Search Results (23)

Background: Nutritional deficiency anemias—including iron, vitamin B12, and folate deficiencies—are common worldwide and are increasingly recognized as potential contributors to venous thromboembolism (VTE). Mechanistic and epidemiologic data suggest that anemia may promote thrombosis through hypoxia, endothelial activation, reactive thrombocytosis, and hyperhomocysteinemia. However, a focused synthesis of clinical and genetic evidence specifically linking nutritional deficiency anemia to VTE has been lacking. Methods: We conducted a systematic search of PubMed and the Cochrane Library from inception to 30 September 2025 to identify studies assessing nutritional deficiency anemia in relation to VTE outcomes. Eligible studies included observational designs, case reports, case series, and Mendelian randomization (MR) analyses. Quality assessment followed the Newcastle–Ottawa Scale (NOS), Joanna Briggs Institute (JBI) checklists, and ROB-MR. The review was registered in PROSPERO (CRD420251235479). Results: Seven studies met the inclusion criteria. Observational analytical studies consistently showed that anemia was associated with adverse VTE-related outcomes. Lower hemoglobin predicted higher short-term mortality in acute pulmonary embolism (HR 1.16 per 1 g/dL decrease), increased symptomatic VTE among hospitalized patients (RR 1.94), and greater long-term bleeding and mortality risk in VTE cohorts (HRs 1.41–2.89). Iron-deficiency anemia increased the odds of VTE in population-based data (OR 1.43), and case reports described unprovoked DVT in young adults with moderate to severe anemia. The MR study indicated a potential causal association between anemia traits and thrombosis at unusual anatomical sites (OR 1.446). No study demonstrated a significant association with recurrent VTE. Most analytical studies were rated as good–high quality. Conclusion: Across multiple study designs, anemia—particularly iron-deficiency anemia and low baseline hemoglobin—appears to be an underrecognized factor associated with elevated VTE risk and adverse VTE-related outcomes. However, direct evidence for vitamin B12- and folate-deficiency anemia remains limited, and further well-designed prospective studies are required to confirm causality and clarify the contribution of specific nutritional deficiency subtypes, as well as to support integration of anemia assessment into VTE risk models. Full article

Background/Objectives: Unusual-site venous thrombosis (USVT) lacks robust evidence guiding anticoagulant selection between vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs). This study aimed to evaluate recanalization, recurrence, and major bleeding outcomes in real-world USVT patients and to replicate these findings through a validated digital twin model with Monte Carlo simulation. Methods: We conducted a retrospective study of 90 USVT patients (72% VKAs, 28% DOACs). A conditional generative adversarial network was used to generate digital twins matched on age, sex, thrombosis site, and malignancy. Logistic regression was applied to estimate treatment-specific outcome probabilities for recanalization, recurrence, and major bleeding. A nested stochastic simulation framework simulated 500 iterations across clinical scenarios, including increased DOAC use, cancer prevalence, cerebral vein thrombosis proportion, and optimized VKA control. Results: The mean age was 67.5 years, and 54.4% were female. 61.1% of splanchnic vein thrombosis, 36.7% of upper extremity deep vein thrombosis, and 2.2% of cerebral vein thrombosis were included. In the real cohort, complete recanalization occurred in 40.0% of patients with DOACs and 36.0% with VKAs. Recurrence was 8.0% with DOACs and 7.7% with VKAs, and major bleeding occurred in 8.0% and 10.8% of cases, respectively. All-cause mortality was 20% in DOAC-treated patients and 60% in those receiving VKAs. Digital Twin-based predictions replicated these results (recanalization 40.3% versus 38.0%; recurrence 10.9% versus 8.6%; bleeding 7.6% versus 9.1%). Simulated scenarios preserved the directionality effect, with the most significant differences observed in high-cerebral vein thrombosis and cancer-enriched patients. Conclusions: DOACs showed comparable efficacy and slightly lower bleeding risk than VKAs in USVT. Digital twin and Monte Carlo modeling provided robust, reproducible simulations of treatment effects under varying clinical conditions. Separating empirical and simulation-based findings, the digital twin supported the internal consistency of real-world observations and demonstrated the potential of in silico modeling as a complementary tool in rare thrombotic diseases. Full article

