Primary Peritoneal Mesothelioma Affecting the Greater Omentum That Mimicked an Omental Infarction: A Case Report.

Introduction: Malignant peritoneal mesothelioma (MPM) is a rare cancer that is associated with asbestos exposure. The diagnosis can be difficult given the nonspecific nature of presenting symptoms and the presence of concomitant confounding findings. Case Presentation: We report a 71-year-old male who presented with right lower quadrant pain and new-onset ascites. CT imaging of the abdomen/pelvis demonstrated omental stranding concerning for a possible omental infarction. Subsequent imaging showed persistent omental edema but no identifiable soft tissue mass. A biopsy of the omentum showed atypical mesothelial proliferation, but pathology was unable to determine if proliferation was a neoplastic versus reactive process. Surgical oncology performed a diagnostic laparoscopy that showed peritoneal studding of the omentum. Subsequent immunohistochemical staining of the omentum demonstrated preservation of BAP1 expression and loss of MTAP expression, consistent with peritoneal mesothelioma. Conclusion: MPM is a rare and aggressive cancer with an overall poor prognosis. The diagnosis of MPM can be difficult based on the nonspecific clinical presentation, insufficient imaging and laboratory testing, and the presence of concomitant confounding findings, such as with this patient and his admitting diagnosis of omental infarction. This case demonstrates the importance of developing a broad differential while maintaining an awareness of heuristics that can influence clinical decision-making.

Improving the palliative-procedure decision-making process for patients with peritoneal carcinomatosis: A secondary analysis.

BACKGROUND: Peritoneal carcinomatosis (PC) is common in patients with advanced gynecologic and gastrointestinal cancers. Frequently, patients with PC undergo palliative surgery or procedures to manage disease-related complications and side effects. However, there are limited data regarding patients' and family caregivers' decision-making processes about these procedures. Thus, we sought to describe the decision-making experiences of patients with PC who elect to pursue palliative surgical procedures and their family caregivers. METHODS: We conducted a secondary analysis of qualitative data collected during a pilot randomized controlled trial of BOLSTER, a nurse-led telehealth intervention for patients with PC and their caregivers after an acute hospitalization and palliative procedure. Participants in both study arms described their experiences in semi-structured interviews. We re-analyzed coded qualitative data with a focus on understanding decision-making experiences surrounding palliative surgery and procedures using conventional content analysis. RESULTS: Interviews from 32 participants, 23 patients and 9 caregivers, were analyzed. Participants reported their decision-making was complicated by illness uncertainty and a desire for clear, effective communication with surgical and medical oncology teams. Participants requested more information about the impact of palliative procedures on their daily life. Several also noted that, without improved understanding, a misalignment between patient and family caregiver goals and palliative procedures may inadvertently increase suffering. CONCLUSION: Discussions related to patients' goals and preferences can improve the quality of treatment decision-making in patients with PC and their caregivers. Future research should test interventions to improve advanced cancer patients' illness understanding and decision-making surrounding palliative surgery and procedures.

Disseminated Carcinomatosis of the Bone Marrow from Castration-Resistant Prostate Cancer Revealed by Choline Positron Emission Tomography-Computed Tomography.

Introduction: Disseminated carcinomatosis of the bone marrow is caused by cancer metastasis to the bone marrow and is the diagnosis is very difficult by imaging. Case Presentation: We report a 75-year-old male with disseminated carcinomatosis of the bone marrow from castration-resistant prostate cancer revealed by 11C-choline positron emission tomography-computed tomography (PET/CT). Although he already received radiotherapy to the prostate, combined androgen blockade, enzalutamide and apalutamide, and external beam radiotherapy for the pelvic bone metastases, serum prostate-specific antigen (PSA) value rapidly increased from 32 ng/mL to 104 ng/mL in recent 1 month. Bone scintigraphy showed almost no abnormal uptake in the whole body, whereas 11C-choline PET/CT showed diffuse bone marrow 11C-choline uptake. The disseminated carcinomatosis of the bone marrow was diagnosed from the discordant findings between bone scintigraphy and 11C-choline PET/CT examinations and confirmed pathologically by iliac marrow biopsy pathologically. Although docetaxel therapy was started, PSA value continued rising and he died after 4 months of the diagnosis. Conclusion: The discordant findings of choline PET/CT and bone scintigraphy can diagnose disseminated carcinomatosis of the bone marrow from prostate cancer.

