Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

PurposeAs a result of various independently proposed nomenclatures and classifications, there is confusion in the diagnosis and prediction of biological behavior of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A comprehensive nationwide study is needed in order to understand the biological characteristics of GEP-NETs in Korea.Materials and MethodsWe collected 4,951 pathology reports from 29 hospitals in Korea between 2000 and 2009. Kaplan-Meier survival analysis was used to determine the prognostic significance of clinicopathological parameters.ResultsAlthough the GEP-NET is a relatively rare tumor in Korea, its incidence has increased during the last decade, with the most significant increase found in the rectum. The 10-year survival rate for well-differentiated endocrine tumor was 92.89%, in contrast to 85.74% in well differentiated neuroendocrine carcinoma and 34.59% in poorly differentiated neuroendocrine carcinoma. Disease related death was most common in the biliary tract (62.2%) and very rare in the rectum (5.2%). In Kaplan-Meier survival analysis, tumor location, histological classification, extent, size, mitosis, Ki-67 labeling index, synaptophysin expression, lymphovascular invasion, perineural invasion, and lymph node metastasis showed prognostic significance (p<0.05), however, chromogranin expression did not (p=0.148). The 2000 and 2010 World Health Organization (WHO) classification proposals were useful for prediction of the prognosis of GEP-NET.ConclusionThe incidence of GEP-NET in Korea has shown a remarkable increase during the last decade, however, the distribution of tumors in the digestive system differs from that of western reports. Assessment of pathological parameters, including immunostaining, is crucial in understanding biological behavior of the tumor as well as predicting prognosis of patients with GEP-NET.

EUS-GBD with an SEMS for acute cholecystitis showed excellent long-term outcomes and may be a definitive treatment in patients who are unsuitable for cholecystectomy because of advanced malignancy or high surgical risk.