Search Results (206)

Background/Objectives: To evaluate the importance of image processing in a previously validated model for detecting pancreatic neuroendocrine tumors (PanNETs) and to introduce Image2Radiomics, a new framework that ensures reproducibility of the image processing pipeline and facilitates the deployment of radiomics models. Methods: A previously validated model for identifying PanNETs from CT images served as the reference. Radiomics features were re-extracted using Image2Radiomics and compared to those from the original model using performance metrics. The impact of nine alterations to the image processing pipeline was evaluated. Prediction discrepancies were quantified using the mean ± SD of absolute differences in PanNET probability and the percentage of classification disagreement. Results: The reference model was successfully replicated with Image2Radiomics, achieving a Cohen’s kappa coefficient of 1. Alterations to the image processing pipeline led to reductions in model performance, with AUC dropping from 0.87 to 0.71 when image windowing was removed. Prediction disagreements were observed in up to 45% of patients. Even minor changes, such as switching the library used for spatial resampling, resulted in up to 21% disagreement. Conclusions: Reproducing image processing pipelines remains challenging and limits the clinical deployment of radiomics models. While this study is limited to one model and imaging modality, the findings underscore a common risk in radiomics reproducibility. The Image2Radiomics framework addresses this issue by allowing researchers to define and share complete processing pipelines in a standardized way, improving reproducibility and facilitating model deployment in clinical and multicenter settings. Full article

Pancreatic neuroendocrine neoplasms (PNENs) are a diverse group of rare tumor subtypes, representing less than 2% of all pancreatic tumors. Often detected late in the clinical course, they are associated with high rates of morbidity and mortality. Hereditary syndromes such as multiple endocrine neoplasia type-1 and von Hippel–Lindau are associated with the development of PNENs, although only a small portion of total tumors have a genetic basis. This review aims to explore the recent advances in laboratory diagnostics, imaging modalities, medical management, and surgical approaches to hormone-producing PNENs (including some common, less common, and some rare subtypes), with the goal of assisting physicians in the integration of evidence-based information into their practice. Full article

Background: Atypical carcinoid of the thymus is an exceptionally rare neuroendocrine tumor originating from neuroendocrine cells within the thymus. These tumors often present with no symptoms or with nonspecific clinical signs, making early diagnosis particularly challenging. Despite their rarity, atypical carcinoids are clinically significant due to their aggressive nature and relatively poor prognosis. Early detection and appropriate management are therefore crucial to improving patient outcomes. Results: In this report, we present the case of a 64-year-old patient in whom an atypical carcinoid of the thymus was incidentally discovered following a thoracic computed tomography scan performed for unrelated reasons. Imaging revealed a suspicious anterior mediastinal mass, which was subsequently surgically resected. Histopathological examination, supported by immunohistochemical analysis, confirmed the diagnosis of an atypical carcinoid of the thymus. The tumor demonstrated coexpression of epithelial and neuroendocrine markers, consistent with this rare entity. Conclusions: This case adds to the limited body of literature on atypical carcinoid of the thymus and highlights the importance of considering this diagnosis when evaluating anterior mediastinal masses. It also underscores the value of thorough radiological and pathological assessment in identifying early-stage disease, which may significantly influence prognosis and therapeutic strategies. Full article

Targeted radionuclide therapy (TRT) utilizes radiopharmaceuticals to deliver radiation directly to cancer cells while sparing healthy tissues. Beyond the absorbed dose of ablative radiation, TRT induces non-targeted effects (NTEs) that significantly enhance its therapeutic efficacy. These effects include radiation-induced bystander effects (RIBEs), abscopal effects (AEs), radiation-induced genomic instability (RIGI), and adaptive responses, which collectively influence the behavior of cancer cells and the tumor microenvironment (TME). TRT also modulates immune responses, promoting immune-mediated cell death and enhancing the efficacy of combination therapies, such as the use of immune checkpoint inhibitors. The molecular mechanisms underlying TRT involve DNA damage, oxidative stress, and apoptosis, with repair pathways like homologous recombination (HR) and non-homologous end joining (NHEJ) playing critical roles. However, challenges such as tumor heterogeneity, hypoxia, and radioresistance limit the effectiveness of this approach. Advances in theranostics, which integrate diagnostic imaging with TRT, have enabled personalized treatment approaches, while artificial intelligence and improved dosimetry offer potential for treatment optimization. Despite the significant survival benefits of TRT in prostate cancer and neuroendocrine tumors, 30–40% of patients remain unresponsive, which highlights the need for further research into molecular pathways, long-term effects, and combined therapies. This review outlines the dual mechanisms of TRT, direct toxicity and NTEs, and discusses strategies to enhance its efficacy and expand its use in oncology. Full article