Background and Objective: Colorectal cancer (CRC) most commonly metastasizes to the liver and lungs; however, synchronous metastases to pelvic structures such as the vagina and urethra are extremely rare, posing a significant diagnostic and therapeutic challenge. This report describes an unusual case of sigmoid colon adenocarcinoma with synchronous metastases to the vagina and urethra, highlighting its diagnostic evaluation and the value of a multidisciplinary approach. Methods: A 59-year-old woman with a history of deep vein thrombosis treated with apixaban presented with chronic constipation and pelvic bleeding. A gynecological evaluation revealed a vaginal lesion. A colonoscopy, biopsy, pelvic magnetic resonance imaging, and molecular profiling were performed. Treatment included chemotherapy (capecitabine and oxaliplatin), panitumumab, and pelvic radiotherapy. Results: The biopsy confirmed a moderately differentiated invasive adenocarcinoma in the sigmoid colon with synchronous metastases to the vagina and urethra. Molecular profiling identified a rat sarcoma virus oncogene and BRAF (B-Raf proto-oncogene), allowing for the use of targeted therapy. The patient achieved a complete response according to RECIST 1.1 criteria and significant symptomatic improvement, including pain reduction, although dosages were adjusted for thrombocytopenia. She is currently continuing palliative treatment with good tolerance and durable symptomatic improvement. Conclusions: This case underscores the need to consider unusual metastatic sites in patients with colorectal cancer presenting with gynecological symptoms. Early diagnosis, based on imaging and histology, alongside molecular characterization, is crucial for effective personalized therapy. Multidisciplinary coordination is key to optimizing clinical outcomes in these rare metastatic presentations. Full article

Direct oral anticoagulants (DOACs) have emerged as the preferred oral anticoagulant therapy for patients with deep vein thrombosis of the lower extremities and pulmonary embolism. DOACs offer several advantages over vitamin K antagonists, including fixed dosage, fewer drug interactions, faster onset of action, and a lower risk of major bleeding, especially intracranial. Although evidence on the use of DOACs in unusual-site venous thrombosis (USVT) is limited, their use in such cases is becoming increasingly common. This narrative review examines the evidence derived from randomized controlled trials, and large observational studies focused on the use of the DOACs in USVT, including cerebral, splanchnic, upper extremity, ovarian, renal, and retinal vein thrombosis. In addition, it also provides practical advice for their use in these clinical settings according to the updated scientific literature. Full article

Background: Acute promyelocytic leukemia (APL) is frequently associated with disseminated intravascular coagulation (DIC), leading to potentially life-threatening bleeding. Compared to bleeding, thromboses are a less commonly encountered problem. Objective: The objective of our study was to identify the incidence and predictive value of demographic data, clinical–laboratory parameters, and thrombosis risk assessment models (RAMs) for venous thromboembolism (VTE) in patients with APL. Methods: This study was a retrospective study conducted on adult patients with APL who were treated between 2006 and 2024 at the Clinic of Hematology UCCS with all-trans retinoic acid (ATRA) and anthracycline. The demographic and clinical–laboratory data related to VTE were collected and analyzed alongside the predictive value of two RAMs proposed by Al-Ani and Paterno and colleagues. Results: Among the one-hundred-fifty-five adult patients with APL, VTE was diagnosed in twenty-eight cases (18.1%). The most common location for thrombosis was in the central venous catheter (CVC), which affected twelve (42.8%) patients. A total of six (21.4%) patients had deep vein thrombosis (DVT), one patient (3.6%) showed a pulmonary embolism (PE), and thrombosis at unusual sites was present in nine (32.1%) patients. Our analyses showed that neither Al-Ani’s RAM nor the RAM proposed by Paterno and colleagues were predictive for VTE in patients with APL. The C statistics value for the Al-Ani model was ROC = 0.514, and, for Paterno’s RAM, it was ROC = 0.521. The independent risk factors for VTE, identified via multivariate analysis, were CD114 expression (p = 0.005, OR = 6.4 IC 95%: [1.8–23.2]) and the absence of bleeding at presentation (p = 0.013, OR = 0.086 IC 95%: [0.01–0.59]). Conclusions: To the best of our knowledge, this is the first study showing that a higher expression of CD114 increases the risk of VTE. The absence of bleeding at presentation in patients with APL correlates with thrombosis. Further analyses are needed to confirm these findings and help to develop therapeutic strategies to prevent VTE complications. So far, no risk assessment model has been sufficient to stratify patients with APL according to their risk of VTE. Full article

