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“It is difficult to make the asymptomatic patient feel better.”

Generations of surgeons have been trained to keep Stanley Hoerr's famous dictum in mind. Physicians are now faced with helping the asymptomatic patient deal with findings uncovered in their routine medical care—findings that may or may not affect their future well-being and are often a source of great concern. Before the introduction of cross-sectional imaging with computed tomographic scanning and magnetic resonance imaging, incidental clinical findings were almost exclusively limited to those discovered in the course of operative procedures to remedy other conditions.

This month's monograph for Current Problems in Surgery highlights a problem in clinical practice generated by increasingly sensitive body imaging. The authors have chosen for review common and vexing incidentally found lesions. These include lesions of the liver, pancreas, gallbladder, adrenal, lung, thyroid, kidney, and ovary. We anticipate that review of management of the lesions in these organs will outline the general approach to incidental lesions. To adequately cover the common “incidentalomas” we have divided the topic into 2 monographs. Volume 1 includes liver, pancreas, gallbladder, and adrenal lesions. Volume 2 will cover lung, thyroid, kidney, and ovary lesions.

For the practicing clinician, what to do about managing incidentalomas has become an everyday problem. Imaging reports commonly contain reference to incidental findings with advice recommending “clinical correlation,” follow-up imaging, or biopsy. We are all sensitive to the concern that the evaluation of some incidental findings has led to unnecessary testing, increased anxiety for the patient, increased cost of medical care, and sometimes significant complications from attempts to exonerate innocent incidental lesions. The liability climate in the United States has magnified the problem because of the significant issue of lawsuits for failure to diagnose problems that led to adverse outcomes. The National Institutes of Health and the “imaging industry” are both expanding research funding for imaging techniques in the hope that this will minimize unnecessary additional testing by developing more specific and sensitive imaging.

Although the majority of incidentally discovered liver lesions are benign in patients without a history of malignancy, it is commonly believed by patients that any liver lesion has serious consequences. By using multiple imaging techniques (eg, ultrasound, computed tomography [CT], magnetic resonance imaging [MRI], and positron emission tomography [PET]-CT—with and without contrast) most lesions can be diagnosed accurately without invasive procedures. The differential diagnosis of both solid and cystic lesions is reviewed and a practical algorithm for their management is provided. The indications for and technique of biopsy are also discussed.

Pancreatic lesions are an exception to the theme of most of the incidentalomas since a high percentage harbor either invasive malignancy or are premalignant (up to 75%). Although we recognize pancreatic malignancies to be among the most aggressive and lethal tumors, our knowledge of their development and natural history lags other solid tumors by 20 to 30 years. Unfortunately current imaging and pathologic techniques are largely imperfect at predicting malignancy in these lesions. Since operative approaches to the pancreas are difficult and have significant risks, the evaluation of these lesions is particularly critical.

Virtually all pathologic pancreatic lesions can be found incidentally. There is a paucity of literature on the subject of pancreatic incidentalomas. Our current thinking relies on a handful of retrospective case series, each with fewer than 120 patients accrued over the last decade, and often with incomplete pathologic confirmation. These series show that inadvertently identified lesions are most often cystic; overall the most common diagnoses are cystadenomas, pancreatic adenocarcinomas, and the newly recognized intraductal papillary mucinous neoplasia (IPMN).

An offshoot of improvements in the identification and management of early pancreatic lesions is that screening of high-risk patients has become more practical. Screening these patients offers the hope of identifying pancreatic carcinoma in its earliest stages.

One of the most prosaic incidentalomas and something that all surgeons have been familiar with for generations is asymptomatic cholelithiasis. We have all had to adapt repeatedly to changing recommendations for the management of asymptomatic gallstones. For example, diabetes and immunosuppression are no longer considered indications for elective cholecystectomy in asymptomatic patients. The single group for whom there is a significant benefit from elective cholecystectomy is the post–cardiac transplant patient. The mortality rate from elective gallbladder surgery after heart transplantation is very low, but heart transplant patients who develop severe biliary sepsis fare poorly. That is currently the only “absolute” indication for elective cholecystectomy in an otherwise asymptomatic patient.

The adrenal gland is one of the first organs in which incidental tumors were reported. As such it has been extensively written about and is possibly the most familiar to readers. The initial evaluation depends on careful review of the imaging. The main criteria for further evaluation in the asymptomatic patient with no personal past history or suggested symptoms of malignancy are the size of the lesion and the specific characteristics of the mass, including any evidence of local infiltration, of metastatic disease, and a description of the consistency of the contents. Indications for biopsy are detailed in a useful algorithm. For patients with even subtle signs of hypercortisolism, further evaluation of adrenal cortical function for possible functioning adenomas is necessary.

Continuing and expected improvements in imaging techniques will undoubtedly result in changes to how we manage these incidental findings. We are likely to find even more “incidentalomas,” which will be managed surgically, medically, or expectantly.