Aggressive Course Research Articles

Advanced treatment-resistant ovarian germ cell tumor (yolk sac tumor) with successful fertility realization 20 years after combined treatment: a case report

Background. Yolk sac tumors (YST) are classified as rare malignant germ cell tumors of the ovaries, most commonly found in young patients interested in preserving fertility. YST is characterized by large size, predominantly unilateral involvement, and increased production of alpha-fetoprotein, which can be used as an important diagnostic criterion for this condition. Among all germ cell tumors, YST has the least favorable prognosis. The primary goals of YST treatment are not only to improve prognosis and quality of life but also to enable the patient to fulfill her reproductive plans in the future.Description of the clinical case. We present a clinical case of an aggressive course of yolk sac tumor in the ovary of a 15-year-old girl, requiring multiple surgeries, repeated courses of high-dose drug therapy, and bone marrow transplantation.Conclusion. This is a rare case of YST with successful preservation of reproductive function due to modern medical technologies despite aggressive treatment.

TMET-04. METABOLOMICS ANALYSIS IN FUNCTIONING AND SILENT CORTICOTROPH ADENOMAS USING A TWO-DIMENSIONAL NANOMATERIAL HIGH-THROUGHPUT PLATFORM

Abstract Functioning pituitary corticotroph adenomas (CAs) originated from T-PIT lineage with an ACTH-positive staining cause Cushing’s Disease. However, silent CAs (SCAs) baring the same histological features present clinically non-functioning with more aggressive courses. Metabolites within the tumor microenvironment play critical roles in regulating tumor behaviors and responses to therapy. Understanding their distribution and concentration provides valuable insights for diagnosis and treatment. This study investigated metabolite patterns in functioning and silent CAs. We developed a novel two-dimensional nanomaterial platform for enhanced surface-assisted laser desorption/ionization mass spectrometry. Utilizing this platform, we analyzed the metabolomes of three functioning CAs and three SCAs. Our platform exhibited exceptional sensitivity and stability in detecting metabolite molecules. Analysis of the metabolomes revealed distinct spatial distributions and peak intensity of various metabolites, including carbohydrates, amino acids, organic acids, nucleotides, and their precursors. Notably, certain metabolites such as tryptophol, clopidogrel carboxylic acid, DG(20:4(8Z,11Z,14Z,17Z)-2OH(5S,6R)/0:0/i-16:0), S-(-)-ureidoglycolate, and PC(20:4(5Z,7E,11Z,14Z)-OH(9)/14:1(9Z)) were significantly enriched in functioning CAs compared to SCAs, while others, including Cer(d18:1/16:0), Dihydrocytochalasin B, and LysoPC(O-18:0/0:0), exhibited higher peak intensity in SCAs. Overall, our findings underscored the existence of unique metabolomic signatures distinguishing functioning CAs and SCAs. Heterogeneous metabolite distributions among functioning CAs and SCAs were revealed by our novel nanomaterial high-throughput platform, and unique metabolic signatures were identified. Metabolomics analysis holds promise for precise biomedical diagnostics and individualized therapeutic strategies in functioning and silent CAs.

CNSC-50. PRIMARY INTRACRANIAL CONGENITAL GLIOBLASTOMA (PICG): A SYSTEMATIC REVIEW OF CASE REPORTS FROM 2000 TO 2023

Abstract BACKGROUND AND OBJECTIVE The most commonly reported congenital intracranial space occupying lesions are teratoma, glioma and neuroblastoma. Primary intracranial congenital glioblastoma (PICG) is one of the most lethal and extremely rare neoplasms. Most pediatricians and gynecologists are unable to detect it congenitally, posing an ominous risk of spread and disease severity. We aim to determine the clinical manifestations, number of reported cases, radiological findings and neuro-oncological management of PICG. MATERIALS AND METHODS A comprehensive literature search using PubMed Central and Google Scholar was done, retrieving 17 case reports and five case series of 31 patients with PICG and included using the Preferred Reporting items for Systematic Reviews and Meta-Analyses guidelines, published between 2000 and 2023. RESULTS The mean age at presentation was 86.00 ± 88.36 days, with both genders affected equally, i.e. 45.16%. The most common symptoms and signs at presentation were seizures (38.70%) and hydrocephalus (51.61%), respectively. Left hemispheric (48.38%), with frontoparietal involvement (16.12%) was the frequently affected site. MRI findings were suggestive of low intensity signal significant of hemorrhage or calcification and a heterogenous mass in 35.58% and 32.25% cases, respectively. Gross total resection (GTR) was achievable in 48.38% patients. Glial fibrillary acid protein and vimentin were positive in 45.16% and 29.03% cases, respectively. Intraoperative mortality and recurrence were noted in 25.80% and 9.68% of patients, respectively. The average follow up duration was 20.57 months. CONCLUSION PICG has an extremely aggressive course of natural progression. Congenital presentation and its lack of awareness among clinicians is itself a challenge for disease management. Adjuvant chemo-radiotherapy has proven fruitful along with GTR. Post-operative CSF diversion is warranted.

