Disseminated malignancy misdiagnosed as thrombotic thrombocytopenic purpura: A report of 10 patients and a systematic review of published cases

Microangiopathic Hemolytic Anemia as a Paraneoplastic Syndrome in a Patient with Metastatic Gastric Cancer

Cancer-associated microangiopathic hemolytic anemia (CA-MAHA) is a rare paraneoplastic syndrome. The most effective approach to treating CA-MAHA is to address the underlying malignancy. Documented cases of CA-MAHA are limited to fewer than 50 patients in the literature. Herein, we present a 51-year-old female patient who developed CA-MAHA as a complication of gastric adenocarcinoma. Despite receiving neoadjuvant and adjuvant chemotherapy for gastric cancer, the patient experienced disease progression with metastatic lesions in the liver, pancreas, and other sites. This report highlights the challenges in diagnosing and distinguishing CA-MAHA from other similar conditions such as disseminated intravascular coagulation (DIC), hemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), and rheumatological paraneoplastic syndromes. Additionally, it concludes that CA-MAHA is associated with a poor prognosis and limited clinical benefit from treatment, emphasizing the need for early diagnosis and effective management strategies.

Undiagnosed Metastatic Breast Carcinoma Presenting as Thrombotic Thrombocytopenic Purpura

Cancer-associated thrombotic microangiopathy has a documented relationship with metastatic disease. Other examples of thrombotic microangiopathy (TMA) include thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). All these conditions can present with microangiopathic hemolytic anemia as well as thrombocytopenia. However, when these findings occur in association with cancer, they often carry a poor prognosis. Though associated with metastasis, microangiopathic hemolytic anemia, and thrombocytopenia have rarely been seen as the presenting signs of malignancy. We present the case of a 66-year-old female with no known history of cancer who exhibited an intriguing clinical presentation, including progressive dyspnea worsening with exertion, diarrhea, and dizziness. Laboratory investigations revealed Coombs-negative hemolytic anemia with schistocytes on blood smears and thrombocytopenia. The patient's condition raised concerns for TTP, prompting the initiation of plasmapheresis. However, despite treatment, the anemia and thrombocytopenia showed no improvement, leading to further investigations. Ultimately, a bone marrow biopsy revealed tumor cells arranged in nests and single files, leading to a diagnosis of metastatic carcinoma, consistent with breast primary. This was the patient's first known sign of breast cancer. This case emphasizes the significance of considering metastatic cancer as a potential differential diagnosis in patients presenting with similar signs and symptoms.

A Rare Case of Thrombotic Thrombocytopenic Purpura (TTP) With Concurrent Renal Cell Carcinoma: Diagnostic and Therapeutic Challenges

Thrombotic thrombocytopenic purpura (TTP) is a potentially life-threatening thrombotic microangiopathy (TMA) that needs prompt identification and treatment. Disseminated malignancy-related TMA can potentially be misdiagnosed as TTP, and patients may be inappropriately subjected to therapeutic plasma exchange (TPE) with serious implications. Likewise, the presence of a concurrent cancer diagnosis in a patient with microangiopathic hemolytic anemia and thrombocytopenia may lead to suspicion of disseminated malignancy as the cause, delaying the TPE with serious outcomes. Testing for ADAMTS13 activity is diagnostic of TTP, but the results may take time. This poses a diagnostic and therapeutic dilemma that includes weighing the benefits of TPE for treating TTP and cancer treatment. We describe a rare case of immune-mediated TTP in a patient concurrently diagnosed with metastatic renal cell cancer. To our knowledge, this is the first case of TTP reported in patients with metastatic renal cell carcinoma (RCC) in a non-treatment-naive patient.

Thrombotic Microangiopathy in the Setting of Colorectal Cancer: A Therapeutic Challenge with a Bad Prognosis

While most cases of thrombotic microangiopathic hemolytic anemias are idiopathic, some can occur in the setting of a malignancy. Differentiating both conditions is crucial to initiate the appropriate treatment. In this case report and literature review, we discuss the occurrence of a thrombotic microangiopathy in a 61-year-old male patient with a treatment-refractory metastatic colorectal cancer invading his bone marrow. Plasmapheresis does not constitute the mainstay of treatment in this setting, as targeting the primary disease is the ultimate management. Treating the condition of our patient has been challenging as multiple lines of treatments of his primary disease had been exhausted. The discrepancy in KRAs status obtained between PCR and later NGS offered a new treatment line with Cetuximab. In this article, we will discuss the different factors that differentiate between idiopathic and cancer-induced microangiopathy. We will emphasize on the fact that the treatment of the primary disease constitutes the most important step in the treatment of cancer-induced thrombotic microangiopathy. We will also raise several explanations to target the disagreement in KRAS status obtained by the different technical modalities.

Retrospective study of 59 cases of cancer-associated thrombotic microangiopathy: presentation and treatment characteristics

Background

Cancer-associated thrombotic microangiopathy (TMA) is a rare disease, with a poor prognosis. The classical treatment is urgent chemotherapy. Few data are available on the efficacy of plasma exchange (PE) and eculizumab in these patients.

Methods

Cases of cancer-related TMA treated between January 2008 and December 2019 in 12 French treatment centres were retrospectively analysed, excluding cases associated with chemotherapy and stem cell transplantation. Patients were divided into four groups depending on the treatment received: none, PE therapy alone, chemotherapy, with or without PE therapy, or eculizumab, with or without chemotherapy and PE therapy.

