title: Primary peritoneal mesotheliomas in children: a clinicopathological and immunohistochemical study of eight cases.
abstract: OBJECTIVE
  To present eight cases of primary diffuse peritoneal malignant mesothelioma in children <15 years old, with a discussion of the pitfalls of this diagnosis in the paediatric age group.
  
  
  RESULTS
  The cases were selected based on the following criteria: (i) primary peritoneal neoplasms confined grossly or radiographically to the abdominal cavity; (ii) negative history of previous or another associated malignancy; (iii) histopathological confirmation. All patients (five female, three male) presented clinically with symptoms of abdominal pain, distention and ascites. Grossly, the tumours showed multiple, diffuse peritoneal nodules. Histologically, seven cases corresponded to epithelioid mesotheliomas and one case displayed biphasic (epithelioid and spindle) cellular proliferation. Immunohistochemical studies for cytokeratin (CK) 5/6, calretinin and low-molecular-weight CK (CAM5.2) showed strong cytoplasmic positivity in the neoplastic cells. Three patients were treated by chemotherapy. On clinical follow-up, four patients with epithelioid mesotheliomas were alive and well from 12 to 18 months after initial diagnosis; one patient with a mixed (biphasic epithelioid/sarcomatoid) mesothelioma died of tumour 24 months after diagnosis.
  
  
  CONCLUSIONS
  Peritoneal malignant mesothelioma in children is a rare condition that can introduce difficulties in histopathological diagnosis.
authors.affiliation: Department of Pathology, M D Anderson Cancer Center, Houston, TX 77030, USA. cesarmoran@mdanderson.org
authors.forename: C A
authors.initials: CA
authors.lastname: Moran
authors.forename: J
authors.initials: J
authors.lastname: Albores-Saavedra
authors.forename: S
authors.initials: S
authors.lastname: Suster
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D064032:Calbindin 2; D002648:Child; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D053555:Keratin-5 / Q000032:analysis; D053553:Keratin-6 / Q000032:analysis; D007633:Keratins / Q000032:analysis; D008297:Male; D008654:Mesothelioma / Q000737:chemistry / Q000188:drug therapy / Q000473:pathology*; D010534:Peritoneal Neoplasms / Q000737:chemistry / Q000188:drug therapy / Q000473:pathology*; D064030:S100 Calcium Binding Protein G / Q000032:analysis
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; C576764:CALB2 protein, human; C400901:CAM 5.2 antigen; D064032:Calbindin 2; D053555:Keratin-5; D053553:Keratin-6; D064030:S100 Calcium Binding Protein G; D007633:Keratins