Document 7Mnq25EZRxyvqMvGnn9bZOK8j

:h*++ THE NEW ENGLAND JOURNAL OF MEDICINE .July 74 IMO CURRENT CONCEPTS be the only causative factor -eventually implicated (n Malignant Mesothelioma mesothelioma, since onv 7.2 per cent of asbestos workers have the disease* and approximately halTthc I^are^i Hamm Antman, M.D. reported patients have no documented asbestos ex posure. Peritoneal primary lesions are common in pa tients reporting heavy exposure.1-* whereas pleural DURING the two decadet tince the association of asbestos and mesothelioma became established, primary lesions predominate in the much larger number of transiently exposed patients; the overall ubstantial progress, has been made in the under*ratio of pleural to peritoneal primary mesothelioma Ts standing of the biology of this previously -rare neo about 3:1.* Reflecting this heavier exposure, asbesto- plasm. The causative role of asbestos exposure has sis (calcified pleural plaques and interstitial fibrosis) been extensively investigated, and populations at in can be delected in half the patients with peritoneal creased risk have been identified.1 Observation of the primary lesions, but only 20 per cent of patients with natural history of mesothelioma reveals that in con pleural primary lesions.* trast to patients with the other sarcomas, who generally die of homatogenously disseminated metastases, patients with mesothelioma succumb to com Clinical Presentation anp Diagnosis plications of their primary lesions.' With more ap Two thirds of patients with mesothelioma arc be propriate treatment regimens designed specifically for tween the ages of 40 and 70 years.* Exposure to as mesotheliomas, series in single institutions have es bestos can seldom be demonstrated in children with tablished that mesotheliomas respond to available mesothelioma; however, patients between 20 and 40 treatment and that substantial palliation of symp years of age frequently have a parent employed in an toms with a small number of long-term, disease-free survivors results. This report reviews the epidemiol ogy, natural history, and pathology of mesothelioma, asbestos industry.'-' Ninetv-five per cent of patients with mesothelioma will first note tne insidious onset of pain or shortness oI breath.* The pain is non- with emphasis on current management and ongoing pleuritic, aching, and frequently referred to the upper clinical trials, I abdomen or shoulder, occasionally prompting an in correct diagnosis of cardiac, orthopedic, or gallblad | Emdimioiocy der disease.* Fascinating but rare presentations have included intermittent hypoglycemia and hypertro Asbestos is a silicate mineral Tiber found in a variety phic pulmonary osteoarthropathy,*' both of which of industrial products, including insulation, roofing are more commonly associated with the benign and ceiling tiles, and brake linings, and in various variant of mesothelioma.*-' . small appliances. Asbestos presents a substantial risk Except for signs of dullness at the site of the lesion to health, however, only when crushed crystals are and occasional finger clubbing, initial physical ex aerosolized and inhaled.1 Not only are people who amination it generally negative.'-* Patients appear work directly with asbestos at risk, but a substantial well, arid many have been initially reassured and sent ' "bystander" risk has also been documented. Meso home. A delay of four to six months frequently occurs thelioma has| developed in engineers, construction between onset of symptoms and accurate diagnosis.* workers, and even secretaries employed in asbestos A chest film when the patient first seeks medical at- mines and mills or in shipyards where asbestos is t'ention, nowever, almost invariably reveals a unilat Used. An increased risk has been documented in eral pleural effusion.5-^-11'noracentesis yields an exu persons residing in areas surrounding asbestos mines date that may be hemorrhagic.'*' Pleural-fluid and mills and in family members of asbestos workers hyaluronic acid levels afrove 0.8 mg P^r milliliter are (who are presumably exposed to asbestos on hair and reported to establish the diagnosis of mesothelioma.1 clothes brought into the home).' However, the majority of patients with mesothelioma A`threshold'below which exposure to asbestos it have intermediate hvaluronic acid levels, also fre aafe or above which exposure to^sbestos is rianr'cr'ous quently seen in metastatic carcinoma. Neither pleu has not been demonstrated.1 Many patients have ral-fluid cytology nor needle biopsy consistently yields reported only a few months of incidental exposure. a definitive diagnosis of mesothelioma and, more fre The percentage of mesothelioma patients exposed quently, they prompt a misleading diagnosis of adeno- to asbestos ranges from 10 per cent in a series from the carcinoma.''* Bronchoscopy and sputum cytology are mid-western United States,' where no substantial as useful only to rule out a bronchogenic prim-try lesion. bestos-using industry exists, to VO per cent in New Thoracotomy is generally required to obi . ii an ade England,' England,* and South Africa, where ship quate specimen for histologic examination.'-*-' A yards or asbestos mines are located. Asbestos may not small portion of the biopsy specimen should be placed in glutaraldchvde (or formaldehyde) for electron mi Fom ihc Diviiion of Mrdicil Oncology. Sidney Forber Oncer Inituutc, nd the Dcpinmrni of Medicine, Peter Bent Bfigh>n; Hospital and Harvard Medical School. Boston (address reprint requests 10 Or. Amman at the Sidney farber Cancer Institute. 44 Binncy St., Boston, MA C2JIH Supported by (he Johanna C. Wood Foundation. croscopy if later indicated in any patient with a clinic,-il presentation consistent with mesothelioma. Computerized axial tomography has recently proved promising in documenting the extent of disease. 8005 0032 uraaw PRODUCED BY FORD