Colorectal cancer (CRC) remains a leading cause of global cancer-related mortality. Cytidine triphosphate synthase 1 (CTPS1) is an essential enzyme for DNA synthesis and cell cycle progression. While CTPS1 has been implicated in the pathogenesis of various malignancies, its clinical significance in colorectal adenocarcinoma remains poorly defined. This study aimed to investigate the immunohistochemical (IHC) expression of CTPS1 in colorectal adenocarcinoma and evaluate its association with clinicopathological features and survival outcomes. CTPS1 expression was assessed via IHC in 168 colorectal adenocarcinoma specimens and 142 matched adjacent non-neoplastic tissues. Statistical associations with clinicopathological parameters were analyzed using χ 2 or Fisher exact tests. Progression-free survival (PFS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method and compared via the log-rank test. Multivariate Cox proportional hazards regression was employed to identify independent prognostic factors. CTPS1 expression was significantly upregulated in tumour tissues compared with adjacent normal mucosa ( P <0.001). High CTPS1 expression was observed in 55.4% of tumor samples and significantly correlated with advanced T stage, TNM stage, and modified Dukes staging, as well as nodal involvement, distant metastasis, tumor recurrence, and elevated serum CEA levels. Furthermore, elevated CTPS1 was associated with aggressive histologic features, including higher grade, tumor budding, poorly differentiated clusters (PDCs), and tumor deposits. Both PFS and DFS were significantly shorter in patients with high CTPS1 expression ( P <0.001). Multivariate analysis confirmed that high CTPS1 expression, along with nodal status and tumor recurrence, was an independent prognostic factor for both PFS and DFS. Therefore, CTPS1 is a robust independent prognostic indicator and a marker of aggressive progression in colorectal adenocarcinoma. These findings suggest that CTPS1 is a promising biomarker for risk stratification and may guide clinical decision-making in the management of CRC.
Follicular dendritic cell sarcoma (FDCS) is a rare malignant neoplasm commonly found in extranodal sites with unclear pathogenesis. Tumor cells typically exhibit a spindled morphology, whereas epithelioid morphology is rarely reported. Here, we have presented a rare biphasic FDCS with distinct immunophenotypic and molecular characteristics. A 63-year-old female presented with constipation and rectal bleeding. Imaging revealed an 11.4 cm lobulated enhancing soft tissue mass in the posterior pelvis. H&E sections revealed 2 sharply demarcated biphasic neoplastic populations: one population comprised spindled cells expressing CD21, CD23, CD35, clusterin, EMA, and D2-40; the other population consisted of epithelioid cells lacking CD21 and other FDC-associated markers except for focal weak clusterin expression. Both populations tested negative for CD163, CD68, S-100, langerin, CD1a, ALK-1, CD30, CD117, HMB45, Pan-CK, and EBER. The tumor was initially misdiagnosed as a collision (FDCS and perivascular epithelioid cell tumor) tumor. Molecular studies revealed a nearly identical mutational profile in both components confirming clonal identity and ruling out a composite tumor. In addition, low-level pathogenic mutations (variant allele frequency <10%) were found in GABRA6, ICOSLG, and VEGFA, alongside altered transcript expression in PDGFRB in both populations. Although no RNA fusions were detected, we demonstrated a significant increase in PDGFRB expression using the RNA Salah Targeted Expression panel, with a log 2 ratio > 2, indicating a more than 4-fold increase compared with a pooled normal control. Here, we have provided molecular characterization of biphasic FDCS. Prior such characterization seems to be unavailable in the literature.