AMIGO2 characterizes cancer-associated fibroblasts in metastatic colon cancer and induces the release of paracrine active tumorigenic secretomes.

Secretomes of cancer-associated fibroblasts (CAFs) in colorectal cancer (CRC) contribute to malignancy. Detailed knowledge is available on the components and functions of CAF secretomes. Little is known about the regulation of CAF secretomes. Here, we searched for receptor-like membrane-bound molecules in CAFs, which may regulate the production and release of tumor-activating secretomes. The adhesion molecule with Ig-like domain 2 (AMIGO2) was significantly upregulated in cultivated CAFs compared to normal tissue-associated fibroblasts (NAFs), and this was confirmed in patient-derived tissues. AMIGO2 expression was low or absent in healthy colon, significantly increased in fibroblasts of primary CRC, and highest in the stromal tissues of CRC-derived liver metastases. AMIGO2 expression in CAFs correlated with a higher T-category, increased lymph node metastasis, progressed tumor stages and was associated with reduced survival in different cohorts of CRC patients. Interestingly, AMIGO2 expression was induced by transforming growth factor-β and higher in female patients, who exhibit a more aggressive disease course. In functional studies, conditioned media of NAFs with experimentally induced AMIGO2 overexpression enhanced proliferation and migration of different CRC tumor cells, while siRNA-mediated inhibition of AMIGO2 in CAFs attenuated these effects. Accordingly, therapeutic inhibition of the receptor-like AMIGO2 protein in CRC CAFs could prevent tumorigenic secretomes in CRC. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

SURG-52. LEPTOMENINGEAL DISSEMINATION AFTER GAMMATILE AND LITT IN HIGH GRADE ASTROCYTOMA PATIENTS

Abstract PURPOSE To present a case series of leptomeningeal dissemination after localized treatment with GammaTile or laser interstitial thermal therapy (LITT) in patients with high grade astrocytoma. BACKGROUND Leptomeningeal dissemination occurs primarily in glioblastoma patients with prolonged survival and those who undergo aggressive treatment courses. Targeted therapies such as GammaTile (which contains cesium-131 radiation-emitting seeds) or LITT may provide localized disease control following recurrence and serve as an immediate treatment modality for patients with recurrent disease in the weeks leading up to radiotherapy or systemic treatment. METHODS We retrospectively reviewed all consecutive patients with high grade astrocytoma treated with GammaTile or LITT who were found to have leptomeningeal dissemination of disease. Histological diagnosis, NGS and immunohistochemistry of tumor tissue were performed at both original diagnosis and at time of GammaTile placement or LITT procedure. Leptomeningeal dissemination was diagnosed through MRI findings on brain and spine. Cases were analyzed for time to development of leptomeningeal dissemination, median overall survival, survival from time of leptomeningeal dissemination diagnosis, time of dissemination to second radiation therapy. Tumor location, MGMT status and other molecular markers were also reviewed. RESULTS Out of 90 high grade astrocytoma patients treated with gamma tile radiation, 4 progressed to exhibit disseminated disease. There were 2 female patients, mean age was 50 years. Location of tumor was in the left temporal lobe in 3 patients and right temporal in 1. They were all IDH wild type. Two were MGMT methylated, two were non methylated. The median time from initial glioma diagnosis to LMD was 221 months (range 11-152) and overall survival after disseminated disease diagnosis was 7.5 weeks (range 3–13). CONCLUSION Leptomeningeal dissemination is a devastating complication of aggressive gliomas. Currently, there is no standard treatment for disseminated disease in high grade astrocytoma patients. Systemic therapy is needed following localized therapies to control disease. Further research into new therapies is needed to allow for better outcomes.

Volume of hepatoid component and intratumor M2 macrophages predict prognosis in patients with hepatoid adenocarcinoma of the stomach.

