Unveiling the risks of ChatGPT in diagnostic surgical pathologyChatGPT.

ChatGPT, an AI capable of processing and generating human-like language, has been studied in medical education and care, yet its potential in histopathological diagnosis remains unexplored. This study evaluates ChatGPT's reliability in addressing pathology-related diagnostic questions across ten subspecialties and its ability to provide scientific references. We crafted five clinico-pathological scenarios per subspecialty, simulating a pathologist using ChatGPT to refine differential diagnoses. Each scenario, aligned with current diagnostic guidelines and validated by expert pathologists, was posed as open-ended or multiple-choice questions, either requesting scientific references or not. Outputs were assessed by six pathologists according to. (1) usefulness in supporting the diagnosis and (2) absolute number of errors. We used directed acyclic graphs and structural causal models to determine the effect of each scenario type, field, question modality, and pathologist evaluation. We yielded 894 evaluations. ChatGPT provided useful answers in 62.2% of cases, and 32.1% of outputs contained no errors, while the remaining had at least one error. ChatGPT provided 214 bibliographic references: 70.1% correct, 12.1% inaccurate, and 17.8% non-existing. Scenario variability had the greatest impact on ratings, and latent knowledge across fields showed minimal variation. Although ChatGPT provided useful responses in one-third of cases, the frequency of errors and variability underscores its inadequacy for routine diagnostic use and highlights the need for discretion as a support tool. Imprecise referencing also suggests caution as a self-learning tool. It is essential to recognize the irreplaceable role of human experts in synthesizing images, clinical data, and experience for the intricate task of histopathological diagnosis.

The "great imitator": IgG4-related disease of the oral cavity. Two case reports and scoping review.

This study aimed to review the lesser-known intraoral manifestations of immunoglobulin G4-related disease (IgG4-RD). In this paper we report an unprecedented case of oral IgG4-RD mimicking angiolymphoid hyperplasia with eosinophilia (ALHE), and another case presenting as plasma cell gingivitis. We then performed a scoping review of published cases of IgG4-RD involving the oral cavity. The following data were collected for each case: age, sex, intraoral site(s) involved, clinical appearance, imaging features, serum IgG4 values, histopathology, treatment, and follow-up duration. Fifty-one cases of oral IgG4-RD were published in literature. The hard palate and jaw bones were the two main locations reported, while the histological identification of a IgG4/IgG plasma cells ratio ≥40% was fundamental for diagnosis. Conversely, the pathological features of storiform fibrosis and obliterative phlebitis were not common. Future reports regarding oral IgG4-RD should report clear adherence to the recognized international diagnostic criteria of the disease.

Clinicopathological, cytogenetic, and molecular profiles of primary cutaneous diffuse large B-cell lymphomas.

We analyzed the clinicopathological, cytogenetic, and molecular features of 18 primary cutaneous diffuse large B-cell lymphomas (PCDLBCLs) and 15 DLBCLs secondarily localized to the skin (SCDLBCLs), highlighting biological similarities and differences between the 2 groups. PCDLBCLs were subclassified after histopathological review as PCDLBCL-leg type (PCDLBCL-LT, 10 cases) and the PCDLBCL-not otherwise specified (PCDLBCL-NOS, 8 cases). Immunohistochemistry for Hans' algorithm markers, BCL2, and MYC was performed. The molecular study included the determination of the cell of origin (COO) by Lymph2Cx assay on NanoString platform, FISH analysis of IgH, BCL2, BCL6, and MYC genes, as well as the mutation analysis of MYD88 gene. In immunohistochemistry analysis, BCL2 and MYC hyperexpression was more frequent in LT than in NOS cases and, according to Hans' algorithm, PCDLBCL-LTs were mostly of the non-GC type (8/10), whereas in PCDLBCL-NOS, the GC type prevailed (6/8). The determination of COO using Lymph2Cx supported and further confirmed these results. In FISH analysis, all but one LT cases versus 5 of 8 PCDLBCL-NOS showed at least one gene rearrangement among IgH, BCL2, MYC, or BCL6. In addition, MYD88 mutations were more frequently present in LT than in NOS subtypes. Interestingly, MYD88-mutated patients were older, with a non-GC phenotype and had worse OS, compared to MYD88 WT cases. Overall, SCDLBCL did not show, at the genetic and expression level, different profiles than PCDLBCL, even if they bear a significantly worse prognosis. At survival analysis, the most important prognostic factors in patients with PCDLBCL were age and MYD88 mutation, whereas relapse and high Ki-67 expression were relevant in patients with SCDLBCL. Our study comprehensively analyzed the clinicopathological and molecular features of PCDLBCL-LT, PCDLBCL-NOS, and SCDLBCL, underlining the differences among them and the importance of properly identifying these entities at the time of diagnosis.

