Management strategy of solitary pulmonary nodules

Solitary pulmonary nodules (SPNs) are increasingly detected with the widespread use of chest computed tomography (CT) scans. The management of patients with SPN should begin with estimating the probability of cancer from the patient’s clinical risk factors and CT characteristics. The decision-making process need to incorporate the probability of cancer, the potential benefits and harms of surgery, the accuracy of the available diagnostic tests and patient preferences. For patients with a very low probability of cancer, careful observation with serial CT is warranted. For patients in the intermediate range of probabilities, either CT-guided fine-needle aspiration biopsy (FNAB) or positron emission tomography (PET), is recommended. For those with a high probability of cancer, surgical diagnosis is warranted.KEYWORDS : Solitary pulmonary nodule (SPNs), ground-glass opacity (GGO), subcentimeter nodules, management strategyLung cancer is currently the leading cause of cancer deaths worldwide (1). Clinically, most patients are diagnosed at an advanced stage, with only about 15% have the opportunity of surgical resection. Early detection followed by surgical resection of stage I lung cancer may lead to a 5-year survival rate of 54-73%, while those with stage IV diseases have a 5-year survival rate of only 2% (2,3). With the established role of low-dose helical computed tomography (CT) screening for lung cancer (4-6), and the wide application of high-resolution CT, solitary pulmonary nodules (SPNs) are increasingly detected (7). Accurate assessment, proper treatment and timely surgical resection of malignant pulmonary nodules will be highly beneficial to the survival of patients with lung cancer. By reviewing the latest literature, combined with our experience in the clinical management of SPNs, we summarized the relevant clinical problems and treatment strategies in this review.     

Management strategies for the solitary pulmonary nodule

PURPOSE OF REVIEW: The challenge of diagnosis and management of solitary pulmonary nodules is among the most common yet most important areas of pulmonary medicine. Ideally, the goal of diagnosis and management is to promptly bring to surgery all patients with operable malignant nodules while avoiding unnecessary thoracotomy in patients with benign disease. RECENT FINDINGS: Effective management of the solitary pulmonary nodule depends upon an understanding of decision analysis principles so that diverse technologies can be integrated into a systematic approach. SUMMARY: In almost all patients computed tomography (CT) is the best first step. Three key questions can then help guide the workup of the SPN. These are what is the pretest probability of cancer, what is the risk of surgical complications, and does the appearance of the nodule on CT scan suggest a benign or malignant etiology. In patients with average surgical risk, positron emission tomography (PET) scan is warranted when there is discordance between pretest probability of cancer and the appearance of the nodule on CT scan. Thus, when either the patient has a low risk of cancer and the CT suggests a malignant origin, or when there is high risk of cancer and the CT appears benign, PET scan will be cost effective. In most other situations, PET scanning is only marginally more effective than CT and fine needle aspiration strategies but costs much more.     

Managing solitary pulmonary nodules. The choice of strategy is a "close call"

The best approach to the initial management of solitary pulmonary nodules is controversial. Using decision analysis, we compared the average life expectancy produced by alternative strategies for managing the patient with a solitary pulmonary nodule: thoracotomy for diagnosis and potential resection (IMMEDIATE SURGERY); needle aspiration biopsy or bronchoscopy (BIOPSY) followed by either thoracotomy or extended observation, depending on the results of the biopsy; and serial chest films with thoracotomy if the nodule grows at a potentially malignant rate (OBSERVATION). IMMEDIATE SURGERY produced a slightly longer average life expectancy when the probability of cancer was very high; BIOPSY had a narrow advantage when the probability of cancer was intermediate; and OBSERVATION produced slightly longer average life-expectancy when the probability of malignancy was very low. But the differences between strategies were so small that, in most circumstances, the decision was a "close call." Therefore, when choosing between these management strategies, physicians should give greater weight to considerations besides life expectancy, and should encourage patients to actively participate in the decisions about how to manage their solitary pulmonary nodules.     