Focal ground glass opacity of the lung in metachronous prostate and gastric cancer: A case report.

Chest computed tomography (CT) revealed a focal ground glass opacity (GGO) with a minimal solid area in a 75-year-old man. The shadow was located in the periphery of the right upper lobe and measured 11 mm in diameter. The patient had a medical history of metachronous prostate and gastric cancers. The patient had been treated with androgen deprivation therapy for prostate cancer for 12 years and underwent subtotal gastrectomy for triple gastric cancers 7 months before. Since primary lung adenocarcinoma was suspected, CT-assisted percutaneous needle biopsy was performed. Histology revealed the sheet-like and trabecular proliferation of atypical cells, suggesting that the lesion was moderately to poorly differentiated adenocarcinoma. Adenocarcinoma cells showed subepithelial extension causing the thickening of alveolar walls. A tumor thrombus was not detected in the blood or lymphatic vessels. Immunohistochemistry revealed that carcinoma cells were negative for cytokeratin 7 (CK7), CK20, thyroid transcription factor-1 and CDX2 and positive for prostate-specific antigen and P504S. Based on these findings, the patient was diagnosed with metastatic carcinoma from prostate cancer. The disease remained stable for 4 months after the diagnosis, and no new lesions were observed on chest CT. Metastatic carcinoma rarely presents with focal GGO. Lung biopsy is necessary to identify the pathology of the lesion, and the primary site needs to be confirmed by immunohistochemistry with specific markers, particularly in a case of metachronous multiple cancers. A tumor thrombus, which is suggestive of lymphangitic carcinomatosis or pulmonary tumor thrombotic microangiopathy, also needs to be evaluated.

Long-Term Outcomes following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis of Colorectal Origin.

BACKGROUND: Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a major treatment of colorectal peritoneal carcinomatosis (CPC). The aim was to determine the disease-free survival (DFS) and overall survival (OS) of patients undergoing CRS-HIPEC for CPC and factors associated with long-term survival (LTS). METHODS: consecutive CPC patients who underwent CRS-HIPEC at a HIPEC center between 2007 and 2021 were included. Actual survival was calculated, and Cox proportional hazards models were used to identify factors associated with OS, DFS and LTS. RESULTS: there were 125 patients with CPC who underwent primary CRS-HIPEC, with mean age of 54.5 years. Median follow-up was 31 months. Average intraoperative PCI was 11, and complete cytoreduction (CC-0) was achieved in 96.8%. Median OS was 41.6 months (6-196). The 2-year and 5-year OS were 68% and 24.8%, respectively, and the 2-year DFS was 28.8%. Factors associated with worse OS included pre-HIPEC systemic therapy, synchronous extraperitoneal metastasis, and PCI ≥ 20 (p < 0.05). Progression prior to CRS-HIPEC was associated with worse DFS (p < 0.05). Lower PCI, fewer complications, lower recurrence and longer DFS were associated with LTS (p < 0.05). CONCLUSION: CRS and HIPEC improve OS in CPC patients but they have high disease recurrence. Outcomes depend on preoperative therapy response, extraperitoneal metastasis, and peritoneal disease burden.

Home-Based Trimodal Prehabilitation in Patients with Peritoneal Carcinomatosis Undergoing Cytoreductive Surgery: Effect on Functional Walking Capacity and Skeletal Muscle Mass.

