Endocrine Pathology最新文献

Formalin-fixed paraffin-embedded (FFPE) tissue samples are important for genomic analysis of thyroid carcinomas, particularly for various molecularly targeted therapies. Therefore, this study developed and validated a technique for preparing FFPE tissue samples that preserves nucleic acid quality, which is fundamental for precise genomic analysis, more effectively than conventional methods. We analyzed surgically resected thyroid gland tumors, lymph node metastases, and separately fixed tumor samples to optimize formalin fixation and assess the influence of specimen type and preparation methods on nucleic acid quality. We assessed several quality indicators, including the DNA integrity number, cycle threshold ratio, RNA integrity number, and DV200. Separately fixed tumor samples consistently exhibited higher DNA and RNA quality than conventionally processed samples. Additionally, lymph node metastases often exhibit nucleic acid quality matching or exceeding that of thyroid gland tumors, highlighting their potential reliability for genomic analysis. These findings suggest the utility of various specimen types for the comprehensive genetic profiling of thyroid carcinomas. In conclusion, this study demonstrated that preparing separately fixed tumor samples is an effective method for preserving DNA and RNA quality for genomic analyses. Biopsy punches enable specimen collection at various facilities, including those without the ability to handle frozen specimens. This contributes to the development of a method for obtaining high-quality pathological samples that can be widely used in general medical practice. Moreover, lymph node metastases often exhibit nucleic acid quality equal to or superior to that of thyroid gland tumors, highlighting their potential as acceptable sources for genomic analyses.

High-grade or grade 3 epithelial neuroendocrine neoplasms (G3 NEN) are now divided into grade 3 well-differentiated neuroendocrine tumor (G3 NET) and neuroendocrine carcinoma (NEC), both defined by Ki-67 > 20% and/or > 20 mitoses per 2 mm². NET and NEC are thought to be distinct tumors with different genetic profiles: NEC classically harbors co-alteration of TP53 and RB1, whereas NET genetics are site-dependent with frequent alterations in MEN1, ATRX, DAXX, and TSC1/2 in pancreatic NETs. Progression from NET to NEC is considered rare and is not well described. While both TP53 and RB1 alterations were initially thought to be rare in NET, recent work has demonstrated the former in up to 35% of high-grade G3 NET and the latter in rare high-grade NEN that progressed from NET. Here, we describe the clinical, pathologic, and molecular features associated with tumor evolution in a series of five patients that had low-grade NET that progressed to high-grade NEN with co-alteration of RB1 and TP53, similar to NEC. Morphology of the high-grade neoplasms remained well-differentiated in some cases despite RB1/TP53 co-alteration and had some NEC-like features in other cases. All five patients died of disease, with a mean overall survival of 41 months from the first metastatic disease and 12 months from acquisition of RB1/TP53 co-alteration. Our data demonstrate that low-grade NET can progress via the acquisition of both TP53 and RB1 alteration, similar to NEC, but whether this represents a transformation from NET to NEC remains unclear.

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive thyroid malignancy typically comprised of undifferentiated tumor cells with various histologic morphologies, which makes the diagnosis challenging. These tumors commonly show loss of thyroglobulin and TTF1 with preservation of cytokeratin (67%) and Paired Box Gene 8 (PAX8) (55%) expression. Identification of a sensitive immunohistochemical stain to aid in the diagnosis of ATC would be beneficial. Immunohistochemistry (IHC) against special AT-rich sequence-binding protein 2 (SATB2) protein is a sensitive and specific marker expressed in colorectal adenocarcinoma and bone or soft tissue tumors with osteoblastic differentiation. However, SATB2 is also expressed in other sarcomatous/undifferentiated neoplasms lacking osteoblastic differentiation. Using quantitative reverse transcription PCR (RT-qPCR) we showed that there is variable expression of SATB2 mRNA expression in ATCs. To evaluate the role of SATB2 protein expression in ATC, we performed PAX8, SATB2, pancytokeratin (AE1/AE3 & CAM5.2), claudin-4 and TTF1 immunostaining on 23 cases. ATCs showed retained expression of PAX8 in 65% (15/23); SATB2 was detected in 74% (17/23); pancytokeratin was expressed in 65% (15/23); claudin-4 was expressed in 35% (8/23) and TTF1 showed expression in 13% (3/23) of cases. Furthermore, 83% (5/6) of ATCs which lacked SATB2 expression, retained PAX8 expression, while 88% (7/8) of the tumors without PAX8 expression were positive for SATB2. Differentiated follicular cell-derived thyroid cancers (n = 30), differentiated high grade thyroid carcinoma (n = 3), and poorly differentiated thyroid carcinoma (n = 8) were negative for SATB2 immunoreactivity. Next-generation selected cases detected the commonly identified oncogenic variants including those in BRAF, RAS, TP53, and TERT promoter. Overall, we hereby demonstrate that SATB2 IHC may be used to support the diagnosis of ATC.

