Objective: To investigate the clinicopathological features of Crooke cell tumor of adrenocorticotropic hormone differentiation specific transcription factor (TPIT, also known as transcription factor 19, TBX19) lineage neuroendocrine tumors. Methods: Six cases of Crooke cell tumor diagnosed at the First Affiliated Hospital of University of Science and Technology of China, Hefei, China from October 2019 to October 2023 were collected. The clinical and pathological features of these cases were analyzed. Results: Among the six cases, one was male and five were female, with ages ranging from 26 to 75 years, and an average age of 44 years. All tumors occurred within the sella turcica. Clinical presentations included visual impairment in two cases, menstrual disorders in one case, Cushing\'s syndrome in one case, headache in one case, and one asymptomatic case discovered during a physical examination. Preoperative serum analyses revealed elevated levels of cortisol and adrenocorticotropic hormones in two cases, elevated cortisol in two cases, elevated adrenocorticotropic hormone in one case, and one case with a mild increase in prolactin due to the pituitary stalk effect. Magnetic resonance imaging revealed uneven enhancement of masses with maximum diameters ranging from 1.7 to 3.2 cm, all identified as macroadenomas. Microscopically, tumor cells exhibited irregular polygonal shapes, solid sheets, or pseudo-papillary arrangements around blood vessels. The cell nuclei were eccentric or centrally located, varying in size, with abundant cytoplasm. Some tumor cells showed perinuclear halo. Immunohistochemistry demonstrated diffuse strong positivity for TPIT in five cases, focal weak positivity for TPIT in one case, diffuse strong positivity for adrenocorticotropic hormone in all cases, and faint staining around the nuclei in a few cells. CK8/18 showed a strong positive ring pattern in more than 50% of tumor cells, focal weak positive expression of p53, and the Ki-67 positive index ranged 1%-5%. Periodic acid-Schiff staining revealed positive cytoplasm and negative perinuclear areas. Conclusions: Crooke cell tumor is a rare type of pituitary neuroendocrine tumors. Its pathological characteristics include a distinctive perinuclear clear zone and immunohistochemical markers, such as CK8/18 exhibiting a ring or halo pattern. This entity represents a high-risk subtype among pituitary neuroendocrine tumors, displaying a high risk of invasion and a propensity for recurrence. Accurate diagnosis is crucial for the postoperative follow-up and multimodal treatment planning.
目的： 探讨垂体Crooke型促肾上腺皮质激素分化特异性转录因子（TPIT，又称transcription factor 19，TBX19）谱系神经内分泌肿瘤的临床及病理学特点。 方法： 收集中国科学技术大学附属第一医院2019年10月至2023年10月诊断的垂体Crooke型TPIT谱系神经内分泌肿瘤6例，分析其临床及病理学特点。 结果： 6例中男性1例，女性5例，年龄26~75岁，平均年龄44岁，均发生于鞍内。临床表现为视觉障碍2例，月经紊乱1例，库欣综合征1例，头痛1例，无症状体检发现1例。术前血清学检查2例皮质醇、促肾上腺皮质激素（ACTH）同时升高，2例皮质醇升高，1例ACTH升高，1例仅出现垂体柄效应引起的泌乳素轻度升高。磁共振成像均显示增强扫描不均匀强化占位，直径1.7~3.2 cm，均为大腺瘤。镜下观察：肿瘤细胞呈不规则多边形，实性片状或围绕血管呈假乳头状排列，细胞核偏位或居中，大小不一，细胞质丰富，部分肿瘤细胞可见核周环状透明样变区域。免疫组织化学显示TPIT 5例弥漫强阳性，1例局灶弱阳性，ACTH细胞膜或细胞质弥漫强阳性，少数细胞核周可见淡染区，细胞角蛋白（CK）8/18可见>50%肿瘤细胞呈环状、戒圈状强阳性，p53局灶性弱阳性表达，Ki-67阳性指数1%~5%。过碘酸雪夫染色显示细胞质近胞膜处阳性，核周阴性。 结论： 垂体Crooke型TPIT谱系神经内分泌肿瘤是一种罕见的垂体神经内分泌肿瘤，病理学特点主要表现为特征性核周环状透明样变及免疫标记CK8/18环状、戒圈状强阳性。该肿瘤属垂体神经内分泌肿瘤的高危亚型之一，侵袭性强，易复发，明确诊断对患者术后随访及多模式治疗具有重要意义。.