Background: Potent androgen receptor pathway inhibitors induce small cell neuroendocrine prostate cancer (SCNC), a highly aggressive subtype of metastatic androgen deprivation-resistant prostate cancer (ARPC) with limited treatment options and poor survival rates. Patients with metastases in the liver have a poor prognosis relative to those with bone metastases alone. The mechanisms that underlie the different behavior of ARPC in bone vs. liver may involve factors intrinsic to the tumor cell, tumor microenvironment, and/or systemic factors, and identifying these factors is critical to improved diagnosis and treatment of SCNC. Metabolic reprogramming is a fundamental strategy of tumor cells to colonize and proliferate in microenvironments distinct from the primary site. Understanding the metabolic plasticity of cancer cells may reveal novel approaches to imaging and treating metastases more effectively. Methods: Using magnetic resonance (MR) imaging and spectroscopy, we interrogated the physiological and metabolic characteristics of SCNC patient-derived xenografts (PDXs) propagated in the bone and liver, and used correlative biochemical, immunohistochemical, and transcriptomic measures to understand the biological underpinnings of the observed imaging metrics. Results: We found that the influence of the microenvironment on physiologic measures using MRI was variable among PDXs. However, the MR measure of glycolytic capacity in the liver using hyperpolarized ¹³C pyruvic acid recapitulated the enzyme activity (lactate dehydrogenase), cofactor (nicotinamide adenine dinucleotide), and stable isotope measures of fractional enrichment of lactate. While in the bone, the congruence of the glycolytic components was lost and potentially weighted by the interaction of cancer cells with osteoclasts/osteoblasts. Conclusion: While there was little impact of microenvironmental factors on metabolism, the physiological measures (cellularity and perfusion) are highly variable and necessitate the use of combined hyperpolarized ¹³C MRI and multiparametric (anatomic, diffusion-, and perfusion- weighted) ¹H MRI to better characterize pre-treatment tumor characteristics, which will be crucial to evaluate treatment response. Full article

Prompt and accurate identification of liver metastases from neuroendocrine tumors, arising from the gastrointestinal system and from the pancreas, through the means of both anatomical and functional diagnostic imaging techniques is mandatory. A patient’s prognosis and treatment planning are dependent on these diagnostic procedures. The aim of this narrative review is to depict the common appearance of liver metastases, as well as to depict atypical imaging patterns. Moreover, this review will cover the differential diagnosis between liver metastases from neuroendocrine tumors and other primary and secondary malignant liver lesions, as well as benign liver lesions. Full article

Pulmonary neuroendocrine proliferations and neoplasms represent a broad spectrum of diseases, ranging from neuroendocrine cell hyperplasia and tumorlets to carcinoid tumors. Carcinoid tumorlets are most commonly located in the peripheral airways and are often incidentally detected as pulmonary micronodules on chest CT. We report the radiological, bronchoscopic, and pathological findings of a case of carcinoid tumorlets presenting as endobronchial nodules in the left main bronchus. The patient had previously undergone a left lower lobectomy five years earlier for a typical carcinoid tumor. Follow-up imaging revealed new endobronchial nodules, which were subsequently confirmed as carcinoid tumorlets through histopathologic analysis. This case highlights the rare presentation of carcinoid tumorlets in the central airways, emphasizing the importance of recognizing their potential for late recurrence and atypical localization. It underscores the necessity for physicians to be aware that pulmonary neuroendocrine tumors can recur over the long term and may present in a multicentric fashion within the disease spectrum. Full article