A cost-minimization analysis of alternative strategies in diagnosing pancreatic cancer

BACKGROUND: Several modalities currently exist for tissue confirmation of suspected pancreatic cancer prior to therapy. Since there is a paucity of cost-minimization studies comparing these different biopsy modalities, we analyzed costs and examined effectiveness of four alternative strategies for diagnosing pancreatic cancer. METHODS: A decision analysis model of patients with suspected pancreatic cancer was constructed. We analyzed costs, failure rate, testing characteristics, and complication rates of four commonly employed diagnostic modalities: 1) computerized tomography or ultrasound-guided fine-needle aspiration (CT/US-FNA), 2) endoscopic retrograde cholangiopancreatography with brushings (ERCP-B), 3) Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA), and 4) laparoscopic surgical biopsy. If the first attempt with a particular modality failed, a different modality was employed to identify the most preferable secondary biopsy strategy. RESULTS: This analysis identifies EUS-FNA as the preferred initial modality for the diagnosis of pancreatic cancer. Resultant expected costs and strategies in decreasing optimality include: 1) EUS-FNA (1,405 dollars), 2) ERCP-B (1,432 dollars), 3) CT/US-FNA (3,682 dollars), and 4) surgery (17,711 dollars). If a patient presents with obstructive jaundice, decision analysis modeling resulted in a total expected costs of 1,970 dollars if ERCP-B is successful at the time of biliary stent placement. Additional analyses to identify the preferred follow-up modality after a failed alternative method showed that EUS-FNA is the preferred secondary modality if any of the other three modalities failed first, in both the setting of and absence of obstructive jaundice. One- and two-way sensitivity analysis of the variables shows unchanged results over an acceptable range. CONCLUSIONS: This cost-minimization study illustrates that EUS-FNA is the best initial and the preferred secondary alternative method for the diagnosis of suspected pancreatic cancer. In addition to local expertise and availability, costs and diagnostic yield should be considered when choosing an optimal diagnostic strategy.     

The cost effectiveness of dual phase 201Tl thyroid scan in detecting thyroid cancer for evaluating thyroid nodules with equivocal fine-needle aspiration results: the preliminary Taiwanese experience

The purposes of this study were to assess the helpfulness of dual phase 201Tl thyroid scan for differentiating malignant from benign thyroid lesions in cases of thyroid nodules with equivocal fine-needle aspiration (FNA) biopsy results. In addition, for thyroid nodules with equivocal FNA biopsy results, we try to make a decision analysis model compared the FNA biopsy alone strategy (strategy A) with decision strategy for the assistance of dual phase 201Tl thyroid scan (strategy B) before diagnostic thyroidectomy as thyroid cancer evaluation strategies for hypothetical cohorts of estimated 17,280-29,160 Taiwanese patients/per year with equivocal FNA biopsy results. Based on the findings of surgical histopathology, dual phase 201Tl thyroid scan sensitivity, specificity, and accuracy were 100%, 90%, and 96%, respectively, in cases of 27 thyroid nodules with equivocal FNA biopsy results. In cost effectiveness analysis, the strategy B showed a cost saving of 16,340,480-27,574,560 US dollars in unnecessary diagnostic thyroidectomy cost. The total cost of strategy B showed a cost saving of 13,932,232-23,520,564 US dollars than that of strategy A. The preliminary data indicate that dual phase 201Tl thyroid scan can save the cost of unnecessary diagnostic thyroidectomy in Taiwanese patients with equivocal FNA biopsy results. In addition, we may provide a noninvasive diagnostic method--dual phase 201Tl thyroid scan, as the first priority for Taiwanese patients with equivocal FNA biopsy before diagnostic thyroidectomy under the coverage of the national health insurance system in Taiwan.     

Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (FNA) of liver lesions.

BACKGROUND: Endoscopic ultrasonography (EUS) is not traditionally thought to be clinically applicable in liver imaging. EUS-guided fine-needle aspiration of the liver has not been well described. METHODS: A prospective study was conducted in which 574 consecutive patients with a history or suspicion of gastrointestinal or pulmonary malignant tumor undergoing upper EUS examinations underwent EUS evaluation of the liver. Fourteen (2.4%) patients were found to have focal liver lesions and underwent EUS-guided fine-needle aspiration. RESULTS: The median largest diameter of the liver lesions was 1.1 cm (range 0.8 to 5.2 cm). The mean number of passes was 2.0 (range 1 to 5 passes). All fine-needle passes yielded an adequate specimen. One of the 14 patients underwent EUS-guided fine-needle aspiration of 2 liver lesions. Fourteen of the 15 liver lesions sampled by means of EUS-guided fine-needle aspiration were malignant and one was benign. Before EUS, computed tomography (CT) depicted liver lesions in only 3 of 14 (21%) patients. Seven of 14 patients had a known cancer diagnosis. For the other 7, the initial diagnosis of cancer was made by means of EUS-guided fine-needle aspiration of the liver. There were no immediate or late complications. CONCLUSIONS: EUS can detect small focal liver lesions that are not detected at CT. Findings of EUS-guided fine-needle aspiration can confirm a cytologic diagnosis of liver metastasis and establish a definitive M stage that may change clinical management.     

