Endodermal cysts of the posterior fossa. Report of three cases and review of the literature

The pathogenesis of endodermal cysts of the posterior fossa is still incompletely understood. The authors reviewed three new cases and those reported in the literature to clarify the clinical, pathological, radiological, and surgical characteristics of these lesions. A total of 49 cases were reviewed. Details on demographic profiles, clinical characteristics, histopathological and radiological features, and surgical methods were collected. These cysts have a predominance in male patients (61%) and can occur at any age (birth-77 years). In patients with posterior fossa endodermal cysts there is a bimodal age distribution and headache is the most frequent complaint. On immunohistopathological examination, endodermal cysts were reactive for epithelial membrane antigen and for keratin immunostains whenever the latter were tested. The cysts were reactive for carcinoembryonic antigen in nine of 11 cases. Endodermal cysts were located anterior to the brainstem in 51% of cases and in the fourth ventricle in 21% of cases. They frequently appeared hypodense on computerized tomography scans, and in five cases, the lesion was missed. The cyst's appearance on magnetic resonance imaging is variable. Resection was complete in 19 cases and partial in 11; marsupialization was achieved in two cases. Three recurrences have been reported. Total excision with preservation of neurological function should be the goal. Cranial base approaches are helpful for surgical access in selected examples of these lesions.     

Complexes in serum between alkaline phosphatase and immunoglobulin G: immunological and clinical aspects

A retrospective study was performed on 31 patients in whose sera an immune complex between alkaline phosphatase and immunoglobulin G had been detected. The average age of these patients was 64 years and the sexes were equally represented. Twenty-three patients (74%) had a disease with either an autoimmune aetiology or associated with circulating immune complexes or autoantibodies. Sera from 16 patients were tested for the presence of circulating immune complexes in addition to the alkaline phosphatase immune complex, and these complexes were detected in 14 cases (88%). Sera from 17 patients were tested for the presence of specific autoantibodies and these were detected in 9 cases (53%). Twelve patients were followed up for a mean period of 11.6 months (range 0.5 to 39 month). At the end of the follow-up period, 10 patients (83%) showed persistence of the immunoglobulin-G-alkaline phosphatase complex.     

Treatment of Goodpasture syndrome with cyclophosphamide, prednisone and plasma exchange transfusions

Repeated plasm exchanges were performed in a 44-year-old man with Goodpasture syndrome, also treated with cyclophosphamide and prednisone. Improvement was observed within 3 weeks of starting the protocol, and by the 76th week, endogenous creatinine clearance had increased from 30 to 56 ml/min/1.73 M2 and serum albumin from 2.7 to 3.7 g/dl. Prior treatment with immunosuppressive drugs had not significantly influenced circulating antibody levels. But sustained suppression of antibody was achieved after the plasma exchanges were begun, suggesting that physical removal of circulating antibody combined with antiproliferative drug treatment may be a useful way to control undesirable humoral immune responses.