Results

The data of 59 patients with cancer-associated TMA were analysed. Twenty of these cases were related to a cancer recurrence. The cancer was metastatic in 90% of cases (53/59). Bone marrow invasion was observed in 20/41 biopsies. Some laboratory results, including DIC, high ferritin and CRP, were suggestive of cancer. None of the 16 patients whose alternative complement pathway was assessed had abnormal levels of protein expression or activity. The median survival time was 27 days. Chemotherapy was significantly associated with improved survival, with a 30-day survival rate of 85% (17/20) among patients who received PE and chemotherapy, versus 20% (3/15) among patients who received PE alone. Patients treated with eculizumab in addition to chemotherapy and PE therapy did not have longer overall survival or higher haematological remission rates than those treated with chemotherapy and PE therapy alone. Renal remission rates were non-significantly higher, and times to remission non-significantly shorter, in the eculizumab group.

Conclusions

Nephrologists and oncologists should make themselves aware of cancer diagnoses in patients with TMA and bone marrow biopsies should be performed systematically in these cases. All 59 patients had poor survival outcomes, but patients treated with urgent initiation of chemotherapy survived significantly longer than those who were not.

Thrombotic microangiopathy (TMA) in adult patients with solid tumors: a challenging complication in the era of emerging anticancer therapies

Thrombotic microangiopathy (TMA) is a syndrome that encompasses a group of disorders defined by the presence of endothelial damage leading to abnormal activation of coagulation, microangiopathic hemolytic anemia and thrombocytopenia, occlusive (micro)vascular dysfunction, and organ damage. TMA may occur in patients with malignancy as a manifestation of cancer-related coagulopathy itself or tumor-induced TMA (Ti-TMA) as a paraneoplastic uncommon manifestation of Trousseau syndrome. TMA can also be triggered by other overlapping conditions such as infections or more frequently as an adverse effect of anticancer drugs (drug-induced TMA or Di-TMA) due to direct dose-dependent toxicity or a drug-dependent antibody reaction. The clinical spectrum of TMA may vary widely from asymptomatic abnormal laboratory tests to acute severe potentially life-threatening forms due to massive microvascular occlusion. While TMA is a rare condition, its incidence may progressively increase within the context of the great development of anticancer drugs and the emerging scenarios in supportive care in cancer. The objective of the present narrative review is to provide a general perspective of the main causes, the key work-up clues that allow clinicians to diagnose and manage TMA in patients with solid tumors who develop anemia and thrombocytopenia due to frequent overlapping causes.

Paraneoplastic Glomerular Diseases

Paraneoplastic glomerular diseases (GNs) are rare manifestations in patients with underlying hematologic and solid organ malignancies and can occur before or after the detection of cancer. In the absence of established algorithms for investigation and reliable tests, they remain difficult to diagnose. Given the heterogeneity and infrequency of cases, the pathogenesis of most paraneoplastic GNs is poorly understood. Most of our recent understanding of paraneoplastic GNs has emerged from the discovery of target antigens in membranous nephropathy such as thrombospondin type-1 domain-containing protein 7A and neural epidermal growth factor-like 1 protein that appear to be promising in differentiating a primary vs paraneoplastic cause of membranous nephropathy. Treatment of paraneoplastic GNs is usually directed at the underlying malignancy. This review will focus on the epidemiology, pathogenesis, and diagnosis of paraneoplastic glomerular processes.

Signet ring cell carcinoma metastasis in the bone marrow accompanied by cancer related thrombotic microangiopathy as a first presentation

Cancer related thrombotic microangiopathies usually cause a diagnostic dilemma for hematologists and clinicians. In this case report, we presented a fifty-nine-year-old man who was admitted to our hospital with microangiopathic hemolytic anemia and thrombocytopenia due to the carcinoma metastasis to the bone marrow. As a result of rapid evaluations, it was revealed that the histological subtype of the cancer was signet ring cell carcinoma, and despite all the interventions, the patient died at a very short time after the initial presentation. Regardless of all the innovations in the diagnosis and treatment of thrombotic microangiopathies, cancer-associated thrombotic microangiopathy is still fatal and deadly today.

Eculizumab in gemcitabine-induced thrombotic microangiopathy: experience of the French thrombotic microangiopathies reference centre

BACKGROUND

Gemcitabine is a broadly prescribed chemotherapy, the use of which can be limited by renal adverse events, including thrombotic microangiopathy (TMA).

METHODS

This study evaluated the efficacy of eculizumab, a monoclonal antibody targeting the terminal complement pathway, in patients with gemcitabine-induced TMA (G-TMA). We conducted an observational, retrospective, multicenter study in 5 French centres, between 2011 and 2016.

RESULTS

Twelve patients with a G-TMA treated by eculizumab were included. The main characteristics were acute renal failure (100%), including stage 3 acute kidney injury (AKI, 58%) and renal replacement therapy (17%), hypertension (92%) and diffuse oedema (83%). Eculizumab was started after a median of 15 days (range 4-44) following TMA diagnosis. A median of 4 injections of eculizumab was performed (range 2-22). Complete hematological remission was achieved in 10 patients (83%) and blood transfusion significantly decreased after only one injection of eculizumab (median of 3 packed red blood cells (range 0-10) before treatment vs 0 (range 0-1) after one injection, P < 0.001). Two patients recovered completely renal function (17%), and 8 achieved a partial remission (67%). Compared to a control group of G-TMA without use of eculizumab, renal outcome was more favourable. At the end of the follow up, median eGFR was 45 vs 33 ml/min/1.73m2 respectively in the eculizumab group and in the control group.

CONCLUSIONS

These results suggest that eculizumab is efficient on haemolysis and reduces transfusion requirement in G-TMA. Moreover, eculizumab may improve renal function recovery.

Thrombotic Microangiopathy: A Rare Breast Cancer-associated Complication Treated Successfully With Doxorubicin and Cyclophosphamide

BACKGROUND

Thrombotic microangiopathy (TMA) is a clinical syndrome consisting of hemolytic anemia, thrombocytopenia, and presence of schistocytes on peripheral blood smear secondary to disorders of systemic microvascular thrombosis. Malignancy-associated TMA is a rare entity and shares clinical features with that of HUS and TTP usually seen in patients with metastatic cancer, tumor cell infiltration of the bone marrow and/or response to cancer-directed therapy.

