Pulmonary tumor thrombotic microangiopathy in patients with gastric carcinoma: an analysis of 6 autopsy cases and review of the literature

An autopsy case of pulmonary tumor thrombotic microangiopathy that developed during chemotherapy for salivary duct carcinoma of the parotid gland

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rapidly progressive cancer-related disease with a dismal clinical course. The patient in this report was a 43-year-old man with metastatic salivary duct carcinoma arising from the parotid gland. Combined androgen blockade therapy was administered started as first-line treatment, but failed after 5 months, followed by docetaxel plus carboplatin therapy as second-line treatment, which failed after 3 months. Genomic profiling revealed a BRAF V600E mutation, and combined BRAF and MEK inhibitor therapy was started as third-line treatment. The cancer remained stable during the first 10 months of third-line treatment, but treatment was subsequently discontinued due to the onset of symptoms of fatigue, myalgia and arthritis. Twenty days after the onset of these symptoms and interruption of third-line treatment, the patient was urgently admitted to hospital with respiratory distress and severe thrombocytopenia. CT images at the time of admission led our radiologist to the possibility of PTTM, but the patient died the day after admission and autopsy findings indicated that PTTM was the cause of death. This report describes a very informative case of PTTM with sequential imaging and detailed autopsy findings were available and provides a literature review.

Dramatic Improvement of Pulmonary Tumor Thrombotic Microangiopathy in a Breast Cancer Patient Treated With Bevacizumab

A 47-year-old woman diagnosed with stage IV left-sided breast cancer (T3N3aM1; OSS, HEP, LYM) 6 months back presented with respiratory distress. On admission, she developed respiratory failure, requiring 4 L of oxygen support. Pulmonary embolism was ruled out because computed tomography revealed no obvious pulmonary artery thrombus. Transthoracic echocardiography revealed a significant enlargement of the right ventricle and atrium. Pulmonary hypertension was confirmed via right heart catheterization. Pulmonary artery wedge aspiration cytology revealed adenocarcinoma cells. Based on these findings, we diagnosed the patient with pulmonary tumor thrombotic microangiopathy (PTTM) caused by breast cancer. Immediate chemotherapy (paclitaxel and bevacizumab) for breast cancer and concurrent treatment for pulmonary hypertension and disseminated intravascular coagulation were initiated. We could successfully control her condition with paclitaxel and bevacizumab for a year, and the patient survived for 1 year and 8 months. PTTM is a rare disease characterized by pulmonary hypertension and hypoxemia arising due to tumor embolization of the peripheral pulmonary arteries. PTTM is a rapidly progressing condition with no established treatment guidelines; its pathogenesis involves vascular endothelial growth factor (VEGF). This report highlighted the potential of bevacizumab, known for its anti-VEGF effect, in improving the pathological condition of patients with PTTM caused by breast cancer.

Improvement of Breast Cancer-Associated Pulmonary Tumor Thrombotic Microangiopathy With Carboplatin and Gemcitabine

We present the case of a 50-year-old woman with stage IV invasive ER+/PR-/HER2-ductal breast carcinoma who was admitted to the intensive care unit (ICU) with obstructive shock and hypoxic respiratory failure due to pulmonary tumor thrombotic microangiopathy (PTTM), which significantly improved with chemotherapy. Upon presentation, her heart rate was 145 beats/min, her blood pressure was 86/47 mmHg, her respiratory rate was 25 breaths/min, and her oxygen saturation was 80% in room air. She underwent a broad non-diagnostic infectious evaluation, received fluid resuscitation, and was placed on broad-spectrum antibiotics. Transthoracic echocardiography showed evidence of severe pulmonary hypertension with a pulmonary arterial systolic pressure (PASP) of 77 mmHg. She initially required oxygen via a high-flow nasal cannula (HFNC) at 40 liters/minute and 80% FiO2 and was subsequently placed on inhaled nitric oxide (iNO) at 40 parts per million (PPM) as well as norepinephrine and vasopressin drips for acute decompensated right heart failure. Despite her poor performance status, she was started on chemotherapy with carboplatin and gemcitabine. Over the ensuing week, she was weaned off supplemental oxygen, vasoactive agents, and iNO and discharged home. Repeat echocardiography performed 10 days after the initiation of chemotherapy demonstrated marked improvement in her pulmonary hypertension with a PASP of 34 mmHg. This case highlights the potential role of chemotherapy in altering the course of PTTM in select patients with metastatic breast cancer.

Case report: apatinib plus selexipag as a novel therapy for pulmonary tumor thrombotic microangiopathy accompanied by pulmonary hypertension associated with gastric carcinoma

RATIONALE

PTTM is a rare but fatal disease, characterized by endothelial intimal proliferation and pulmonary hypertension due to micro-vascular remodeling. In view of the poor prognosis, new effective strategies are urgently required.

PATIENT CONCERNS AND DIAGNOSIS

A 51-year-old woman was admitted to hospital for acute progressive dyspnea and dry cough. Clinical tests revealed hypercoagulable state and signs of severe pulmonary hypertension, without evidence of pulmonary embolism on contrast-enhanced CT. CT showed interlobular septal thickening and diffuse ground-glass opacity. Lung perfusion scan indicated multiple segment defect. Further right heart catherization proved a significant increase in pulmonary vascular resistance.

INTERVENTIONS

A combination therapy of apatinib and selexipag was administered for treatment of PTTM. The conventional therapies of ventilation, anticoagulation and diuretic medicines were initiated after admission.