BACKGROUND: Patients with peritoneal carcinomatosis often suffer from loss of skeletal muscle mass and require extensive surgery. Multimodal prehabilitation may improve physical status but its benefits for these specific patients remain unknown. This study aimed to evaluate the effect of prehabilitation on functional walking capacity and skeletal muscle mass, as well as its association with postoperative complications. PATIENTS AND METHODS: A prospective study of patients with peritoneal carcinomatosis following a home-based trimodal prehabilitation program was carried out. Functional walking capacity was assessed with the 6-min walk test (T6MWT), and by the appendicular skeletal muscle index (ASMI) estimated by bioelectrical impedance analysis. Data were collected at the first medical appointment and on the day before surgery. A 90-day postoperative morbidity was registered according to the Clavien-Dindo classification. RESULTS: A total of 62 patients were included in the analysis. Women were more prevalent (77.4%) and peritoneal metastasis from ovarian origin accounted for 48.4%. Clavien II-V grades occurred in 30 (57.7%) patients. After prehabilitation, functional walking capacity improved by 42.2 m (39.62-44.72 m) compared with baseline data (p < 0.001), but no improvement was observed in the ASMI (p = 0.301). Patients able to walk at least 360 m after prehabilitation suffered fewer Clavien-Dindo II-V postoperative complications (p = 0.016). A T6MWT of less than 360 m was identified as an independent risk factor in the multivariable analysis (OR 3.99; 1.01-15.79 p = 0.048). CONCLUSIONS: This home-based trimodal prehabilitation program improved functional walking capacity but not ASMI scores in patients with peritoneal metastasis before surgery. A T6MWT of less than 360 m was found to be a risk factor for postoperative complications.

A non-enhancing, T2 fluid-attenuated inversion recovery hyperintense, diffusion-restricting brainstem lesion in an EGFR tyrosine kinase inhibitor-treated non-small-cell lung cancer patient.

Leptomeningeal metastasis (LM) is a devastating complication of malignancy. Diagnosis relies on both contrast enhancement on imaging and malignant cells in cerebral spinal fluid cytology. Though early detection and prompt intervention improves survival, the detection of LM is limited by false negatives. A rare brainstem imaging finding uncovered specifically in EGFR mutation-positive lung cancer patients may represent an early sign of LM. This sign demonstrates high signal on T2 fluid-attenuated inversion recovery and diffusion-weighted imaging sequences, but paradoxically lacks correlative contrast enhancement. Here we report a case of a 72-year-old female EGFR-positive lung cancer patient who developed this lesion following treatment with two first-generation EGFR tyrosine kinase inhibitors then showed subsequent response to osimertinib, an irreversible third-generation EGFR tyrosine kinase inhibitor.

A non-enhancing, T2 FLAIR hyperintense, diffusion-restricting brainstem lesion in an EGFR-positive lung cancer patient may represent an early indicator of leptomeningeal metastases.

Intraperitoneal drug delivery systems for peritoneal carcinomatosis: Bridging the gap between research and clinical implementation.

Several abdominal-located cancers develop metastasis within the peritoneum, what is called peritoneal carcinomatosis (PC), constituting a clinical challenge in their therapeutical management, often leading to poor prognoses. Current multidisciplinary strategies, including cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC), demonstrate efficacy but have limitations. In response, alternative strategies are explored in the drug delivery field for intraperitoneal chemotherapy. Controlled drug delivery offers a promising avenue, maintaining localized drug concentrations for optimal PC management. Drug delivery systems (DDS), including hydrogels, implants, nanoparticles, and hybrid systems, show potential for sustained and region-specific drug release. The present review aims to offer an overview of the advances and current designs of DDS for PC chemotherapy administration, focusing on their composition, main characteristics, and principal experimental outcomes, highlighting the importance of biomaterial rationale design and in vitro/vivo models for their testing. Moreover, since clinical data for human subjects are scarce, we offer a critical discussion of the gap between bench and bedside in DDS translation, emphasizing the need for further research.

Efficacy of Hyperthermic Pressurized Intraperitoneal Aerosol Chemotherapy in an In Vitro Model Using a Human Gastric Cancer AGS Cell Line and an Abdominal Cavity Model.

