[A case of desmoplastic malignant pleural mesothelioma]

A 71-year-old woman with no history of asbestos exposure was referred to our hospital for evaluation of mediastinal soft tissue density. Six months prior to the admission, she had developed back pain and had been diagnosed as having intercostal neuralgia. Since the symptoms progressed, she was referred to another hospital. While chest radiography revealed no abnormality, chest computed tomography showed the prominence of mediastinal soft tissue, extending to the left hilum and partially destroying the nearby vertebrae. However, no pleural effusion was noted. After admission, a thoracoscopic examination was performed, and a whitish mass was found on the pleural surface partially adhering to the chest wall. Histological examination of the biopsied material showed dense areas of collagenous tissue with small foci of slightly atypical spindle cells. These findings led to the diagnosis of desmoplastic malignant pleural mesothelioma. The patient was treated with combined chemo-radiotherapy, but the response to this treatment was unclear. To date, reports for this subgroup of malignant mesothelioma are still rare.