The increasing frequency with which incidentalomas occur has become a worldwide problem. Here are just a few percentages from various nations that quantify the frequency of incidentalomas among specific patient groups: Greece, 34 % of patients with stable blunt trauma (Sgourakis et al. 2011); the Netherlands, 35 % of patients with thoracoabdominal blunt trauma (van Vugt et al. 2012); Ireland, 67 % of patients undergoing emergency abdominal CT scans (Redmond et al. 2015); and the USA, 49 % of patients undergoing aortoiliac CT angiography (Apfaltrer et al. 2012), 82 % of patients being imaged by CT for staging of prostate cancer (Elmi et al. 2012), 40 % of patients undergoing research imaging exams at the Mayo Clinic (Orme et al. 2010), 34 % of patients undergoing MR imaging in a large neuroimaging research project (Shoemaker et al. 2011), and up to 67 % of patients undergoing ultrasound of the neck (Hoang et al. 2015). Welch has summarized the appearance of incidentalomas as follows: 50 % in the lungs on chest CTs, 23 % in the kidneys and 15 % in the liver on abdominal CTs, and 67 % in the thyroid gland on ultrasound of the neck (Welch et al. 2011). His comprehensive review of the radiologic literature disclosed that less than 4 % of lung nodules and overall less than 1 % of incidentalomas elsewhere evolve into a lethal carcinoma.

The growing incidence of incidentalomas presents an increasingly serious dilemma for radiologists throughout the world: if there is reasonable belief that the incidentaloma is of no clinical significance, then mentioning it will likely lead to a cascade of expensive tests, some of which occasionally result in iatrogenic complications. However, if radiologists decide not to report an incidentaloma and in the unlikely event the incidentaloma later turns out to have been an early carcinoma or other serious disease that jeopardizes the patient’s health, medical malpractice litigation could well ensue. Let us look more closely at this dilemma from medicolegal and ethical perspectives. The judicial statement that “Any human being of adult years and sound mind has a right to determine what shall be done with his own body” (Schloendorff v The Society of New York Hosp 1914), quoted at the beginning of this chapter, was rendered 102 years ago. In subsequent years, American appeals courts strengthened patient’s rights of self-determination by imposing upon their physicians a duty to disclose to the patient all pertinent medical information:

A physician undertaking a physical exam has a duty to disclose what he has found and to warn the examinee of any finding that would indicate the patient is in any danger. (Betesh v United States of America 1974)

Those who place themselves in the hands of a person who is skilled in the medical profession have a reasonable expectation that the radiologist will warn of any dangers of which he is cognizant. By failing to inform the patient of the abnormality, the radiologist prevents the patient from halting the progress of his disease. (Daly v United States of America 1991)

A doctor who undertakes to read x-rays, on which he observes abnormalities, must act reasonably in reading the x-rays and reporting the results. What constitutes reasonable reporting must be determined by a jury. (Stanley v McCarver 2004)

Emphasizing that ethical duties often surpass legal duties, the Code of Ethics of the American Medical Association states: “The physician’s obligation is to present the medical facts accurately …and disclose all relevant medical information to patients” (American Medical Association Council on Ethical and Judicial Affairs 2015).

Physicians in all nations are legally and morally obligated to adhere to a standard of care (SOC). There is no single written definition of SOC, but courts throughout the USA and elsewhere have generally agreed on what conduct does, and does not, constitute the standard of care (Berlin 1998). The following American court commentaries give the readers a reasonable understanding of the term standard of care:

When a person assumes the profession of physician and surgeon, he must…be held to employ a reasonable amount of skill and care. For anything short of that degree of skill in his practice, the law will hold him responsible for any injury that may result from its absence. While he is not required to possess the highest order of qualification, to which some men attain, still he must possess and exercise that degree of skill, which is ordinarily possessed by members of the profession. (Richie v West 1860)

Every person who enters the medical profession must exercise a reasonable degree of care and skill. He does not undertake to use the highest possible degree of skill, for there may be persons who, for having enjoyed a better education and greater advantage, are possessed of greater skill in their profession; but he undertakes that he will bring a fair, reasonable and competent degree of skill. (Smith v Overby 1860)