CASE REPORT

We present a rare case of TMA secondary to breast cancer without evidence of bone marrow infiltration responsive to doxorubicin and cyclophosphamide treatment, after failed plasmapheresis with prednisone and later, eculizumab.

CONCLUSION

Despite being a rare manifestation of metastatic carcinoma, early identification and treatment are essential to improving survival.

[Breast cancer-related thrombotic microangiopathy: A review]

Thrombotic Microangiopathies (TM) have been described since the 1960s. They are characterized by presence of mechanical haemolytic anemia associated with peripheral thrombocytopenia. TM in cancer can be related to several causes, whose cancer himself: cancer-related microangiopathic haemolytic anaemia (MAHA). Incidence of cancer related MAHA remains unknown. Cancer-related MAHA are mainly observed in mucin-producer adenocarcinomas, such as gastric (half of reported cases) and breast cancer. We conducted a review of all original published cases of TM reported in breast cancer, and we specifically investigated BC-MAHA cases. A Medline search identified 158 MAHA cases including 118 BC-MAHA, and 40 drug-related MAHA. Most of BC-MAHA occur in disseminated cancers, mainly with medullar involvement, and/or bone metastasis. Patients typically suffer from poor general state, bone pain, and/or dyspnea. Laboratory abnormalities such as myelemia or erythromyelemia in peripheral blood are frequently observed. Incidence of coagulation disorders is increased, compared to other MAHA causes. BC-MAHA prognosis is dramatically poor. Treatments classically used in other MAHA causes, such as plasmapheresis or immunoglobulins, are inefficient. Urgent anti-neoplastic therapy may be the only effective treatment, associated to symptomatic therapies (transfusions, blood pressure control).

Thrombotic microangiopathy in oncology - a review

Thrombotic microangiopathy is a syndrome triggered by a wide spectrum of situations, some of which are specific to the Oncology setting. It is characterized by a Coombs-negative microangiopathic haemolytic anemia, thrombocytopenia and organ injury, with characteristic pathological features, resulting from platelet microvascular occlusion.

TMA is rare and its cancer-related subset even more so. TMA triggered by drugs is the most common within this group, including classic chemotherapy and the latest targeted therapies. The neoplastic disease itself and hematopoietic stem-cell transplantation could also be potential triggers.

Evidence-based medical guidance in the management of cancer-related TMA is scarce and the previous knowledge about primary TMA is valuable to understand the disease mechanisms and the potential treatments.

Given the wide spectrum of potential causes for TMA in cancer patients, the aim of this review is to gather the vast information available. For each entity, pathophysiology, clinical features, therapeutic approaches and prognosis will be covered.

Characteristics and outcome of breast cancer-related microangiopathic haemolytic anaemia: a multicentre study

BACKGROUND

Cancer-related microangiopathic haemolytic anaemia (MAHA) is a rare but life-threatening paraneoplastic syndrome. Only single cases or small series have been reported to date. We set up a retrospective multicentre study focusing on breast cancer-related MAHA.

METHODS

Main inclusion criteria were known diagnosis of breast cancer, presence of schistocytes and either low haptoglobin or cytopenia and absence of any causes of MAHA other than breast cancer, including gemcitabine- or bevacizumab-based treatment. Patient characteristics, treatments and outcome were retrieved from digital medical records.

RESULTS

Individual data from 54 patients with breast cancer-related MAHA were obtained from 7 centres. Twenty-three (44%) patients had a breast tumour with lobular features, and most primary tumours were low grade (grade I/II, N = 39, 75%). ER+/HER2-, HER2+ and triple-negative phenotypes accounted for N = 33 (69%), N = 7 (15%) and N = 8 (17%) cases, respectively. All patients had stage IV cancer at the time of MAHA diagnosis. Median overall survival (OS) was 28 days (range 0-1035; Q1:10, Q3:186). Independent prognostic factors for early death (≤ 28 days) were PS > 2 (OR = 7.0 [1.6; 31.8]), elevated bilirubin (OR = 6.9 [1.1; 42.6]), haemoglobin < 8.0 g/dL (OR = 3.7 [0.9; 16.7]) and prothrombin time < 50% (OR = 9.1 [1.2; 50.0]). A score to predict early death displayed a sensitivity of 86% (95% CI [0.67; 0.96]), a specificity of 73% (95% CI [0.52; 0.88]) and an area under the curve of 0.90 (95% CI [0.83; 0.97]).

CONCLUSIONS

Breast cancer-related MAHA appears to be a new feature of invasive lobular breast carcinoma. Prognostic factors and scores may guide clinical decision-making in this serious but not always fatal condition.

Cancer-related microangiopathic hemolytic anemia in patients with advanced gastric cancer: A retrospective single-center analysis

BACKGROUND

Microangiopathic hemolytic anemia (MAHA) with thrombocytopenia and organ failure caused by tumor-associated thrombotic microangiopathy (TMA) is a life-threatening oncological emergency. Rapid diagnosis and precise distinction from other forms of TMA is crucial for appropriate therapy, which aims at treating the underlying malignancy. However, the prognosis of patients with cancer-related (CR)-MAHA is limited. To date, less than 50 patients with gastric cancer and CR-MAHA have been reported, mainly as single case reports, and detailed information on treatment strategies and outcome are scarce. We analyzed the characteristics and outcomes data of CR-MAHA patients with gastric cancer treated at our center between 2012 and 2019.

AIM

To gain knowledge about CR-MAHA and the course of disease.