The 5th edition of the WHO Endocrine and Neuroendocrine Oncology Blue Book, released in 2022, contained some changes in the classification of neuroendocrine tumors. A brief summary of the main changes has been provided in this section. Mainly summarized as changes in naming, differentiation and classification of neuroendocrine tumors, and tumor grading systems related to anatomical locations, morphological characteristics of neuroendocrine tumors in different locations, auxiliary diagnostic and prognostic/therapeutic markers, differential diagnosis and diagnostic difficulties of neuroendocrine tumors.
2022年出版的第5版WHO内分泌与神经内分泌肿瘤蓝皮书，其中关于神经内分泌肿瘤分类有一定的改变，我们就该部分的主要改变做简要的总结和概括。主要归纳为命名改变，神经内分泌肿瘤分化、分级定义及解剖部位相关肿瘤分级系统，不同部位神经内分泌肿瘤形态特征，辅助诊断及预后/治疗标志物，神经内分泌肿瘤鉴别诊断及诊断难点。.

UNASSIGNED: To develop and validate radiomics models utilizing endoscopic ultrasonography (EUS) images to distinguish insulinomas from non-functional pancreatic neuroendocrine tumors (NF-PNETs).
UNASSIGNED: A total of 106 patients, comprising 61 with insulinomas and 45 with NF-PNETs, were included in this study. The patients were randomly assigned to either the training or test cohort. Radiomics features were extracted from both the intratumoral and peritumoral regions, respectively. Six machine learning algorithms were utilized to train intratumoral prediction models, using only the nonzero coefficient features. The researchers identified the most effective intratumoral radiomics model and subsequently employed it to develop peritumoral and combined radiomics models. Finally, a predictive nomogram for insulinomas was constructed and assessed.
UNASSIGNED: A total of 107 radiomics features were extracted based on EUS, and only features with nonzero coefficients were retained. Among the six intratumoral radiomics models, the light gradient boosting machine (LightGBM) model demonstrated superior performance. Furthermore, a peritumoral radiomics model was established and evaluated. The combined model, integrating both the intratumoral and peritumoral radiomics features, exhibited a comparable performance in the training cohort (AUC=0.876) and achieved the highest accuracy in predicting outcomes in the test cohorts (AUC=0.835). The Delong test, calibration curves, and decision curve analysis (DCA) were employed to validate these findings. Insulinomas exhibited a significantly smaller diameter compared to NF-PNETs. Finally, the nomogram, incorporating diameter and radiomics signature, was constructed and assessed, which owned superior performance in both the training (AUC=0.929) and test (AUC=0.913) cohorts.
UNASSIGNED: A novel and impactful radiomics model and nomogram were developed and validated for the accurate differentiation of NF-PNETs and insulinomas utilizing EUS images.

胃肠胰神经内分泌肿瘤（GEP-NENs）是一类具有神经内分泌系统标志物，并且能够合成生物活性胺和/或多肽类激素的异质性较高的肿瘤。近十年来，GEP-NENs临床诊治取得了明显进展，不论是流行病学、诊断方法、治疗手段均取得长足进步。目前，围绕GEP-NENs仍有不少问题需要未来进一步研究解决。.