Proof of a bad result or a mishap is not evidence of lack of skill or negligence. If a doctor has given a patient his best judgment, assuming that judgment is equal to that ordinarily used by reasonably well-qualified doctors in similar cases, he is not liable for negligence. (Spike v Sellett 1981)

Perfection is a standard to which no profession can possibly adhere. Doctors are required to exercise reasonable care; they are not required to be perfect. (Blake v Gunderson Clinic, Ltd 1989)

The term “standard of care” is generally understood to mean conduct against which a defending doctor’s actions is to be measured…The established standard of care is stated as “use of the same degree of knowledge, skill, and ability as an ordinarily careful physician would exercise under similar circumstances.” (Advincula v United Blood Services 1996)

Although the source of the above descriptions of the SOC is American courts, similar wording appears in courts worldwide. The SOC as described here is international.

Inasmuch as SOC is considered usual and customary conduct practiced by physicians in the local community under the same or similar circumstances, the question arises as to what constitutes “usual and customary conduct” regarding how radiologists handle incidentalomas. The SOC would be very clear if virtually all “reasonable and ordinary” radiologists managed incidentalomas in the same manner. However, data reveal that there is no consistency; some radiologists report them, and some radiologists ignore them. A recently published survey of 27 radiologists at three well-known and prestigious medical centers in the USA – Johns Hopkins University, New York University, and Stanford University – disclosed the degree of agreement on whether, and if so how, to report incidental findings ranged as low as 30 % (Johnson et al. 2012). There was wide disagreement not only across the three academic institutions but among radiologists in the same institution as well. Furthermore, in an attempt to bring about general agreement on the reporting of incidentalomas, the American College of Radiology (ACR) published a “White Paper” containing guidelines that, based on specific characteristics of an incidentaloma, would lead radiologists to be consistent in deciding whether to report the finding if it was suspicious for a malignancy or to ignore it if it was clearly benign (Berland Berland et al. 2010). Not surprisingly but nonetheless still disappointedly, one survey disclosed that as few as 29 % of radiologists adhered to guidelines published by the Fleischner Society, an internationally known society of thoracic radiologists (Esmaili et al. 2011). In a survey of 14,200 radiologists, inquiring about their knowledge of and adherence to guidelines of the ACR White Paper (WP) regarding recommendations on the reporting of abdominal incidental findings, 2865 (20 %) responded. Of these respondents, 1088 (38 %) indicated that they had read the WP, and of these, close to 90 % indicated that they at least sometimes adhere to the WP recommendations. However, when compared to the total number who responded to the survey, the percentage of respondents who adhered to the guidelines drops to 34 %. If we use as the denominator the entire 14,200 who were contacted, the percentage could drop to as low as 7 %. When asked with the question of whether their concern for being sued for malpractice leads them to increase recommendations for additional imaging of incidentalomas, 76 % answered affirmatively (Berland et al. 2014).

Notwithstanding that 99 % of all incidentalomas are benign and are not in the least bit a threat to the health of the patient, most radiologists are reluctant to ignore them because of the fear of being sued, given the unpleasant malpractice environment that exists in the USA and which, unfortunately, seems to be spreading to other nations as well. This fear is exemplified by a published lamentation of a well-known expert in obstetrical ultrasound, Dr. Roy Filly. He pointed out that in 10 % of normal pregnancies, sonograms contain apparent abnormalities that can be interpreted as markers of Down syndrome; however, in reality, almost all turn out to be clinically unimportant. Filly opines that if he informed all parents of this so-called abnormality, “enjoyment of the anticipation of the birth” of their baby would be replaced by “anxiety and concern” (Filly 2000). Statistically, the likelihood that the fetus would be born with Down syndrome is extremely rare, and thus informing the parents of the marker would put 10 % of all pregnant women with perfectly normal fetuses through a great deal of worry. Filly asked himself, “Should I have the courage of my conviction and ignore these features?” He concluded that he wished he had the courage, but does not, because the American medicolegal climate is not conducive to his unilaterally ignoring such findings. If Filly, a well-known and prestigious expert in radiology, fears ignoring incidentalomas because of potential legal consequences, it is no surprise that most radiologists share the same fear. One American university disclosed that even when incidental findings that were not considered important enough to require medical follow-up were discovered, all patients were notified nevertheless because of “medical legal concerns” (Sperry et al. 2010).