Posterior pituitary tumors (PPTs) are rare, non-neuroendocrine neoplasms derived from pituicytes of the neurohypophysis or infundibulum. According to the 2025 WHO classification, PPTs comprise four distinct but related low-grade entities: pituicytoma, granular cell tumor of the sellar region, spindle cell oncocytoma, and ependymal pituicytoma. All share nuclear TTF-1 expression, confirming their common origin, but differ in morphology, immunophenotype, and ultrastructure. Histologically, pituicytomas consist of bipolar spindle cells in fascicles; granular cell tumors show polygonal cells with PAS-positive, diastase-resistant cytoplasmic granules; spindle cell oncocytomas display oncocytic change and abundant mitochondria; and ependymal pituicytomas exhibit perivascular pseudorosettes and EMA positivity in apical or dot-like patterns. Immunohistochemically, all are S100 and vimentin positive, and negative for pituitary hormones and lineage-specific transcription factors. Clinically, PPTs are typically non-functioning but may be associated with corticotroph or somatotroph hyperfunction. Imaging features are nonspecific. Surgical resection is the treatment of choice, although hypervascularity and adherence—especially in spindle cell oncocytomas—can hinder complete excision. Radiotherapy is reserved for recurrences. Molecular analyses reveal recurrent alterations in MAPK/PI3K pathways (e.g., HRAS, BRAF, FGFR1, NF1, TSC1) and suggest a shared histogenesis. Copy number imbalances correlate with reduced progression-free survival in some subtypes. Despite a generally favorable prognosis, recurrence—particularly in spindle cell oncocytomas—necessitates long-term follow-up. The WHO 2025 update provides a unified framework for classification, diagnosis, and prognostic stratification of these rare tumors. Full article

Background: Pancreatic neuroendocrine tumors (PanNETs) are relatively rare neoplasms with heterogeneous behavior, ranging from indolent to aggressive disease. The evolution of nuclear medicine has allowed the development of an efficient and advanced toolkit for the diagnosis and treatment of PanNETs. Case: A 45-year-old woman was diagnosed with a grade 1 PanNET and multiple liver metastases. She underwent distal pancreatectomy with splenectomy, extended liver resection, and radiofrequency ablation (RFA). Surgical planning was guided by [^99mTc]Tc-EDDA/HYNIC-TOC SPECT/CT (single-photon emission computed tomography/computed tomography) and preoperative [^99mTc]Tc-mebrofenin-based functional liver volumetry. Functional liver volumetry based on dynamic [^99mTc]Tc-mebrofenin SPECT/CT facilitated precise surgical planning and reliable assessment of the efficacy of parenchymal modulation, thereby aiding in the prevention of post-hepatectomy liver failure. Liver fibrosis was non-invasively evaluated using two-dimensional shear wave elastography (2D-SWE). Tumor progression was monitored using somatostatin receptor scintigraphy, chromogranin A, and contrast-enhanced CT. Recurrent disease was treated with somatostatin analogues (SSAs) and [¹⁷⁷Lu]Lu-DOTA-TATE peptide receptor radionuclide therapy (PRRT). Despite progression to grade 3 disease (Ki-67 from 1% to 30%), the patient remains alive 53 months post-diagnosis, in complete remission, with an ECOG (Eastern Cooperative Oncology Group) status of 0. Conclusions: Functional imaging played a pivotal role in guiding therapeutic decisions throughout the disease course. This case not only underscores the clinical utility of advanced nuclear imaging but also illustrates the dynamic nature of pancreatic neuroendocrine tumors. The transition from low-grade to high-grade disease highlights the need for further studies on tumor progression mechanisms and the potential role of adjuvant therapies in managing PanNETs. Full article

Neuroendocrine neoplasms (NENs) represent a heterogenous group of tumors with significant inter- and intra-patient variability. Once considered to be rare, neuroendocrine neoplasms are being increasingly recognized through the advent of advanced diagnostic techniques, which may be contributing to the significant increase in the incidence and detection rate of these tumors. NENs can be classified into well differentiated and poorly differentiated neuroendocrine tumors (NETs) or neuroendocrine carcinomas (NECs). The proliferation rate of NETs can vary from Ki-67 1–55%. In addition, the SSTR expression can vary significantly. Because of this high “heterogeneity”, their detection and characterization have become essential to disease management, leading to dual-tracer imaging, most commonly with FDG- and SSTR-targeted PET/CT. Because of the complexity of the disease, the optimal treatment of patients depends on a combination of imaging, serological biomarkers, and clinical information. There remains a significant portion of patients who do not respond as anticipated, and the management of their disease remains challenging with current techniques, necessitating the refinement of our technologies and the development of new ones. In addition to new biological targets, improved peptide vector targeting for the somatostatin receptor needs further development. This review aims to evaluate the existing imaging techniques utilized in the diagnosis, assessment, and treatment of NENs, as well as the emerging radiopharmaceuticals and technologies, which will expand our imaging repertoire as well as our management options. Full article