Phyllodes tumors (PTs) are rare fibroepithelial breast tumors, albeit clinically significant. This study was implemented to investigate the immunohistochemical (IHC) expression of cyclin D1 in PT subtypes and in metaplastic spindle cell carcinoma. Fifty-three resected cases of PT subtypes were analyzed. IHC analysis assessed the percentage of positive stromal tumor cells and the intensity of cyclin D1 staining. The score was classified as either negative, low, or high positive. Statistical analysis was implemented to evaluate the outcomes. Significant variations in scores were observed among various subtypes of PT, with cyclin D1 exhibiting positive nuclear expression in the stromal component of borderline and malignant tumors (P=0.001). Malignant PTs also showed significantly different cyclin D1 expression compared with triple-negative metaplastic spindle cell carcinoma (P=0.028). Tumor recurrence was significantly associated with high cyclin D1 expression (P=0.013). Receiver Operating Characteristic (ROC) curve analysis demonstrated moderate discriminatory ability, with an area under the curve (AUC) of 0.701 (95% CI: 0.535-0.856, P=0.023). Univariate analysis confirmed high cyclin D1 expression as a predictor of recurrence (P=0.035). In conclusion, cyclin D1 overexpression provides insights into tumor progression and prognosis in PTs. Notably, positive cyclin D1 expression in metastatic malignant PT could be a diagnostic challenge, if not carefully considered within clinical context. Furthermore, the significant difference in cyclin D1 expression between malignant PT and triple-negative metaplastic spindle cell carcinoma highlights its potential utility in distinguishing between them.
Pituitary adenoma (pituitary neuroendocrine tumor) can present a diagnostic pitfall when it involves the sinonasal tract ectopically or by direct extension due to morphologic and immunohistochemical overlap with sinonasal small round blue cell tumors. T-box transcription factor (T-PIT), pituitary-specific transcription factor (PIT-1), and steroidogenic factor 1 (SF-1) have emerged as lineage-specific markers for corticotroph, somatotroph, and gonadotroph-type adenomas, respectively, but have not been extensively tested in sinonasal tumors. We examined T-PIT, PIT-1, and SF-1 expression across sinonasal and skull base tumors to assess their specificity in this differential diagnosis. Staining for T-PIT, PIT-1, and SF-1 was performed on tissue microarrays including 199 sinonasal tumors and 12 nonsinonasal head and neck neuroendocrine carcinomas. Whole tissue sections from 20 adenomas, 2 olfactory carcinomas, and 1 Merkel cell carcinoma of nasal skin also underwent staining for all 3 markers, while 9 other sinonasal or skull base tumors underwent staining for T-PIT and PIT-1 only. All 223 sinonasal tumors and neuroendocrine carcinomas of the head and neck were negative for T-PIT and PIT-1. Only 7 of 214 nonpituitary tumors (3.3%) showed SF-1 expression, including 2 of 43 HPV-positive squamous cell carcinomas, 1 of 75 HPV-negative squamous cell carcinomas, 2 of 8 SMARCB1-deficient sinonasal carcinomas, 1 of 4 salivary neuroendocrine carcinomas, and 1 of 5 NUT carcinomas. All pituitary tumors stained as expected. These findings demonstrate that T-PIT and PIT-1 are highly specific for pituitary origin, while SF-1 shows limited off-target expression in certain high-grade sinonasal tumors with chromatin remodeling (e.g., NUT carcinoma and SMARCB1-deficient carcinoma).
Although immune checkpoint inhibition has proven to be efficacious in a subset of breast cancer patients, there remains a heterogeneity in clinical responses. Major histocompatibility complex class I (MHC I) expression has been touted as a possible predictor of response to immune checkpoint inhibition given its role in the adaptive immune system. Loss of tumoral MHC I expression in breast cancer as an evasion of immune checkpoint inhibition has been described; however, outcome data are limited. We herein evaluate the relationship between PD-L1 and MHC I expression and response to PD-1/PD-L1 inhibitors in a cohort of treated metastatic triple-negative breast cancer (TNBC) patients. Best treatment response was assessed in 46 metastatic TNBC patients treated with anti-PD-1/PD-L1 immune checkpoint inhibition with or without chemotherapy. Primary tumors were evaluated by immunohistochemistry (IHC) for expression of PD-L1 and MHC I. PD-L1 was scored via the combined positive score (CPS). MHC I was evaluated for retention, partial loss (≥10%), or complete loss within the tumor cells. Models using logistic ordinal regression were constructed to determine the ability of PD-L1 and MHC I by IHC to predict treatment response. The best responses by RECIST 1.1 were 16 (34%) with complete response (CR), 15 (33%) with partial response (PR), and 15 (33%) with stable or progressive disease (no response; NR). Of the patients with CR, 13 (87%) had retained MHC, and of those, 12 (92%) were positive for PD-L1. Of the patients with PR, 7 (47%) had retained MHC, and of those, 4 (57%) were positive for PD-L1. Of the patients with NR, 8 had partial or complete loss of MHC (53%), and of those, all (100%) expressed PD-L1. We found that MHC I status is independently and significantly associated with treatment response ( P =0.024), with intact MHC I more common in complete responders and partial or complete loss of MHC I more common in partial responders and nonresponders. We found no association between PD-L1 expression alone with treatment response in our cohort of TNBC patients. Loss of tumoral MHC I expression is more frequently seen in patients without treatment response, despite most of these tumors having some PD-L1 expression (CPS ≥1). Using a logistical ordinal regression model, we found that both MHC I and binary PD-L1 (bPD-L1) status play significant roles in the prediction of grouped treatment response (MHC I P =0.002 and bPD-L1 P =0.03). Additional studies evaluating MHC I loss as a potential barrier to successful immune checkpoint inhibition are needed to ascertain the potential use of MHC I as a predictive biomarker in combination with PD-L1.