High frequency of BCL2 gene rearrangement-negative follicular lymphoma in northwestern Italy.

BCL2 rearrangement is reported to be an early pathogenetic event in follicular lymphoma (FL) and it is considered as a reliable marker in the follow up of the disease. We aimed to investigate the frequency of BCL2 rearrangement in FLs from northwestern Italy, to evaluate their clinicopathological features, and to investigate alternative genetic aberrations in BCL2-negative FLs. We collected a series of 76 consecutive FLs diagnosed between 2013 and 2016. All lymphomas underwent histopathological review. Interphasic fluorescent in situ hybridization (FISH) was performed with break apart probes targeting BCL2, IGH, BCL6 and MYC on paraffin embedded (PE) and fresh frozen (FF) specimens. 1p36 region and p53 locus in BLC2-negative cases were investigated using dual color probes. Karyotype analysis was available in a subset of cases. BCL2 rearrangements were detected in 39 cases (51,3%). Of the remaining 37, 6 showed IGH rearrangement, and were further tested: 1 showed variant BCL2 translocation, 1 had BCL6 rearrangement, and the other 4 were negative for further gene rearrangements. FISH on FF specimens detected small BCL2+ clones in cases otherwise categorized as BCL2-. 1p36 and p53 deletion were observed in 1 and 8 BCL2- FLs, respectively. Karyotype analysis documented 3q, 1p and BCL6 alternative abnormalities in 3 cases. In conclusion, BCL2 rearrangement is not a constant finding in FL, its frequency being probably affected by geographical factors. Thus, it should not be considered as a reliable molecular marker in the follow up of the disease, unless it is found to be present at the initial diagnosis of FL. Alternative genetic aberrations exist in BCL2-negative cases.

Composite follicular lymphoma and "early" (in situ and mantle zone growth pattern) mantle cell neoplasia: A rare entity with peculiar cytogenetic and clinical features.

Composite follicular lymphoma (FL) and mantle cell lymphoma (MCL) is rare and not fully characterized from a genetic and clinicopathological point of view. We report a composite lymphoma (CL) in which a G1-2 FL was associated with an in situ mantle cell neoplasia (ISMCN) and a mantle zone growth pattern (MZGP) MCL, followed-up for six years after the first diagnosis, until the exitus of the patient. We performed a comprehensive immunohistochemical study and a detailed cytogenetic analysis, including conventional karyotyping, SKY FISH, FISH on metaphases and interphasic separated nuclei, and FISH on histological sections. The study was completed by the review of the 13 published composite FL and MCL. Our results show that this entity generally behaves like an indolent lymphoma, with the outcome of patients driven by the progression of the FL component. The MCL component generally does not evolve in an aggressive disease. Indeed, half of the cases present exclusively ISMCN. In our case, mantle cell neoplasia at diagnosis was represented by ISMCN and MZGP MCL and it was characterized by a simple karyotype, with t(11;14) as the sole cytogenetic abnormality. This cytogenetic aspect well correlates with the indolent behavior of the mantle cell component. Conversely, the complex karyotype of the FL component was associated with disseminated disease that influenced patient's outcome. Finally, we suggest that not only ISMCN, but also isolated MZGP MCL, may be considered as lesions with low potential of transformation in an aggressive MCL.

Unraveling Tumor Heterogeneity in an Apparently Monolithic Disease: BCL2 and Other Players in the Genetic Landscape of Nodal Follicular Lymphoma.

Follicular lymphoma (FL) is the most common form of non-Hodgkin lymphoma in Western countries. Although traditionally considered a well-defined, easy to diagnose lymphoproliferative disorder, in the last few years it has become clear that it is in fact composed of many different clinicopathological entities, encompassing a variegated and complex genetic background. This has led to the inclusion of specific FL variants and separate entities in the latest update of the WHO classification. However, even in the context of classical FL, many aspects of intra- and inter-tumoral heterogeneity have been recognized, with a major influence on diagnosis and clinical practice at different time points during the course of the disease. This review focuses on the molecular cytogenetic heterogeneity in classical FL from precursors and early development to progression and transformation, in terms of both clonal heterogeneity and unusual genetic features. Several factors have been investigated and suggested to contribute to the broad spectrum of clinicopathological, phenotypic, and genetic features observed in otherwise morphologically classical cases. Among them, deregulation of the epigenetic machinery and interactions with tumor microenvironment seem to play a pivotal role, together with genetic aberrations involving well-known molecular pathways and mechanisms physiologically operating in the germinal center. In the era of personalized medicine, precision diagnostics based both on understanding of the complex interplay among all these factors and on novel developments will become crucial to predict the outcome and guide the treatment of FL patients.