OUTCOMES

Symptoms of PTTM were ameliorated with a reduction in pulmonary artery pressure. The resolution of interlobular septal thickening and ground-glass opacity on CT constituted the clinical benefits from treatment.

LESSONS

Patient with PTTM will benefit from the combination strategy of apatinib, a VEGF-receptor antagonist, and selexipag, an oral prostacyclin receptor agonist.

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.

Pulmonary Tumor Thrombotic Microangiopathy Caused by Recurrent Gastric Cancer 26 Years After Total Gastrectomy

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare cancer-related complication that induces pulmonary hypertension (PH). PTTM can be caused by recurrent cancer, with 12 years being the longest reported interval from primary cancer to the development of PTTM. We herein report a 74-year-old woman who presented with dyspnea due to PH. The postmortem diagnosis was PTTM caused by recurrent gastric cancer 26 years after total gastrectomy. An autopsy revealed PTTM-specific histological characteristics. Our findings indicate that PTTM should be considered as a diagnosis for patients with a history of cancer who develop PH, even several decades after treatment.

Pulmonary Tumor Thrombotic Microangiopathy in a Patient of Gastric Carcinoma: A Rare Entity

How to cite this article: Choudhury S, Mishra SB, Panda S. Pulmonary Tumor Thrombotic Microangiopathy in a Patient of Gastric Carcinoma: A Rare Entity. Indian J Crit Care Med 2022;26(6):763–764.

Pulmonary Tumor Thrombotic Microangiopathy Due to Gastric Cancer Diagnosed Antemortem by a Cytological Examination of Aspirated Pulmonary Artery Blood

A 66-year-old Japanese man receiving systemic chemotherapy for advanced gastric cancer presented with exertional dyspnea. D-dimer was elevated in the blood. Echocardiography revealed pulmonary hypertension, and a ventilation-perfusion scan indicated decreased perfusion in the bilateral lungs. Cardiac catheterization showed no evidence of pulmonary artery embolization and revealed cytologically confirmed adenocarcinoma. Thus, pulmonary tumor thrombotic microangiopathy (PTTM) was diagnosed. The patient died of respiratory failure on the 17th hospitalization day despite systemic chemotherapy. Retrospective serological testing revealed increased vascular endothelial growth factor in the pulmonary artery blood. This is a rare case with antemortem cytologically proven PTTM mediated by VEGF.

Fatal pulmonary tumour thrombotic microangiopathy in patient with ovarian adenocarcinoma: review and a case report

Background

Pulmonary tumour thrombotic microangiopathy (PTTM) is a fatal disease in which tumour cells embolize to the pulmonary vasculature leading to pulmonary hypertension and right heart failure. Early diagnosis is essential for timely treatment which can reduce intimal pulmonary vascular proliferation and prolong survival, improve the symptoms. Due to rare occurrences and no clear diagnostic guidelines the disorder usually is found post-mortem. We present a review of this rare disease and a case of post-mortem diagnosed pulmonary tumour thrombotic microangiopathy in a young female.

Case presentation

51 years old woman presented with progressively worsening dyspnea, right ventricular failure signs and symptoms. Computerized tomography denied pulmonary embolism. 2D transthoracic echocardiography demonstrated right ventricle dilatation and dysfunction, severely increased systolic pulmonary pressure. Right heart catheterization revealed pre-capillary pulmonary hypertension with mean pulmonary artery pressure of 78 mmHg, pulmonary wedge pressure of 15 mmHg, reduced cardiac output to 1.78 L/min with a calculated pulmonary vascular resistance of 35 Wood units, and extremely low oxygen saturation (26%) in pulmonary artery. Because of worsening ascites, pelvic magnetic resonance imaging was performed, tumours in both ovaries were diagnosed. Due to the high operative risk, detailed tumour diagnosis surgically was not established. The patient developed progressive cardiorespiratory failure, unresponsive to optimal heart failure drug treatment. A postmortem morphology analyses revealed tumorous masses in pre-capillary lung vessels, right ventricle hypertrophy, ovary adenocarcinoma.

Conclusions

An early diagnosis of PTTM is essential. Most cases are lethal due to respiratory failure progressing rapidly. Patients with a history of malignancy, symptoms and signs implying of PH should be considered of having PTTM. If detected early enough, combination of chemotherapy with specific PH therapy is believed to be beneficial in reducing intimal proliferation and prolonging survival, along with improving the symptoms.

Pulmonary tumor thrombotic microangiopathy in occult early gastric cancer that was undetectable on upper endoscopy: a case report and review of similar cases

Background

Pulmonary tumor thrombotic microangiopathy (PTTM), a rare manifestation of metastatic cancer with poor prognosis, is characterized by subacute/acute fatal pulmonary hypertension. The main cause of PTTM is gastric cancer, and cases of early gastric cancer confirmed using autopsy have been reported. Moreover, several cases of early gastric cancer that are undetectable on endoscopy or macroscopic postmortem examination have been reported.

Case presentation

A previously healthy 50-year-old man presented with progressive dyspnea and cough for 1 month. Echocardiography suggested pulmonary hypertension. Computed tomography revealed diffuse lymphadenopathy, whereas blood work revealed an elevation in several serum tumor marker levels. Despite normal upper endoscopic findings, a presumptive diagnosis of PTTM due to gastric cancer was made based on pathological findings of cervical lymph node biopsy, which indicated signet ring cell carcinoma. Imatinib and tegafur/gimeracil/oteracil plus oxaliplatin therapy were started on day 7. The patient’s condition was initially stable. However, his symptoms suddenly progressed, and the patient died on day 8. Macroscopic postmortem examination revealed no abnormal gastric wall findings. Microscopically, PTTM was confirmed, and multiple serial sections of the stomach revealed early gastric cancer.