Hepatoid adenocarcinoma of the stomach (HAS), a subtype of gastric cancer (GC), includes multiple tumor components, such as enteroblastic and tubular adenocarcinoma components. However, which component mostly contributes to the aggressive behavior of HAS remains unclear. Moreover, the role of tumor-associated macrophages (TAMs) has not been explored in HAS. This study evaluated the clinical significance of the proportion of the hepatoid component within the tumor, CD163 + macrophages, and macrophage colony-stimulating factor-1 (CSF-1) in HAS. In total, 56 cases of primary HAS were analyzed. In each case, hepatoid (HC), enteroblastic (EC), and tubular (TC) components were identified, and the ratio of HC to the entire tumor (hepatoid component ratio, HCR) was assessed to examine the correlation between HCR and clinicopathological features. Immunohistochemical staining for CD163 and CSF-1 was performed, and differences in immunohistochemical results among the three tumor components were analyzed. In each tumor component, the prognostic impact of CD163 and CSF-1 was examined. A high HCR was associated with worse overall survival (OS). CD163 + TAMs and CSF-1 immunoreactivity score in HC were significantly higher than those in the other components. High infiltration of CD163 + TAMs and a high CSF-1 immunoreactivity score in HC were associated with an aggressive course and worse OS. Multivariate analysis revealed the proportion of HC in HAS as an independent prognostic factor (HR = 3.176, p = 0.006). The HCR and CD163 + TAMs may be useful prognostic predictors, and TAMs may be novel therapeutic targets of HAS.

The place of pasireotide in precision treatment of patients with acromegaly

Due to the syndromal nature of acromegaly, the effectiveness of its treatment depends on the consideration of age, clinical and pathomorphological features of the disease, which determine the logistics of the selection of personalized therapeutic measures. The disadvantage of the used empirical pharmacotherapy scheme with the help of the ‘trial and error’ method is the formal prescription of drugs without taking into account the peculiarities of the morphofunctional status of the supervised GH-secreting tumors and the targeting of drugs. The lack of differentiated approach to acromegaly treatment is accompanied by a high percentage of therapeutic failures, and also deliberately deprives a significant proportion of patients of the opportunity to achieve timely and safe control of the disease and improve the quality of life. The review presents a comparative analysis of modern drugs used in acromegaly with a focus on the clinical efficacy of the second-generation somatostatin receptor ligand – pasireotide. The mechanism of action and pharmacotherapeutic possibilities of pasireotide LAR are considered. The therapeutic niche for this drug is patients with the presence of sparsely granulated somatotrophic tumor (SGST), characterized by aggressive course, tendency to recurrence and refractoriness to therapy with first-generation somatostatin receptor ligands.Implementation of a precision approach using clinical, morphological, radiological and functional predictors allows not only to identify the specific morphotype of somatotrophic tumor, but also to predict the efficacy of the planned treatment. A table of multidirectional biomarkers of long-term sensitivity of tumor cells to first- and second-generation somatostatin receptor ligands is presented. When SGST, large size of the residual tumor and poor expression of the 2nd subtype of somatostatin receptors are detected, pasireotide LAR can be used as a 1st-line treatment, in both mono- and combination therapy with pegvisomant. Special caution is required when treating patients with diabetes mellitus or predisposition to its development. The paper discusses in detail the measures aimed at prevention, dynamic control and correction of pasireotide-associated hyperglycemia.

Association of Genetic Variants at the CDKN1B and CCND2 Loci Encoding p27Kip1 and Cyclin D2 Cell Cycle Regulators with Susceptibility and Clinical Course of Chronic Lymphocytic Leukemia.

Beyond the essential role of p27Kip1 and cyclin D2 in cell cycle progression, they are also shown to confer an anti-apoptotic function in peripheral blood (PB) lymphocytes. Although the aberrant longevity and expression of p27Kip1 and cyclin D2 in leukemic cells is well documented, the exact mechanisms responsible for this phenomenon have yet to be elucidated. This study was undertaken to determine the associations between polymorphisms in the CDKN1B and CCND2 genes (encoding p27Kip1 and cyclin D2, respectively) and susceptibility to chronic lymphocytic leukemia (CLL), as well as their influence on the expression of both cell cycle regulators in PB leukemic B cells and non-malignant T cells from untreated CLL patients divided according to the genetic determinants studied. Three CDKN1B single-nucleotide polymorphisms (SNPs), rs36228499, rs34330, and rs2066827, and three CCND2 SNPs, rs3217933, rs3217901, and rs3217810, were genotyped using a real-time PCR system. The expression of p27Kip1 and cyclin D2 proteins in both leukemic B cells and non-malignant T cells was determined using flow cytometry. We found that the rs36228499A and rs34330T alleles in CDKN1B and the rs3217810T allele in the CCND2 gene were more frequent in patients and were associated with increased CLL risk. Moreover, we observed that patients possessing the CCND2rs3217901G allele had lower susceptibility to CLL (most pronounced in the AG genotype). We also noticed that the presence of the CDKN1Brs36228499CC, CDKN1Brs34330CC, CDKN1Brs2066827TT, and CCND2rs3217901AG genotypes shortened the time to CLL progression. Statistically significant functional relationships were limited to T cells and assigned to CDKN1B polymorphic variants; carriers of the polymorphisms rs34330CC and rs36228499CC (determining the aggressive course of CLL) expressed a decrease in p27Kip1 and cyclin D2 levels, respectively. We indicate for the first time that genetic variants at the CDKN1B and CCND2 loci may be considered as a potentially low-penetrating risk factor for CLL and determining the clinical outcome.

