Nodular glomeruloid pleuroblastoma: a biphasic pleural-based malignant tumor with immature elements.

An unusual diffuse pleural-based tumor arising in an elderly asbestos-exposed male is presented. The tumor presented in a 72-year-old male with a 30-year history of dockyard work and likely significant asbestos exposure. Macroscopically, at post mortem, the pleural tumor diffusely encased the right lung and was composed of an admixture of neoplastic macro-, and by light microscopy, micro-nodules. Histologically, the tumor had a biphasic growth pattern with glomeruloid epithelioid elements and immature blastematous mesenchymal stroma. Immunophenotypically, the tumor had a complex pattern with epithelioid elements expressing cytokeratins, desmin, carcinoembryonic antigen (CEA), Ber EP4 and E-cadherin. The diagnostic problems and medicolegal issues surrounding the diagnosis and differentiation from malignant pleural mesothelioma and other tumors are discussed.