Endocrine Pathology最新文献

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine malignancy accounting for 1-2% of thyroid carcinomas. As a neuroendocrine neoplasm, it shares molecular features with other aggressive neuroendocrine carcinomas, including alterations in the Myc and Notch pathways. Delta-like ligand 3 (DLL3), an inhibitory ligand of the Notch pathway and a validated therapeutic target in small cell lung carcinoma, has attracted interest as a biomarker and potential target in other neuroendocrine tumors; however, its relevance in MTC remains poorly characterized. We performed a multicenter retrospective study of 119 MTC cases resected between 2000 and 2024 across five European institutions. DLL3 immunohistochemistry was assessed on whole sections using the Ventana SP347 antibody, with expression categorized as null (< 1%), low (1-49%), or high (≥ 50%). Interobserver agreement between two endocrine pathologists was substantial (weighted kappa = 0.80). DLL3 positivity (≥ 1%) was observed in 89.1% of cases; 53.8% showed low and 35.3% high expression. DLL3-high expression correlated with adverse histopathological features, including larger tumor size, high-grade histology, desmoplasia, positive surgical margins, and lymph node metastases. In survival analyses, DLL3-high expression was associated with significantly shorter disease-free survival (HR 7.96, p = 0.05) and overall survival (HR 11.6, p = 0.01). Our findings indicate that DLL3 is frequently expressed in MTC and its high expression identifies tumors with aggressive pathological characteristics and poor clinical outcomes. These results support DLL3 as a potential prognostic biomarker and therapeutic target in MTC, highlighting the need for further validation and integration into clinical trials of DLL3-directed therapies.

Endocrine and neuroendocrine malignancies, including epithelial neuroendocrine neoplasms (NENs), phaeochromocytoma/paraganglioma (PPGL), adrenocortical carcinoma (ACC) and thyroid cancers, represent a heterogeneous group of tumours often characterised by dysregulated receptor tyrosine kinase signalling and with limited systemic treatment options. Cabozantinib is a multikinase inhibitor implicated in tumour angiogenesis, growth, and therapeutic resistance, and its use has been reported in many of these tumours. We performed a narrative review assessing cabozantinib monotherapy or combination regimens in patients with progressive neuroendocrine neoplasms. In NENs, monotherapy achieved a disease control rate (DCR) of up to 83% and a progression-free survival (PFS) of 8.4 months in extra-pancreatic subtypes, and 13.8 months in pancreatic subtypes. Combination therapies yielded modest efficacy with a PFS up to 13.0 months. In metastatic PPGLs, monotherapy achieved an objective response rate (ORR) of 25%, a median PFS of 16.6 months and overall survival (OS) of 24.9 months; combination with atezolizumab showed an ORR of 15.4% and a PFS of 8.4 months. In adrenocortical cancer, the DCR reached 78%, PFS up to 7.2 months, and OS up to 23.9 months. In differentiated thyroid cancer, PFS 11.4 months and OS 26.3 months; in RET M918T-mutant medullary thyroid cancer, OS improved to 44.3 months. Cabozantinib represents a promising therapeutic option across endocrine and neuroendocrine malignancies, particularly in settings with limited treatment alternatives, although the reported rates of control have not been dramatic and adverse effects not insignificant. However, it offers the possibility of exploring more effective molecular approaches, especially with biomarker-based stratification and combinatorial approaches.

The diagnosis and prognosis of follicular thyroid neoplasms are based on the identification of capsular and vascular invasion. Although conventional histology allows accurate classification in most cases, its inherent limitations in tissue sampling can result in misjudgment of both the presence and extent of invasion, and occasionally result in diagnostic inaccuracies. Consequently, unexpected tumor recurrence or overtreatment still represent significant clinical challenges. To mitigate these limitations, emerging diagnostic approaches are exploring advanced imaging modalities. X-ray 3D virtual histology has been reported to enable non-destructive and comprehensive sampling of the entire tumor volume embedded in formalin-fixed paraffin-embedded blocks. In thisstudy, the X-ray 3D virtual histology technique is first evaluated by classifying 99 follicular thyroid carcinomas and 31 follicular adenomas, achieving an accuracy of 89.2%. It is then applied to tissue blocks from five relapse cases that were postoperatively diagnosed as adenomas using conventional histology. Three of five tumors exhibited at least one unequivocal focus of vascular invasion, reinforcing that even a single well-defined focus portends significant risk of recurrence and distant metastasis. Although histological confirmation at this stage remained necessary, X-ray 3D virtual histology proved to be a valuable screening method.