Radiomics-Based Machine Learning with Natural Gradient Boosting for Continuous Survival Prediction in Glioblastoma.

(1) Background: Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with an aggressive disease course that requires accurate prognosis for individualized treatment planning. This study aims to develop and evaluate a radiomics-based machine learning (ML) model to estimate overall survival (OS) for patients with GBM using pre-treatment multi-parametric magnetic resonance imaging (MRI). (2) Methods: The MRI data of 865 patients with GBM were assessed, comprising 499 patients from the UPENN-GBM dataset and 366 patients from the UCSF-PDGM dataset. A total of 14,598 radiomic features were extracted from T1, T1 with contrast, T2, and FLAIR MRI sequences using PyRadiomics. The UPENN-GBM dataset was used for model development (70%) and internal validation (30%), while the UCSF-PDGM dataset served as an external test set. The NGBoost Survival model was developed to generate continuous probability estimates as well as predictions for 6-, 12-, 18-, and 24-month OS. (3) Results: The NGBoost Survival model successfully predicted survival, achieving a C-index of 0.801 on internal validation and 0.725 on external validation. For 6-month OS, the model attained an AUROC of 0.791 (95% CI: 0.742-0.832) and 0.708 (95% CI: 0.654-0.748) for internal and external validation, respectively. (4) Conclusions: The radiomics-based ML model demonstrates potential to improve the prediction of OS for patients with GBM.

MicroRNAs are enriched at COVID-19 genomic risk regions, and their blood levels correlate with the COVID-19 prognosis of cancer patients infected by SARS-CoV-2

BackgroundCancer patients are more susceptible to an aggressive course of COVID-19. Developing biomarkers identifying cancer patients at high risk of COVID-19-related death could help determine who needs early clinical intervention. The miRNAs hosted in the genomic regions associated with the risk of aggressive COVID-19 could represent potential biomarkers for clinical outcomes.Patients and methodsPlasma samples were collected at The University of Texas MD Anderson Cancer Center from cancer patients (N = 128) affected by COVID-19. Serum samples were collected from vaccinated healthy individuals (n = 23) at the Municipal Clinical Emergency Teaching Hospital in Timisoara, Romania. An in silico positional cloning approach was used to identify the presence of miRNAs at COVID-19 risk-associated genomic regions: CORSAIRs (COvid-19 RiSk AssocIated genomic Regions). The miRNA levels were measured by RT-qPCR.ResultsWe found that miRNAs were enriched in CORSAIR. Low plasma levels of hsa-miR-150-5p and hsa-miR-93-5p were associated with higher COVID-19-related death. The levels of hsa-miR-92b-3p were associated with SARS-CoV-2 test positivity. Peripheral blood mononuclear cells (PBMC) increased secretion of hsa-miR-150-5p, hsa-miR-93-5p, and hsa-miR-92b-3p after in vitro TLR7/8- and T cell receptor (TCR)-mediated activation. Increased levels of these three miRNAs were measured in the serum samples of healthy individuals between one and nine months after the second dose of the Pfizer-BioNTech COVID-19 vaccine. SARS-CoV-2 infection of human airway epithelial cells influenced the miRNA levels inside their secreted extracellular vesicles.ConclusionsMiRNAs are enriched at CORSAIR. Plasma miRNA levels can represent a potential blood biomarker for predicting COVID-19-related death in cancer patients.

Radiation-Induced Breast Angiosarcoma-A Single-Institution Experience.