Primary extranodal diffuse large B-cell lymphomas: Many sites, many entities? Clinico-pathological, immunohistochemical and cytogenetic study of 106 cases.

We analyzed the clinicopathological, immunohistochemical and cytogenetic features of 106 extranodal (EN) diffuse large B-cell lymphomas (DLBCLs) from stomach (34 cases), intestine (10), cervico-cephalic region (11), central nervous system (13), testes (21), skin (8), and miscellaneous sites (9). Hans' algorithm and the immunohistochemical double expressor score (DES) for MYC and BCL2 were applied to all cases. A subset of fifty-eight cases were analyzed with fluorescent in situ hybridization (FISH) with specific break apart probes for BCL6, MYC, BCL2, CCND1, BCL10 and MALT1 genes. Clinical records were available for all patients. The immunohistochemical study showed that, in our series of EN-DLBCLs, the Hans' subgroup and the DES differed significantly according to the site of origin. At FISH analysis, BCL6 and BCL2 were the most commonly rearranged genes in non-GC and in GC cases, respectively. Gastrointestinal lymphomas displayed the highest rate of gene rearrangements, often with MYC involvement. One testicular DLBCL showed BCL2/MYC double hit. At survival analysis, cerebral and testicular origin was associated with poor prognosis. In addition, Hans' subgroup and other immunohistochemical markers influenced patients' outcome. In conclusion, our data suggest that immunophenotypic, genetic and survival characteristics of EN-DLBCL are related to the specific primary site of the disease.

EBV⁺ and MSI Gastric Cancers Harbor High PD-L1/PD-1 Expression and High CD8⁺ Intratumoral Lymphocytes.

Both EBV⁺ and MSI gastric cancers (GCs) have high lymphoid infiltration which is rare in MSS/EBV- cancers. PD-L1/PD-1 interaction leads to a down-regulated immune response and it is one of the most promising targets for gastric cancer immunotherapy. PD-L1/PD-1 and CD8 expression were immunohistochemically investigated in a series of 169 FFPE GCs, including 33 EBV⁺, 59 MSI and 77 MSS/EBV- cases. PD-L1 membrane immunoreactivity in more than 5% of tumor cells was present in 31/169 GCs and was associated with high levels of CD8 intraepithelial lymphocytes (TILs; p < 0.001). PD-L1⁺ cases were mainly poorly differentiated (71%), intestinal type (85%) and high lymphoid response (HLR; 90%) tumors. PD-L1 expression was only present in EBV⁺ (46%), MSI (24%) and rare MSS/EBV- (3%) GCs with high CD8⁺ TILs (p < 0.001). Despite being associated with a better prognosis both in the whole series (p < 0.05) and in the MSI subset, PD-L1 is not an independent prognostic factor. PD-L1 gene amplification was detected in 3/17 cases, including 2/7 EBV⁺ and 1/8 MSI GC. PD-1⁺ TILs were significantly higher in EBV⁺ than MSI and MSS/EBV- cases. PD-L1/PD-1 pathway is selectively activated in HLR GCs and could be considered an emerging therapeutic target, particularly for EBV and MSI GCs.

Primary Extranodal Marginal Cell Lymphoma, MALT Type, of the Endometrium Arising in a Patient With Rheumatoid Arthritis: Report of a Case.

Primary marginal zone B-cell MALT-type lymphomas of the uterine corpus are exceedingly rare entities, with only 6 cases reported in the literature to date. We present the additional case of a 70-yr-old white woman who underwent a laparoscopic total hysterectomy with bilateral salpingo-oophorectomy for an asymptomatic ovarian cyst. At microscopic examination, endometrial samples showed a dense, nodular lymphocytic infiltrate, suggestive of a lymphoproliferative disorder. Morphology, immunohistochemistry, and molecular analysis supported the diagnosis of MALT-type lymphoma of the endometrium. Benign reactive conditions, such as endometritis and other small B-cell lymphomas were ruled out. Moreover, we investigated the pathogenesis of our case, focusing on Chlamydia trachomatis infection, chromosomal translocations affecting the NF-kB pathway, and discussing the role of autoimmunity in the development of MALT-type lymphomas.

Aberrant DNA methylation profiles of inherited and sporadic colorectal cancer.