Conclusions

Despite normal endoscopic findings, micro-occult gastric cancer can lead to PTTM. Physicians should be aware of this disease presentation. Taking prompt action is needed when PTTM is suspected, even if the patient appears stable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02009-8.

A 57-year-old man with rapidly progressive pulmonary hypertension

Pulmonary Tumor Thrombotic Microangiopathy (PTTM) is a rare condition associated with neoplastic disorders, predominantly gastric cancer, leading to pre-capillary Pulmonary Hypertension (PH). The pathologic mechanism involved is a fibrocellular intimal proliferation of small pulmonary vessels sustained by nests of carcinomatous cells lodged in pulmonary vasculature. Clinical presentation is nonspecific, including progressive dyspnea and dry cough. Diagnosis of PTTM is extremely challenging ante-mortem and prognosis is poor. Here we describe the case of a middle-aged man, without known previous cancer history. The clinical course was rapidly unfavorable, with progressive dyspnea and PH associated with hemodynamic instability, eventually culminating in patient's death. PTTM diagnosis was made post-mortem. PTTM should be considered in any patient presenting with unexplained PH, especially if it is rapidly progressive, poorly responsive to standard approaches or there is suspected history of malignancy. A prompt diagnosis of PTTM could help in bringing light into this still under-recognized condition.

A Long-term Survival Case of Pulmonary Tumor Thrombotic Microangiopathy due to Gastric Cancer Confirmed by the Early Diagnosis based on a Transbronchial Lung Biopsy

Pulmonary tumor thrombotic microangiopathy (PTTM) is an acute, progressive, and fatal disease. PTTM manifests as subacute respiratory failure with pulmonary hypertension, progressive right-sided heart failure, and sudden death. An antemortem diagnosis of PTTM is very difficult to obtain, and many patients die within several weeks. We herein report a case of PTTM diagnosed based on a transbronchial lung biopsy. In this case, we finally diagnosed PTTM due to gastric cancer because of its histological identity. The patient was administered chemotherapy, including angiogenesis inhibitors, against gastric cancer at an early age and survived for a long time.

An autopsy case of a patient with systemic sclerosis who developed marked pulmonary hypertension because of pulmonary tumor thrombotic microangiopathy caused by gastric carcinoma

We performed an autopsy on a patient with systemic sclerosis who developed uncontrollable pulmonary hypertension due to pulmonary tumour thrombotic microangiopathy (PTTM) caused by gastric carcinoma. The case was of a 62-year-old woman with systemic sclerosis who was admitted to the intensive care unit (ICU) with severe pulmonary hypertension accompanied by respiratory insufficiency. Pulmonary hypertension could not be controlled despite aggressive medical treatment including vasodilators. Approximately 10 days after admission, a unilateral pleural effusion developed. Thoracentesis was performed, and cytology examination of the pleural fluid revealed carcinomatous pleurisy. Because of the presence of a known gastric carcinoma, PTTM was clinically diagnosed. Although chemotherapy was administered, she died 33 days after ICU admission. An autopsy revealed diffuse fibrocellular intimal thickening of the peripheral pulmonary arterioles, which indicated PTTM. In patients with connective tissue disease complicated with pulmonary hypertension, it is necessary to differentiate not only pulmonary arterial hypertension but also other pathological conditions such as PTTM.

Recurrent metastatic breast cancer manifesting as pulmonary tumor thrombotic microangiopathy with interstitial pulmonary fibrosis and infarcts: A clinicopathological correlation

Pulmonary Tumor Thrombotic Microangiopathy (PTTM) is a fatal complication of malignancy characterized by embolization of tumor cells to the pulmonary vasculature leading to a vascular reaction resulting in stenosis and pulmonary hypertension. Because the clinical manifestations of PTTM overlap with those of other entities, premortem diagnosis is challenging. We describe an unusual case of PTTM as the only clinical manifestation of recurrent metastatic breast cancer. A 50 year-old woman presented with hypoxemia and echocardiographic findings consistent with pulmonary hypertension and cor pulmonale. Correlation of premortem pulmonary imaging with autopsy histopathologic findings revealed that ill-defined ground-glass opacities identified on CT angiogram corresponded to areas of cellular interstitial fibrosis and widespread intrapulmonary tumor emboli involving predominantly small-sized arteries with associated florid intimal fibrosis. The radiologic nodularities and scattered peripheral wedge-shaped consolidations corresponded to evolving pulmonary infarcts on histopathology. Although retrospectively, the imaging findings were concordant with a spectrum of increasing severity of tumor embolization and vascular remodeling, the diagnosis of PTTM was not made premortem. PTTM is a rare entity that must be considered in cancer patients with unexplained hypoxemia, pulmonary hypertension and lung opacities on imaging.