Introduction: Radiation-induced breast angiosarcoma (RIBAS) is a rare adverse event associated with postoperative breast irradiation. The data from the literature indicate that RIBAS occurs in less than 0.3% of patients treated with adjuvant radiotherapy for breast cancer. Given the rarity, diverse clinical presentation, poor prognosis, and lack of consensus on the management, this study aimed to present experiences of our specialized cancer center with RIBAS, in terms of the incidence, presentation, management, and outcomes. Methods: We reviewed the medical records of 10,834 breast cancer patients treated at the Institute for Oncology and Radiology of Serbia between January 2013 and June 2024 to detect patients that had breast-conserving surgery, followed by postoperative irradiation, and developed angiosarcoma in the irradiated area at least 3 years after radiotherapy, without distant metastases. The incidence, latency period, management, and treatment outcomes were analyzed. Results: A total of nine female patients with RIBAS were identified and included in this study. The median age at RIBAS diagnosis was 64 years (range: 36-68), with a median latency of 64 months (95% CI > 57) from irradiation to diagnosis. The mean tumor size was 55 mm (SD 32.78). Patients were followed for a median of 30 months (range: 7-40) after initial RIBAS surgery. Local recurrence occurred in seven patients (77.8%), with five undergoing re-do surgery with curative intent. Three patients developed distant metastases during follow-up. The median overall survival (OS) was 31 months (95% CI > 30), with a 3-year survival rate of 15.2% (95% CI 2.5-91.6%). The median local recurrence-free interval was 10 months (95% CI > 3). Median OS after RIBAS local recurrence and after breast cancer treatment was 17 months (95% CI > 15) and 108 months (95% CI > 88), respectively. Conclusions: RIBAS is a rare but increasingly prevalent adverse event associated with BC irradiation, marked by an aggressive disease course and high relapse rates. Awareness, prompt diagnosis, and a radical surgical approach with wide clear margins are critical for improving patients' outcomes.

Light Chain Multiple Myeloma: A Case of Distinctive Presentations

Multiple Myeloma (MM) is a malignancy of immunoglobulin-producing plasma cells. Lambda Light Chain Multiple Myeloma (LCMM) is a less common type of MM with a more aggressive course, which presents a diagnostic challenge due to the absence of typical M-spike on screening and unspecific manifestations. This case presented an initially misdiagnosed patient, who had an uncommon light chain pattern on electrophoresis, atypical plasmocytes in bone marrow smear, particular complications and risks associated with LCMM, and a worse prognosis.

Genetic Profiling in Chronic Lymphocytic Leukemia: The Role of TP53 Mutations and IGHV Status in Treatment Decision-Making – A Case Report

Introduction. The TP53 gene encodes the p53 protein, crucial for DNA damage response, apoptosis, and cell cycle regulation. In chronic lymphocytic leukemia (CLL), TP53 loss due to 17p deletion or mutation leads to poor chemoimmunotherapy response and shorter survival. Patients with unmutated immunoglobulin heavy chain variable (IGHV) status exhibit a more aggressive disease course, poorer outcomes, and reduced response to standard chemoimmunotherapy. These genetic variations significantly affect disease progression, treatment choice, and response to therapy. Case Report. In November 2023, a 61-year-old man presented to our clinic with complaints of generalized weakness and rapid fatigue since October 2023. CLL was diagnosed in 2018 through pathohistological and immunohistochemical analysis of the bone marrow. The patient received no therapy until 2023 due to the absence of active disease signs. From March 28, 2023, to July 25, 2023, the patient received chemoimmunotherapy with the bendamustine and rituximab (BR) regimen. Five courses of therapy were administered; however, further treatment was discontinued due to side effects that occurred during the fifth course of bendamustine administration. A subsequent diagnostic evaluation aimed at assessing treatment efficacy, prognosis, and genetic profiling included a cytomorphological analysis, which revealed that lymphocytes comprised 80% of the cellular composition. Immunocytological analysis confirmed the presence of monoclonal atypical lymphocytes, accounting for 70% of the cell population. Next-generation sequencing identified a pathogenic TP53 mutation, and fragment analysis confirmed an unmutated IGHV status. The presence of the TP53 mutation and unmutated IGHV status categorizes the patient as being in the very high-risk group, for which the use of Bruton’s tyrosine kinase inhibitors (BTKIs) and/or B-cell lymphoma-2 (BCL-2) inhibitors is recommended. Conclusions. This case highlights the significance of comprehensive genetic profiling in CLL patients using techniques such as fluorescence in situ hybridization, polymerase chain reaction, and next-generation sequencing. Such profiling detects molecular genetic alterations, facilitating personalized and effective treatment.