The TP53 gene is the most frequently mutated gene in human cancers, with alterations occurring in ∼50% of all malignancies. When properly optimized, p53 immunohistochemistry (IHC) can serve as a reliable surrogate for detecting TP53 mutations. However, many laboratories struggle to identify p53 IHC reaction patterns beyond overexpression, particularly the absence, cytoplasmic, and wild-type patterns. As the clinical relevance of these additional patterns became recognized, NordiQC updated its assessment in 2021 to include wild-type and absence patterns, thereby increasing the complexity of p53 IHC and revealing widespread difficulties across laboratories. In this study, we analyze data from 6 consecutive NordiQC external quality assessment rounds from 2007 to 2024, covering 1,796 submitted p53 IHC assays. Our findings show that while most laboratories can reliably detect high antigen expression of overexpression, many protocols fail to adequately demonstrate low-level p53 expression, limiting the validity of the IHC assay. Ready-To-Use products, particularly when used according to manufacturer recommendations, performed suboptimally. These kits are calibrated exclusively to detect overexpression, leading to false-negative or too-weak results for other mutation-associated patterns. Our data represents the most comprehensive evaluation of p53 IHC assay performance to date. The findings underscore an urgent need to recalibrate p53 IHC protocols, with a special focus on improving analytical sensitivity and ensuring consistent use of both internal and external controls. Aligning IHC assays calibrated to identify the full spectrum of TP53 mutations, including those that result in absent and wild-type patterns, can significantly enhance the diagnostic accuracy of p53 IHC.
Paget disease (PD) is histologically characterized by malignant glandular epithelial cells singly or in clusters within the epidermis. PD most commonly involves the nipple, though it may also occur at extramammary sites. Immunohistochemistry is helpful in highlighting PD and its extent. Differentiating PD from histologic mimics with overlapping immunophenotypes can be challenging. TRPS1, a GATA family transcription factor, has emerged as a breast origin marker with greater sensitivity than GATA3. In this study, we comprehensively examined the immunohistochemical expression of TRPS1 in mammary PD (n=29) with different biomarker profiles, including ER-/HER2+ (n=12), ER+/HER2+ (n=7), ER+/HER2- (n=6), and ER-/HER2- (n=4) cases, as well as benign and malignant histologic mimics and extramammary PD (EMPD). TRPS1 demonstrated strong to moderate nuclear staining of PD tumor cells across all ER/HER2 subgroups. Toker cells/Toker cell hyperplasia (n=11) also exhibited strong TRPS1 immunoreactivity, while melanoma in situ (n=10) and cutaneous sebaceous carcinoma (n=9) were essentially negative. Squamous cell carcinoma in situ (n=13) showed predominantly weak staining for TRPS1. Two cases of presumed intraepidermal metastases in patients with breast cancer demonstrated strong TRPS1 expression. Notably, TRPS1 highlighted PD tumor cells from background keratinocytes more distinctly compared with GATA3. Among EMPD cases, perivulvar (n=10) and periscrotal (n=5) cases were consistently positive, whereas perianal lesions (n=10) showed no/weak expression. In summary, TRPS1 demonstrates universal expression in mammary PD of all ER/HER2 subgroups and in Toker cells, and corroborates recent reports regarding the utility of TRPS1 in site-of-origin studies.