UNASSIGNED: 177Lu-oxodotreotide peptide receptor therapy (LuPRRT) is an efficient treatment for midgut neuroendocrine tumors (NETs) of variable radiological response. Several clinical, biological, and imaging parameters may be used to establish a relative disease prognosis but none is able to predict early efficacy or toxicities. We investigated expression levels for mRNA and miRNA involved in radiosensitivity and tumor progression searching for correlations related to patient outcome during LuPRRT therapy.
UNASSIGNED: Thirty-five patients received LuPRRT for G1/G2 midgut NETs between May 2019 and September 2021. Peripheral blood samples were collected prior to irradiation, before and 48 h after the second and the fourth LuPRRT, and at 6-month follow-up. Multiple regression analyses and Pearson correlations were performed to identify the miRNA/mRNA signature that will best predict response to LuPRRT.
UNASSIGNED: Focusing on four mRNAs and three miRNAs, we identified a miRNA/mRNA signature enabling the early identification of responders to LuPRRT with significant reduced miRNA/mRNA expression after the first LuPRRT administration for patients with progressive disease at 1 year (p < 0.001). The relevance of this signature was reinforced by studying its evolution up to 6 months post-LuPRRT. Moreover, nadir absolute lymphocyte count within the first 2 months after the first LuPRRT administration was significantly related to low miRNA/mRNA expression level (p < 0.05) for patients with progressive disease.
UNASSIGNED: We present a pilot study exploring a miRNA/mRNA signature that correlates with early hematologic toxicity and therapeutic response 12 months following LuPRRT. This signature will be tested prospectively in a larger series of patients.

Purpose: This study aims to elucidate the role of quantitative SSTR-PET metrics and clinicopathological biomarkers in the progression-free survival (PFS) and overall survival (OS) of neuroendocrine tumors (NETs) treated with peptide receptor radionuclide therapy (PRRT). Methods: A retrospective analysis including 91 NET patients (M47/F44; age 66 years, range 34-90 years) who completed four cycles of standard 177Lu-DOTATATE was conducted. SSTR-avid tumors were segmented from pretherapy SSTR-PET images using a semiautomatic workflow with the tumors labeled based on the anatomical regions. Multiple image-based features including total and organ-specific tumor volume and SSTR density along with clinicopathological biomarkers including Ki-67, chromogranin A (CgA) and alkaline phosphatase (ALP) were analyzed with respect to the PRRT response. Results: The median OS was 39.4 months (95% CI: 33.1-NA months), while the median PFS was 23.9 months (95% CI: 19.3-32.4 months). Total SSTR-avid tumor volume (HR = 3.6; P = 0.07) and bone tumor volume (HR = 1.5; P = 0.003) were associated with shorter OS. Also, total tumor volume (HR = 4.3; P = 0.01), liver tumor volume (HR = 1.8; P = 0.05) and bone tumor volume (HR = 1.4; P = 0.01) were associated with shorter PFS. Furthermore, the presence of large lesion volume with low SSTR uptake was correlated with worse OS (HR = 1.4; P = 0.03) and PFS (HR = 1.5; P = 0.003). Among the biomarkers, elevated baseline CgA and ALP showed a negative association with both OS (CgA: HR = 4.9; P = 0.003, ALP: HR = 52.6; P = 0.004) and PFS (CgA: HR = 4.2; P = 0.002, ALP: HR = 9.4; P = 0.06). Similarly, number of prior systemic treatments was associated with shorter OS (HR = 1.4; P = 0.003) and PFS (HR = 1.2; P = 0.05). Additionally, tumors originating from the midgut primary site demonstrated longer PFS, compared to the pancreas (HR = 1.6; P = 0.16), and those categorized as unknown primary (HR = 3.0; P = 0.002). Conclusion: Image-based features such as SSTR-avid tumor volume, bone tumor involvement, and the presence of large tumors with low SSTR expression demonstrated significant predictive value for PFS, suggesting potential clinical utility in NETs management. Moreover, elevated CgA and ALP, along with an increased number of prior systemic treatments, emerged as significant factors associated with worse PRRT outcomes.

Pancreatic neuroendocrine tumors (PNETs) arise from neuroendocrine cells and are a rare class of heterogenous tumors with increasing incidence. The diagnosis, staging, treatment, and prognosis of PNETs depend heavily on identifying the histologic features and biological mechanisms. Here, the authors provide an overview of the diagnostic workup (biomarkers and imaging), grade, and staging of PNETs. The authors also explore associated genetic mutations and molecular pathways and describe updated guidelines on surgical and systemic treatment modalities.