Paroxysmal Nocturnal Hemoglobinuria (PNH) constitutes a rare bone marrow failure syndrome characterized by hemolytic anemia, thrombotic events (TEs), and bone marrow aplasia of variable degrees. Thrombosis is one of the major clinical manifestations of the disease, affecting up to 40% of individuals with PNH. Venous thrombosis is more prevalent, affecting mainly unusual sites, such as intrabdominal and hepatic veins. TEs might be the first clinical manifestation of PNH. Complement activation, endothelial dysfunction, hemolysis, impaired bioavailability of nitric oxide, and activation of platelets and neutrophils are implicated in the pathogenesis of TEs in PNH patients. Moreover, a vicious cycle involving the coagulation cascade, complement system, and inflammation cytokines, such as interleukin-6, is established. Complement inhibitors, such as eculizumab and ravulizumab (C5 inhibitors), have revolutionized the care of patients with PNH. C5 inhibitors should be initiated in patients with PNH and thrombosis, while they constitute a great prophylactic measure for TEs in those individuals. Anticoagulants, such as warfarin and low-molecular-weight heparin, and, in selected cases, direct oral anticoagulants (DOACs) should be used in combination with C5 inhibitors in patients who develop TEs. Novel complement inhibitors are considered an alternative treatment option, especially for those who develop extravascular or breakthrough hemolysis when terminal inhibitors are administered. Full article

Metastasis to the penis from renal cell carcinoma (RCC) or any other primary cancer site is unusual; when it does occur, it often involves multiple organs. A 75-year-old man presented with penile pain and swelling. Three months earlier, he had open radical nephrectomy with thrombectomy and was diagnosed with clear-cell RCC with tumor thrombosis in the inferior vena cava. The follow-up imaging indicated metastasis to the penis, prompting a total penectomy due to worsening pain. The excised mass displayed features consistent with metastatic RCC. This case underscores the need to consider rare metastatic sites, such as the metastasis of RCC to the penis, in RCC patients. Full article

Introduction: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare yet severe adverse complication first identified during the global vaccination effort against SARS-CoV-2 infection, predominantly observed following administration of the ChAdOx1-S (Oxford-AstraZeneca) and Ad26.CoV2.S (Johnson & Johnson/Janssen) adenoviral vector-based vaccines. Unlike other anti-platelet factor 4 (PF4) antibody-mediated disorders, such as heparin-induced thrombocytopenia (HIT), VITT arises with the development of platelet-activating anti-PF4 antibodies 4–42 days post-vaccination, typically featuring thrombocytopenia and thrombosis at unusual sites. Aim: To explore the unique properties, pathogenic mechanisms, and long-term persistence of VITT antibodies in patients, in comparison with other anti-PF4 antibody-mediated disorders. Discussion: This review highlights the complexity of VITT as it differs in antibody behavior and clinical presentation from other anti-PF4-mediated disorders, including the high incidence rate of cerebral venous sinus thrombosis (CVST) and the persistence of anti-PF4 antibodies, necessitating a re-evaluation of long-term patient care strategies. The nature of VITT antibodies and the underlying mechanisms triggering their production remain largely unknown. Conclusion: The rise in awareness and subsequent prompt recognition of VITT is paramount in reducing mortality. As vaccination campaigns continue, understanding the role of adenoviral vector-based vaccines in VITT antibody production is crucial, not only for its immediate clinical implications, but also for developing safer vaccines in the future. Full article