Trophoblast cell surface antigen 2 (TROP2) is a popular current antibody-drug conjugate target due to its high expression in various solid tumor types. With the recent FDA-approval of sacituzumab govitecan and datopotamab deruxtecan in breast cancer, TROP2-targeting therapies showed promising clinical outcomes. Despite the prevalent expression of TROP2 in breast cancer (about 90%), the objective response rates from clinical trials are around 30% with nonsignificant hazard ratios for benefit from sacituzumab govitecan in low TROP2-expressing tumors. This suggests that there may be value in a companion diagnostic assay to measure TROP2 protein expression in tumor samples, but H-score assessment is not required. Here, we develop a quantitative immunofluorescence (QIF) assay and a quantitative hematoxylin-DAB (QH-DAB) assay for potential use as a future companion diagnostic test. TROP2 peptide concentrations were measured in cell lines using mass spectrometry to convert fluorescent signal or chromogen optical density to protein concentrations in amol/mm2. Coupled with QuPath-based image analysis tool Qymia, our QIF and QH-DAB assays have limits of detection of 90 amol/mm2 and 667 amol/mm2, and limits of quantifications of 272 amol/mm2 and 2021 amol/mm2, respectively. Using these assays, we measured the TROP2 expression in a breast cancer serial cohort (N=264) and a triple-negative breast cancer cohort (N=100) from Yale New Haven Hospital, identifying a broad dynamic range of TROP2 expression in breast cancer samples. Since the H-score method is the current standard of practice in the clinics, we selected 68 breast cancer biopsies and compared the measurements from our assays to H-scores evaluated by 5 certified pathologists. There is an overall agreement between our QIF and QH-DAB measurements and pathologists' readings. However, the quantitative assay has better sensitivity and less subjectivity. In summary, these assays allow for an accurate and reproducible TROP2 protein measurement that could be incorporated into a clinical workflow. This work represents only analytic validation, but work on clinical validation has begun. In the future, this assay may help identify patients who are more likely to benefit from TROP2-targeted therapies.
Validation in immunohistochemistry is a well-established and regulated process when it pertains to assays. However, little guidance currently exists on how to best validate automated instrumentation, including validation of a completely new platform or validation of a new instrument of the same make and model. Here, we share insights gained from our laboratory's recent instrument validations, identifying key challenges such as variability in stain intensity related to tissue location on slides and the prevalence of "cold zones" affecting stain interpretation. Through these scenarios, we emphasize the importance of a robust validation plan that incorporates diverse assay-tissue combinations, strategic tissue placement, and the evaluation of larger tissue sections. In addition, we advocate for vendors to enhance their instrument testing protocols to proactively identify subtle performance issues. We propose a framework for more effective validation strategies, including emerging quantitative technologies in this field.
Molecular alterations in the CDKN2A gene have been identified as a poor prognostic marker in a small subset of gastrointestinal stromal tumors (GISTs). Investigations into the potential utility of p16 protein loss by immunohistochemistry (IHC) as a surrogate marker of CDKN2A deletion have revealed contradictory findings in various cancers. Recently, high concordance of MTAP and CDKN2A codeletion has been identified, suggesting the potential use of MTAP as a surrogate marker for CDKN2A deletion in various other tumor types. Our objective was to investigate the prognostic significance of MTAP and p16 expression in GISTs, with the aim of shedding light on its potential in refining risk stratification and optimizing patient management. We assembled our institutional cohort of 225 surgically resected GISTs. MTAP and p16 immunohistochemical stains were performed on the tissue microarrays, and we recorded the cytoplasmic expression (for MTAP) or cytoplasmic/nuclear (for p16) as negative (loss), weak to moderate/heterogenous (wild type), or strong diffuse (overexpression). We found MTAP loss in 11 (5%) cases and overexpression in 40 (18%), while p16 overexpression was found in 5 (2%) cases and loss in 45 (21%). Overexpression as well as loss of MTAP and p16 expression correlated with the presence of epithelioid histology (either pure or mixed with a spindle cell component), higher grade and pT-stage, necrosis, higher NCCN risk groups, and widespread disease at presentation. Overexpression as well as loss of MTAP and p16 expression predicts shortened progression-free survival and is associated with various known poor prognostic clinicopathologic parameters.
