Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

Pancreatic neuroendocrine tumors (PNETs) are uncommon pancreatic neoplasms with malignant potential, heterogeneous clinical behavior, as well as imaging appearance. These tumors represent less than 3% of all pancreatic neoplasms with typical CT presentation as solid, well-circumscribed, hypervascular lesions. Cystic PNET is a rare pancreatic tumor which is nowadays more often detected due to the widespread use of high-resolution cross-sectional imaging. They are mainly solitary lesions most commonly localized in the body and the tail of the pancreas. Due to cystic presentation these lesions often present a diagnostic challenge to both experienced radiologists and pathologists. Herein, we present a rare case of synchronous, multiple cystic and solid pancreatic neuroendocrine tumors, which due to their extensiveness required total dudenopancreatectomy with splenectomy. Histopathological findings confirmed microscopic and macroscopic cystic components as well as typical solid variants of neuroendocrine tumors along the entire pancreas.

Non-somatostatin receptor expressing hypovascular insulinomas can be challenging to prove through imaging. This case highlights the utility of a structured approach to molecular imaging in patients with confirmed endogenous hyperinsulinemia. A 54-year-old woman was admitted because of a sudden loss of consciousness. Her relative reported that she complained of dizziness, intense sweating, blurry vision, and upper extremity tingling before becoming unresponsive for 20 min, after which the patient had little recollection of the event. She experienced similar episodes of shorter duration, trouble recalling everyday events, and unintentional weight gain of over 10 kg during the previous two years. Abdominal magnetic resonance imaging (MRI) and multidetector computerized tomography (MDCT) were unremarkable. Selective arterial calcium stimulation significantly increased hepatic venous insulin concentrations when the superior mesenteric and gastroduodenal arteries were stimulated. Technetium-99m (99mTc) octreotide single-photon emission computed tomography (SPECT) did not localize the lesion. Gallium-68 DOTA-Exendin-4 PET/CT acquisition was performed. A single intense 2 cm hyperperfused pancreatic lesion was located anteriorly in the head of the pancreas. Earlier targeted PET/CT imaging and recognition of significant neuropsychiatric symptoms attributable to the patient’s hypoglycemic state might have accelerated the resolution of her condition and obviated the need for unnecessary testing.

Introduction. Malignant melanoma is a tumor of the melanocytes and is one of the most aggressive tumors. In most cases, the first symptoms appear in the metastatic phase of the disease. In clinical practice, malignant melanoma very rarely metastasizes to the gallbladder. Modern diagnostic methods include 18F-fluorodeoxyglucose positron emission tomography, new computed tomography protocols, new nuclear magnetic resonance for melanoma protocols, and contrast-enhanced ultrasound. The article aims to emphasize the necessity of radical surgical treatment of metastatic melanoma of the gallbladder. Case outline. We present a rare case of metastatic malignant melanoma of the gallbladder, which was treated with cholecystectomy and radical surgical excision of all metastatic lesions. Conclusion. All patients with a positive anamnesis for malignant melanoma require to be checked for the spread of the disease to the gallbladder and subsequent surgical treatment.

Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cystic lesions with malignant potential. This review outlines current guidelines, surgical indications, outcomes, and surveillance strategies. It also highlights recent advances in minimally invasive surgery and emerging biomarkers aimed at improving risk stratification and reducing unnecessary resections.