FISH Analysis of Intrapulmonary Malignant Mesothelioma without a Clinically Detectable Primary Pleural Lesion: An Autopsy Case

Abstract

Patients with malignant mesothelioma typically present with a pleural effusion or pleural thickening and masses. A rare autopsy case of mesothelioma presenting with multiple bilateral lung nodules without clinically detectable pleural lesions is presented. A definitive diagnosis of the video-assisted thoracic surgery specimen could not be made, though a pattern of fibrosis mimicking organizing pneumonia was identified. Despite corticosteroid therapy, follow-up chest computed tomography showed enlargement of multiple nodules accompanied by the appearance of pleural thickening and effusions. The patient died of respiratory failure 11 months after initial presentation. Autopsy and retrospective analysis of the video-assisted thoracic surgery specimen using a p16 fluorescence in situ hybridization assay showed p16 homozygous deletion. The final diagnosis was sarcomatoid mesothelioma, and the lung nodules were intrapulmonary metastases from a clinically undetectable pleural sarcomatoid mesothelioma. It is important both to consider the possibility of mesothelioma with unusual clinical, radiological and pathological presentations and to remember that p16 fluorescence in situ hybridization analysis can play an important role in the diagnosis of mesothelioma.

Localized intrapulmonary desmoplastic mesothelioma: A case report

“…Desmoplastic mesothelioma is a relatively rare histological subtype of mesothelioma with sarcomatoid histology (1) arising most frequently in the pleura, peritoneum or pericardium and less frequently in organs such as lung, spleen [4], pancreas [5] and liver [6]. In fact, few cases of intrapulmonary malignant mesothelioma have been described [2,3,7,8] presenting with bilateral miliary pulmonary nodules and diffuse bilateral opacities or characterized by diffuse intrapulmonary growth, among which some cases [7,8] were pathologically con irmed as intrapulmonary metastases from a clinically undetectable pleural mesothelioma, while the others [2,3] were diagnosed as diffuse intrapulmonary malignant mesothelioma. However, we described an unusual presentation of intrapulmonary mesothelioma characterized by a localized mass without pleural lesions.…”

Rare presentation of a localised malignant pleural mesothelioma with cranial metastasis

“…MM has two forms; diffused and localised. LMPMs are very rare and could present with diffuse parenchymal infiltration without clinically or radiologically detectable pleural lesions 8. Localised forms are difficult to diagnose 9.…”