Oncocytic thyroid tumors are characterized by an elevated mitochondrial density within the cells, distinguishing them from other thyroid tumors, exhibit distinct clinical behaviors, including increased invasiveness and iodine therapy resistance. However, the proteomic alterations in oncocytic thyroid tumors remain inadequately characterized. In this study, we analyzed 156 Asian patients with oncocytic thyroid adenomas (OA) and carcinomas (OCA) to explore their clinical, genetic, and proteomic features. Genetic testing of 73 samples revealed frequent mutations in TERT, NRAS, EIF1AX, EZH1, and HRAS, with TERT promoter mutations being exclusive to OCAs. Proteomic analysis identified 66 mitochondrial-specific proteins significantly highly expressed in oncocytic tumors than in non-oncocytic tumors. This led to the development of a thyroid oncocytic score (TOS) to quantify oncocytic characteristics. Among these proteins, isocitrate dehydrogenase 2 (IDH2) was substantially overexpressed in oncocytic tumors and further confirmed by immunohistochemistry in oncocytic tumor slides (n = 41) and non-oncocytic tumor slides (n = 40). Moreover, IDH2 is significantly overexpressed in OCA compared to OA highlighting its potential as a biomarker for differential diagnosis of oncocytic tumors and malignancy. These findings improve the understanding of oncocytic thyroid tumors molecular pathology and suggest IDH2 as a valuable marker for clinical management.

Inhibiting the immune checkpoint (ICP) PD-1 based on PD-L1 expression status has revolutionized the treatment of various cancers, yet its efficacy in anaplastic thyroid carcinoma (ATC) remains limited. The therapeutic response depends upon multiple factors, particularly the conduciveness of the tumor's immune milieu. This study comprehensively evaluated and classified ATC's immune microenvironment (IME) to elucidate the factors behind suboptimal response to anti-PD therapy. Utilizing multiplex-immunofluorescence and immunohistochemistry, we retrospectively analyzed 26 cases of ATC for expression of ICPs PD-L1, PD-1, CTLA4, TIM3, and Galectin-9 and tumor-infiltrating cytotoxic T lymphocytes (CTL)-the effector cells, the anti-tumor NK cells, the immune-inhibitory myeloid-derived suppressor (MDSC) and regulatory T (Treg) cells, and B lymphocytes. Most ATCs (65%) exhibited PD-L1 positivity, but only 31%, in addition, had abundant CTL (type I IME), a combination associated with a better response to ICP inhibition. Additionally, PD-1 expression levels on CTL were low/absent in most cases-a "target-missing" situation-unfavorable for an adequate therapeutic response. All but one ATC showed nuclear Galectin-9 expression. The documentation of nuclear expression of Galectin-9 akin to benign thyroid is a first, and its role in ATC pathobiology needs further elucidation. In addition to less abundant PD-1 expression on CTL, the presence of MDSC, Treg, and exhausted cytotoxic T lymphocytes in the immune milieu of ATC can contribute to anti-PD resistance. TIM3, the most frequently expressed ICP on CTL, followed by CTLA4, provides alternate therapeutic targets in ATC. The co-expression of multiple immune checkpoints is of great interest for ATC since these data also open the avenue for combination therapies.

Pheochromocytomas (PCCs) and paragangliomas (PGLs, together PPGLs) are the most hereditary tumors known. PPGLs were considered benign, but the fourth edition of the World Health Organisation (WHO) classification redefined all PPGLs as malignant neoplasms with variable metastatic potential. The metastatic rate differs based on histopathology, genetic background, size, and location of the tumor. The challenge in predicting metastatic disease lies in the absence of a clear genotype-phenotype correlation among the more than 20 identified genetic driver variants. Recent advances in molecular clustering based on underlying genetic alterations have paved the way for improved cluster-specific personalized treatments. However, despite some clusters demonstrating a higher propensity for metastatic disease, cluster-specific therapies have not yet been widely adopted in clinical practice. Comprehensive genomic profiling and transcriptomic analyses of large PPGL cohorts have identified potential new biomarkers that may influence metastatic potential. It appears that no single biomarker alone can reliably predict metastatic risk; instead, a combination of these biomarkers may be necessary to develop an effective prediction model for metastatic disease. This review evaluates current guidelines and recent genomic and transcriptomic findings, with the aim of accurately identifying novel biomarkers that could contribute to a predictive model for mPPGLs, thereby enhancing patient care and outcomes.