Pancreatic neuroendocrine tumors originate from hormone-producing islet cells and have a propensity to metastasize to the liver once they reach 2 cm in size. Their diagnosis relies upon a combination of computed tomography, MRI, DOTATATE PET, and endoscopic ultrasound with or without tissue biopsy. Biochemical work-up is driven by patient symptoms of hormone excess.

UNASSIGNED: Primary intracranial neuroendocrine tumors (NETs) are exceedingly rare, often posing diagnostic challenges, particularly in non-secreting variants. These tumors may initially present with nonspecific symptoms, leading to delayed diagnosis and potential neurological complications.
METHODS: We present the case of a 33-year-old male admitted with a one-year history of progressively worsening headache accompanied by acute left ptosis and diplopia. Initial examination revealed left eye ptosis and hypotropia, indicative of third and fourth cranial nerve paralysis. Cavoscopy revealed a mild anterior wall bulge of the sphenoid with normal mucosa. MRI imaging unveiled an expansive clival process extending towards the sellar region and left cavernous sinus, completely occupying the sphenoid sinus and exerting mass effect on the pituitary stalk. Hormonal assays were within reference ranges, ruling out a hormonally-active tumor. Endoscopic endonasal surgery for biopsy revealed a low-grade neuroendocrine tumor positive for cytokeratin AE1/AE2, chromogranin A, synaptophysin, and beta-catenin, with a Ki-67-labeling index <2 %. Somatostatin receptor scintigraphy confirmed intense hyper fixation of the tracer in the sphenoidal tumor, supporting its neuroendocrine origin. The patient declined surgical intervention after informed consent, opting for C1 somatostatin analogs prior to radiotherapy. One-year follow-up demonstrated symptom stability with no tumor progression.
UNASSIGNED: To this day, no consensus among reports concerning the optimal management of these cases. Imaging assessment is crucial to validate the primary nature of the tumor and to exclude any distant localization. Various therapeutic modalities, such as surgery, radiotherapy, and somatostatin analogs, should be considered based on the specific characteristics and extent of the tumor.
CONCLUSIONS: Our case is a clear reminder that neuroendocrine tumors should be considered as a differential diagnosis for skull base neoplasms.

Peptide receptor radionuclide therapy (PRRT) is an established therapy for metastatic neuroendocrine neoplasms (NEN). The role of PRRT as a neoadjuvant treatment prior to surgery or other local therapies is uncertain. This scoping review aimed to define the landscape of evidence available detailing the utility of PRRT in the neo-adjuvant setting, including the clinical contexts, efficacy, and levels of evidence. A comprehensive literature search of PUBMED, SCOPUS, and EMBASE through to December 2022 was performed to identify reports of PRRT use as neoadjuvant therapy prior to local therapies. Observational studies and clinical trials were included. A total of 369 records were identified by the initial search, and 17 were included in the final analysis, comprising 179 patients treated with neoadjuvant PRRT. Publications included case reports, retrospective cohort series and a phase 2 trial. Definitions of unresectable disease were variable. Radioisotopes used included 177Lu (n = 142) and 90Y (n = 36), used separately (n = 178) or in combination (n = 1). A combination of PRRT with chemotherapy was also explored (n = 2). Toxicity data was reported in 11/17 studies. Survival analysis was reported in 3/17 studies. Surgical resection following PRRT was reported for both the primary tumor (n = 71) and metastases (n = 12). Resection rates could not be calculated as not all publications reported whether resection was completed. Published literature exploring the use of PRRT in the neoadjuvant setting is mostly limited to case reports and retrospective cohort studies. From these limited data there is reported to be a role of PRRT in neoadjuvant setting in the literature. However, the low quality of evidence precludes any definite conclusion on the grade of disease, site of primary, isotope used or use of concomitant chemotherapy that can benefit from this application. Further prospective studies will require collaboration between multiple centers to gain sufficient high-quality evidence.