Myeloproliferative neoplasms (MPNs) are the leading causes of unusual site thrombosis, affecting nearly 40% of individuals with conditions like Budd–Chiari syndrome or portal vein thrombosis. Diagnosing MPNs in these cases is challenging because common indicators, such as spleen enlargement and elevated blood cell counts, can be obscured by portal hypertension or bleeding issues. Recent advancements in diagnostic tools have enhanced the accuracy of MPN diagnosis and classification. While bone marrow biopsies remain significant diagnostic criteria, molecular markers now play a pivotal role in both diagnosis and prognosis assessment. Hence, it is essential to initiate the diagnostic process for splanchnic vein thrombosis with a JAK2 V617F mutation screening, but a comprehensive approach is necessary. A multidisciplinary strategy is vital to accurately determine the specific subtype of MPNs, recommend additional tests, and propose the most effective treatment plan. Establishing specialized care pathways for patients with splanchnic vein thrombosis and underlying MPNs is crucial to tailor management approaches that reduce the risk of hematological outcomes and hepatic complications. Full article

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a very rare but serious adverse reaction that can occur after Ad26.COV2.S vaccination in humans, leading to thrombosis at unusual anatomic sites. One hypothesis is that accidental intravenous (IV) administration of Ad26.COV2.S or drainage of the vaccine from the muscle into the circulatory system may result in interaction of the vaccine with blood factors associated with platelet activation, leading to VITT. Here, we demonstrate that, similar to intramuscular (IM) administration of Ad26.COV2.S in rabbits, IV dosing was well tolerated, with no significant differences between dosing routes for the assessed hematologic, coagulation time, innate immune, or clinical chemistry parameters and no histopathologic indication of thrombotic events. For both routes, all other non-adverse findings observed were consistent with a normal vaccine response and comparable to those observed for unrelated or other Ad26-based control vaccines. However, Ad26.COV2.S induced significantly higher levels of C-reactive protein on day 1 after IM vaccination compared with an Ad26-based control vaccine encoding a different transgene, suggesting an inflammatory effect of the vaccine-encoded spike protein. Although based on a limited number of animals, these data indicate that an accidental IV injection of Ad26.COV2.S may not represent an increased risk for VITT. Full article

Cancer is associated with an increased risk of developing venous thromboembolism, due to its direct influence on the three pillars of Virchow’s triad (e.g., compression on the blood vessels by the tumour, blood vessels invasion, and cytokine release), together with the effect of exogenous factors (such as chemotherapy, radiotherapy, surgery). In cancer patients, the risk of thrombosis at unusual sites, such as splanchnic, ovarian and renal vein thrombosis, is also increased. Abdominal vein thromboses are frequently incidental findings on abdominal imaging performed as part of the diagnostic/staging workup or the follow-up care of malignancies. There is little evidence on the management of unusual site venous thromboembolism in cancer patients since there are only a few specific recommendations; thus, the management follows the general principles of the treatment of cancer-associated deep vein thrombosis and pulmonary embolism. This narrative review summarises the latest evidence on cancer-associated abdominal vein thrombosis, i.e., thrombosis of the splanchnic, ovarian and renal veins. Full article

Autoimmune thrombocytopenia (aHIT) is a severe subtype of heparin-induced thrombocytopenia (HIT) with atypical clinical features caused by highly pathological IgG antibodies (“aHIT antibodies”) that activate platelets even in the absence of heparin. The clinical features of aHIT include: the onset or worsening of thrombocytopenia despite stopping heparin (“delayed-onset HIT”), thrombocytopenia persistence despite stopping heparin (“persisting” or “refractory HIT”), or triggered by small amounts of heparin (heparin “flush” HIT), most cases of fondaparinux-induced HIT, and patients with unusually severe HIT (e.g., multi-site or microvascular thrombosis, overt disseminated intravascular coagulation [DIC]). Special treatment approaches are required. For example, unlike classic HIT, heparin cessation does not result in de-escalation of antibody-induced hemostasis activation, and thus high-dose intravenous immunoglobulin (IVIG) may be indicated to interrupt aHIT-induced platelet activation; therapeutic plasma exchange may be required if high-dose IVIG is ineffective. Also, aHIT patients are at risk for treatment failure with (activated partial thromboplastin time [APTT]-adjusted) direct thrombin inhibitor (DTI) therapy (argatroban, bivalirudin), either because of APTT confounding (where aHIT-associated DIC and resulting APTT prolongation lead to systematic underdosing/interruption of DTI therapy) or because DTI inhibits thrombin-induced protein C activation. Most HIT laboratories do not test for aHIT antibodies, contributing to aHIT under-recognition. Full article