Pulmonary tumor thrombotic microangiopathy: a systematic review

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal disease process in which pulmonary hypertension (PH) develops in the setting of malignancy. The purpose of this study is to present a detailed analysis of cases of PTTM reported in literature in the hopes of achieving more ante-mortem diagnoses. We conducted a systematic review of currently published and available cases of PTTM by searching the term “pulmonary tumor thrombotic microangiopathy” on the Pubmed.gov database. Seventy-nine publications were included consisting of 160 unique cases of PTTM. The most commonly reported malignancy was gastric adenocarcinoma (94 cases, 59%). Cough and dyspnea were reported in 61 (85%) and 102 (94%) cases, respectively. Hypoxemia was reported in 96 cases (95%). Elevation in D-dimer was noted in 36 cases (95%), presence of anemia in 32 cases (84%), and thrombocytopenia in 30 cases (77%). Common findings on chest computed tomography (CT) included ground-glass opacities (GGO) in 28 cases (82%) and nodules in 24 cases (86%). PH on echocardiography was noted in 59 cases (89%) with an average right ventricular systolic pressure of 71 mmHg. Common features of PTTM that are reported across the published literature include presence of dyspnea and cough, hypoxemia, with abnormal CT findings of GGO, nodules, and mediastinal/hilar lymphadenopathy, and PH. PTTM is a universally fatal disease process and this analysis provides a detailed examination of all the available published data that may help clinicians establish an earlier diagnosis of PTTM.

Tumoral pulmonary hypertension

Tumoral pulmonary hypertension (PH) comprises a variety of subtypes in patients with a current or previous malignancy. Tumoral PH principally includes the tumour-related pulmonary microvascular conditions pulmonary tumour microembolism and pulmonary tumour thrombotic microangiopathy. These inter-related conditions are frequently found inpost mortemspecimens but are notoriously difficult to diagnoseante mortem. The outlook for patients remains extremely poor although there is some emerging evidence that pulmonary vasodilators and anti-inflammatory approaches may improve survival. Tumoral PH also includes pulmonary macroembolism and tumours that involve the proximal pulmonary vasculature, such as angiosarcoma; both may mimic pulmonary embolism and chronic thromboembolic PH. Finally, tumoral PH may develop in response to treatments of an underlying malignancy. There is increasing interest in pulmonary arterial hypertension induced by tyrosine kinase inhibitors, such as dasatanib. In addition, radiotherapy and chemotherapeutic agents such as mitomycin-C can cause pulmonary veno-occlusive disease. Tumoral PH should be considered in any patient presenting with unexplained PH, especially if it is poorly responsive to standard approaches or there is a history of malignancy. This article will describe subtypes of tumoral PH, their pathophysiology, investigation and management options in turn.

Impact of a multidisciplinary team for the management of thrombotic microangiopathy

Background

Thrombotic microangiopathy (TMA) is an important complication associated with several diseases that are rare and life-threatening. TMA is common to thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). TTP is defined by a severe deficiency of ADAMTS13, and early treatment is associated with good prognosis. The diagnosis of HUS can be difficult due to the potential multiple etiologies, and the best treatment option in most cases is not well-established yet. The implementation of a multidisciplinary team (MDT) could decrease the time to diagnosis and treatment for HUS and may improve the outcomes of these patients.

Objective

To determine the impact of MDT on morbidity and mortality [death or chronic renal replacement therapy (CRRT) requirements], incidence and response time [(RT) defined as the period between hospital admission and the first day of direct therapy administration], length of stay at an intensive care unit (ICU-LOS) and total hospitalization (T-LOS) were also assessed.

Methods

We compared a pre-MDT implementation period (from January/2008 to May/2016) versus post-MDT period (from May/2016 to December/2016). The screening TMA diagnosis was made according the following criteria: hemolytic anemia, thrombocytopenia and acute renal damage and without ADAMTS13 deficiency. An online chat was implemented to provide instant medical information.

Results

Twenty-eight patients were included. The incidence changed from 2.3 cases/pre-MDT: (all cases: n = 18) to 10 cases/year post-MDT (all cases: n = 10). Two patients died in pre-MDT and post- MDT (11% versus 20%, P = 0.60). From pre-MDT, the number of patients who required CRRT by post-MDT decreased from 7 (39%) to 0, P = 0.03. Similarly, RT, ICU-LOS and T-LOS [median(p25-p75)] decreased from 10 (2–12) days to 0.5 (0–1.5) days, P = 0.04, from 16 (9–30) days to 10 (4–13) days, P = 0.01 and from 33 (22–53) days to 16 (12–32) days, P < 0.01, respectively.

Conclusion

MDT implementation was associated with a greater number of patients who meet TMA criteria. A decrease in the RT and T-LOS periods were observed and associated with better outcomes in these patients.

Signet Ring Cell Carcinoma of Unknown Primary Complicated with Pulmonary Tumor Thrombotic Microangiopathy and Krukenberg Tumor

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare disease that shows hypoxia with severe pulmonary hypertension related to malignant tumor. Diagnosis is difficult due to rapid clinical progression and the need to demonstrate pathological findings from lung biopsy. A 64-year-old woman visited our hospital with hypoxia and pulmonary hypertension. Diffuse granular shadows in the centrilobular area and ground-glass shadows in both lungs and left ovarian tumor were found on radiological imaging. PTTM was suspected, but pulmonary artery blood aspiration by right cardiac catheter failed to detect cancer cells. We could not obtain lung or ovary biopsies because of hypoxia or pulmonary hypertension. The patient died due to respiratory failure. Signet ring cell carcinoma of unknown primary, PTTM, and Krukenberg tumor were diagnosed on autopsy. Since early diagnosis facilitates adequate treatment, physicians should not miss the opportunity for biopsy in cases of suspected PTTM.

