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

Clinical-radiological-pathological correlation in pulmonary hypertension with unclear and/or multifactorial mechanisms

Ever since the second world symposium on pulmonary hypertension (PH) held in Evian, France, in 1998, PH has been classified into five major clinical groups. Group 5 PH includes a variety of distinct conditions with unclear and/or multifactorial underlying pathologies. Management of these patients is challenging as the number of patients within these groups is often small, not all individuals with certain underlying conditions are affected by PH and patients exhibit distinct symptoms due to different underlying diseases. Studies and clinical trials in these groups are largely lacking and mostly restricted to case series and registry reports. Nonetheless, the worldwide burden of group 5 PH is estimated to be significant in terms of the prevalence of some associated diseases. Group 5 PH encompasses six subgroups, including haematological disorders (inherited and acquired chronic haemolytic anaemia and chronic myeloproliferative disorders), systemic disorders (sarcoidosis, pulmonary Langerhans's cell histiocytosis and neurofibromatosis type 1), metabolic disorders (glycogen storage diseases and Gaucher disease), chronic renal failure with or without haemodialysis, pulmonary tumour thrombotic microangiopathy and fibrosing mediastinitis.

An unexpected cause of pulmonary hypertension in a young woman: a case report

Background

Pulmonary hypertension (PH) is defined as a progressive disease that leads to right heart failure and death if untreated. This case report presents a young woman with reversible precapillary PH in the setting of a gastric cancer.

Case summary

A 37-year-old woman presented with exertional dyspnoea and syncope. The transthoracic echocardiographic findings were consistent with a cor pulmonale. Right heart catheterization (RHC) proved a precapillary PH. Specific PH therapy with macitentan and tadalafil was initiated. Shortly thereafter, a gastric carcinoma was diagnosed, and oncologic treatment with neoadjuvant chemotherapy and subsequent gastrectomy was promptly initiated. Retrospectively, we considered a pulmonary tumour thrombotic microangiopathy the most probable cause of PH. Follow-up after successful oncologic treatment and cumulative 10 months of specific PH medication showed an excellent clinical response with complete remission of PH confirmed by RHC at rest.

Discussion

Tumour-related PH is very rare and might be largely underdiagnosed as the clinical course often results in a rapid deterioration and fatal outcome before diagnostics are completed. Post mortem studies have documented tumoural emboli in pulmonary microcirculation in ∼26% of patients with a solid tumour, markedly associated with adenocarcinoma. Prompt initiation of cancer treatment on tumoural PH is essential. To our knowledge, this report documents the first full recovery of tumoural PH at rest after successful cancer treatment and temporary specific PH medication. We therefore conclude that a multidisciplinary approach with an initially combined oncologic and PH therapy may be most beneficial with the potential of complete remission of PH.

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.

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.

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.

A case of pulmonary tumor thrombotic microangiopathy associated with lung cancer diagnosed by cell-block immunohistochemistry of pulmonary microvascular cytology

Pulmonary tumor thrombotic microangiopathy (PTTM) is rare but should be considered as a possible diagnosis in patients with cancer. In this case, PTTM induced by lung cancer was more accurately diagnosed using cell block immunohistochemistry of pulmonary microvascular cytology (PMC) because we could confirm that lung adenocarcinoma was the origin of PTTM by the positive result of TTF-1 for atypical cells in PMC. The PMC procedure was minimally invasive and safer than lung biopsy. We believe that the cell block technique of PMC should be considered as one diagnostic option in PTTM.

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.

Pulmonary Tumor Thrombotic Microangiopathy due to Advanced Gastric Cancer with Virchow's Node Metastasis

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related complication characterized by severe progressive pulmonary hypertension. Antemortem diagnosis is difficult owing to the rapid progression of the condition, especially when the patient has no known malignancies and initially presents with pulmonary hypertension. Here we report a case of PTTM due to occult gastric cancer with metastasis in the left supraclavicular lymph node, also known as Virchow's node. Enlarged Virchow's node is an important indicator of advanced gastric cancer. In patients with progressive pulmonary hypertension of unknown origin, enlarged Virchow's node can be an important indicator for the diagnosis of PTTM.

[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.

Acute cor pulmonale due to pulmonary tumour thrombotic microangiopathy from renal cell carcinoma

We report the case of a previously healthy man who presented with subacute dyspnoea after a long drive. He developed hypoxic respiratory failure, thought secondary to a massive pulmonary embolism and was treated with tissue plasminogen activator but died in the hospital despite aggressive medical measures. Autopsy revealed pulmonary tumour thrombotic microangiopathy (PTTM) from papillary renal cell carcinoma. PTTM is a rare clinicopathological syndrome that clinically results in symptoms of dyspnoea and right heart failure. Pathologically, a localised paraneoplastic process evolves from tumour microemboli in the pulmonary arterioles, resulting in fibrocellular proliferation and narrowing of the vessels, causing subacute right heart failure. To our knowledge, this is the first case of PTTM due to papillary renal cell carcinoma.

Pulmonary Tumor Thrombotic Microangiopathy: A New Paraneoplastic Syndrome?

This report, based on data from a clinical case, proposes that pulmonary tumor thrombotic microangiopathy, an underdiagnosed cause of pulmonary hypertension and death in patients with adenocarcinoma, is a paraneoplastic syndrome (PNS). Clinicians in general must be alert to the presence or development of PNS that may precede, coincide with, follow, or herald the recurrence or the primary diagnosis of malignancy since early recognition facilitates prompt diagnosis and treatment.

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.