Mesothelin is a surface glycoprotein overexpressed in several solid tumors and a known immunotherapy target. While present on blast cells in acute myeloid leukemia (AML), its role in acute lymphoblastic leukemia (ALL) remains unclear. This study evaluated mesothelin expression in 181 newly diagnosed acute leukemia cases using immunohistochemistry (IHC) on bone marrow biopsies and ELISA on plasma samples. Mesothelin was expressed in 31% of pediatric and 15% of adult AML cases (n=65), with no significant differences among AML subtypes. It was absent or rare in ALL (n=51) and undetectable in normal bone marrow. In AML, mesothelin was detected in 49% of CD38⁺, 60% of CD64⁺, 62.5% of KMT2A-rearranged, and 69% of core binding factor AML [83% with inv(16)/ t (16;16) , 57% with t (8;21) ]. It was largely absent in cases with NPM1 (87.5%), GATA2, and DNMT3A mutations. Expression correlated significantly with age, CD38, CD64, and mutations in NPM1, GATA2, DNMT3A, and KDM6A. No significant association was found between mesothelin expression and 5-year overall or event-free survival, measurable residual disease, remission, or relapse. In ALL, 83.3% of T-ALL and 85% of B-ALL cases showed no expression. However, mesothelin correlated with CD11c, PHF6, and CBLC mutations in ALL. Soluble mesothelin was present in 17.6% of AML and 2.7% of ALL cases (all adults), but not in healthy individuals. In AML, it correlated with CD33 expression and inv(16)/ t (16;16) . In conclusion, mesothelin is rare in ALL but enriched in specific AML subtypes and not prognostic for survival.
BACKGROUND:Signal transducer and activator of transcription 3 (STAT3), a transcription factor and Integrin αvβ6 (ITGB6), a transmembrane protein are upregulated in a wide array of cancers. Oral squamous cell carcinoma (OSCC) has an invasive potential and a tendency to metastasize chiefly to cervical lymph nodes ultimately affecting the survival rate. This study endeavours to determine the role and correlation of STAT3 and ITGB6 in OSCC with and without lymph node metastasis and their association with overall survival. MATERIAL AND METHODS:A total of 100 cases of OSCC were included, comprising 50 cases with lymph node metastasis (nodal group) and 50 without nodal metastasis (non-nodal group). All cases were assessed histologically for prognostic scoring and were immunohistochemically stained using STAT3 and ITGB6 markers. Clinicopathological parameters with STAT3 and ITGB6 immunoexpressions along with overall survival with a mean follow-up period of 48 months were assessed as Immunoreactive score (IRS). RESULTS:Significantly stronger expression (IRS 2) of STAT3 and ITGB6 was observed in OSCC cases with lymph node metastasis. The nodal group with stronger STAT3 and ITGB6 expressions showed lower survival although no statistically significant differences were found. These markers showed prognostic significance independently, but no significant correlation was observed between the 2. CONCLUSION:On the basis of our findings, STAT3 and ITGB6 were statistically associated with lymph node metastasis. Thus, we hypothesised that their increased expression can lead to the migration of cancer cells, resulting in lymph node metastasis and affecting overall survival. Further understanding of the signalling pathways mediating STAT3 and ITGB6 may help identify valid therapeutic targets for OSCC patients.
The present study assessed the expression of different isoforms of PPAR, an important regulator of cell metabolism and proliferation, in meningiomas and correlated it with different clinicopathological variables and clinical outcomes. A total of 238 meningiomas were studied, including grade 1 (n=133), grade 2 (n=66), grade 3 (n=2), and brain-invasive otherwise benign meningiomas (BIOB) (n=37). The expression of PPAR-γ, phosphorylated PPAR-γ, and PPAR-β was assessed by immunohistochemistry. A semiquantitative grading was used to classify the cases into high and low expression. High nuclear and cytoplasmic immunoreactivity of PPAR-γ was significantly more frequent in grade 2 meningiomas than in grade 1 or BIOB ( P =0.023, 0.006 for nuclear expression, and 0.001, 0.004 for cytoplasmic expression, respectively). It was also associated with higher proliferative activity and p53 positivity ( P =0.002 and 0.001, respectively). Phosphorylated PPAR-γ and PPAR-β expression did not show any association with grade. PPAR-γ immunoreactivity, extent of resection, and histologic grade were associated with overall survival (OS) [ P =0.031 (nuclear)/0.005 (cytoplasmic), 0.002, and <0.001, respectively]. Interestingly, BIOB cases had OS similar to grade 2 tumors, significantly shorter than that of their grade 1 counterparts. Further, high PPAR-γ expression was associated with better outcomes with no death in patients who received adjuvant radiotherapy. The present study, for the first time, highlights that PPAR expression is implicated in the pathobiology of meningiomas and has prognostic implications, especially in cases receiving radiotherapy. Considering the availability of PPAR modulatory drugs, it may be an important therapeutic target. In addition, the meticulous examination of the brain invasion still holds significant promise for prognostication.
