Aggressive Malignant Mesothelioma In A Patient Without Previous Asbestos Exposure

摘要

We describe an 80-year-old male with a history of idiopathic lung fibrosis who was feeling generally unwell over a few weeks. Tissue biopsy from a rapidly growing ulceratedskin lesion on the abdomen showed a malignant epithelioid tumour positive for epithelial, mesothelial and embryonal tumour markers. The patient deteriorated rapidly and passed away. A post mortem examination was carried out and revealed thickened right pleura with multiple intra and extra-thoracic metastatic deposits. Histology of the pleural thickening and the multiple deposits were identical to that seen in the skin. The diagnosis of malignant epithelioid mesothelioma with rhabdoid features was made on histology. This is a rare case of malignant metastatic mesothelioma with ectopic hCG production and rhabdoid morphology in a patient without previous asbestos exposure. Introduction Malignant mesothelioma is an uncommon, pleural tumour which accounted for 2% of all cancer deaths in the UK in 2014 (1). Approximately seven new cases are reported every day in the UK and the incidence is increasing (1). A majority of pleural mesotheliomas are related to asbestos exposure with a long latency period (2). Malignant mesotheliomas uncommonly give rise to clinically detected metastases with a small number of distant subcutaneous metastasis cases reported (3). Only a handful of malignant mesothelioma cases showing rhabdoid morphology have been reported (4). Malignant mesothelioma with ectopic hCG (human chorionic gonadotropin) production is rare though described in literature (5, 6). We report a case of metastatic malignant mesothelioma presenting with a skin lesion in a patient without previous exposure to asbestos.We also report malignant mesothelioma associated with ectopic production of hCG and rhabdoid morphology, both of which are rare features and have not been reported together before. Case report An 80-year-old retired banker with multiple medical comorbidities including idiopathic lung fibrosis was admitted to hospital for feeling generally unwell in the last few weeks. He was a non-smoker and had no previous history of exposure to asbestos. He was under the care of the respiratory physicians for his lung condition and had been on an anti-fibrotic agent, Pirfenidone for the last two years. He remained clinically stable whilst on this agent. He was last seen in the respiratory clinic one month prior to feeling unwell when he was recruited for a pharmacokinetics drug trial. This trial lasted for one week where he was on both Pirfenidone and Nintedanib. Both drugs were stopped when his blood test results showed an increase in inflammatory markers. He was briefly admitted for pneumonia and then discharged. Three days after his discharge, he became progressively poorly and was readmitted.During this admission, he was found to have massive right pleural effusion and a chest drain was inserted. The pleural fluid was sent for cytology and the result was reported as blood only. An ulcerated skin lesion (figure 1) was identified on his abdomen which the patient noticed only a few weeks ago.