Pituitary neuroendocrine tumors (PitNET) that metastasize comprise ~ 0.2% of adenohypophyseal tumors are aggressive and are challenging to treat. However, many non-metastatic tumors are also aggressive. Herein, we review 21 specimens from 13 patients at UCSF with metastatic PitNETs (CSF or systemic, N = 7 patients), high-grade pituitary neuroendocrine neoplasms (HG-PitNEN, N = 4 patients), and/or PitNETs with sarcomatous transformation (PitNET-ST, N = 5 patients). We subtyped cases using the World Health Organization (WHO) and International Agency for Research on Cancer (IARC) criteria for neuroendocrine neoplasms (NENs). Lineage subtypes included acidophil stem cell, null cell, thyrotroph, corticotroph, lactotroph, and gonadotroph tumors. The median Ki-67 labeling index was 25% (range 5-70%). Lack of p16 was seen in 3 cases, with overexpression in 2. Strong diffuse p53 immunopositivity was present in 3 specimens from 2 patients. Loss of Rb expression was seen in 2 cases, with ATRX loss in one. Molecular analysis in 4 tumors variably revealed TERT alterations, homozygous CDKN2A deletion, aneuploidy, and mutations in PTEN, TP53, PDGFRB, and/or PIK3CA. Eight patients (62%) died of disease, 4 were alive at the last follow-up, and 1 was lost to the follow-up. All primary tumors had worrisome features, including aggressive lineage subtype, high mitotic count, and/or high Ki-67 indices. Additional evidence of high-grade progression included immunohistochemical loss of neuroendocrine, transcription factor, and/or hormone markers. We conclude that metastatic PitNET is not the only high-grade form of pituitary NEN. If further confirmed, these histopathologic and/or molecular features could provide advanced warning of biological aggressiveness and be applied towards a future grading scheme.

Little is known about the morphomolecular features of G3 neuroendocrine tumors (G3NETs) under prolonged systemic treatments, although rapid progression is increasingly observed. This longitudinal study aims to elucidate the course and morphomolecular features of metastasized G3NETs with high-grade transformation. Clinical and histological findings in 40 patients with metastasized and treated G3NETs, which were histologically examined at least twice with an interval time of more than 6 months (median 27), were reviewed and the morphomolecular changes recorded and assigned to treatment. Neuroendocrine carcinoma (NEC)-like histology defined by high-grade atypia, diffuse growth pattern, and/or necrosis was identified in nine (22%) G3NETs (seven pancreatic, two rectal) patients. All NEC-like tumors showed a significantly higher Ki67 increase and longer interval time between first and last examination than non-NEC-like G3NETs (53 vs. 19% and 60 vs. 24 months, respectively). Moreover, all NEC-like G3NETs had TP53 (100%), but rarely RB1 (12%) mutations, and retained NET-typical mutations such as MEN1 or DAXX (five of the pancreatic NETs). The last treatments received prior to the NEC-like transformation included PRRT (n = 3), somatostatin analog, everolimus, sunitinib (n = 1 each), and alkylating agents (n = 2). Abrupt clinical progression in patients with metastasized G3NETs is associated with a significant increase in Ki67, accelerated growth, and NEC-like histology. These findings are most likely attributable to the novel TP53 mutation, which was detected in all nine cases at the last evaluation. However, none of the cases exhibited a complete transformation to a typical NEC, as the tumors retained partial histological and genetic features of NETs.

De-escalation of thyroid cancer treatment is crucial to prevent overtreatment of indolent disease, but it remains important to identify clinically aggressive cases. TERT promoter mutations are molecular events frequently associated with high-risk thyroid tumors with poor outcomes and may identify cases at risk of dissemination. In various international guidelines, small minimally invasive follicular thyroid carcinoma and oncocytic thyroid carcinoma (miFTC/miOTC) are classified as low-risk lesions and are not recommended adjuvant treatment. Our study aimed to explore the association between size-based risk assessment and TERT promoter mutations. Between 2019 and May 2024, 84 miFTCs/miOTCs diagnosed at our department underwent digital droplet PCR analysis targeting TERT promoter mutational hotspots C228T and C250T in clinical routine. TERT promoter mutations were found in 10 out of 84 cases (11.9%). Mutated cases were pT1 (n = 1), pT2 (n = 3), or pT3 (n = 6). Patients with mutated tumors were older compared to patients with wild-type tumors (median age of 71 years vs. 57 years, p = 0.041). There were no significant differences regarding patient sex, tumor size, Ki-67 labeling index, or the presence of distant metastases. Notably, 30% of mutations displayed variant allele frequencies < 10%, possibly suggesting subclonal events. To conclude, TERT promoter mutations in miFTCs and miOTCs were associated with higher patient age and were often suspected to be subclonal. However, they did not affect clinical outcomes, possibly due to short follow-up. Reflex testing for this genetic alteration in miFTCs and miOTCs could be justified regardless of tumor size, though the clinical benefit remains uncertain.