Systematic inclusion of clinical and laboratory data improves diagnostic accuracy of fine-needle aspiration biopsy in solitary thyroid nodules.

In this study, we identified clinical and laboratory markers of malignant thyroid nodules and determined whether systematic inclusion of these data could improve diagnostic accuracy of fine-needle aspiration biopsy in solitary thyroid nodules. The patients were 24 men and 105 women who underwent surgical removal of solitary thyroid nodules and had adequate fine-needle aspiration biopsy performed prior to surgery. Including fine-needle aspiration biopsy's diagnosis of suspected of malignancy in the same category as malignancy, the sensitivity and specificity of fine-needle aspiration biopsy were 71.4% and 85.1%, respectively, with an accuracy of 82.2%. Using stepwise linear regression analysis, clinical data, i.e. increasing age, irregular nodule surface, hard consistency of nodule, and high serum thyroglobulin concentration, were associated with an increased risk of malignancy when the cytological result was excluded. When cytology was also considered, male sex, irregular nodule surface and high serum thyroglobulin concentration were found to be associated with an increased risk of malignancy. The diagnostic value of clinical data alone, even in combination with cytology or laboratory data, was inferior to that of fine-needle aspiration biopsy alone. The specificity and accuracy of fine-needle aspiration biopsy could be increased to 98.0% and 90.7%, respectively, whereas its sensitivity was decreased to 64.3% when these variables were considered in combination. Therefore, of fine-needle aspiration biopsy, clinical and laboratory data, fine-needle aspiration biopsy alone has the highest diagnostic value, which can be increased only when both clinical characteristics and serum thyroglobulin concentration are systematically included.     

Nontuberculous mycobacterial infections involving solitary pulmonary nodules]

Over the course of 11 years (1993-2003) we encountered 5 cases of pulmonary nontuberculous mycobacterium (NTM) involving a solitary pulmonary nodule. In this report we analyze the chest computed tomography (CT) of these patients, the utility of bronchoscope and transthoracic fine-needle aspiration techniques, the mycobacterium species involved, and treatment results. Four of the 5 NTM cases were due to infection with M. avium and one was due to infection with M. intracellulare. The characteristic findings of the chest CTs were as follows: A solitary nodule was present just under the pleura. No definite distribution pattern was evident. Some cases had agglutinated nodules or fine calcifications. Although fiberoptic bronchoscopy was not used as a diagnostic tool in all 5 NTM cases and histological samples did not contain granulomas, we determined the presence of NTM and we also verified that no cancer cells were present in any of the 5 NTM patients, using transthoracic fine-needle aspiration. Four out of the 5 NTM patients were treated only with drug therapy and they displayed clinical improvement. We resected a solitary nodule in one of the 5 NTM patients because of slow response to drug therapy. We conclude that the solitary pulmonary nodule of NTM is often due to M. avium and that transthoracic fine-needle aspiration is an easy and effective method of detecting NTM.     

Neoplastic superior vena caval obstruction: diagnosis with percutaneous needle aspiration

Obstruction of the superior vena cava arises from a spectrum of etiologies that include both benign and malignant conditions. Therefore, management of this serious disorder varies and depends on the underlying cause. Pursuit of a histologic diagnosis with invasive procedures has been associated with a wide range of diagnostic yields and complications. Percutaneous fine-needle aspiration biopsy has been shown to be highly reliable and well tolerated in the diagnosis of a variety of mediastinal and lung masses. Three patients are presented with obstruction of the superior vena cava in whom computed tomography safely guided percutaneous needle biopsy in obtaining a correct histologic diagnosis. It appears that transthoracic percutaneous needle aspiration biopsy is safe and efficacious in patients with superior vena cava syndrome, but further experience with this increasingly available procedure is warranted.     