PURPOSE: Peritoneal carcinomatosis (PC) presents a major challenge in the treatment of late-stage, solid tumors, with traditional therapies limited by poor drug penetration. We evaluated a novel hyperthermic pressurized intraperitoneal aerosol chemotherapy (HPIPAC) system using a human abdominal cavity model for its efficacy against AGS gastric cancer cells. MATERIALS AND METHODS: A model simulating the human abdominal cavity and AGS gastric cancer cell line cultured dishes were used to assess the efficacy of the HPIPAC system. Cell viability was measured to evaluate the impact of HPIPAC under 6 different conditions: heat alone, PIPAC with paclitaxel (PTX), PTX alone, normal saline (NS) alone, heat with NS, and HPIPAC with PTX. RESULTS: Results showed a significant reduction in cell viability with HPIPAC combined with PTX, indicating enhanced cytotoxic effects. Immediately after treatment, the average cell viability was 66.6%, which decreased to 49.2% after 48 hours and to a further 19.6% after 120 hours of incubation, demonstrating the sustained efficacy of the treatment. In contrast, control groups exhibited a recovery in cell viability; heat alone showed cell viability increasing from 90.8% to 94.4%, PIPAC with PTX from 82.7% to 89.7%, PTX only from 73.3% to 74.8%, NS only from 90.9% to 98.3%, and heat with NS from 74.4% to 84.7%. CONCLUSIONS: The HPIPAC system with PTX exhibits a promising approach in the treatment of PC in gastric cancer, significantly reducing cell viability. Despite certain limitations, this study highlights the system's potential to enhance treatment outcomes. Future efforts should focus on refining HPIPAC and validating its effectiveness in clinical settings.

Enhancing precision in colorectal cancer surgery: development of an LGR5-targeting RSPO1 peptide mimetic as a contrast agent for intraoperative fluorescence molecular imaging.

Colorectal cancer (CRC) is the third most common cancer worldwide. In the United States alone, CRC was responsible for approximately 52,550 deaths in 2023, with an estimated 153,020 new cases. CRC presents with synchronous peritoneal spread in 5-10% of patients, and up to 20-50% of patients with recurrent disease will develop metachronous colorectal cancer peritoneal metastatic (CRC-PM) disease. Eradication of the tumor, tumor margins and microscopic residual disease is paramount, as microscopic residual disease is associated with local recurrences, with 5-year survival rates of less than 35%. The success of resection and reduction of residual disease depends on the accuracy with which cancer cells and normal tissue can be intra-operatively distinguished. Fluorescence Molecular Imaging (IFMI) and tumor-targeted contrast agents represent a promising approach for intraoperative detection and surgical intervention. Proper target selection, the development of scalable imaging agents and enhanced real-time tumor and tumor microenvironment imaging are critical to enabling enhanced surgical resection. LGR5 (leucine-rich repeat-containing G-protein-coupled receptor 5), a colonic crypt stem cell marker and the receptor for the R-spondins (RSPO) in the Wnt signaling pathway, is also expressed on colorectal cancer stem cells (CSC) and on CRC tumors and metastases, suggesting it could be a useful target for imaging of CRC. However, there are numerous diverging reports on the role of LGR5 in CRC therapy and outcomes. Herein, we report on the synthesis and validation of a 37 amino acid RSPO1-mimetic peptide, termed RC18, that was specifically designed to access the R-spondin binding site of LGR5 to potentially be used for interoperative imaging of CRC-PM. The receptor-binding capabilities of the RC18 indicate that direct interactions with LGR5 neither significantly increased LGR5 signaling nor blocked RSPO1 binding and signal transduction, suggesting that the RSPO1-mimetic is functionally inert, making it an attractive contrast agent for intraoperative CRC-PM imaging.

Glofitamab-Associated Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) Presenting as Serial Seizures and Responding Positively to Antiseizure Drugs and Anakinra: A Case Report.

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a well-known side effect of chimeric antigen receptor (CAR) T-cell therapy but has occasionally been described with immune checkpoint inhibitors as well. Glofitamab-associated ICANS with a bispecific monoclonal antibody has rarely been reported. The patient is a 63-year-old male with a history of mantle cell lymphoma, diagnosed at age 37, and aggressive large-cell B-cell lymphoma, diagnosed at age 50. Despite adequate chemotherapy, immunotherapy, autologous stem cell transplantation, and CAR T-cell therapy, there were several relapses, including meningeal carcinomatosis at age 61 and intracerebral lymphoma at age 62. For this reason, glofitamab was started. One week after the ninth cycle, the patient developed drowsiness, behavioral changes, word-finding difficulties, aphasia, focal to bilateral tonic-clonic seizures, and focal onset seizures, which resolved after 16 days with levetiracetam, valproic acid, lorazepam, and midazolam. Since there was no infectious disease, electrolyte disturbance, metabolic disorder, cardiovascular disease, or relapse of lymphoma, glofitamab-associated ICANS was suspected, and anakinra was administered. The case shows that ICANS with drowsiness, behavioral changes, aphasia, and seizures can develop with glofitamab and that patients with structural brain abnormalities may be prone to this.