About 40% of non-functioning (NF) Pancreatic Neuroendocrine Tumors (PanNETs) harbour mutations in MEN1, often co-occurring with DAXX/ATRX. While the ADM group (MEN1 and DAXX/ATRX co-mutated) exhibits homogeneous genetic and epigenetic features and a consistent risk of relapse, it shows considerable variability in treatment response, suggesting an underlying molecular diversity. In this study we aimed to elucidate the molecular mechanisms underlying this heterogeneity of ADM PanNETs by integrating transcriptomic (n = 36) and DNA methylation (n = 93) data. First, DNA methylation discriminates ADM-PanNET from PanNET mutated only in MEN1 (α-like), revealing enhancer, peri-centromeric, and telomeric methylation changes associated with alternative lengthening of telomeres and increased chromosomal instability. Transcriptomic analysis further revealed three distinct ADM subtypes: ADM hypoxic, ADM NST (No Special Type), and ADM immunosuppressive. The ADM hypoxic subtype is characterized by strong hypoxia signature, likely regulated epigenetically. The ADM NST subtype appears to be primarily driven by epigenetic changes that promote proliferation. Notably, the ADM immunosuppressive subtype, although significantly smaller (< 2.5 cm, p = 0.023), exhibits strong immune and metastasis-like signatures, suggesting a uniquely aggressive biology despite its reduced size. By defining these three novel ADM subtypes, our study provides a refined framework for understanding PanNET heterogeneity. This classification underscores potential diagnostic markers and highlights distinct biological vulnerabilities that may inform the development of subtype-tailored therapeutic strategies.

Recent studies have shown that pulmonary neuroendocrine tumor (NET) subgroups, defined by the transcription factors OTP and ASCL1, correlate with age, sex, and tumor location. Their relationships with histology and hormone production, however, remain unclear. We analyzed 170 pulmonary NETs classified by OTP (O) and ASCL1 (A) expression into four groups: O + /A + , O + /A-, O-/A + , and O-/A-. Subgroups were assessed for histology, hormone expression, therapy-related markers, outcomes, and matched metastases. Among 152 resected primaries, O + /A + tumors (38%) were most frequent, occurring mainly in females (median age 72 years), and typically showed central or peripheral location, solid/spindle morphology with diffuse gastrin-releasing peptide (GRP), and focal ACTH/calcitonin. They also showed strong DLL3 expression and pronounced neuroendocrine cell hyperplasia. O + /A- tumors (23%) occurred predominantly in females (median age 56 years) with solid/trabecular patterns, occasional/ACTH, and strong SSTR2A/5 expression. O-/A- tumors (25%) were more common in males (median age 70 years), often central with solid/trabecular or oncocytic histology, serotonin expression (24%), and frequently SSTR2A-positivity. O-/A + tumors (14%) occurred across both sexes (median age 58 years), were centrally located, and solid, sometimes oncocytic features with moderate DLL3/SSTR2A expression. Metastases mirrored their primaries in transcription factor and hormone profiles. In the univariate analysis, OTP-negative tumors were associated with poorer disease-free survival (DFS). However, the multivariate analysis identified Ki67-based WHO grades (G1-G3) as the only independent prognostic factors. In conclusion, integrating OTP and ASCL1 refines pulmonary NET classification into four histologically and biologically distinct subgroups, providing additional insight into tumor heterogeneity. O + /A + tumors showed solid-spindle features and diffuse GRP and frequent ACTH expression, trabecular patterns characterized ASCL1-negative tumors, while oncocytic histology predominated in OTP-negative tumors, highlighting their role in defining tumor heterogeneity.

Alkylating agent-based chemotherapy is one of the main treatment options for patients with metastatic pancreatic neuroendocrine tumors (PanNETs).However, it favors the acquisition of a hypermutator phenotype, suggesting a potential benefit of immunotherapy.We aimed to describe the efficacy of immunotherapy in an international retrospective cohort of patients with metastatic well-differentiated PanNETs pretreated with alkylating therapy. The primary endpoint was progression-free survival (PFS) and the main secondary endpoint was the radiological objective response rate (ORR). We explored the impact of tumor mutation burden (TMB) and mismatch repair deficiency (MMRd), and evaluated variables associated with PFS.We included 64 patients with heavily pretreated PanNETs (median Ki-67 28%). Among 51 PanNETs with mutational profiling, 37 (73%) were TMB^high (median 35 mut/Mb). Among 46 PanNETs with available MMR status, 18 (39%) were MMRd, representing 49% of all TMB^high PanNETs. Immunotherapy consisted of a single (31%) or a dual (69%) immune checkpoint inhibitor. Median PFS was 3.2 months (95% CI, 1.3-5.0.3.0) and the ORR was 17%. Patients with TMB^high PanNETs had longer PFS (median 3.8 vs. 2.3 months, p = 0.015) and higher ORR (30% vs. 0%, p = 0.002) compared with TMB^low/unk cases. Patients with MMRd PanNETs had longer PFS (median 8.9 vs. 2.7 months, p = 0.003) and higher ORR (44% vs. 7%, p < 0.001) compared with MMRp/unk. On multivariable analyses, MMRd predicted longer PFS (HR 0.42, 95% CI [0.20-0.82], p = 0.015).Overall, immunotherapy may be effective against alkylating-pretreated metastatic PanNETs exhibiting TMB^high and MMRd. MMR immunohistochemistry and TMB assessment could be implemented in the routine assessment of alkylating-pretreated metastatic PanNETs.