METHODS

We retrospectively analyzed patients using an institutional prospectively maintained database. Patients who had CR-MAHA but other cancer types or cancer of unknown primary were excluded. The basic requirements for inclusion were: Histologically proven gastric adenocarcinoma; and clinical diagnosis of hemolytic anemia with schistocytes with or without thrombocytopenia. The observation period for each patient started with the first day of documented symptoms. The follow-up period for this analysis ended on February 1, 2020.

RESULTS

We identified eight patients with a median age of 54 years. Histologically, all patients had (partial) diffuse subtypes of gastric adenocarcinoma with partial or complete signet cell morphology. All patients had metastatic disease and one patient had a microsatellite instability-high (MSI-H) tumor. In three patients, clinical signs of MAHA preceded the diagnosis of cancer, and in two patients, CR-MAHA indicated recurrent disease. All patients had severe hemolytic anemia and thrombocytopenia. Six patients experienced severe bone pain, and five patients had dyspnea. Systemic, 5-fluorouracil-based combination chemotherapy was initiated in six patients, which resulted in rapid initial response with significant improvement of clinical symptoms and blood values. Progression-free survival (PFS) of the whole cohort was 1.9 wk and median overall survival (OS) was 1.9 wk. For patients with chemotherapy, PFS was 9.0 wk and OS was 10.3 wk. The patient with the MSI-H tumor has been undergoing immunotherapy for more than 3 years.

CONCLUSION

The benefit of chemotherapy in CR-MAHA patients is limited. Immunotherapy for patients with MSI-H tumors may lead to long-term tumor control even in CR-MAHA patients.

Etiology and Outcomes of Thrombotic Microangiopathies

BACKGROUND AND OBJECTIVES

Thrombotic microangiopathies constitute a diagnostic and therapeutic challenge. Secondary thrombotic microangiopathies are less characterized than primary thrombotic microangiopathies (thrombotic thrombocytopenic purpura and atypical hemolytic and uremic syndrome). The relative frequencies and outcomes of secondary and primary thrombotic microangiopathies are unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective study in a four-hospital institution in 564 consecutive patients with adjudicated thrombotic microangiopathies during the 2009-2016 period. We estimated the incidence of primary and secondary thrombotic microangiopathies, thrombotic microangiopathy causes, and major outcomes during hospitalization (death, dialysis, major cardiovascular events [acute coronary syndrome and/or acute heart failure], and neurologic complications [stroke, cognitive impairment, or epilepsy]).

RESULTS

We identified primary thrombotic microangiopathies in 33 of 564 patients (6%; thrombotic thrombocytopenic purpura: 18 of 564 [3%]; atypical hemolytic and uremic syndrome: 18 of 564 [3%]). Secondary thrombotic microangiopathies were found in 531 of 564 patients (94%). A cause was identified in 500 of 564 (94%): pregnancy (35%; 11 of 1000 pregnancies), malignancies (19%), infections (33%), drugs (26%), transplantations (17%), autoimmune diseases (9%), shiga toxin due to Escherichia coli (6%), and malignant hypertension (4%). In the 31 of 531 patients (6%) with other secondary thrombotic microangiopathies, 23% of patients had sickle cell disease, 10% had glucose-6-phosphate dehydrogenase deficiency, and 44% had folate deficiency. Multiple causes of thrombotic microangiopathies were more frequent in secondary than primary thrombotic microangiopathies (57% versus 19%; P<0.001), and they were mostly infections, drugs, transplantation, and malignancies. Significant differences in clinical and biologic differences were observed among thrombotic microangiopathy causes. During the hospitalization, 84 of 564 patients (15%) were treated with dialysis, 64 of 564 patients (11%) experienced major cardiovascular events, and 25 of 564 patients (4%) had neurologic complications; 58 of 564 patients (10%) died, but the rates of complications and death varied widely by the cause of thrombotic microangiopathies.

CONCLUSIONS

Secondary thrombotic microangiopathies represent the majority of thrombotic microangiopathies. Multiple thrombotic microangiopathies causes are present in one half of secondary thrombotic microangiopathies. The risks of dialysis, neurologic and cardiac complications, and death vary by the cause of thrombotic microangiopathies.

Acute Hepatitis Caused by Genotype 4 HCV Presenting with Microangiopathic Hemolytic Anemia

Many cases have been reported about the role of chronic hepatitis C and interferon therapy in the development and recurrence of thrombotic thrombocytopenic purpura (TTP), but to our knowledge there is no previous report about the association between acute hepatitis C and any microangiopathic hemolytic anemia (MAHA) including TTP. We report a case of acute hepatitis C that presented with MAHA resembling TTP, which resolved with spontaneous clearance of viral infection.

Recurrent Atypical Hemolytic Uremic Syndrome in Children With Acute Lymphoblastic Leukemia Undergoing Maintenance Chemotherapy

Chemotherapy-associated myelosuppression and renal dysfunction is not uncommon during childhood acute lymphoblastic leukemia (ALL) therapy. Here we report 2 cases of atypical hemolytic uremic syndrome (aHUS) presenting with pancytopenia and renal dysfunction that developed during maintenance chemotherapy characterized by hypocomplementemia. Both cases experienced recurrence after resolution of the initial aHUS episode upon resumption of chemotherapy, raising a possible contributory role for chemotherapy in the disease pathogenesis.

A Metastatic Signet Ring Cell Carcinoma Presented as Acquired Thrombotic Thrombocytopenic Purpura: A Case Report

Microangiopathic hemolytic anemia (MAHA) may occur as a paraneoplastic syndrome in some solid tumors, but MAHA accompanied by signet ring cell carcinoma (SRCC) of an unknown origin is very rare. We report a patient who presented with an acute onset of Coombs negative hemolytic anemia and frequent schistocytes in the peripheral blood smear which are typical for MAHA as initial presentation of metastatic SRCC. Our patients fulfilled the criteria of thrombotic thrombocytopenic purpura (TTP) and received the specific treatment for TTP without improvement.

