Solitary Pulmonary Nodules: Part I. Morphologic Evaluation for Differentiation of Benign and Malignant Lesions
Abstract
The solitary pulmonary nodule is a common radiologic abnormality that is often detected incidentally. Although most solitary pulmonary nodules have benign causes, many represent stage I lung cancers and must be distinguished from benign nodules in an expeditious and cost-effective manner. Evaluation of specific morphologic features of a solitary pulmonary nodule with conventional imaging techniques can help differentiate benign from malignant nodules and obviate further costly assessment. Small size and smooth, well-defined margins are suggestive of but not diagnostic for benignity. Lobulated contour as well as an irregular or spiculated margin with distortion of adjacent vessels are typically associated with malignancy. There is considerable overlap in the internal characteristics (eg, attenuation, cavitation, wall thickness) of benign and malignant nodules. The presence of intranodular fat is a reliable indicator of a hamartoma. The presence and pattern of calcification can also help differentiate benign from malignant nodules. Computed tomography (CT) (particularly thin-section CT) is 10–20 times more sensitive than standard radiography and allows objective, quantitative assessment of calcification. Initial evaluation often results in nonspecific findings, in which case nodules are classified as indeterminate and require further evaluation to exclude malignancy. Growth rate assessment, Bayesian analysis, contrast material–enhanced CT, positron emission tomography, and transthoracic needle aspiration biopsy can be useful in this regard.
References
- 1 Khouri NF, Meziane MA, Zerhouni EA, Fishman EK, Siegelman SS. The solitary pulmonary nodule. Chest 1987; 91:128-133. Crossref, Medline, Google Scholar
- 2 Viggiano RW, Swensen SJ, Rosenow EC, III. Evaluation and management of solitary and multiple pulmonary nodules. Clin Chest Med 1992; 13:83-95. Crossref, Medline, Google Scholar
- 3 Lillington GA. Disease-a-Month 37th ed. St Louis, Mo: Mosby–Year Book, 1991; 271-318. Medline, Google Scholar
- 4 Midthun DE, Swensen SJ, Jett JR. Approach to the solitary pulmonary nodule. Mayo Clin Proc 1993; 68:378-385. Crossref, Medline, Google Scholar
- 5 Holin SM, Dwork RE, Glaser S, Rikli AE, Stocklen JB. Solitary pulmonary nodules found in a community-wide chest roentgenographic survey. Am Rev Tuberc 1959; 79:427-439. Medline, Google Scholar
- 6 Higgins GA, Shields TW, Keehn RJ. The solitary pulmonary nodule. Arch Surg 1975; 110:570-575. Crossref, Medline, Google Scholar
- 7 Gomstock GW, Vaughan RH, Montgomery G. Outcome of solitary pulmonary nodules discovered in an x-ray screening program. N Engl J Med 1956; 254:1018-1022. Crossref, Medline, Google Scholar
- 8 Lillington GA, Caskey CI. Evaluation and management of solitary and multiple pulmonary nodules. Clin Chest Med 1993; 14:111-119. Crossref, Medline, Google Scholar
- 9 Gurney JW. Determining the likelihood of malignancy in solitary pulmonary nodules with Bayesian analysis. Radiology 1993; 186:405-413. Link, Google Scholar
- 10 Steele JD, Kleitsch WP, Dunn JE, Jr, Buell P. Survival in males with bronchogenic carcinomas resected as asymptomatic solitary pulmonary nodules. Ann Thorac Surg 1996; 2:368-376. Google Scholar
- 11 Jackman RJ, Good CA, Claggett OT, Woolner LB. Survival rates in peripheral bronchogenic carcinomas up to four centimeters in diameter presenting as solitary pulmonary nodules. J Thorac Cardiovasc Surg 1969; 57:1-8. Crossref, Medline, Google Scholar
- 12 Zwirewich CV, Vedal S, Miller RR, Müller NL. Solitary pulmonary nodule: high-resolution CT and radiologic-pathologic correlation. Radiology 1991; 179:469-476. Link, Google Scholar
- 13 Zerhouni EA, Stitik FP, Siegelman SS, et al. CT of the pulmonary nodule: a cooperative study. Radiology 1986; 160:319-327. Link, Google Scholar
- 14 Siegelman SS, Khouri NF, Leo FP, Fishman EK, Braverman RM, Zerhouni EA. Solitary pulmonary nodules: CT assessment. Radiology 1986; 160:307-312. Link, Google Scholar
- 15 Siegelman SS, Zerhouni EA, Leo FP, Khouri NF, Stitik FP. CT of the solitary pulmonary nodule. AJR 1980; 135:1-13. Crossref, Medline, Google Scholar
- 16 Erasmus JJ, Gilkeson RC, Goodman PC, McAdams HP, Murray JG, Patz EF, Jr. Chest imaging. In: Provenzale JM, Nelson RC, eds. Duke radiology case review: imaging, differential diagnosis, and discussion. Philadelphia, Pa: Lippincott-Raven, 1998; 1-57. Google Scholar
- 17 Sider L. Radiographic manifestations of primary bronchogenic carcinoma. Radiol Clin North Am 1990; 28:583-597. Medline, Google Scholar
- 18 Theros EG. Varying manifestations of peripheral pulmonary neoplasms: a radiologic-pathologic correlative study. AJR 1977; 128:893-914. Crossref, Medline, Google Scholar
- 19 Weisbrod GL, Towers MJ, Chamberlain DW, Herman SJ, Matzinger FRK. Thin-walled cystic lesions in bronchioalveolar carcinoma. Radiology 1992; 185:401-405. Link, Google Scholar
- 20 Lee KS, Kim Y, Han J, Ko EJ, Park C, Primack SL. Bronchioloalveolar carcinoma: clinical, histopathologic, and radiologic findings. RadioGraphics 1997; 17:1345-1357. Link, Google Scholar
- 21 Woodring JH, Fried AM. Significance of wall thickness in solitary cavities of the lung: a follow-up study. AJR 1983; 140:473-474. Crossref, Medline, Google Scholar
- 22 Woodring JH, Fried AM, Chuang VP. Solitary cavities of the lung: diagnostic implications of cavity wall thickness. AJR 1980; 135:1269-1271. Crossref, Medline, Google Scholar
- 23 Siegelman SS, Khouri NF, Scott WW, Jr, et al. Pulmonary hamartoma: CT findings. Radiology 1986; 160:313-317. Link, Google Scholar
- 24 Bennett LL, Lesar MSL, Tellis CJ. Multiple calcified chondrohamartomas of the lung: CT appearance. J Comput Assist Tomogr 1985; 9:180-182. Crossref, Medline, Google Scholar
- 25 Oldham HN, Jr, Young WG, Jr, Sealy WC. Hamartoma of the lung. J Thorac Cardiovasc Surg 1967; 53:735-742. Crossref, Medline, Google Scholar
- 26 Ledor K, Fish B, Chaise L, Ledor S. CT diagnosis of pulmonary hamartomas. J Comput Assist Tomogr 1981; 5:343-344. Crossref, Google Scholar
- 27 Mahoney MC, Shipley RT, Corcoran HL, Dickson BA. CT demonstration of calcification in carcinoma of the lung. AJR 1990; 154:255-258. Crossref, Medline, Google Scholar