Clinical Impact of Endoscopic Ultrasound and Endoscopic Ultrasound-Guided Fine-Needle Aspiration in the Management of Rectal Carcinoma

PURPOSE: There is scant data about the clinical impact of endoscopic ultrasound-guided fine-needle aspiration in rectal carcinoma. This study was designed to determine the impact of endoscopic ultrasound-guided fine-needle aspiration on the staging and management of rectal carcinoma and to compare the staging accuracy of computed tomography scan, endoscopic ultrasound, and endoscopic ultrasound-guided fine-needle aspiration. METHODS: The records of 60 consecutive patients diagnosed with rectal carcinoma referred for endoscopic ultrasound staging were reviewed. Computed tomography scans, endoscopic ultrasound imaging, endoscopic ultrasound-guided fine-needle aspiration staging, surgical pathology, and subsequent treatment were compared. RESULTS: Of 48 patients who underwent computed tomography scan imaging, the additional information provided by endoscopic ultrasound changed management in 38 percent of patients. Sixteen patients identified as having nonjuxtatumoral lymph nodes underwent fine-needle aspiration and the additional information obtained changed therapy in three (19 percent) of these patients. All five cases of recurrent rectal carcinoma were correctly diagnosed by fine-needle aspiration. Tumor staging accuracy was 45 percent (computed tomography) and 89 percent (endoscopic ultrasound; P < 0.0001); nodal staging accuracy was 68 percent (computed tomography), 85 percent (endoscopic ultrasound), and 92 percent (endoscopic ultrasound-guided fine-needle aspiration; P = not significant). CONCLUSIONS: Endoscopic ultrasound imaging was better than computed tomography scanning at overall tumor staging, whereas endoscopic ultrasound-guided fine-needle aspiration demonstrated a trend toward more accurate nodal staging. Preoperative staging with endoscopic ultrasound resulted in a change of management in 38 percent of patients. The addition of fine-needle aspiration changed the management in 19 percent of those who underwent nonjuxtatumoral lymph node sampling. Endoscopic ultrasound-guided fine-needle aspiration accurately diagnosed 100 percent of those with recurrent rectal carcinoma. Clearly, endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration are important for the staging and management of rectal carcinoma and for detecting disease recurrence.Presented at the EUS 13th International Symposium on Endoscopic Ultrasound, New York, New York, October 4 to 6, 2002     

Efficacy of ultrasound-guided fine-needle aspiration biopsy in the diagnosis of complex thyroid nodules.

Cystic thyroid nodules are considered to be one of the major causes of nondiagnostic and false-negative results on conventional fine-needle aspiration biopsy, thus limiting the potential of this method for the evaluation of complex (solid-cystic) thyroid nodules. Although ultrasound-guided fine-needle aspiration biopsy has emerged as a highly effective diagnostic method for the assessment of nonpalpable and difficult to palpate nodules, its role in complex nodules has not yet been carefully evaluated. In this study, we report the efficacy of ultrasound-guided fine-needle aspiration biopsy in 124 complex nodules in 113 patients. This method proved to be highly effective, yielding a satisfactory specimen for cytological evaluation in 94% of the nodules, suggesting that it is an excellent modality for the evaluation of complex nodules and also for the reevaluation of those nodules with a nondiagnostic result on conventional fine-needle aspiration biopsy.     

Radiologische Abklärung pulmonaler Rundherde

Solitary pulmonary nodules (SPN) are a frequent diagnostic problem in the clinical routine. The main aim of the management of patients with SPNs is to differentiate malignant from benign nodules with a high level of confidence. Knowledge of the pretest probability of malignancy is essential. Recently, the radiological morphology has been expanded to differentiate solid, semi-solid and ground glass nodules by the density in computed tomography (CT). In addition, diagnostic algorithms are well established for small SPNs ≤ 8 mm and normal sized SPNs > 8 mm in diameter. For normal SPNs the presence of homogeneous calcification and lack of growth are highly suggestive of a benign lesion. For the indeterminate small SPNs CT follow-up is recommended, at time intervals depending on the size, pretest probability for malignancy and CT morphology. Calculation of tumor doubling times with CT-based 3D volumetry of SPNs has recently been included in the clinical routine. For the indeterminate SPNs > 8 mm the management should be based on the pretest probability for malignancy, with CT follow-up, functional imaging, guided biopsy for fine tissue diagnostics and possibly surgical removal as diagnostic options.     

Solitary pulmonary nodule evaluation with 99mTc-methoxy isobutyl isonitrile in a tuberculosis-endemic area.