Malignancy Associated Microangiopathic Hemolytic Anemia and Thrombocytopenia

Disseminated malignancy can rarely present with microangiopathic hemolytic anemia and thrombocytopenia clinically similar to thrombotic thrombocytopenic purpura (TTP), but does not respond to plasma exchange. TTP carries a grave prognosis if plasma exchange is delayed. Evaluating patients presenting with microangiopathic hemolytic anemia and thrombocytopenia is challenging for clinicians. Thrombotic thrombocytopenic purpura (TTP) should be considered in such patients and emergency plasma exchange is to be initiated. But all the clinical features seen in TTP can be caused by a disseminated malignancy. The awareness of such a rare presentation of disseminated malignancy helps clinicians to avoid unnecessary delay in appropriate treatment and the complications due to plasma exchange. We report two patients who presented with microangiopathic hemolytic anemia and thrombocytopenia due to disseminated malignancy.

Microangiopathic Hemolytic Anemia and Thrombocytopenia in Patients With Cancer

The unexpected occurrence of thrombotic microangiopathy (TMA), characterized by microangiopathic hemolytic anemia and thrombocytopenia, in a patient with cancer requires urgent diagnosis and appropriate management. TMA is a term used to describe multiple syndromes caused by microvascular thrombosis, including thrombotic thrombocytopenic purpura (TTP), Shiga toxin-mediated hemolytic uremic syndrome, and complement-mediated TMA. In patients with cancer, systemic microvascular metastases and bone marrow involvement can cause microangiopathic hemolytic anemia and thrombocytopenia. This occurs most often in patients with known metastatic cancer, but microangiopathic hemolytic anemia and thrombocytopenia may occur unexpectedly in patients without known metastatic disease or be the presenting features of undiagnosed cancer. TMA may also be caused by commonly used chemotherapy agents, either through dose-dependent toxicity or an acute immune-mediated reaction. These causes of TMA must be distinguished from TTP, which results from a severe deficiency of ADAMTS13 and is the most common cause of TMA among adults without cancer. The importance of this distinction is to avoid inappropriate use of plasma exchange, which is associated with major complications. Plasma exchange is the essential treatment for TTP, but it has no known benefit for patients with cancer-induced or drug-induced TMA. We will describe cancer-induced and drug-induced TMA using the experience of the Oklahoma TTP-Hemolytic Uremic Syndrome Registry and data from a systematic review of all published reports of drug-induced TMA. We will illustrate the principles of evaluation and management of these disorders with patients' stories.

Complement C5-inhibiting therapy for the thrombotic microangiopathies: accumulating evidence, but not a panacea

Thrombotic microangiopathy (TMA), characterized by organ injury occurring consequent to severe endothelial damage, can manifest in a diverse range of diseases. In complement-mediated atypical haemolytic uraemic syndrome (aHUS) a primary defect in complement, such as a mutation or autoantibody leading to over activation of the alternative pathway, predisposes to the development of disease, usually following exposure to an environmental trigger. The elucidation of the pathogenesis of aHUS resulted in the successful introduction of the complement inhibitor eculizumab into clinical practice. In other TMAs, although complement activation may be seen, its role in the pathogenesis remains to be confirmed by an interventional trial. Although many case reports in TMAs other than complement-mediated aHUS hint at efficacy, publication bias, concurrent therapies and in some cases the self-limiting nature of disease make broader interpretation difficult. In this article, we will review the evidence for the role of complement inhibition in complement-mediated aHUS and other TMAs.

Insights on pulmonary tumor thrombotic microangiopathy: a seven-patient case series

Pulmonary tumor thrombotic microangiopathy (PTTM) is a disease process wherein tumor cells are thought to embolize to the pulmonary circulation causing pulmonary hypertension (PH) and death from right heart failure. Presented herein are clinical, laboratory, radiographic, and histologic features across seven cases of PTTM. Highlighted in this publication are also involvement of pulmonary venules and clinical features distinguishing PTTM from clinical mimics.

We conducted a retrospective chart review of seven cases of PTTM from hospitals in the greater Los Angeles metropolitan area.

Patients in this series exhibited: symptoms of cough and progressive dyspnea; PH and/or heart failure on physical exam; laboratory abnormalities of anemia, thrombocytopenia, elevated LDH, and elevated D-dimer; chest computed tomography (CT) showing diffuse septal thickening, mediastinal and hilar lymphadenopathy and nodules; elevated pulmonary artery pressures on transthoracic echocardiogram and/or right heart catheterization; and presence of malignancy. Tumor emboli and fibrocellular intimal proliferation were seen in pulmonary arterioles, while two patients had pulmonary venopathy.

PTTM is a devastating disease occurring in patients with metastatic carcinoma. An early diagnosis is challenging. Understanding the clinical presentation of PTTM and distinguishing PTTM from clinical mimics may help achieve an early diagnosis and allow time for initiation of treatment.

[Thrombotic microangiopathy and cancer]

Thrombotic microangiopathy (TMA) is a group of disorders characterized by mechanical hemolytic anemia with thrombocytopenia and an ischemic organic lesion of variable and potentially fatal importance affecting mostly the kidneys and the brain with histologically a disseminated and occlusive microvasculopathy. The incidence of TMA represents 15% of acute kidney failure in oncological setting, largely due to the introduction of anti-angiogenic agents over the past decade. It may be more rarely related to cancer itself. The iatrogenic TMA can be classified into 2 types: The type I, secondary to chemotherapy (mitomycinC, gemcitabine), exposes to a chronic dose-dependent renal injury as well as an increase in morbidity and mortality; iatrogenic type II, secondary to anti-angiogenic agents', results in a dose-independent renal involvement and renal functional recovery is usual when the drug is discontinued. There is no randomized controlled trial to establish EBM-type management in TMA support. However, complement activation pathways and regulatory factors analyses allowed us to understand the mechanisms of endothelial lesions. As a result, the current trend includes the use of immunosuppressive agents in recurrent or plasmapheresis-refractory MAT.