Crosstalk between cancer and haemostasis

Cancer is characterized by bidirectional interrelations between tumour progression, coagulation activation, and inflammation. Tissue factor (TF), the principal initiator of the coagulation protease cascade, is centrally positioned in this complex triangular network due to its pleiotropic effects in haemostasis, angiogenesis, and haematogenous metastasis. While formation of macroscopic thrombi is the correlate of cancer-associated venous thromboembolism (VTE), a major healthcare burden in clinical haematology and oncology, microvascular thrombosis appears to be critically important to blood-borne tumour cell dissemination. In this regard, expression of TF in malignant tissues as well as shedding of TFbearing microparticles into the circulation are thought to be regulated by defined genetic events relevant to pathological cancer progression, thus directly linking Trousseau’s syndrome to molecular tumourigenesis.

Because pharmacological inhibition of the TF pathway in selective tumour types and patient subgroups would be in line with the modern concept of individualized, targeted anti-cancer therapy, this review will focus on the role of TF in tumour biology and cancer-associated VTE.

[Pulmonary tumor thrombotic microangiopathy]

Pulmonary tumor thrombotic microangiopathy syndrome is a rare clinicopathological entity in which tumor cell micro-emboli in the pulmonary microcirculation induced thrombotic microangiopathy. This can cause respiratory failure, and acute or sub-acute right heart failure. Histological features include micro tumor emboli in the small arteries and arterioles of the lung associated with thrombus formation and fibro-cellular and fibro-muscular intimal proliferation. The diagnosis is however extremely difficult to make before death. Thus, most of the observations reported are based on autopsy data. Very rare diagnostic observations made before death suggest the potential effectiveness of chemotherapy. Many details remain to be elucidated, interdisciplinary research is a priority with close collaboration between pathologists and clinicians to better understand this, often fatal, syndrome. It may be that the use of targeted therapies will improve the very poor prognosis allowing survival of several weeks or months after diagnosis.

Pulmonary tumour thrombotic microangiopathy

PURPOSE OF REVIEW

Pulmonary tumour thrombotic microangiopathy (PTTM) describes tumour cell microemboli with occlusive fibrointimal remodelling in small pulmonary arteries, veins and lymphatics. Progressive vessel occlusion ultimately results in pulmonary hypertension, which is often severe and rapid in onset. PTTM is associated with carcinomas, notably gastric carcinoma, with vascular endothelial growth factor and platelet-derived growth factor (PDGF) signalling implicated in driving the intimal remodelling. PTTM is a rare cause of pulmonary hypertension, but given that up to a quarter of autopsy specimens from patients dying of carcinoma show evidence for PTTM, it is probably underdiagnosed.

RECENT FINDINGS

Until recently, prognosis in PTTM was universally abysmal from weeks to a few months. Diagnostic utilities include aspiration of tumour cells at wedged right heart catheterization, high-resolution computed tomography (HRCT) findings and computed tomography-positron emission tomography (CT-PET), although definitive diagnosis requires histological analysis. Reports of PTTM treated with a combination of targeted pulmonary vasodilator therapies, anticoagulation, specific chemotherapy and PDGF inhibition, for example using imatinib, suggest that these approaches can prolong survival.

SUMMARY

PTTM is increasingly recognized as an important cause of pulmonary hypertension, often in patients presenting with new-onset pulmonary hypertension and as yet undiagnosed malignancy. Prospects of survival are improving with targeted combination therapy, and early recognition and diagnosis are likely to be the key factors to improve outcome.

Subacute right heart failure revealing three simultaneous causes of post-embolic pulmonary hypertension in metastatic dissemination of breast cancer

A 72‐year‐old woman with history of breast cancer only treated surgically was referred to our department for pulmonary hypertension (PH) suspicion. Echocardiogram revealed elevated right ventricular systolic pressure. Computed tomography (CT) angiogram showed no pulmonary embolism (PE), but lung scan revealed two ventilation‐perfusion mismatch areas. Right cardiac catheterization established precapillary PH. Despite treatment with PH specific therapy (sildenafil, ambrisentan, and epoprostenol), her condition worsened rapidly with acute right heart failure (RHF). She died 22 days after admission. Post‐mortem microscopic examination showed a rare combination of PH etiologies consistent with metastasis of breast cancer in pulmonary vasculature including the rare pulmonary tumour thrombotic microangiopathy (PTTM).

Imatinib could be a new strategy for pulmonary hypertension caused by pulmonary tumor thrombotic microangiopathy in metastatic breast cancer

Introduction

Pulmonary tumor thrombotic microangiopathy (PTTM) is rare, cancer-related pulmonary complication leading to hypoxia, pulmonary hypertension, and heart failure. The standard treatment for PTTM is not established. However, imatinib, a tyrosine kinase inhibitor of the PDGF receptor, may cause regression of pulmonary hypertension and pulmonary artery remodeling in PTTM.

Case descriptions

We report two cases of PTTM who received an anti-PDGF agent of imatinib for PTTM developed during chemotherapy for metastatic breast cancer. Case 1: 61-year-old woman who underwent resection of the left breast and axillary lymph node dissection and received adjuvant chemotherapy (CAF followed by docetaxel), then endocrine therapy for 5 years. Twelve years after surgery, multiple bone and mediastinal lymph node metastases occurred. She was under treatment with eribulin for one year but admitted because of rapid progressing dyspnea. Case 2: 45-year-old woman with metastatic breast cancer in multiple bones was under treatment for 5 years. Receiving capecitabine, she suffered from dyspnea for 2 months, she was admitted to our hospital with diagnosis of severe hypoxia. In both cases, the wedged pulmonary arterial blood cell sampling revealed cytologically malignant cells which confirmed the diagnosis of PTTM. They were treated with imatinib, which alleviated pulmonary hypertension. However, they died due to progression of metastatic breast cancer.