BACKGROUND: Aberrant DNA methylation has been widely investigated in sporadic colorectal carcinomas (CRCs), and extensive work has been performed to characterize different methylation profiles of CRC. Less information is available about the role of epigenetics in hereditary CRC and about the possible clinical use of epigenetic biomarkers in CRC, regardless of the etiopathogenesis. Long interspersed nucleotide element 1 (LINE-1) hypomethylation and gene-specific hypermethylation of 38 promoters were analyzed in multicenter series of 220 CRCs including 71 Lynch (Lynch colorectal cancer with microsatellite instability (LS-MSI)), 23 CRCs of patients under 40 years in which the main inherited CRC syndromes had been excluded (early-onset colorectal cancer with microsatellite stability (EO-MSS)), and 126 sporadic CRCs, comprising 28 cases with microsatellite instability (S-MSI) and 98 that were microsatellite stable (S-MSS). All tumor methylation patterns were integrated with clinico-pathological and genetic characteristics, namely chromosomal instability (CIN), TP53 loss, BRAF, and KRAS mutations. RESULTS: LS-MSI mainly showed absence of extensive DNA hypo- and hypermethylation. LINE-1 hypomethylation was observed in a subset of LS-MSI that were associated with the worse prognosis. Genetically, they commonly displayed G:A transition in the KRAS gene and absence of a CIN phenotype and of TP53 loss. S-MSI exhibited a specific epigenetic profile showing low rates of LINE-1 hypomethylation and extensive gene hypermethylation. S-MSI were mainly characterized by MLH1 methylation, BRAF mutation, and absence of a CIN phenotype and of TP53 loss. By contrast, S-MSS showed a high frequency of LINE-1 hypomethylation and of CIN, and they were associated with a worse prognosis. EO-MSS were a genetically and epigenetically heterogeneous group of CRCs. Like LS-MSI, some EO-MSS displayed low rates of DNA hypo- or hypermethylation and frequent G:A transitions in the KRAS gene, suggesting that a genetic syndrome might still be unrevealed in these patients. By contrast, some EO-MSS showed similar features to those observed in S-MSS, such as LINE-1 hypomethylation, CIN, and TP53 deletion. In all four classes, hypermethylation of ESR1, GATA5, and WT1 was very common. CONCLUSIONS: Aberrant DNA methylation analysis allows the identification of different subsets of CRCs. This study confirms the potential utility of methylation tests for early detection of CRC and suggests that LINE-1 hypomethylation may be a useful prognostic marker in both sporadic and inherited CRCs.

Treatment strategies for primary early-stage sinonasal adenocarcinoma: A retrospective bi-institutional case-control study.

OBJECTIVE: To investigate different treatment strategies for primary early-stage (pT1-T2) sinonasal adenocarcinomas. METHODS: Retrospective case-control study. From 2000 to 2011, 61 cases were radically resected using an endoscopic endonasal approach. Surgery as a single treatment modality was adopted for 33 patients (study group) while it was followed by postoperative radiotherapy (poRT) in 28 patients (control group). RESULTS: Median follow-up was 61 and 67 months for the study and control group respectively. Patients were stratified according to the pT classification and no statistically significant differences were found in terms of Overall (OS) and Recurrence-free (RFS) survival. When analyzing the high-grade tumors (47 cases), statistically significant differences were observed between the control and study groups both in terms of OS (90.5% ± 6.5% versus 57.6% ± 15.4%, P = 0.03) and RFS (92.3% ± 7.39% versus 80.2% ± 8.88%, P = 0.05). Using multivariate analysis, OS was independently determined by poRT (Hazard Ratio = 0.16; P = 0.03) thus confirming its protective role for high-grade adenocarcinomas. CONCLUSION: Our preliminary results suggest that endoscopic endonasal surgery could be used as a single treatment modality for primary early-stage low-grade sinonasal adenocarcinoma, resected with negative margins. Surgery followed by poRT offers the best treatment strategy not only for advanced-stage lesions but also for high-grade adenocarcinomas, regardless of the stage of disease at presentation.

Renal cell carcinoma metastatic to a pituitary FSH/LH adenoma: case report and review of the literature.

Abstract Metastases to the pituitary occur more frequently in patients with widespread cancer and mainly involve the posterior lobe. A few cases of metastatic carcinoma to a pituitary adenoma have been described so far. Here, the authors present an additional case of a clear cell renal cell carcinoma (CCRCC) metastatic to a FSH/LH/α-subunit pituitary adenoma and systematically review the literature. Immunohistochemistry and electron microscopy were performed to characterize both neoplastic components at the morphological level. Moreover, it was hypothesized that expression of VEGF and of the corresponding receptor VEGFR1 could be implicated in the development of the carcinomatous metastasis within the adenoma.