Background: Thymic carcinoids are rare neuroendocrine tumors arising in the anterior mediastinum, often diagnosed at an advanced stage due to nonspecific clinical manifestations. Their management remains challenging because of the paucity of data, rarity of occurrence, and aggressive biological behavior compared to other well-differentiated neuroendocrine neoplasms. Methods: We conducted a comprehensive review of the current literature focusing on the classification, clinical presentation, diagnostics, treatment options, prognostic factors, and emerging experimental therapies for thymic carcinoids. Emphasis was placed on integrating recent molecular and therapeutic advances into clinical practice. Results: Surgical resection remains the cornerstone of treatment for localized disease, while systemic therapies such as everolimus, somatostatin analogs, platinum-based chemotherapy, and peptide receptor radionuclide therapy (PRRT) are options for advanced cases. Novel diagnostic modalities, including NETest, 64Cu-DOTATATE PET, and 18F-FDOPA PET, offer promise in early detection and disease monitoring. Molecular insights, particularly involving MEN1, ATRX, and DAXX mutations, pave the way for individualized targeted therapies. Immunotherapy and radioimmunotherapy represent emerging, albeit still experimental, approaches. Prognosis largely depends on tumor stage, differentiation, resectability, and functional activity, with a high recurrence rate necessitating prolonged surveillance. Conclusions: Thymic carcinoids pose significant diagnostic and therapeutic challenges. Advances in molecular profiling, novel imaging techniques, and systemic therapies offer hope for improved outcomes. Given the disease rarity, continued collaboration through registries and multicenter studies is essential to refine evidence-based management strategies. Full article

Background: There is limited data on somatostatin receptor (SSTR) expression of metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs) using modern imaging techniques and stratifying by primary site and tumor grade (G). Understanding patterns of SSTR expression and tumor heterogeneity is essential when determining the relevance of cold and radiolabeled somatostatin analog treatments. Methods: A single-institutional retrospective analysis of metastatic well-differentiated G1-3 GEP-NET patients who underwent Gallium-68 ([⁶⁸Ga])-DOTATATE or Copper-64 ([⁶⁴Cu])-DOTATATE positron emission tomography (PET) imaging from September 2016 to June 2024 was performed. Results: A total of 1192 patients were considered eligible for this study. Among them, 26 (2.2%) were completely negative on SSTR PET/computed tomography (CT), and 27 (2.3%) had weak uptake (less or equal to the normal liver). Up to 40 (3.4%) had heterogeneous SSTR expression on PET/CT: 26 (2.2%) displayed the coexistence of strongly avid lesions with the absence or near absence of SSTR uptake in measurable tumors (heterogeneous strong), while 14 (1.2%) had a combination of absent and weakly expressing SSTR tumors (heterogeneous low). An additional nine cases with prior homogeneous expression (0.8%) developed new SSTR-negative tumors along with disease progression, potentially indicating dedifferentiation. The absent or heterogeneous SSTR expression rates were greater in NET G3 than G1/G2 and in tumors originating outside the small bowel (midgut). Most NETs with absent or heterogeneous SSTR expression were fluorodeoxyglucose-F-18 ([¹⁸F]FDG)-avid. Conclusions: The large majority of metastatic GEP-NETs demonstrate strong and relatively uniform SSTR expression, but approximately 8% are SSTR-negative, weak or heterogeneous on PET/CT. Higher than average rates of absent/heterogeneous/weak SSTR expression occur in G3 NETs and lower rates among small intestine primaries. Full article