Discussion and Evaluation

Single use of imatinib did not showed sufficient efficacy. It is necessary to conduct a well-designed clinical trial using chemotherapies combined with imatinib for PTTM.

Conclusions

Imatinib, which alleviated pulmonary hypertension, could be a new strategy for pulmonary tumor thrombotic microangiopathy in patient with metastatic breast cancer.

Pulmonary tumor thrombotic microangiopathy caused by prostate carcinoma

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal malignancy-related condition that involves rapidly progressing hypoxia and pulmonary hypertension. We report a case of PTTM caused by prostate carcinoma, which was diagnosed before autopsy in an 81-year-old man. Computed tomography showed diffuse ground-glass opacities, consolidation, and small nodules in the peripheral regions of the lung. Autopsy showed adenocarcinoma cells embolizing small pulmonary arteries with fibrocellular intimal proliferation, which was consistent with PTTM caused by prostate carcinoma.

The Case of a Zebra That Was Misdiagnosed as a Horse: Pulmonary Tumor Thrombotic Microangiopathy, a New Paraneoplastic Syndrome, Mimicking PD-1-Induced Pneumonitis

A case report of a 47-year-old woman with triple-negative breast cancer on a clinical trial called PRIMETIME (NCT02518958) who received the anti-PD-1 inhibitor nivolumab and the experimental anticancer agent RRx-001 is presented. Although initially diagnosed and treated for anti-PD-1-induced pneumonitis, clinical and radiological abnormalities triggered further investigation, leading to the diagnosis of pulmonary tumor thrombotic microangiopathy (PTTM). This example highlights the importance of exercising due diligence in determining immune-related adverse events and suggests that PD-1-induced pneumonitis should be a diagnosis of exclusion rather than a diagnosis by default. A case history and review of the literature are presented for PTTM, which we propose to define as a paraneoplastic syndrome.

Pulmonary Tumor Thrombotic Microangiopathy Caused by Urothelial Carcinoma Expressing Vascular Endothelial Growth Factor, Platelet-derived Growth Factor, and Osteopontin

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication. It is generally caused by gastric adenocarcinoma, and several molecules produced by tumor cells are reported to play important roles in its pathogenesis. We herein report an autopsy case of PTTM caused by urothelial carcinoma. Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and osteopontin were found to be expressed in both the primary tumor cells and metastatic cells in the PTTM lesions. These findings implicate the possible involvement of VEGF, PDGF, and osteopontin in the pathogenesis of PTTM caused by urothelial carcinoma.

Tetrahydro-β-carboline-3-carboxyl-thymopentin: a nano-conjugate for releasing pharmacophores to treat tumor and complications

To improve the therapeutic efficacy of cancer patients a novel conjugate of thymopentin (TP5) and (1S,3S)-1-methyl-tetrahydro-β-carboline-3-carboxylic acid (MTC) was presented. In water and mouse plasma MTCTP5 forms the nanoparticles of 14-139 nm in diameter, the suitable size for delivery in blood circulation. In mouse plasma MTCTP5 releases MTC, while in the presence of trypsin MTCTP5 releases MTC and TP5. On mouse and rat models the MTCTP5 dose dependently slows down the tumor growth, inhibits inflammatory response and blocks thrombosis. The anti-tumor activity as well as the anti-inflammation activity and anti-thrombotic activity of MTCTP5 are 100 fold and 10 fold higher than those of MTC, respectively, which are attributed to the fact that it down-regulates the plasma levels of TNF-α and IL-8 of the treated animals. The immunology enhancing activities in vitro and in vivo of MTCTP5 are similar to those of TP5, which is attributed to the fact that MTCTP5 up-regulates the plasma levels of IL-2 and CD4 as well as down-regulates the plasma level of CD8 of the treated animals. The plasma alanine transaminase, aspartate transaminase and creatinine assays indicate that MTCTP5 therapy does not injure the liver and the kidney of the animals. The survival time of MTCTP5 treated mice is significantly longer than that of TP5 treated mice.

Pulmonary tumor thrombotic microangiopathy: the challenge of the antemortem diagnosis

Pulmonary tumor thrombotic microangiopathy (PTTM) is known as a rare and severe cancer-related pulmonary complication. Nowadays, fewer than 80 cases have been reported in the literature and very few cases have been diagnosed antemortem. We describe an autopsy case of PTTM associated with cancer of unknown origin. A 56-year-old male patient came to our attention due to a 2-day history of dyspnea. Analysis of the clinical context in combination with laboratory and imaging tests led us to suspect acute pulmonary thromboembolism. However, the computed tomography pulmonary angiogram was negative for thromboembolism; on the contrary it revealed multiple lymphadenopathy. Microscopic pulmonary tumor embolism was suspected and a lymph node biopsy was planned. However, the patient's condition progressively worsened; death occurred 3 days after admission. After autopsy, histologically extensive neoplastic emboli involved the small pulmonary arteries and arterioles, often admixed with fibrin thrombi. The involved and noninvolved arteries also demonstrated fibrocellular intimal proliferation causing marked luminal stenosis and occlusion. These pathological features were characteristic of PTTM, which should be distinguished from microscopic tumor embolism and should be considered in the differential diagnosis of acute/subacute cor pulmonale and pulmonary hypertension in cancer as well as in noncancer patients. We propose a review of the literature and an algorithm to improve PTTM antemortem diagnosis.