High prevalence of tuberculosis increases the odds for nonmalignant solitary pulmonary nodules (SPNs). Positron emission tomography (PET) using (18)F-fluorodeoxyglucose is the method of choice for the identification of malignant SPNs requiring curative surgery. However, PET is not widely available. Technetium-99m methoxy isobutyl isonitrile (MIBI) is inexpensive, widely available and shows increased uptake in malignant SPNs. The aim of the present study was to prospectively evaluate the diagnostic value of MIBI single photon emission computed tomography to distinguish between benign and malignant SPNs in a tuberculosis-endemic area. In total, 49 patients with radiologically indeterminate SPNs (single lesion < or =6 cm in diameter) were prospectively evaluated with MIBI. The final diagnosis was established with bronchoscopy, fine-needle aspiration, surgical resection or clinical follow-up for > or =2 yrs. A total of 12 (92%) out of 13 malignant lesions showed increased uptake of MIBI, while no uptake was observed in 33 (92%) out of 36 benign lesions. MIBI uptake indicated malignancy with a sensitivity and specificity of 92% and a negative predictive value of 97%. In this tuberculosis-endemic area, technetium-99m methoxy isobutyl isonitrile single photon emission computed tomography evaluation of solitary pulmonary nodules had a high negative predictive value. Therefore, it has the potential to prevent unnecessary surgical resections of benign nodules and serve as a low-cost alternative when positron emission tomography is not available.     

Fine-needle aspiration cytology of abdominal wall scar lesions for diagnosing recurrent colorectal cancer.

Nodules in the abdominal wall scar after resection of colorectal cancer may represent nonmalignant or malignant lesions. We report clinical and fine-needle aspiration (FNA) cytologic findings in five patients with nodules suspected of being malignant. All patients had had adenocarcinoma, four of the colon and one of the rectum. Postoperative abdominal wall irradiation had been administered to three patients. The median time from surgical removal of the cancer to FNA of scar nodules was 27 months. Three patients had malignant and two patients had nonmalignant FNA cytology, histologically confirmed at surgical biopsy of scar nodules. The malignant histologic cell type demonstrated by FNA cytology of the scar lesions was identical to that exhibited by histology. The survival of patients with positive cytology and histology ranged between 9 and 43 months; survival of patients with negative cytology and histology was between 53 and 138 months. We conclude that FNA cytology is a simple, sensitive, and specific procedure to evaluate patients with scar nodules appearing after resection of colorectal cancer. This procedure may safely replace surgical biopsy in the initial evaluation of scar nodules.     

Pulmonary Extranodal Natural Killer/T-Cell Lymphoma (Nasal Type): A Case Report and Radiological Image Review

An 83-year-old woman presented with intermittent fever for 2 weeks. Chest radiography and computed tomography images showed multiple nodules and masses scattered in both lung fields. Tissue samples obtained by computed tomography-guided needle biopsy revealed extranodal natural killer/T-cell lymphoma (ENKL). The lung is the major site of involvement and the skin may be the primary site. The radiological imaging of this case is different from the cases reported before. Besides, we reviewed the medical records of our hospital and searched the Pubmed database and found 12 cases altogether (include the case presented), which were diagnosed with pulmonary ENKL, and the features of chest images were studied. To our knowledge, this is the first time that the chest imaging features of pulmonary ENKL were reviewed. We conclude that if the radiographic manifestations are multiple patchy consolidations or multiple nodules and masses in both lungs with or without bilateral pleural effusions, the diagnostic considerations should include ENKL.     

Continuing controversies in the management of thyroid nodules

Although thyroid nodules are common, few are malignant and require surgical treatment. A systematic approach to their evaluation is important to avoid unnecessary surgery. Fine-needle aspiration biopsy has resulted in substantial improvements in diagnostic accuracy, cost reductions, and higher malignancy yield at time of surgery. The preferred approach when repeated fine-needle aspiration biopsy fails to yield an adequate specimen remains a challenge. Management of patients with nodules "suspicious for follicular neoplasm" is difficult, since only 15% to 20% of such lesions have been shown to be malignant. Immunohistochemical markers, such as galectin-3 and human bone marrow endothelial cell (HBME-1), have shown promise in preliminary studies. Routine calcitonin measurement in patients with thyroid nodules has been advocated for early detection of medullary thyroid cancer. However, the low frequency of this cancer, coupled with the high cost associated with case detection, has resulted in a lack of general acceptance of this recommendation.     

Ultrasound-guided aspiration biopsy of small peripheral pulmonary nodules.

