antigens recognized by 3C6 and G4 antibodies are mostly expressed by aneuploid cells.

A monoclonal antibody (BL2-10D1) reacting with a bladder-cancer-associated antigen

A hybridoma cell line secreting an IgM monoclonal antibody (MAb) was produced after immunizing a mouse with RT4 cells and a crude suspension of human bladder carcinoma cells (WHO grades II and III TCC). This MAb reacted with RT4 target cells derived from a human transitional bladder cancer but failed to react with a majority of non-bladder cancer cell lines. Immunohistological studies indicate that this MAb reacts inconstantly with normal bladder: in positive cases only a few superficial cells (5% to 10% umbrella cells) are stained but not intermediate or basal cells of the urothelium. This MAb was evaluated on 118 tumors: it reacted with tumor tissue in a majority of grade I (79.5%) and grade II papillary TCC (77.3%), less with grade III papillary TCC (45%) and very rarely with invasive non-papillary TCC (14%). In cases of flat lesions a strong reactivity of superficial, intermediate and/or basal layer cells was observed in 50% of moderate and severe dysplasia and in all cell layers of carcinomas in situ (CIS)(9/9).

[Bilateral ureteral metastases, a 1st symptom of gastric cancer. Gastrectomy. Bilateral ureteral replacement]

Renal colic in a young adult led to the discovery of very extensive bilateral ureteral stenosis. Exploration and biopsy showed metastatic lesions of an asymptomatic gastric cancer. Gastrectomy and subtotal bilateral ureteral replacement by prosthesis gave excellent short term results.

Hypothesis on microangiopathy of cutaneous capillaries

Microangiopathy is a more or less pronounced PAS deposit-located exterior to the endothelial cells of the lymphatics and the basal membrane of the capillaries. This lesion, found in various normal and pathological states, has generated numerous pathogenic hypotheses. The presence of microangiopathy in 5 groups of 50 subjects representing five different clinical conditions, subjects over 60 years old or less than 40, diabetics, latent diabetics or patients with severe coronary heart disease, together with microscopic and/or ultrastructural lesions of the connective tissue (fibroblasts, collagen and elastic fibers, ground substance) has enabled us to propose a pathogenic hypothesis applicable to any microangiopathy. The initial change, hereditary or acquired, would be fibroblastic or interstitial. It would be characterized by the accumulation of glycoproteins, proteoglyacans and soluble collagen in the interstitium. Incomplete drainage of these macromolecules would occur around the blood and lymphatic capillaries and manifest itself by a PAS deposit, the hallmark of the microangiopathy.