To Image Screen or Not to Screen?
The following brief case vignette raises an important issue of incidental finding after screening imaging. In many instances, expensive and occasionally dangerous investigations are pursued. Nonfunctioning pituitary adenomas can be completely asymptomatic and detected at autopsy or after a head computed tomography (CT) or magnetic resonance imaging (MRI) scan, or visual field compromise.1 A recent report found a high rate of incidental abnormalities among individuals participating in research on brain MRI, raising bioethical issues.2 Brain MRI screening of asymptomatic patients regardless of age, health, or medical history is an example of an ineffective screening program that could produce many inconsequential findings. Valuable screening must either address a highly prevalent disease or be applied to high-risk individuals, and must accurately uncover a treatable disease.3 Chest CT angiograms ordered in the Emergency Department are more than twice as likely to find an incidental pulmonary nodule or adenopathy than a pulmonary embolism, suggesting that a systemic approach be developed to help primary care physicians contend with a growing number of new incidental pulmonary nodules.4 In many instances, this creates a “Hobson’s choice” for the physician.
Case Presentation
Dr. X, an 83-year-old physically active general internist and geriatrician in active clinical practice, was hospitalized in January 2004 with a 3-lobe pneumonia. Hypoxia and toxic encephalopathy were also part of the clinical presentation. The CT scan showed a sellar mass; a follow-up MRI with enhancement showed a macroadenoma of the pituitary gland with the mass extended in close proximity but not encroaching directly on the anterior optic chiasm. The mass also had spread to involve the right cavernous sinus and also encase the right internal carotid artery, but not causing narrowing. Past medical history revealed right hemicolectomy for a very large atypical villous adenoma 21 years previously and radiation for cancer of the prostate 20 years previously (with no recurrences to date). The patient had no history or clinical findings to suggest that any of the hormones of the anterior or posterior pituitary gland were being made in excess or were deficient. Following recovery from pneumonia, visual fields were found to be normal. Despite the absence of clinical symptoms to suggest an excess or deficiency of pituitary hormones, Dr. X’s primary care physician, also an endocrinologist, ordered blood tests for all of the pituitary hormones: prolactin; gonadotropin; testosterone; cortisol; and thyroid. The prolactin level was 1000 times normal! All of the other endocrine levels were normal. The diagnosis was functioning prolactinoma. A dopamine agonist was started, with prompt normalization of the prolactin level. The most recent MRI in January 2009 showed no changes. The patient is currently active in an administrative capacity at an academic medical center.
Dr. Finestone is Director, Institute on Aging, Associate Dean CME, Emeritus, Adjunct Professor of Medicine, Temple University School of Medicine, Philadelphia, PA, and Consortium Project Director, Geriatric Education Center of Pennsylvania Partially HRSA Funded (Consortium of University of Pittsburgh, Penn State University, and Temple University).
Acknowledgment
Uday Kanamalla, MD, Associate Professor of Radiology, Temple University School of Medicine, supplied the images and captions.
References
1. Molitch M. Pituitary tumours: Pituitary incidentalomas. Best Pract Res Clin Endocrinol Metab 2009;23:667-675.
2. Hoggard N, Darwent G, Capener D , et al. The high incidence and bioethics of findings on magnetic resonance brain imaging of normal volunteers for neuroscience research. J Med Ethics 2009;35:194-199.
3. Komotar RJ, Starke RM, Connolly E. Brain magnetic resonance imaging scans for asmptomatic patients: Role in medical screening. Mayo Clin Proc 2008;83:563-565.
4. Hall WB, Truitt SG, Scheunemann LP, et al. The prevalence of clinically relevant incidental findings on chest computed tomographic angiograms ordered to diagnose pulmonary embolism. Arch Intern Med 2009;169:1961-1965.