Atypical Hemolytic Uremic Syndrome: A Brief Review

Atypical hemolytic uremic syndrome (aHUS) is a disease characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia and acute kidney injury. The histopathologic lesions of aHUS include thrombotic microangiopathy involving the glomerular capillaries and thrombosis involving arterioles or interlobar arteries. Extra-renal manifestations occur in up to 20% of patients. The majority of aHUS is caused by complement system defects impairing ordinary regulatory mechanisms. Activating events therefore lead to unbridled, ongoing complement activity producing widespread endothelial injury. Pathologic mutations include those resulting in loss-of-function in a complement regulatory gene (CFH, CFI, CD46 or THBD) or gain-of-function in an effector gene (CFB or C3). Treatment with the late complement inhibitor, eculizumab – a monoclonal antibody directed against C5 – is effective.

None of the above: thrombotic microangiopathy beyond TTP and HUS

Acquired thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are appropriately at the top of a clinician's differential when a patient presents with a clinical picture consistent with an acute thrombotic microangiopathy (TMA). However, there are several additional diagnoses that should be considered in patients presenting with an acute TMA, especially in patients with nondeficient ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity (>10%). An increased awareness of drug-induced TMA is also essential because the key to their diagnosis more often is an appropriately detailed medical history to inquire about potential exposures. Widespread inflammation and endothelial damage are central in the pathogenesis of the TMA, with the treatment directed at the underlying disease if possible. TMA presentations in the critically ill, drug-induced TMA, cancer-associated TMA, and hematopoietic transplant-associated TMA (TA-TMA) and their specific treatment, where applicable, will be discussed in this manuscript. A complete assessment of all the potential etiologies for the TMA findings including acquired TTP will allow for a more accurate diagnosis and prevent prolonged or inappropriate treatment with plasma exchange therapy when it is less likely to be successful.

Adenocarcinoma of the lung presenting as thrombotic thrombocytopenic purpura

Acquired thrombotic thrombocytopenic purpura (TTP) usually presents as severe microangiopathic hemolytic anemia (MAHA) and thrombocytopenia in a previously healthy individual. It occurs in approximately three in one million adults and 1 in 10 million children annually. The incidence is increased in females and blacks. Diagnosing TTP and initiating therapy with plasma exchange is a must to avoid preventable complications. Acquired thromotic microangiopathy has been linked to collagen vascular diseases, use of certain medications, organ transplants, infections, pregnancy and cancer. We report a rare case of a 56-year-old African American male diagnosed with TTP who found to have an asymptomatic adenocarcinoma of the lung. Prompt cancer management resulted in completed remission of the thrombotic microangiopathy.

Acute myocardial infarction as the initial thrombotic event of thrombotic thrombocytopenic purpura

Acquired thrombotic thrombocytopenic purpura (TTP) is characterized by the coemergence of microangiopathic hemolytic anemia, thrombocytopenia, and thrombosis-mediated ischemic injuries of various organs, such as the central nervous system and kidneys. Acute myocardial infarction (AMI) has also occasionally been reported as a complication with TTP as the secondary thrombotic event; however, its emergence as the initial thrombotic event in TTP is extremely rare. This report describes an 80-year-old male patient with acquired TTP, who was affected by AMI without any clinically apparent damage to other organs or abnormal laboratory findings that would be suggestive of TTP at the first presentation. Although AMI was successfully treated by percutaneous coronary intervention (PCI), the patient developed marked thrombocytopenia with acute kidney injury and hemolytic anemia 5 days after PCI. The patient was diagnosed as having acquired TTP based on decreased ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13) below the level of detection and the presence of the inhibitor against ADAMTS13, and eventually died of multiorgan failure due to TTP despite undergoing repeated plasma exchanges and immunosuppressive therapies, including corticosteroid and rituximab. Although caution is often paid to therapy-related thrombocytopenia or renal damage after PCI, that is, those caused by antiplatelet drugs, heparin, or contrast agents, our report alerts us to the presence of TTP as an extremely rare, but underlying cause for AMI that could be subclinical at the initial presentation.

Disseminated gastric carcinoma in disguise-presentation as microangiopathic haemolytic anemia with bone marrow necrosis

Cancer related microangiopathic hemolytic anemia (MAHA) and bone marrow necrosis (BMN) are two rare and distinct clinicopathological entities reported in patients with disseminated malignancy. When they emerge as initial findings in a previously undetected case of malignancy, the diagnosis is often missed resulting in inappropriate management. We report the extremely rare association of cancer related MAHA and BMN as the first presentation of unsuspected disseminated gastric carcinoma in a 63 years old male. Early institution of chemotherapy is the only effective option for both these conditions, though with little improvement in outcome. This emphasises the need for increased awareness of such presentations in advanced malignancies.

Microangiopathic Hemolytic Anemia Due to Malignancy in Pregnancy

BACKGROUND

Microangiopathic disorders during pregnancy remain a diagnostic challenge because these conditions often imitate more common obstetric diseases.

CASE

A 31-year-old multigravid woman delivered at term with a postpartum course complicated by laboratory indices consistent with hemolysis, elevated liver enzymes, and low platelet count syndrome. After clinical recovery, she was readmitted 2 weeks after delivery with presumptive pyelonephritis. Persistent hemolysis and worsening thrombocytopenia suggested a diagnosis of thrombotic microangiopathy, which did not respond to plasma exchange. Directed bone biopsy revealed metastatic signet ring cell adenocarcinoma.