CRTC1::TRIM11-fusion tumor with rare sinonasal presentation and locally aggressive disease course

Abstract Introduction/Objective Cutaneous melanocytic tumor with CRTC1::TRIM11 fusion (CMTCT) is a rare dermatological neoplasm that has not yet been formally recognized by the World Health Organization. At present, our knowledge of this disease is limited to single reports and a series 41 cases with limited follow-up information. It is typically described as a skin lesion expressing melanocytic makers, often leading to its misdiagnosis as melanoma or clear cell sarcoma. CMTCT is regarded as an indolent tumor with infrequent recurrence after complete surgical excision. However, we present a case with uncommon sinonasal presentation and metastasis after multiple resections. Methods/Case Report A 23-year-old woman presented with a right nasal vestibule mass, requiring partial rhinectomy in a foreign country, where she subsequently received chemoradiation. Her tumor at the time was diagnosed as a mucosal melanoma. Eleven years following initial presentation, she demonstrated a recurrent right nasal tumor, as well as neck mass, cervical lymphadenopathy, and lung nodules. The patient then underwent a nasal endoscopic resection and modified neck dissection, which demonstrated a high-grade neoplasm with intersecting fascicles of medium-to-large monomorphic cells; whole exome and whole transcriptome sequencing performed on the resected neck mass identified a pathogenic TERT c.-146C>T alteration and CRTC1 exon 1::TRIM11 exon 2 fusion. The patient is currently alive and undergoing post-surgical chemoradiation. Results (if a Case Study enter NA) NA Conclusion This case expands our understanding of CMTCT and emphasizes its potentially aggressive behavior. The sinonasal presentation contrasts the tumor’s typical appearance on the skin and could mimic mucosal melanoma. Of note, our patient developed recurrent disease and distant metastases, thereby emphasizing the possible role of systemic therapy and suggesting that simple surgical excision may not be curative in all cases. Our case illustrates that CMTCT is an uncommon and potentially misidentified neoplasm, but that its proper diagnosis is essential for treatment selection and follow up.

Treatment Modalities for Refractory-Recurrent Tenosynovial Giant Cell Tumor (TGCT): An Update

Background and Objectives: Tenosynovial giant cell tumor (TGCT) is a rare, locally aggressive, benign neoplasm arising from the synovium of joints, tendon sheaths, and bursa. There are two main subtypes of TGCT: localized-type TGCT(L-TGCT) and diffuse-type TGCT (D-TGCT). While surgical excision is still considered the gold standard of treatment, the high recurrence rate, especially for D-TGCT, may suggest the need for other treatment modalities. Materials and Methods: This study reviews current literature on the current treatment modalities for refractory-relapsed TGCT disease. Results: The gold standard of treatment modality in TGCT remains surgical excision of the tumor nevertheless, the elevated recurrence rate and refractory disease, particularly in D-TGCT indicates and underscores the necessity for additional treatment alternatives. Conclusions: TGCT is a benign tumor with inflammatory features and a potential destructive and aggressive course that can lead to significant morbidity and functional impairment with a high impact on quality of life. Surgical resection remains the gold standard current treatment and the optimal surgical approach depends on the location and extent of the tumor. Systemic therapies have been recently used for relapsed mainly cases.

Efficacy of Doxorubicin in the Adjuvant Treatment of Canine Splenic Visceral Hemangiosarcoma

Introduction. Splenic hemangiosarcoma is a highly malignant neoplasm that affects geriatric patients. The incidence in dogs is 45–50% of all splenic tumours and about 2% of all oncological pathologies. The visceral form of splenic hemangiosarcoma is characterised by the most aggressive course of the disease and early metastasis to other organs. The average life expectancy of animals after splenectomy, according to various scientific data, is from 20 to 90 days. The article studies the efficacy of additional doxorubicin-based adjuvant chemotherapy to increase the life expectancy of dogs at different stages of the disease.Materials and Methods. To compare the life expectancy, the patients were divided into 4 groups receiving different treatments for splenic hemangiosarcoma. Examination of patients, visual diagnostics and pathomorphological diagnostics were used for making a diagnosis, determining the stage of the disease and prescribing treatment. Treatment efficacy was assessed based on the median relapse-free period, median life expectancy and survival rate of patients after 3, 6, and 12 month periods. Statistical analysis was performed using the Fisher's exact test.Results. The obtained data demonstrated a more favourable course of disease in dogs with the stage I tumour process. Splenectomy made it possible to increase the life expectancy of patients to 243 days with a 6–month survival rate in 62.5% of patients. Postoperative chemotherapy treatment combined with doxorubicin significantly improved the longterm prognosis and led to more than twofold increase in life expectancy of dogs (up to 475 days) with a one-year survival rate in 83.3% of patients. However, no substantial statistical significance was determined in the studied groups (p=0.7).Discussion and Conclusion. The results of the research have revealed the efficacy of adjuvant doxorubicin-based chemotherapy in dogs with the visceral forms of splenic hemangiosarcoma. In animals with early stages of the disease, a significant increase in life expectancy has been discovered. The development of hemagdomain and/or the presence of metastasis to abdominal organs indicate the unfavourable course of the disease and, as a consequence, early metastasis. Nevertheless, even at these stages, doxorubicin can increase the life expectancy of patients.