To observe and analyze the variation status of BRAF, K-RAS, N-RAS, RET, TERT and PIK3CA genes and the expression of PD-L1 immune factors in patients with papillary thyroid carcinoma (<1 cm in diameter) combined with lateral cervical lymph node metastasis, and to further explore the potential relationship and significance between the above 7 indexes and clinical ultrasound pathology and multiple parameters of ER, PR, and KI-67 protein. Seventy-eight cases of papillary thyroid carcinoma (<1 cm in diameter) combined with lateral cervical lymph node metastasis diagnosed after the first treatment in Yantai Yuhuangding Hospital from April 1, 2013, to April 1, 2021, were retrospectively analyzed (another 102 cases were not included in this study due to incomplete information), and the relevant clinical ultrasonic pathologic data were collected. The tumor DNA was extracted and the mutations of BRAF, K-RAS, N-RAS, RET, TERT, and PIK3CA were analyzed by ARMS fluorescence quantitative PCR. The expressions of PD-L1, ER, PR, and KI-67 were detected by immunohistochemistry. There were 78 patients of papillary thyroid carcinoma (<1 cm in diameter) combined with lateral cervical lymph node metastasis, including 20 males (mean age: 32.75 y) and 58 females (mean age: 49.97 y). Other clinical ultrasound pathologic parameters include: (1) preoperative serological thyroid function analysis includes TSH, FT4, FT3, TGAB, ATPO, and TRAB. (2) Ultrasound abnormalities include calcification, aspect ratio ≥1, unclear boundary and irregular shape. (3) Pathologic image analysis included tumor size, capsule invasion, extraglandular strap muscle invasion, the number of lymph node metastasis and the expression of ER, PR, and KI-67. (4) Postoperative I131 treatment. Combined molecular detection showed that, in 78 cases, BRAF gene mutation was the most common (52 cases), followed by N-RAS gene mutation (30 cases), then K-RAS (12 cases), TERT (7 cases), and RET (4 cases), while PIK3CA gene was wild-type. BRAF and K-RAS gene mutations only appeared in female patients. The former was related to 7 parameters: patient sex ( P =0.000), onset age ( P =0.000), TSH ( P =0.000), ultrasonic aspect ratio ( P =0.030), tumor size ( P =0.002), ER ( P =0.000), and PR ( P =0.003). The latter was related to 5 parameters: sex ( P =0.000), onset age ( P =0.008), TSH ( P =0.018), TGAB ( P =0.049), and strap muscle invasion ( P =0.021). Only one case of N-RAS gene mutation was male, and the other 29 cases were female. It was related to 5 parameters: patient sex ( P =0.000), onset age ( P =0.001), TF4 ( P =0.027), strap muscle invasion ( P =0.048), and KI-67 index ( P =0.009). TERT gene mutation was slightly more in men (4 cases) than in women (3 cases), which was not only related to sex ( P =0.045), but also related to strap muscle invasion( P =0.013). The RET gene mutation was associated with capsule invasion ( P =0.031) and strap muscle invasion ( P =0.022). Single gene, double gene and triple gene mutations were found in 63 of 78 tumors: single gene mutations were found in 26 cases, among which BRAF gene mutations were the most common (17 cases). There were 32 cases of double gene mutation, and the simultaneous mutation of BRAF + N-RAS gene was the most common (25 cases). There were 5 cases of triple gene mutation, and the combined mutation of BRAF + N-RAS + TERT gene was the most common (2 cases). PD-L1 immune factor status showed that the positive expression rate of PD-L1 in 78 tumors was about 94.9% (74 cases), which was related to 4 parameters: patient sex ( P =0.000), onset age ( P =0.000), TSH ( P =0.036), and ER ( P =0.025). Among them, 17.9% (14 cases) were ≥ 50% strong positive, and all of them were female patients (accounting for 34.5% of female patients). Papillary thyroid carcinoma (<1 cm in diameter) combined with lateral cervical lymph node metastasis mainly occurs in young and middle-aged female (female: male = 2.9:1), but male patients are younger. In molecular genetics, 5 gene abnormalities of BRAF, K-RAS, N-RAS, RET, and TERT were detected, which can be manifested in 3 modes: single gene mutation, double