Material density dual-energy CT images: value added in early diagnosis of peritoneal carcinomatosis : Original research.

OBJECTIVE: To assess the value of material density (MD) images generated from a rapid kilovoltage-switching dual-energy CT (rsDECT) in early detection of peritoneal carcinomatosis (PC). MATERIALS AND METHODS: Thirty patients (60 ± 13 years; 24 women) with PC detected on multiple abdominal DECT scans were included. Four separate DECTs with varying findings of PC from each patient were used for qualitative/quantitative analysis, resulting in a total of 120 DECT scans (n = 30 × 4). Three radiologists independently reviewed DECT images (65 keV alone and 65 keV + MD) for diagnosis of PC (diagnostic confidence, lesion conspicuity, sharpness/delineation and image quality) using a 5-point Likert scale. Quantitative estimation of contrast-to-noise ratio (CNR) was done. Wilcoxon signed-rank test and Odds ratio calculation were used to compare between the two protocols. Inter-observer agreement was evaluated using Kappa coefficient analysis. P values < 0.05 were considered statistically significant. RESULTS: 65 keV + MD images showed a slightly higher sensitivity (89%[95%CI:84,92]) for PC detection compared with 65 keV images alone without statistical significance (84%[95%CI:78,88], p = 0.11) with the experienced reader showing significant improvement (98%[95%CI:93,100] vs. 90%[95%CI:83,94], p = 0.02). On a per-patient basis, use of MD images allowed earlier diagnosis for PC in an additional 13-23% of patients. On sub-group analysis, earlier diagnosis of PC was particularly beneficial in patients with BMI ≤ 29.9 kg/m2. 65 keV + MD images showed higher diagnostic confidence, lesion conspicuity, and lesion sharpness for the experienced reader (p < 0.001). CNR was higher in MD images (1.7 ± 0.5) than 65 keV images (0.1 ± 0.02, p < 0.001). All readers showed moderate interobserver agreement for determining PC by both protocols (κ = 0.58 and κ = 0.47). CONCLUSION: MD images allow earlier and improved detection of PC with the degree of benefit varying based on reader experience and patient body habitus.

Leptomeningeal Carcinomatosis in Early Gastric Cancer: A Case Report and Literature Review.

Leptomeningeal carcinomatosis (LC) is a rare site of metastasis in solid tumors, and it is associated with poor prognosis due to disabling symptoms and a scarcity of treatment options. This condition is an uncommon entity in gastric cancer (GC). We present a case of primary LC manifestation in a patient with an incidental diagnosis of localized node-negative GC. We additionally perform a literature review and discuss the diagnostic and therapeutic challenges. In conclusion, LC from GC represents a rare condition with a dramatic prognosis. Its diagnosis might be very challenging. A multidisciplinary approach appears to be the best strategy for the management of LC from GC.

Risk Scoring System to Predict Mortality in Gastric Cancer with Peritoneal Carcinomatosis.

Gastric cancer (GC) with peritoneal carcinomatosis (PC) has a particularly unfavorable prognosis. This limited survival raises doubts about which factors confer an extremely worse outcome and which patients could benefit from more aggressive treatments, in an attempt to improve survival and better control the disease. This study aimed to evaluate the survival outcomes of patients with PC due to GC and develop a prognostic score to predict 6-month mortality. We performed an analysis of clinical stage IV GC with PC. Scores were assigned to risk factors and calculated for each patient from nine variables. Among 326 IVB GC, 211 (64.7%) had PC and were included. After calculating the score, 136 (64.5%) GCs were classified as a low-risk group and 75 (35.5%) as a high-risk group. Median OS was 7.9 and 1.9 months for low- and high-risk patients (p < 0.001). In the high-risk group, 77.3% of the patients died in <6 mo (p < 0.001). Palliative surgery and chemotherapy were associated with better survival, and the prognostic groups maintained statistical significance even when the same type of treatment was performed. In conclusion, the scoring system developed with variables related to patient performance status and clinical data was able to distinguish GC with PC with a high risk of 6-month mortality. Accordingly, verifying and validating our findings in a large cohort of patients is necessary to confirm and guarantee the external validation of the results.