Pulmonary tumour thrombotic microangiopathy as a cause of new-onset pulmonary hypertension in a patient with metastatic low-grade serous ovarian cancer

A 78-year-old woman with metastatic low-grade serous ovarian cancer presented with rapidly progressive exertional dyspnoea and hypoxia, and was found to have new-onset severe pulmonary hypertension (PH) by right heart catheterisation. A diagnosis of pulmonary tumour thrombotic microangiopathy (PTTM) was made at autopsy. PTTM is a rare complication of advanced cancer that often presents as rapidly progressive PH or acute hypoxic respiratory failure. Widespread tumour cell emboli in the pulmonary arteries and arterioles are hypothesised to induce fibrocellular subintimal proliferation and microthrombi, leading to increased pulmonary vascular resistance and PH. PTTM arising from serous ovarian cancer is exceedingly rare, with only two previously reported cases. A discussion of the pathophysiology, diagnosis and management of PTTM is presented.

Pulmonary Tumor Thrombotic Microangiopathy: Clinical, Radiologic, and Histologic Correlation

Pulmonary tumor thrombotic microangiopathy (PTTM) is a clinicopathologic disease entity in which the tumor cells embolize to the pulmonary vasculature leading to a series of maladaptive reactions including the activation of coagulation and fibrocellular intimal thickening. The resultant stenosis of blood vessels leads to pulmonary hypertension and eventual death from cor pulmonale. In this report, we present a case of PTTM presenting as the initial manifestation of metastatic gastric carcinoma in a young man. Although unusual in its occurrence as the initial manifestation of gastric carcinoma, the case is illustrative in its clinical, radiological and histological presentation.

A rare cause of postoperative hypotension

A 62-year-old woman presented with a 3-month history of abdominal distension and decreased exercise tolerance. A chest radiograph showed a probable left pleural effusion (Fig 1). A CT scan of the abdomen revealed a solid ovarian mass with omental caking and a large volume of ascites; there was also confirmation of a left pleural effusion. Three days before surgery a CT pulmonary angiogram (CTPA) showed no evidence of pulmonary thromboembolism (PTE). The patient had some improvement in her symptoms after paracentesis and thoracentesis with drainage of 2,000 mL and 250 mL of fluid, respectively. She underwent total abdominal hysterectomy, bilateral oophorectomy, and partial sigmoid resection with an estimated blood loss of 850 mL. During the operation, she received 5 L of crystalloid and required phenylephrine at 40 to 80 μg/min to maintain a mean arterial pressure &gt; 65 mm Hg. She was extubated after surgery, but immediately after extubation, she became markedly hypotensive and hypoxemic with a BP of 50/20 mm Hg and an oxygen saturation of 70%. An ECG showed T-wave inversions from V1 to V5 and an S1Q3T3 pattern (Fig 2). A bedside echocardiogram showed an enlarged right ventricle (RV), septal dyskinesia, and obliteration of the left ventricle, all consistent with systolic and diastolic RV overload (Fig 3).

Non-immune Hemolysis: Diagnostic Considerations

Non-immune hemolytic anemia (NIHA) is characterized by positive routine hemolytic tests but negative anti-human immunoglobulin (Coombs) test. Hereditary non-immune hemolysis includes disorders of erythrocytic enzymes, membrane, hemoglobin (qualitative and quantitative disorders), as well as the rare hereditary forms of thrombotic microangiopathies. Acquired NIHA includes paroxysmal nocturnal hemolysis (PNH), infections, drug and metal intoxications with as a target red blood cells or endothelium of capillaries, the rare acquired forms of thalassemia or erythrocytic membrane disorders, and hemolysis secondary to a dysfunctioning artificial (prosthetic) cardiac valve. Identification of the specific cause of NIHA is sometimes difficult and requires not only a good knowledge of this entity but mainly a qualified specialized hematologic laboratory. An algorithm to be used in every new patient consulting for NIHA is proposed in the last part of this article.

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.

A case of pulmonary tumour thrombotic microangiopathy

Pulmonary tumour thrombotic microangiopathy (PTTM) is a rapidly progressive pulmonary disease that is a fatal complication of malignancy. It manifests clinically as subacute respiratory failure with pulmonary hypertension, progressive right sided heart failure, and sudden death. We describe here a case of PTTM associated with occult metastatic signet ring cell carcinoma of the stomach. Although rare, PTTM needs to be considered in the differential diagnosis of dyspnoea of unknown origin, particularly in patients with respiratory failure and also pulmonary hypertension, and in patients were there is no improvement in respiratory symptoms with steroid therapy.

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.

Pulmonary tumor thrombotic microangiopathy associated with right ventricular rupture and hemopericardium: A case report

Pulmonary tumor thrombotic microangiopathy is a rare form of pulmonary tumor embolism clinically indistinguishable from pulmonary thromboembolic disease. It is characterized by fibrocellular intimal proliferation of small pulmonary arteries and arterioles in patients with intraluminal tumor embolization. We report the case of a 67-year-old Caucasian woman who had been treated for breast cancer 5 years prior to presentation and had been free of recurrence on routine clinical surveillance. She was admitted for evaluation of three witnessed syncopal events accompanied by tachypnea and hypotension. Transthoracic echocardiography revealed severe right ventricular dilatation and severely reduced right ventricular function. Shortly after admission, the patient became acutely unresponsive and expired despite aggressive resuscitation measures. The proximate cause of death was a rupture of the right ventricular free wall and a large hemopericardium. Histopathology revealed extensive microscopic occlusions of small pulmonary arteries and arterioles by metastatic breast carcinoma with superimposed acute thrombi. Pulmonary tumor thrombotic microangiopathy should be included in the differential diagnosis of patients presenting with symptoms of pulmonary thromboembolism and a history of malignancy. <Learning objective: Pulmonary tumor thrombotic microangiopathy is a rare form of pulmonary tumor embolism clinically indistinguishable from pulmonary thromboembolic disease. It is characterized by fibrocellular intimal proliferation of small pulmonary arteries and arterioles in patients with intraluminal tumor embolization. The disease has a fulminant course and poor prognosis. It should be included in the differential diagnosis of patients presenting with symptoms of pulmonary thromboembolism and a history of malignancy.>.