gene mutation, and triple gene mutation. The tumors with double gene mutation and triple gene mutation may be more invasive. The above 5 gene mutations and PD-L1-mediated immune escape play an important role in the pathogenesis of papillary thyroid carcinoma (<1 cm in diameter) and lateral cervical lymph node metastasis, while the PIK3CA gene may not be involved in the pathogenesis of the tumor. BRAF, K-RAS, and N-RAS gene mutations were more common in female patients, while RET and TERT gene mutations were more common in male patients. Among them, patients with BRAF and K-RAS gene mutations are usually accompanied by positive expression of ER and PR, suggesting that these patients may benefit from endocrine therapy. In addition, PD-L1-mediated immunotherapy has broad application prospects in this tumor, female patients may benefit more, and immunotherapy combined with endocrine therapy is expected to become a good adjuvant treatment option for female cases.
The SHH signaling regulates cell proliferation in the ectomesenchyme, thus controlling tooth morphogenesis, while TGF-ß and bone morphogenetic proteins (BMPs) have been associated with reactionary and reparative dentinogenesis. The aim of this study was to investigate the role of signaling proteins in odontogenesis and odontoma formation. In this retrospective cross-sectional study, we analyzed the immunohistochemical expression of TGF-ß, BMP4, and SHH pathway proteins in 23 compound odontomas, 21 complex odontomas, and 17 tooth germs. The results demonstrated immunoexpression of BMP4, especially in the ectomesenchyme of complex odontomas (median=33.7; P <0.001). SHH was more immunoexpressed in the epithelium of tooth germs ( P <0.001) and in the ectomesenchyme of complex odontomas ( P =0.029). Similarly, TGF-ß exhibited higher immunoexpression in the epithelium of tooth germs ( P <0.001) and in the ectomesenchyme of complex odontomas ( P =0.002). SHH was more immunoexpressed in the ectomesenchyme of odontomas and in the inner enamel epithelium of tooth germs. Furthermore, SHH and BMP4 were significantly correlated. In developing teeth, the highest concentrations of these proteins were found in the odontogenic epithelium during the bud and cap stages. Differential expression occurred mainly in the ectomesenchyme of tumors, indicating that this component is indeed more proliferative.
Cancers of unknown primary (CUP) are tumors whose site of origin remains undetectable despite thorough clinical, radiologic, and histopathologic evaluations. They make up about 2% to 3% of all epithelial tumors and generally have a poor prognosis. Immunohistochemical (IHC) markers complement epidemiological and histomorphologic approaches to determine tumor type, subtype, and primary site, influencing patient prognosis, outcome, and treatment. This retrospective observational study examined patients who underwent liver biopsies for hepatic metastasis between January 2022 and January 2024. Data on age, gender, liver segment localization, tumor number and size, histomorphology, and IHC work-up were analyzed. The average age of metastatic patients was 62±12 years, with 85.5% aged 50 or older. Males slightly outnumbered females (51.1% vs. 49.9%). On average, there were 1.8 metastatic foci per case. The most common metastasizing tumors included colorectal (30.5%), pancreaticobiliary (29%), breast (8.4%), lung (6.9%), and lymphomas (4.6%). Histomorphologically, 66.4% were adenocarcinomas, followed by poorly differentiated tumors (9.2%) and neuroendocrine neoplasms (8.4%). At the time of biopsy, 33.6% had initial CUP (i-CUP), 22.9% had their primary site detected by IHC, and 10.7% had true CUP (t-CUP). On average, 9.4 IHC markers were used per case, rising to 13.8 in t-CUP cases. Significant correlations were found between histomorphologic patterns, primary site detection, and IHC marker usage ( P =0.01 and 0.02). IHC continues to enhance the diagnosis and treatment of metastatic liver tumors with its use of tumor-specific or organ-specific antibodies, including newly developed transcription factors, aiding pathologists in personalized medicine.
