Pancreatic Incidentaloma

The widespread use of highly sensitive imaging techniques has led to the serendipitous identification of subclinical tumors in some organs [1]. Pancreatic incidentaloma (PI) has been defined as a mass that is incidentally discovered during an image study for symptoms other than the ones of the mass itself or the organ affected. The term ‘‘pancreatic incidentaloma’’ was first described by Ho and Kostiuk [2, 3]. The incidence of PI varies among different studies. In a series of 333 asymptomatic potential kidney donors, two cases of PI (0.6%) were found [4]. In a recent report analyzing the Japanese experience of PET for cancer screening in 39,785 asymptomatic subjects, six cases of unsuspected pancreatic cancer (0.01%) were discovered [5]. Some studies have suggested that the incidence is rising [6]. When encountering a PI, the aim is to determine the benign or malignant nature of the lesion. There is a general idea that early treatment of incidental malignant lesions may render a higher cure rate and prolonged survival. However, series studying subclinical tumors in different organs have shown that the rate of malignancy and the impact of early treatment vary. The outcome is thus related not only to the stage of the disease at the time of diagnosis but also to the biologic aggressiveness of the tumor. Some authors have suggested that the identification and early treatment of an incidental lesion in certain organs, such as the kidney, reduces morbidity and mortality. In a study of 633 patients with renal carcinoma, earlier stages were significantly more frequent, and the 5-year cancer-specific survival rate was higher in the 15% of tumors discovered incidentally, when compared with patients with overt disease [7]. Studies analyzing the benefit of identifying hepatic incidentalomas have reported contradicting results. Little and colleagues in a series of 64 hepatic incidentalomas found that only 11 (17%) of patients were benefited from the early identification of a tumor. In contrast, 83% of the patients did not experience any benefit in terms of quality of life or prolonged survival [8]. Lui et al., in a study where 58% of hepatic incidentalomas were malignant, found that patients with hepatocellular carcinoma had a significantly better survival than those patients with clinically suspected malignancy who underwent treatment during the same period of time [9]. Obsessive search for small incidental tumors has, on the other hand, the risk that a significant number of patients may undergo extensive diagnostic evaluation and treatment without any positive impact on their health status, with the added risk of well-known surgical complications [10]. Etiology of PI involves a variety of benign and malignant diseases, which are depicted in Table 41.1. Demographic characteristics of PI located in the pancreatic head (age, gender, and comorbidities) have been shown to be similar to those of patients with symptomatic