Not only has the prevalence of malignant pleural mesothelioma (MPM) increased over the past 40 years, it is anticipated that the increase will continue because of the widespread use of asbestos from the 1940s to the end of the 1970s. MPM is a highly lethal neoplasm, and diagnosis is difficult because of the frequency of vague symptoms present over a long period of time. Chest radiography and computed tomographic (CT) scans can be helpful only in revealing the presence of pleural effusion. Enthusiasm for the use of pleural biopsy has waned, and other procedures such as percutaneous needle biopsy, fluoroscopy and CT biopsy have significant limitations. Heilo and associates assessed the clinical use of ultrasonographically (US)-guided core-needle biopsy performed with a one-hand automatic sampling technique in the diagnosis of MPM.
This retrospective study included 70 patients admitted to a single hospital over a 10-year period with a tentative diagnosis of MPM. All study participants underwent US-guided core-needle biopsy; punctures were made under local anesthesia. Automatic high-speed core biopsy equipment used different-sized needle-gun combinations. One to five needle punctures were made in 82 procedures.
Of the 70 patients, first-attempt biopsy facilitated the diagnosis of MPM in 40 patients and the diagnosis of other diseases in 16 patients. The US-guided core-needle biopsy had an accuracy rate in the detection of MPM of 80 percent, a positive predictive value of 100 percent and a negative predictive value of 57 percent. In two patients with MPM, the diagnosis was not 100 percent conclusive, but the histologic specimens showed a sarcomatous-type MPM. These patients were treated for MPM without further investigation.
In 14 patients, the biopsy specimen was inadequate. Twelve had MPM; two had another disease. Six patients did not undergo additional procedures but were treated for MPM based on prior biopsy. Eight patients underwent repeat procedures and in six of these patients, the correct diagnosis was determined. One of the two patients who did not have a conclusive diagnosis underwent surgical biopsy and was found to have MPM. The other patient underwent treatment for MPM based on clinical presentation.
No significant differences in diagnostic accuracy between the various needle-gun combinations was evident. Two minor complications occurred—mild hemoptysis and local chest pain that resolved within an hour. No skin metastases developed at the biopsy needle entry site over the study period.
Results of the study demonstrated that the US needle guidance technique is a quick and safe procedure. With US guidance, focal tumors and diffuse pleural thickening can be localized, regardless of the presence of pleural fluid, and biopsy can be performed.
The authors conclude that the best results are obtained when the biopsy is performed in the lateral costophrenic angle. Because of the presence of fluid in the pleural cavity in this region, the procedure is technically easier in this location. Tumor seeding or direct tumor growth through the chest wall is not evident with US-guided biopsy but is a potential complication of the other procedures used to obtain pleural biopsy specimens. Although surgically and thoracoscopically-guided biopsies have a higher accuracy rate than US-guided biopsy, the ease and low complication rate of US-guided tissue sampling offers an alternative choice for diagnosing MPM. As the US-guided technique is performed more frequently, accuracy will most likely improve.