As compared to most immunohistochemistry (IHC) assays, a minority of IHC tests detect loss of protein expression in tumor tissues. One may encounter unique challenges in assay optimization, validation, and standardization, illustrated here through case studies in implementing Succinate Dehydrogenase subunit B (SDHB) and H3K27me3 IHC assays. For SDHB, antibody protocols showing stronger staining in internal controls and normal tissues resulted in a staining pattern in some cases of SDH-mutated tumors that was difficult to distinguish from retained staining. For H3K27me3, some malignant peripheral nerve sheath tumors (MPNST) and non-MPNST tumors showed heterogeneous staining, with staining results differing between different autostainer platforms used. In IHC tests with loss of protein expression, antibody protocols need to account for optimal staining in internal control elements, in addition to appropriate staining in tumor cells. "Intermediate" staining patterns, such as heterogeneous or weak expression, pose a challenge for protocol calibration and diagnostic interpretation. The choice of tissue used for analytical validation is important and warrants further evaluation and guidance. Establishing an optimal balance between analytical sensitivity and analytical specificity during protocol optimization is key.
The melanin affects the pathologic diagnosis, so melanin bleaching must be performed. Our study was to investigate the effect of different melanin-bleaching methods on hematoxylin-eosin staining and immunohistochemical staining. We were used 10 malignant melanoma tissues as experimental subjects, and 3 tissues from T cell lymphoma, B cell lymphoma, neurofibroma and colon as control. Melanin was detected in all 10 malignant melanoma tissues before bleaching. Our study compared among permanganate/oxalic acid treatment, hydrogen peroxide treatment, and double oxidation treatment. The antibodies CD3 and MUM1 negative after potassium permanganate/oxalic acid treatment, but normal expression after hydrogen peroxide treatment. Antibodies CD20 and S-100 can be expressed normally after bleaching. Thus, the 10% hydrogen peroxide for 24 hours at 37°C is the mildest on melanin bleaching, its almost no effect on hematoxylin-eosin staining and immunohistochemical staining. It is suitable for different tissues and antibodies.
SMARCA4 -deficient non-small cell lung cancers are usually of poor prognosis and associated with smoking-related mutations. Here, we report the case of a SMARCA4 -deficient non-small cell lung cancer (NSCLC) occurring in a non-smoker female and harboring ALK fusion. Our case highlights for physicians to be especially cautious with molecular biological results in case of SMARCA4 -deficient non-small cell lung cancer occurring in nonsmokers.
Adopting a HER2-specific treatment approach for HER2-low breast cancer has been suggested after DESTINY-Breast04 (phase 3) trials. Hence, accurate pathologic evaluation gained higher importance, making interobserver agreement and interassay agreement questionable in this regard. To evaluate these, a cohort of 116 invasive breast cancer cases were stained with Dako A0485 and Ventana 4B5. Cases were evaluated by 5 observers independently and results were compared, together with in situ hybridization findings. Interobserver agreement (Kappa) for Ventana 4B5 and Dako A0485 were 0.62 and 0.63, respectively. Agreement was more prominent for IHC 3+ cases, followed by IHC 0 cases. Comparing the assays with one another, 74 cases had the same score in Ventana 4B5 and Dako A0485, while 37 and 5 cases had higher scores in Dako A0485 and Ventana 4B5, respectively. The results of the study demonstrate that pathologists are relatively unanimous on distinguishing 3+ cases (Kappa-0.76: Ventana/0.78: Dako), but have less consistency in 1+ or 2+ cases (Kappa-0.59: Ventana/0.60: Dako). It also illustrates that the case can obtain different HER2 IHC scores with different assays being used. Therefore, it is suggested for pathologists to recognize the pitfalls in HER2 IHC, be aware of the assay that is being used in their laboratory and hence evaluate the results in the accurate context.