Remodeling of the pulmonary artery induced by metastatic gastric carcinoma: a histopathological analysis of 51 autopsy cases

BACKGROUND

Gastric carcinoma remains the second commonest cause of cancer deaths worldwide. Presence of the carcinoma cell in the pulmonary artery is serious condition that might cause remodeling of the pulmonary artery. The present study conducted detailed histopathological analyses to elucidate how gastric carcinoma cells may affect the structure and hemodynamics of pulmonary arteries.

METHODS

Remodeling of the pulmonary artery was assessed based on measurements of arterial diameters and stenosis rates from the autopsies, and their correlation were also validated. We additionally calculated 95 percent confidential intervals (CIs) for the rate of stenosis in groups of pulmonary arteries of different caliber zones (under 100, 100 to 300, and over 300 micrometer). The right ventricular thickness was measured and examined whether it correlated with the rate of pulmonary arterial stenosis.

RESULTS

A total of 4612 autopsy cases were recorded at our institute, among which 168 had gastric carcinoma. Finally, 51 cases of the gastric carcinoma were employed for the study which had carcinoma cells in the lumen of the pulmonary artery. The mean right ventricular wall thickness of these cases was 3.14 mm. There were significant positive associations between the rates of pulmonary arterial stenosis and right ventricular thickness from pulmonary arteries of diameter under 100, 100 to 300, and over 300 micrometer. In these zones, 31, 31, and 33 cases had rates of pulmonary arterial stenosis that were below the lower limit of the 95 percent CI values, respectively. On the other hand, among cases with significant pulmonary stenosis, 17 of 18 cases with stenosis in the over 300 micrometer zone involved pulmonary arteries of both in the under 100 and 100 to 300 micrometer zones.

CONCLUSION

One-third of autopsy with advanced gastric carcinoma had carcinoma cells in lumen of pulmonary artery, but implantation and proliferation may be essential to induce intimal thickening that causes an increasing of pulmonary arterial pressure, because our study revealed a significant positive association between the rate of pulmonary arterial stenosis and right ventricular thickness. In addition, diffuse type gastric carcinoma may be apt to cause the remodeling of the pulmonary artery.

Rapidly progressive symptom development of pulmonary arterial hypertension: a case report of Trousseau syndrome

Trousseau syndrome is most commonly defined as a hypercoagulability syndrome associated with mucin-producing adenocarcinoma. We report here a rare case of Trousseau syndrome presenting as pulmonary arterial hypertension. The patient complained of cough and increasing exertional dyspnea. Rapidly progressive symptom development of pulmonary arterial hypertension accompanied by right heart failure was observed, and the patient died on hospital day 2. An autopsy revealed Krukenberg tumors on both ovaries and a signet-ring cell gastric carcinoma. In the lungs there was tumor embolism with signet-ring cells to some extent, but the peripheral pulmonary arteries were occupied primarily by pulmonary embolism with platelets, fibroblasts, and fibrotic organized thrombi.

World Health Organization group 5 pulmonary hypertension

World Health Organization (WHO) group 5 pulmonary hypertension (PH) entails a heterogeneous group of disorders that may cause PH by unclear and/or multiple mechanisms. In particular, group 5 includes PH caused by hematologic disorders, systemic diseases, metabolic disorders, chronic renal failure, and disorders leading to pulmonary vascular occlusion or compression. This article discusses common pathogenic mechanisms leading to group 5 PH, followed by a detailed overview of epidemiology, pathogenesis, and disease-specific management of the individual group 5 conditions. Off-label use of vasomodulatory therapies, typically indicated for pulmonary arterial hypertension (WHO group 1 PH), in group 5 conditions is also discussed.

Pulmonary tumor thrombotic microangiopathy showing aggressive course after transurethral resection of urinary bladder: an autopsy case report

A 77-year-old man developed pulmonary tumor thrombotic microangiopathy (PTTM) 2 days after undergoing transurethral resection for urothelial carcinoma (G3) of the urinary bladder and died of respiratory failure 6 days later. Histological findings demonstrated marked intimal fibrocellular proliferation, fibrin thrombi, and both cancer cells and fibrin thrombi in the arteries of the lungs, findings consistent with PTTM. Prominent stenosis in arteries smaller than 300 μm was also seen. The Ki-67 labeling index of primary and metastasized cancer cells was 62.4 % and 70.2 %, respectively. The membranes of metastasized cancer cells expressed E-cadherin, similar to membranes in the urinary bladder. An aggressive PTTM course is affected by intimal fibrocellular proliferation and the high cell proliferation of cancer cells. Furthermore, prominent stenosis in small arteries and membranous staining of E-cadherin of metastasized cells suggest that cancer cells formed clusters by maintaining adhesion molecules and migrated into the arteries of the lungs, where they easily caused damage to the endothelium of small arteries, in contrast to dispersed cancer cells.