6421 Imaging Phenotype May Predict Genotype In Human Pheochromocytoma: Relationships Between Genetic Mutation Clusters, Metabolite Transporter Expression, And Radiotracer Uptake

Abstract Disclosure: I. Sakuma: None. M. Fujimoto: None. D.F. Vatner: None. K. Yokote: None. T. Tanaka: None. Context [1]23I-metaiodobenzylguanidine scintigraphy (MIBG) and [1]8F-fluoro-2-doxy-D-glucose positron emission tomography (FDG-PET) are helpful for the localization of pheochromocytoma. The norepinephrine transporter (NET) and the glucose transporter 1 (GLUT1) are thought to be critical for the uptake of these radioisotopes. NET expression is activated by Paired Like Homeobox (PHOX2) and glucocorticoid receptor (GR) in neuroblastoma cells. Around 70% of pheochromocytomas carry well-known mutations. Pheochromocytoma-associated genes are divided into two clusters: the pseudohypoxia-related cluster 1 and the kinase signaling-related cluster 2. Cluster 1 mutation are associated with noradrenergic pheochromocytomas with an elevated metastatic risk. Cluster 2 tumors demonstrate an adrenergic phenotype with a less aggressive course. How mutations of cluster 1 and cluster 2 impact the expression of NET/GLUT1 and on radiotracer uptake remains unclear. Hypothesis Cluster 1 and cluster 2 will have different effects on the expression of transcription factors associated with chromaffin cell differentiation with resultant differential effects on NET/GLUT1 expression. Methods 42 patients with pheochromocytoma were evaluated by MIBG and FDG-PET. Tumor gene expression was evaluated by real-time qPCR, and mutation analyses were performed by Sanger or next-generation sequencing. Results 88% of tumors were MIBG-avid, and 67% were FDG-avid. The expression of NET in MIBG-negative tumors was 70% lower than in MIBG-positive tumors. The expression of GLUT1 in FDG-PET-negative tumors was 75% lower than in FDG-PET-positive tumors. The expression of NET positively correlated with transcription factors involved in chromaffin cell maturation, including PHOX2A, PHOX2B, GATA binding protein 3 (GATA3), GR, catecholamine synthases, and insulinoma associated 1 (INSM1). The JASPAR database for promoter analysis revealed putative responsive regions of the transcription factors PHOX2A, PHOX2B, GATA3, GR, and INSM1 on the NET gene. Seven patients (16.7%) had mutations in cluster 1, and fourteen patients (33.3%) had mutations in cluster 2. Cluster 2 exhibited elevated NET, PHOX2A, PHOX2B, GATA3, GR, and INSM1 expression levels compared to cluster 1. Cluster 1 showed a higher expression level of GLUT1 and BMP4 that is associated with early chromaffin cell differentiation. Conclusions In pheochromocytomas, MIBG and FDG uptake correlated with the expression levels of NET and GLUT1, respectively. NET expression is associated with chromaffin cell differentiation transcription factor expression. We propose that pheochromocytomas that carry Cluster 1 mutations are more likely to be missed in MIBG due to low NET expression, while pheochromocytomas that carry Cluster 2 mutations are more likely to be missed on FDG-PET due to low GLUT1 expression with a more mature chromaffin cell phenotype. Presentation: 6/2/2024

