title: Nodular histiocytic/mesothelial hyperplasia as consequence of chronic mesothelium irritation by subphrenic abscess.
abstract: OBJECTIVE
  Pleural nodular histiocytic/mesothelial hyperplasia is a nodular histiocytic/mesothelial proliferation, often delimiting cystic cavities, due to irritation by a pulmonary noxa. Case report results: The patient had right pleural parietal and diaphragmatic thickness, with pleural effusion, without lung alterations. He previously underwent left hemicolectomy and liver resection, due to a diverticulitis and a liver histiocytes-rich abscess. Video-assisted thoracoscopy biopsy showed a double population of reactive mesothelial cells and histiocytes.
  
  
  CONCLUSIONS
  Nodular histiocytic/mesothelial hyperplasia represents a potential pitfall for pathologists. Immunohistochemistry is crucial for the differential diagnosis with some malignancies. We suggest that in our patient, a chronic mesothelium inflammation happened by transdiaphragmatic involvement as a consequence of the liver abscess. Some pathogenetic mechanisms are hypothesized.
authors.affiliation: Department of Pathology, Piazza delle Cliniche, Universita, Palermo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Cabibi
authors.affiliation: Department of Thoracic Surgery, University of Palermo.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Lo Iacono
authors.affiliation: Department of Thoracic Surgery, University of Palermo.
authors.forename: Francesco
authors.initials: F
authors.lastname: Raffaele
authors.affiliation: Department of Thoracic Surgery, University of Palermo.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Dioguardi
authors.affiliation: Department of Pathology, Piazza delle Cliniche, Universita, Palermo, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Ingrao
authors.affiliation: Department of Pathology, Piazza delle Cliniche, Universita, Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pirrotta
authors.affiliation: Department of Thoracic Surgery, University of Palermo.
authors.forename: Federica
authors.initials: F
authors.lastname: Fatica
authors.affiliation: Department of Thoracic Surgery, University of Palermo.
authors.forename: Massimo
authors.initials: M
authors.lastname: Cajozzo
mesh_terms: D001706:Biopsy; D004848:Epithelium / Q000473:pathology*; D006644:Histiocytes / Q000473:pathology*; D006801:Humans; D006965:Hyperplasia / Q000209:etiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010994:Pleura / Q000473:pathology; D013369:Subphrenic Abscess / Q000150:complications*
keywords: VATS; mesothelial hyperplasia; pleural effusion