In this article, we present a case of a 49-year-old woman presenting with a recurrent metastatic neuroendocrine tumor. Background: Insulinomas are neuroendocrine tumors derived from beta cells of the pancreas that secrete insulin. Usually, they are benign tumors; however, metastatic insulinomas are an extremely rare malignant form of these tumors, carrying a significantly worse prognosis. Case Presentation: A 49-year-old woman, a patient in the University Hospital in Wroclaw in the Department of Endocrinology, Diabetes and Isotope Therapy, first presented with abdominal pain in 2009, when ultrasound and further examination led to the diagnosis of a tumor in the pancreas (a solid pseudopapillary tumor of the pancreas—meta NET G2), and the patient underwent distal pancreatectomy with splenectomy. For ten years, she was under observation, and her symptoms, such as abdominal pain, nausea, weight loss, and general weakness, reappeared in 2019. Then, magnetic resonance imaging (MRI) showed a lesion in the liver, and further histopathology revealed neuroendocrine tumor (NET) metastasis to the liver. In 2022, the patient presented with loss of consciousness and convulsion, loss of weight, and hypoglycemia after meals. In April 2022, the daily glycemic profile was recorded and a 72 h fasting test was performed; however, their results excluded insulinoma. Positron emission tomography–computed tomography (PET-CT) with 18F-fluorodeoxyglucose (18F-FDG) and PET with gallium-68-DOTA-(Tyr3)-octreotate (68Ga-DOTA-TATE) showed a metastatic proliferative process in the liver. Persistent hypoglycemia led to another hospitalization in May 2022, and repeated tests allowed for the diagnosis of insulinoma. Treatment with somatostatin analogs and diazoxide was started. A CT scan in November 2022 and a PET scan in January 2023 showed new metastases to the liver, bones, and cervical lymph nodes, and it was decided to intensify the treatment. In May 2023, the patient was qualified for Lutathera treatment for insulinoma at the University Clinical Hospital in Poznań. In June 2023, another disturbing symptom was reported by the patient, a painful lump in the breast. During diagnostics, metastases with high proliferation markers were found in both breasts. Two months later, in August 2023, the patient received another dose of Lutathera. In October 2023, significant progression of liver lesions, metastases to bones of the spine, ribs, and pelvis, and periaortic and pelvic lymphadenopathy were found as well as elevated values of neuron-specific enolase and calcitonin. The patient was also referred to the Palliative Medicine Home Hospice. In consultation with the Lower Silesian Cancer Center, the decision was made to forgo further treatment with PRRT and initiate systemic chemotherapy. Despite the chosen treatment, the patient died on 27/DEC/2023. Conclusions: This case report can serve clinicians, as it presents a case of an extremely rare and insidious tumor, metastatic insulinoma. Full article

Background/Objectives: Pancreatic neoplasms, including adenocarcinoma, pancreatic neuroendocrine tumors (pNETs), intraductal papillary mucinous neoplasms (IPMNs), and high-grade cystic lesions, often require surgical resection as a form of curative treatment. However, comorbidities and high-risk features may preclude surgery. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has emerged as a minimally invasive alternative with proven cytoreductive efficacy in solid tumors. This case series evaluates the safety and efficacy of EUS-RFA in patients with various unresectable, non-metastatic pancreatic neoplasms. Methods: A retrospective review was conducted on eight patients who underwent EUS-RFA at our institutions between July 2021 and February 2025. All patients were deemed unsuitable surgical candidates due to comorbidities such as advanced age, cardiovascular disease, renal insufficiency, and COPD or due to patient resistance to surgical intervention. EUS-RFA was performed using a 19-gauge RFA needle (Taewoong Corporation). Follow-up imaging was conducted 3 to 6 months after the completion of RFA treatment. Results: All eight patients demonstrated a good to excellent response in terms of tumor size reduction. The most notable response was observed in a patient with pNET, resulting in complete resolution from 15.6 × 12.0 mm to 0.0 × 0.0 mm after two RFA treatments. Other neoplasms, including pancreatic adenocarcinoma and intraductal papillary mucinous neoplasms (IPMNs), also demonstrated significant reductions. Mild post-procedure complications, including pancreatitis and abdominal pain, were noted in three cases. Conclusions: EUS-RFA is a promising alternative for managing unresectable pancreatic neoplasms in high-risk patients. Our findings support its use across various tumor types with favorable outcomes and minimal complications, reinforcing its role in expanding therapeutic options beyond surgery. Full article

Gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) represent a rare and varied class of neoplasms, characterized by diverse clinical presentations and prognostic trajectories. Accurate and prompt diagnosis is vital to inform and optimize therapeutic decisions. Ultrasound, including standard B-mode imaging and advanced methods such as contrast-enhanced ultrasound (CEUS) and endoscopic ultrasound (EUS), serves as a key component in the diagnostic evaluation of these tumors. B-mode US and CEUS provide non-invasive, accessible methods for early detection and characterization. On B-mode imaging, GEP-NETs typically present as well-defined, hyperechoic, or iso-echoic lesions, while CEUS highlights their characteristic vascularity, marked by arterial-phase hyperenhancement and venous-phase washout. Compared to CT and MRI, ultrasound offers real-time, dynamic imaging without ionizing radiation or nephrotoxic contrast agents, making it particularly advantageous for patients requiring frequent monitoring or with contraindications to other imaging modalities. CT and MRI are widely regarded as the preferred methods for staging and surgical planning due to their detailed anatomical visualization. However, ultrasound, especially CEUS, provides a significant adjunctive role in both early detection and the follow-up on GEP-NETs. This analysis delves into the strengths, challenges, and innovations in ultrasound technology for diagnosing pancreatic NETs, focusing on its contribution to comprehensive imaging strategies and its impact on patient care decisions. Full article