The term 'pseudomesotheliomatous adenocarcinoma was coined for these lesions by Harwood et al.

History of asbestos exposure is present one study. A smoking history is present in more than 70% cases.

By light microscopy and immunophenotype many of the tumours mimicked malignant mesothelioma.

Age: Usually occurs in elderly patients.

Clinical symptoms: Chest pain, dyspnea, cough, infiltrative pleural tumour. The symptoms are indistinguishable from those of malignant mesothelioma.

Macroscopic features: Thick, fleshy pleural plaques and masses that extend along the pleura surface and encase the lung.

Microscopic features: Pleura is infiltrated by nests and sheets of cells ; Tumour may focally form glandular structures or tubulo-papillary structures ;  Psammoma bodies may be present ; Isolated glands may be present in a fibrous stroma.

Histochemistry: PAS -positive diastase resistant mucin or intracytoplasmic vacuoles are often present in the glandular lumen.

Immunohistochemistry: CEA & low molecular weight cytokeratins are positive in almost all cases. BER-EP4 and Leu M1 may also be positive.

Misdiagnosis of this tumour may have medico-legal implications in asbestos-related compensation claims.

Clinical comparison of diffuse malignant mesothelioma of the pleura and pseudomesotheliomatous carcinoma of the lung for each case.Kyobu Geka. 1999 Sep;52(10):836-9.

Pseudomesotheliomatous carcinoma of the lung with histochemical and immunohistochemical study.Acta Pathol Jpn. 1983 Mar;33(2):415-23.

Pseudomesotheliomatous carcinoma of the lung. A variant of peripheral lung cancer.Am J Clin Pathol. 1976 Feb;65(2): 159-67.

PULMONARY PATHOLOGY: Congenital Cystic Adenomatoid  Malformation ; Acute Respiratory Distress Syndrome  ;Sarcoidosis ;Bronchiolitis ; Emphysema ; Bronchial Asthma ;Chronic Bronchitis Pulmonary Alveolar Proteinosis ; Lipid Pneumonia ; Pulmonary Hypertension ;Pulmonary edema ;Pulmonary Infection ; Pneumococcal Pneumonia ; Haemophilus influenza Infection;Klebsiella Pneumoniae ; Mycoplasma Pneumonia ; Pneumocystis Pneumonia ; Legionellosis ; Localized Fibrous Tumour of the Pleura ; Biphasic Epithelial/Mesenchymal Lung Tumours ; Pulmonary Carcinosarcoma ;Pulmonary Blastoma ; Large Cell Neuroendocrine tumour;

Aetiology and Pathogenesis of Mesothelioma