CONCLUSION

Microangiopathic hemolytic anemia is rarely the initial clinical manifestation of malignancy. Given the similar features of several common obstetric complications, additional diagnostic measures may be necessary to refine the diagnosis in cases unresponsive to standard obstetric management.

Thrombotic Microangiopathy Care Pathway: A Consensus Statement for the Mayo Clinic Complement Alternative Pathway-Thrombotic Microangiopathy (CAP-TMA) Disease-Oriented Group

Thrombotic microangiopathies (TMAs) comprise a heterogeneous set of conditions linked by a common histopathologic finding of endothelial damage resulting in microvascular thromboses and potentially serious complications. The typical clinical presentation is microangiopathic hemolytic anemia accompanied by thrombocytopenia with varying degrees of organ ischemia. The differential diagnoses are generally broad, while the workup is frequently complex and can be confusing. This statement represents the joint recommendations from a multidisciplinary team of Mayo Clinic physicians specializing in the management of TMA. It comprises a series of evidence- and consensus-based clinical pathways developed to allow a uniform approach to the spectrum of care including when to suspect TMA, what differential diagnoses to consider, which diagnostic tests to order, and how to provide initial empiric therapy, as well as some guidance on subsequent management.

Thrombotic Microangiopathy Revealing Bone Metastases from an Ethmoid Sinus Carcinoma

Cancer-related thrombotic microangiopathy (TMA) is a rare entity whose clinical and biological characteristics have been described in various tumors. Here we describe the first case of cancer-related TMA revealing diffuse bone metastases from an ethmoid sinus carcinoma.

Cancer-associated thrombotic microangiopathy

Cancer-associated thrombotic microangiopathy refers to a group of disorders characterised by microvascular thrombosis, thrombocytopenia, and ischaemic end-organ damage. Haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura are the two major subtypes. It can be a manifestation of the malignancy itself or a complication of its therapy. The addition of several new drugs to the therapeutic armamentarium of cancer has brought to light several novel causative factors of this hitherto uncommon complication. This review covers the aetiology, pathogenesis, clinical manifestations, complications, and the management of cancer-associated thrombotic microangiopathy. Careful review of the patient’s medical records coupled with the correlation of clinical findings and laboratory reports can help clinch the diagnosis and institute appropriate treatment on time.

Collapsing glomerulopathy associated with hemophagocytic syndrome in a patient with NK/T cell lymphoma

Hemophagocytic syndrome (HPS) is a rare condition caused by dysregulated activation of the immune system leading to infiltration of bone marrow and organs by nonmalignant macrophages that phagocytose blood cells. Primary HPS is caused by inherited immune dysregulation whereas secondary HPS is triggered by neoplastic, infectious or autoimmune diseases. Clinically, the syndrome presents with continuous high-grade fever in association with multi-organ involvement. Few data are available regarding renal manifestations of HPS. We report a 60-year-old patient with NK/T cell nasopharyngeal extranodal lymphoma who presented with acute kidney injury and nephrotic range proteinuria in association with fever and pancytopenia. A kidney biopsy was consistent with collapsing glomerulopathy. A final diagnosis of HPS was made on the basis of clinical, laboratory, and bone marrow biopsy findings in accordance with established diagnostic criteria. Steroid therapy was initiated. However, the patient failed to recover his renal function and remained hemodialysis-dependent. Key diagnostic and therapeutic challenges and strategies used to overcome those challenges are discussed.

Metastatic cancer-related thrombotic microangiopathies: a cohort study

Thrombotic microangiopathies (TMAs) in patients with metastatic cancer are poorly characterized. We recorded 17 patients who had TMAs associated with disseminated solid cancer in our intensive care unit over an 11-year period. We compared them with a group of 20 patients with proven idiopathic thrombotic thrombocytopenic purpura hospitalized during the same period. We aimed to specify the clinical and biological features of cancer-related TMAs (CR-TMAs). CR-TMAs can either be inaugural of the underlying cancer or reflect worsening course. Clues to the presence of CR-TMA include respiratory symptoms, bone pain, myelemia or higher platelet count than in thrombotic thrombocytopenic purpura. In this context, bone marrow aspiration is a fast and gainful investigation to avoid plasmatherapy and immunosuppressive drugs. Indeed, this severe and poor-prognosis disease requires prompt diagnosis and rapid initiation of specific chemotherapy.

Clinical Evidence that Coagulation Activation Drives Cancer Progression--a Report of 2 Cases

BACKGROUND

Tissue factor (TF), the principal initiator of the extrinsic coagulation pathway, is expressed by many tumors and can be released into the bloodstream on plasma microparticles (MPs). Experimental studies indicate that TF may facilitate hematogenous metastasis by promoting tumor cell-induced microvascular thrombosis, but clinical data supporting this hypothesis is sparse.

CASE REPORTS

Here, we report 2 unusual cases of rapidly progressive solid malignancies (gastric and urothelial carcinoma). In both patients, cancer cell dissemination with diffuse bone marrow involvement was either strongly suggested by leukoerythroblastic changes on peripheral blood smear or directly proven by positive findings on aspiration cytology. Furthermore, laboratory evidence of thrombotic microangiopathy (TMA) and disseminated intravascular coagulation was accompanied by new-onset severe pulmonary hypertension and a hemolytic uremic syndrome-like disorder in the gastric and the urothelial carcinoma patient, respectively. TF-specific procoagulant activity of isolated plasma MPs, as assessed by single-stage clotting assay, was dramatically increased in both patients compared to healthy controls (21- and 55-fold), and primary tumor samples stained strongly positive for TF by immunohistochemistry.

