title: Schistosoma mansoni granuloma in late evolutive phase, in a case of tumoral form in man.
abstract: BACKGROUND
  Authors describe human schistosomal granuloma in late chronic phase, from the morphological and evolutionary viewpoints.
  
  
  METHODS
  The study was based on a histological analysis of two fragments obtained from a surgical biopsy of peritoneum and large intestine of a 42-year-old patient, with a pseudotumoral form mimicking a peritoneal carcinomatosis associated to the schistosomiasis hepatointestinal form.
  
  
  RESULTS
  Two hundred and three granulomas were identified in the pseudotumor and 27 in the intestinal biopsy, with similar morphological features, most in the late chronic phase, in fibrotic healing. A new structural classification was suggested for granulomas: zone 1 (internal), 2 (intermediate) and 3 (external).
  
  
  CONCLUSIONS
  Regarding granuloma as a whole, we may conclude that fibrosis is likely to be controlled by different and independent mechanisms in the three zones of the granuloma. Lamellar fibrosis in zone 3 seems to be controlled by matrix mesenchymal cells (fibroblasts and myoepithelial cells) and by inflammatory exudate cells (lymphocytes, plasmocytes, neutrophils, eosinophils). Annular fibrosis in zone 2, comprising a dense fibrous connective tissue, with few cells in the advanced phase, would be controlled by epithelioid cells involving zone 1 in recent granulomas. In zone 1, replacing periovular necrosis, an initialy loose and tracery connective neoformation, housing stellate cells or with fusiform nuclei, a dense paucicellular nodular connective tissue emerges, probably induced by fibroblasts. In several granulomas, one of the zones is missing and granuloma is represented by two of them: Z3 and Z2, Z3 and Z1 or Z2 and Z1 and, ultimately, by a scar.
authors.affiliation: Departamento de Anatomia Patológica e Medicina Legal, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Raso
authors.forename: Leonardo Arruda Moraes
authors.initials: LA
authors.lastname: Raso
authors.forename: Ferdinan de Almeida
authors.initials: Fde A
authors.lastname: Melo
authors.forename: Wagner Luiz
authors.initials: WL
authors.lastname: Tafuri
mesh_terms: D000328:Adult; D000818:Animals; D005355:Fibrosis; D006099:Granuloma / Q000469:parasitology / Q000473:pathology*; D006801:Humans; D056747:Immunomodulation / Q000502:physiology; D007411:Intestinal Diseases, Parasitic / Q000469:parasitology / Q000473:pathology*; D008099:Liver / Q000469:parasitology / Q000473:pathology; D008109:Liver Diseases, Parasitic / Q000473:pathology; D008297:Male; D058069:Neglected Diseases / Q000469:parasitology / Q000473:pathology*; D010532:Peritoneal Diseases / Q000473:pathology*; D012550:Schistosoma mansoni; D012555:Schistosomiasis mansoni / Q000276:immunology / Q000473:pathology*