(1) Background and Objectives: Venous thromboembolism (VTE) is strongly associated with cancer, and may be the first event revealing occult neoplasia. Nonetheless, the reasonable extent of the etiological assessment after an unprovoked VTE event remains debated. The main objective of this study was to evaluate the incidence of occult neoplasia one year after an episode of VTE, in consecutively hospitalized patients for VTE from the REMOTEV registry. The secondary objectives were to assess the performance of the various tests used for occult cancer screening in a real-life setting and analyze the risk factors associated with the discovery of cancer and the 1-year prognosis. (2) Methods: REMOTEV is a prospective, non-interventional cohort study of patients with acute VTE. Patients included in the registry from 23 October 2013 to 28 July 2018 were analyzed after a follow-up of 12 months. Cancer detection was performed according to local practices and consisted of a limited strategy to which an abdominal ultrasound was added. In the presence of suggestive clinical manifestations, further examinations were performed on an individual basis. (3) Results: A total of 993 patients were included in the study. At 1 year, the incidence of newly diagnosed cancer was low (5.3%). Half of the detected cancers were metastatic at discovery (51%) and had a poor global prognosis (32% of mortality at 1 year). Admission pulmonary CT scans as well as (thoracic)-abdomino-pelvic CT scans (when performed) were responsible for the majority of detected cancers. Age over 65 years and the concomitant presence of an unusual site and lower-limb deep vein thrombosis were the only factors associated with occult neoplasia in this cohort. After 1-year FU, mortality was higher in cancer patients (HR 6.0 (CI 95% 3.5–10.3, p < 0.0001)), and cancer evolution was the leading cause of death in the cancer group. (4) Conclusions: In REMOTEV, VTE-revealed occult cancer prevalence was low, but similar to recent reports and associated with higher age, multiple thrombotic sites and worse prognosis. Full article

Spontaneous events have been reported after COVID-19 vaccination. In this case, we report a thrombotic event in an unusual site (ulnar artery) after COVID-19 vaccination. The patient (69 year-old-male) had no changes after a laboratory investigation regarding thrombophilic pattern, but nevertheless had atherothrombotic predisposing conditions. Arterial thrombotic events have more frequently been reported after mRNA vaccines than after adenovirus vaccines. This is the first case reported of thrombosis of the ulnar artery occurring in the same side of the body where the vaccination took place. However, it must be noted that COVID-19 vaccines cumulatively offer a net positive effect, despite rare adverse effects. Full article

The coronavirus disease 2019 (COVID-19), a deadly pandemic that has affected millions of people worldwide, is associated with cardiovascular complications, including venous and arterial thromboembolic events. Viral spike proteins, in fact, may promote the release of prothrombotic and inflammatory mediators. Vaccines, coding for the spike protein, are the primary means for preventing COVID-19. However, some unexpected thrombotic events at unusual sites, most frequently located in the cerebral venous sinus but also splanchnic, with associated thrombocytopenia, have emerged in subjects who received adenovirus-based vaccines, especially in fertile women. This clinical entity was soon recognized as a new syndrome, named vaccine-induced immune thrombotic thrombocytopenia, probably caused by cross-reacting anti-platelet factor-4 antibodies activating platelets. For this reason, the regulatory agencies of various countries restricted the use of adenovirus-based vaccines to some age groups. The prevailing opinion of most experts, however, is that the risk of developing COVID-19, including thrombotic complications, clearly outweighs this potential risk. This point-of-view aims at providing a narrative review of epidemiological issues, clinical data, and pathogenetic hypotheses of thrombosis linked to both COVID-19 and its vaccines, helping medical practitioners to offer up-to-date and evidence-based counseling to their often-alarmed patients with acute or chronic cardiovascular thrombotic events. Full article