CONCLUSION

TMA was likely caused by TF-triggered tumor cell embolization in both patients. Further clinical evidence is thus provided that TF directly links coagulation activation to cancer cell dissemination.

Thrombotic microangiopathy, cancer, and cancer drugs

Thrombotic microangiopathy (TMA) is a complication that can develop directly from certain malignancies, but more often results from anticancer therapy. Currently, the incidence of cancer drug-induced TMA during the last few decades is >15%, primarily due to the introduction of anti-vascular endothelial growth factor (VEGF) agents. It is important for clinicians to understand the potential causes of cancer drug-induced TMA to facilitate successful diagnosis and treatment. In general, cancer drug-induced TMA can be classified into 2 types. Type I cancer drug-induced TMA includes chemotherapy regimens (ie, mitomycin C) that can potentially promote long-term kidney injury, as well as increased morbidity and mortality. Type II cancer drug-induced TMA includes anti-VEGF agents that are not typically associated with cumulative dose-dependent cell damage. In addition, functional recovery of kidney function often occurs after drug interruption, assuming a type I agent was not given prior to or during therapy. There are no randomized controlled trials to provide physician guidance in the management of TMA. However, previously accumulated information and research suggest that endothelial cell damage has an underlying immunologic basis. Based on this, the emerging trend includes the use of immunosuppressive agents if a refractory or relapsing clinical course that does not respond to plasmapheresis and steroids is observed.

Secondary thrombotic microangiopathy in two patients with Philadelphia-positive hematological malignancies treated with imatinib mesylate

Drug-mediated thrombotic microangiopathy may cause life-threatening medical emergencies. Novel targeted therapies have dramatically changed the prognosis of a number of oncological diseases. Tyrosine kinase inhibitors of the Breakpoint Cluster Region-Abelson (BCR-ABL) oncoprotein are used in patients with chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia. Imatinib mesylate, which was the first anti-BCR-ABL tyrosine kinase inhibitor, has demonstrated a high tolerance profile and efficacy in these patients for many years. Good results have also been observed in patients with gastrointestinal stromal tumors. In this study, we describe two patients with Philadelphia chromosome-positive hematological malignancies who presented with secondary thrombotic microangiopathy that was most likely linked to the use of imatinib. Other potential causes of thrombotic microangiopathy were discarded, and the predisposing role of some comorbidities and potential short or long-term drug-drug interactions was assessed. The clinical and biological data were more indicative of atypical secondary hemolytic uremic syndrome in one of the cases and of secondary thrombotic microangiopathy with renal and cardiac impairment in the other, which is also categorized as secondary hemolytic uremic syndrome. The outcome was favorable after imatinib discontinuation and the treatment of severe cardiac and renal failures.

Non-secreting benign glucagonoma diagnosed incidentally in a patient with refractory thrombocytopenic thrombotic purpura: report of a case

Thrombotic thrombocytopenic purpura (TTP) is a rare hematologic disorder, which may be idiopathic or secondary to a variety of diseases. However, there are very few reports of TTP in the context of pancreatic neoplasms. We report a case of relapsing TTP after initial treatment with plasmapheresis, corticosteroids, and rituximab, in a 59-year-old woman. During diagnostic work-up, a pancreatic lesion 35 × 25 mm in size was discovered incidentally and splenopancreatectomy was performed. The pathological diagnosis was benign glucagonoma. The hematological symptoms resolved completely after the procedure and 3 years later, the patient is well with no sign of recurrence of TTP or glucagonoma. To our knowledge, this represents the first documented case of a non-secreting benign pancreatic neuroendocrine tumor (glucagonoma) associated with TTP that is refractory to standard treatment.

Pulmonary tumor thrombotic microangiopathy: report of 3 cases and review of the literature

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare clinical entity where tumor cell embolisms in pulmonary circulation induce thrombotic microangiopathy (TMA), respiratory failure, and subacute cor pulmonale.We describe 3 cases of PTTM that presented as the initial manifestation of metastatic gastric adenocarcinoma with TMA and pulmonary infiltrates.All 3 cases had similar clinical and laboratory features, which included moderate thrombocytopenia without renal failure, hemolysis with extremely high serum lactate dehydrogenase levels, leukoerythroblastosis in peripheral blood smear, altered coagulation tests, lymphadenopathies, and interstitial pulmonary infiltrates. All patients died within 2 weeks of diagnosis. Two cases were initially misdiagnosed as idiopathic thrombotic thrombocytopenic purpura and treated with plasma exchange with no response. One patient had bone marrow infiltration by malignant cells. Autopsies revealed PTTM associated with gastric disseminated adenocarcinoma (signet-ring cell type in 2 patients and poorly differentiated type in 1).PTTM should be considered in the differential diagnosis of patients with fulminant microangiopathic hemolytic anemia, such as atypical thrombotic thrombocytopenic purpura, mainly those with pulmonary infiltrates, disseminated intravascular coagulation, or Trousseau syndrome.

Isolated hemolytic anemia: an unusual manifestation of occult malignancy

Hemolysis is an uncommon and usually late complication of malignancy, and very rarely the presenting feature. Cancer-associated hemolysis may be immune-mediated, or may result from thrombotic microangiopathy accompanied by thrombocytopenia. We describe an unusual case of isolated hemolysis in the setting of occult metastatic breast cancer. The patient initially presented with symptomatic anemia, with evidence of hemolysis but with negative direct antiglobulin testing and a normal platelet count. Subsequent investigation discovered metastatic adenocarcinoma of the breast involving bone marrow. Hemolysis worsened despite initial treatment with cytotoxic chemotherapy and a trial of corticosteroids, but later resolved with aromatase inhibitor therapy.