6918 A Unique Case of Oncocytic Thyroid Cancer with an NBN Gene Pathogenic Variant

Abstract Disclosure: A. Grover: None. S. Jhawar: None. S. Shekhar: None. S.A. Avadhanula: None. G. Al-Naqeeb: None. G. Thota: None. P. Veeraraghavan: None. C. Cochran: None. M.Y. Kao-Hsieh: None. A. Gharib: None. F.E. Escorcia: None. J. Del Rivero: None. J. Klubo-Gwiezdzinska: None. S. Gubbi: None. Introduction: Oncocytic thyroid carcinoma (OTC), previously known as “Hürthle cell” carcinoma, makes up less than 5% of all thyroid cancers. OTCs are often aggressive with a high risk of metastasis, and a poorer prognosis compared to other forms of differentiated thyroid carcinoma (DTC). Molecular drivers of OTC include pathogenic variants (PVs) in NRAS, DAXX, CDKN1A, the mitochondrial genome and chromosomal alterations. PVs in the NBN gene in OTC have not been previously reported. Case: A 53-year-old male was noted to have a thyroid nodule on a routine physical examination. Patient denied any hyper/hypothyroid or compressive symptoms, and family history was unremarkable. Cytopathologic analysis of the fine needle aspiration biopsy of the nodule was consistent with a thyroid follicular neoplasm (Bethesda IV). A total thyroidectomy with central compartment neck dissection was performed. Histopathologic examination demonstrated a 7 cm x 4 cm x 4 cm OTC with capsular and lymphovascular invasion, but without extra-thyroidal extension or lymph node metastasis (pT3aN0Mx). Subsequently, adjuvant radioiodine (RAI) I131 therapy with 165 mCi was administered and post-therapy scan revealed neck uptake. One-year post-therapy RAI diagnostic scan was negative. Three years following the initial thyroid surgery, elevated serum thyroglobulin (Tg) levels were noted. A computed tomogram of the chest revealed multiple bilateral lung nodules. Further imaging ruled out involvement of other distant sites. A diagnostic lower lung wedge resection demonstrated metastatic OTC. The tumor stained positive for CK7, PAX8, TG, TTF-1 and negative for CK20 on immunohistochemistry. Next-generation sequencing of the tumor tissue (Oncomine Comprehensive Assay v3) revealed a PV in the NBN gene (c.2166_2167delGCinsAT; p.Trp722Ter). A year later, the serum Tg levels continued to rise, and the lung nodules had increased in size. Due to disease progression, lenvatinib was initiated. A [F18]-fluorodeoxyglucose positron emission tomography performed one year later demonstrated persistent pulmonary tumor burden with new osseous metastasis in the right scapula, left acetabulum, and the sternum. Zoledronic acid was initiated for the treatment of the skeletal metastases, and palliative external beam radiation (2000 cGy in 5 fractions) was administered to the sternal lesion to alleviate the bone pain. Conclusion: The NBN gene encodes for the protein nibrin, a member of the MRE11/RAD50 complex that is involved in DNA repair. PVs in NBN are commonly identified in non-thyroidal malignancies such as breast and lung carcinomas. While NBN PVs are rarely reported in DTCs, as per our knowledge, this is the first described case of OTC with a PV in NBN as the molecular driver, manifesting with an aggressive disease course. Identification of this novel PV therefore adds to the current knowledge of the molecular landscape of OTC. Presentation: 6/3/2024

Long-term Outcomes and Prognostic Factors of Gastric MALT Lymphoma.

This study aimed to evaluate the long-term prognosis of patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, including overall survival (OS), remission, and factors associated with an aggressive disease course. Medical records of 153 patients diagnosed with gastric MALT lymphoma between 2013 and 2020 were retrospectively reviewed. Patients experiencing relapse, progression, high-grade transformation, or residual diseasewere included in the aggressive group and were compared with those in the indolent group. Additionally, the endoscopic findings of Helicobacter pylori-negative patients were reviewed. Patient characteristics were as follows: mean age (56.9±11.2 years), sex (male, 51.0%), H. pylori infection (positive, 79.7%), endoscopic location (distal, 89.5%), endoscopic feature (superficial, 89.5%), clinical stage (stage I, 92.8%), invasion depth by endoscopic ultrasound (mucosa, n=115, 75.7%), and bone marrow result (no involvement, n=77, 100.0%). The median follow-up period was 59 months (mean, 61; range, 36-124) and the continuous remission period (n=149) was 51 months (mean, 50; range, 3-112). The 5-year survival rate was 97.7% while the 5-year continuous remission was 88.3%. Factors associated with the patients in the aggressive group were old age, sex(male), and clinical stage II or higher. H. pylori-negative patients' endoscopy revealed a high incidence of atrophic gastritis in the antrum. The long-term prognosis of gastric MALT lymphoma appears indolent and is indicated by the 5-year OS and continuous remission rates. Aggressive disease courses are associated with old age, sex (male), and clinical stage II or higher, but are not related to OS.

Conjunctival Melanoma with Rhabdomyosarcomatous Differentiation:

This is a case of malignant melanoma with rhabdomyosarcomatous differentiation presenting as a conjunctival mass in a 50-year-old male. Melanoma cells were seen to react with desmin, myogenin and vimentin, indicating rhabdomyosarcomatous differentiation. This condition is very rare, with less than twenty cases reported in the literature, which contributes to the limitations in molecular characterization and standard treatment protocols for this entity. This condition has an aggressive course with a poor prognosis.