We compared the diagnostic yields of ultrasound-guided aspiration biopsy, sputum cytology, and fiberoptic bronchoscopy with biopsy in 30 patients with peripheral pulmonary nodules smaller than 3.0 cm in diameter. Among them, there were 4 minute nodules with diameter less than 1.0 cm, 12 between 1.1 to 2.0 cm, and 14 between 2.1 to 3.0 cm. The final diagnoses in these 30 patients, as confirmed by histologic findings, microbiology, and clinical follow-up, revealed 24 malignant lesions and 6 benign. All of these 30 nodules received ultrasound-guided transthoracic fine-needle aspiration biopsy, and confirmative diagnoses were obtained in 27 (90 percent). Twenty-two (92 percent) of 24 patients with malignant nodules had positive cytology for malignancy and 5 (83 percent) of 6 patients with benign lesions had diagnosis made by cytologic and microbiologic examinations. One patient developed asymptomatic pneumothorax after needle aspiration. The size of the lesions did not affect the diagnostic yield and complication rate. None of the lesions was diagnosed by sputum cytology (0 of 19; 0 percent). Two patients had diagnoses obtained by fiberoptic bronchoscopy with biopsy (2 of 10; 20 percent). We conclude that ultrasound-guided aspiration biopsy is a useful and safe method for diagnosis of peripheral pulmonary nodules, even when the size of the nodule is less than 3 cm in diameter. The diagnostic yield far exceeds that which can be obtained by sputum cytology and fiberoptic bronchoscopy with biopsy.     

Bilateral thyroid hematomas after fine-needle aspiration causing acute airway obstruction.

BACKGROUND: Fine-needle aspiration of the thyroid gland is a common procedure that is increasingly being used to evaluate thyroid nodules incidentally found by other imaging means such as computed tomography scans. Rare complications include hematoma, transient vocal cord paralysis, seeding of carcinoma cells, and infection. Of these, hematoma is the most common and is usually small and adequately treated with compression of the site. Only two cases have been previously reported describing large thyroid hematoma after fine-needle aspiration resulting in acute airway compromise and requiring surgical decompression. SUMMARY: We report an interesting case of large bilateral thyroid hematomas after routine fine-needle aspiration causing acute airway obstruction in a patient with hypertension and end stage renal disease taking aspirin.     

Transthoracic needle aspiration biopsy: value in the diagnosis of mycobacterial lung opacities.

The purpose of this study was to assess the value of transthoracic fine-needle aspiration in the diagnosis of mycobacterial infection as the cause of focal lung opacities. Six hundred twelve fine-needle aspiration biopsies were performed from 1985 to 1997 in 587 patients with solitary or multiple lung opacities. Initial procedures, including sputum analysis and bronchoscopy, had been nondiagnostic. Fluoroscopic or computed tomography guidance was used, and a pathologist was present. A diagnosis of mycobacterial infection was established when acid-fast bacilli were demonstrated in the aspirate. In 487 patients, a malignant cause was confirmed, and six other patients had carcinoid tumor. Of 94 nonmalignant opacities, 24 (26%) were determined to have a mycobacterial cause. Fine-needle aspiration biopsy detected acid-fast bacilli in 15 of 24 cases (sensitivity, 62.5%; specificity, 100%). Radiologic findings included upper lobe involvement (17 of 24 cases), single opacities (12 of 24 cases), satellite nodules (4 of 12 cases with single opacities), irregular borders (19 of 24), eccentric calcification (2 of 24), and cavitation (8 of 24). The authors conclude that fine-needle aspiration biopsy must be processed for acid-fast bacilli when nonmalignant cytologic findings result, even if the results of sputum smears, cultures, and bronchoscopy are negative.     

PEEP and pulmonary edema

We studied the impact of fine-needle aspiration biopsy on the management of patients with solitary thyroid nodules. Sixty-four patients were examined before the introduction of fine-needle aspiration biopsy, and 147 patients were examined after its introduction. The percentage of patients who underwent thyroid operation decreased from 67 percent to 43 percent, while the yield of carcinoma increased from 14 percent to 29 percent. Cost of medical care per patient declined by 25 percent. The results suggest that fineneedle aspiration biopsy provides valuable information to assist in the selection for surgery of patients with solitary nodules. Fineneedle aspiration appears to be safe, reliable, and cost-effective. The merits of the technique commend it for routine use in the evaluation of thyroid nodules.