A Rare Type of Malignant Mesothelioma Reported by Japanese Doctors

Although malignant pleural mesothelioma is a rare and incurable cancer caused by exposure to asbestos, the disease is similar to many other types of cancer in the composition of tumor cells. However, in the Journal of Thoracic Imaging, Japanese researchers reported a rare case of mesothelioma even after treating a patient whose tumors had mesothelioma tissue resembled that found in cartilage and bone. 

Often called "asbestos cancer" mesothelioma is a cancer of mesothelial cells caused by inhaling asbestos fibers that lodge in the thin membrane that covers and surrounds the lungs. The cases of mesothelioma will continue to grow in Japan, and between 2,500 and 3,000 new cases are diagnosed each year in the United States. 

The male 69-year-old building contractor had been exposed to asbestos for 48 years and was diagnosed with malignant mesothelioma by CT scan and a biopsy of tissue. The man underwent extrapleural pneumonectomy, complex surgery involved the removal of the affected lung and the right parietal pleura and visceral pleura associated with the lung lining. 

The surgeons found the tumor had compressed the right lung, and I could feel hardened calcifications in the tumor and pleural tissue. Despite the removal of tumors and cancerous tissues, the spread of mesothelioma and the patient died 19 months after surgery. 

Symptoms of mesothelioma may not appear until 50 years after initial exposure to asbestos. However, after the onset of symptoms, mesothelioma can rapidly progress to cause life-threatening complications. The average survival time of mesothelioma varies 4-18 months after diagnosis. 

Japanese researchers, and other researchers hypothesized that cells of the mesothelium, the lining of the lungs, have multipotency-in other words, the potential to become any of several types of mature cells, including bone.