ED diagnosis of peritoneal carcinomatosis.

PURPOSE: The goal of our study was to better characterize new CT diagnoses of peritoneal carcinomatosis (PC) in the ED, and to evaluate how to best identify the primary lesion. Prompt identification of the source of the carcinomatosis may allow for the patient to receive early initial care from the correct clinical service. METHODS: All new CT cases of PC-like appearance identified on CT in the ED from January 2017 through July 2020. Each report and corresponding medical record were manually reviewed. Patient demographics, presence/absence of intravenous contrast, source organ predicted by the radiologist in the CT scan report, pathologic diagnosis, and amount of ascites were tabulated. Chi-tests were used to test the statistical significance of differences between groups. RESULTS: Of the 131 CT cases of new PC-like appearance which received workup, 108 cases had pathologically proven PC and 23 cases had no underlying malignancy yielding a positive predictive value for actual PC of 82%. The most common cause of new PC in women was gynecological (66%), and in men was of GI tract origin (57%). Concordance between radiologist prediction and final pathology was higher with intravenous contrast (58%) compared to without contrast (40%); although this difference was not statistically significant (p = 0.19). A moderate or large amount of ascites was found in more than half of GYN primaries and in adenocarcinoma of unknown primary and there was a statistically significant difference in amount of ascites between cancer primaries (p = 0.01). CONCLUSION: A PC-like appearance on CT in the ED will likely be in patients with known malignancy, but of the new cases, there is a high PPV for it to represent new peritoneal carcinomatosis. Gynecological and GI malignancies are the most common cause in women and men, respectively, and this may help in focusing the radiologist's search pattern. Usage of intravenous contrast may help in identifying a primary lesion, and the presence of high-volume ascites should suggest a GYN primary or adenocarcinoma of unknown primary when there is no other obvious primary lesion.

Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) in the Treatment of Gastric Cancer: Feasibility, Efficacy and Safety-A Systematic Review and Meta-Analysis.

Background: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is an emerging technique for delivering chemotherapy directly to the peritoneum via a pressurized aerosol. Its growing attention stems from its effectiveness in treating peritoneal carcinomatosis (PC) originating from various primary tumors, with gastric cancer (GC) being among the most prevalent. This study aimed to systematically investigate PIPAC's therapeutic role in gastric cancer peritoneal metastasis (GCPM). Methods: The systematic review and meta-analysis followed the PRISMA 2020 guidelines, searching Pubmed, Web of Science, and SCOPUS databases. The meta-analysis of relative risks and mean differences compared patients undergoing one or two PIPAC sessions with those completing three or more, assessing various outcomes. Results: Eighteen studies underwent qualitative analysis, and four underwent quantitative analysis. Patients with three or more PIPAC procedures had shorter hospital stays (MD = -1.2; 95%CI (-1.9; -0.5); p < 0.001), higher rates of histopathological response (RR = 1.77, 95%CI 1.08; 2.90; p = 0.023), and significantly improved overall survival (MD = 6.0; 95%CI 4.2; 7.8; p < 0.001). Other outcomes showed no significant differences. Conclusions: PIPAC demonstrated efficacy in carefully selected patients, enhancing histopathologic response rates and overall survival without prolonging hospital stays. This study underscores the necessity for randomized controlled trials and precise selection criteria to refine PIPAC's implementation in clinical practice.

A Case of Peritoneal Carcinomatosis After Hyperprogression in Human Papillomavirus-Positive (HPV+) Oropharyngeal Squamous Cell Carcinoma.

Immunotherapy has been shown to provide clinical benefit in selected patients with head and neck squamous cell carcinoma (HNSCC), regardless of human papillomavirus (HPV) infection, and including recurrent/metastatic (R/M) platinum refractory tumors. Hyperprogression is an uncommon negative outcome of treatment with immunotherapy. We present the case of a patient with HPV+ HNSCC who presented hyperprogression after immunotherapy and a rare metastasis location with peritoneal carcinomatosis and subcutaneous nodules. HPV+ HNSCC is related to distant recurrence after a longer interval of time and more diverse metastasis sites compared with HPV- disease. However, the literature on peritoneal metastasis in HNSCC remains limited, with few documented cases. To the best of our knowledge, this is the first case reporting peritoneal carcinomatosis after hyperprogression in HNSCC.

Demographic and clinical characteristics of patients with metastatic breast cancer and leptomeningeal disease: a single center retrospective cohort study.

PURPOSE: Leptomeningeal disease (LMD) is a devastating complication of metastatic breast cancer (MBC). It is critical to better understand the risk factors, natural history, and treatment outcomes, including patients in a modern cohort. METHODS: In this single center retrospective cohort study, we identified patients with MBC and LMD who received care from 2000 to 2024 and abstracted key clinical, treatment, and survival data. RESULTS: We identified 111 patients with MBC and LMD, including patients with the following subtypes: HR+/HER2- (n = 53, 47.7%), HER2+ (n = 30, 27.0%), and triple negative breast cancer (TNBC; n = 28, 25.2%). Median time from the diagnosis of MBC to LMD was 16.4 months (range 0-101.3 months). After the diagnosis of LMD, most patients received systemic therapy (n = 66, 59.5%) and/or central nervous system (CNS)-directed therapy (n = 94, 84.7%) including intrathecal therapy (n = 42, 37.8%) and/or CNS-directed radiation therapy (n = 70, 63.1%). In all patients, median overall survival (OS) from the diagnosis of LMD to death was 4.1 months (range 0.1-78.1 months) and varied by subtype, with HR+/HER2- or HER2+ MBC patients living longer than those with TNBC (4.2 and 6.8 months respectively vs. 2.0 months, p < 0.01, HR 2.15, 95% CI 1.36-3.39). Patients who received CNS-directed therapy lived longer than those who did not (4.2 vs. 1.3, p = 0.02 HR 0.54, 0.32-0.91). Patients diagnosed with LMD from 2015 to 2024 lived longer than those diagnosed from 2000 to 2014 (6.4 vs. 2.9 months, p = 0.04, HR 0.67, 95% CI 0.46-0.99). On multivariable analysis, having TNBC was associated with shorter OS from time of LMD to death (p = 0.004, HR 2.03, 95% CI 1.25-3.30). CONCLUSION: This is one of the largest case series of patients with MBC and LMD. Patients diagnosed with LMD from 2015 to 2024 lived longer than those diagnosed from 2000 to 2014, although median OS was short overall. Patients with TNBC and LMD had particularly short OS. Novel therapeutic strategies for LMD remain an area of unmet clinical need.

Disseminated peritoneal leiomyomatosis mimicking carcinomatosis: A case report.

INTRODUCTION AND IMPORTANCE: Disseminated Peritoneal Leiomyomatosis (DPL) is a rare benign proliferation of solid peritoneal lesions along the abdominopelvic cavity comprised of smooth muscle and connective tissue. Though hormonal and iatrogenic causes have been theorized, the exact etiology remains unknown. Most patients with DPL are frequently premenopausal with a history of myomectomy or prior hysterectomy. These patients can present asymptomatically or with abnormal uterine bleeding and abdominal discomfort. DPL is a rare entity with less than 150 cases reported in the literature, showcasing the need of awareness of this poorly understood neoplasm. Imaging, if performed, is helpful as positron emission tomography (PET) can differentiate DPL from malignant peritoneal disease. Treatment involves medical and surgical options based on patient's clinical presentation, with medical treatment with gonadotropin-releasing hormone agonist being first line. CASE PRESENTATION: We report a case of a previously healthy female presenting for desired laparoscopic tubal ligation with incidental countless peritoneal nodules suspicious for carcinomatosis found during the operative event but proven leiomyomas after histologic examination. CLINICAL DISCUSSION: Differentiating DPL from mimickers such as leiomyosarcoma, endometriosis, and carcinomatosis remains a challenge as macroscopic appearances are similar ultimately requiring histology evaluation. CONCLUSION: Awareness of the entity is crucial to avoid misdiagnosis and unnecessary anxiety associated with a presumptive diagnosis of malignancy for a largely benign entity.