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

Cancer-Associated Thrombotic Microangiopathy: Literature Review and Report of Five Cases

Thrombotic microangiopathy (TMA) is an anatomopathological lesion mediated by endothelial dysfunction and characterized by the creation of microthrombi in small vessels. In patients with cancer, it may be due to toxicity secondary to chemotherapy, tumor embolization, or hematopoietic progenitor transplantation. Cancer-associated TMA is an underestimated entity that generally appears in the final stages of the disease, although it may also be the initial manifestation of an underlying cancer. Support treatment is necessary in all cases and, depending on the cause, different targeted therapies may be used. The prognosis is very poor. In this article we present a comprehensive review of the existing literature on the physiological mechanisms of cancer-associated TMA. Afterwards, five clinical cases will be presented of patients who developed TMA and were diagnosed in our Department in 2023. We present a discussion of the different causes that triggered the condition, the possible reasons behind the underestimation of this pathology, and the measures that may be adopted.

Pulmonary tumor thrombotic microangiopathy: Two case reports and literature review

RATIONALE

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare but serious complication in patients with malignancy; its main manifestation includes acute pulmonary hypertension with severe respiratory distress. More than 200 cases have been reported since it was first identified in 1990. PTTM accounts for approximately 0.9% to 3.3% of deaths due to malignancy, but only a minority of patients are diagnosed ante-mortem, with most patients having a definitive diagnosis after autopsy.

PATIENT CONCERNS

Two middle-aged women both died within a short period of time due to progressive dyspnea and severe pulmonary hypertension.

DIAGNOSES

One patient was definitively confirmed as a gastrointestinal malignant tumor by liver puncture biopsy pathology. Ultimately, the clinical diagnosis was pulmonary tumor thrombotic microangiopathy.

INTERVENTIONS

The patient was treated symptomatically with oxygen, diuresis, and anticoagulation, while a liver puncture was perfected to clarify the cause.

OUTCOMES

Two cases of middle-aged female patients with rapidly progressive pulmonary hypertension and respiratory failure resulted in death with malignant neoplasm.

LESSONS

PTTM has a rapid onset and a high morbidity and mortality rate. Our clinicians need to be more aware of the need for timely diagnosis through a targeted clinical approach, leading to more targeted treatment and a better prognosis.

Pulmonary tumor thrombotic microangiopathy during good response to immuno-chemotherapy for advanced non-small cell lung cancer: a case report

BACKGROUND

Pulmonary tumor thrombotic microangiopathy is a rapidly progressive and fatal disease in which tumor cells embolize to the pulmonary microvasculature. This condition is characterized by severe dyspnea and right heart failure. Although pulmonary tumor thrombotic microangiopathy typically occurs in patients with untreated and/or advanced cancer, its occurrence in patients who are responding well to medical therapy is poorly documented.

CASE PRESENTATION

A 68-year-old Japanese woman who had received four cycles of immuno-chemotherapy (pembrolizumab, carboplatin, and pemetrexed) followed by three cycles of maintenance therapy (pembrolizumab and pemetrexed) for advanced non-small cell lung cancer and had achieved a partial response with a stable clinical course was admitted to the emergency ward because of worsening breathlessness and general fatigue for 1 week. Chest computed tomography showed no evidence of tumor progression or any new lung lesion. Two-dimensional transthoracic echocardiography demonstrated right atrial and ventricular dilatation, tricuspid regurgitation, and a high trans-tricuspid pressure gradient of 65 mmHg. Despite her percutaneous oxygen saturation being 96% on room air at the time of admission, it worsened rapidly; the patient requiring 8 L/min of oxygen within 4 h. Repeat computed tomography with contrast medium revealed no evidence of pulmonary embolism. The patient developed progressive respiratory failure that was unresponsive to optimal cardio-pulmonary supportive therapy. An autopsy revealed tumorous clusters in pre-capillary lung vessels, whereas the primary lesion had shrunk to the point of almost complete resolution.

CONCLUSION

Pulmonary tumor thrombotic microangiopathy occurs not only in patients with advanced and/or uncontrolled cancer but also in those whose primary lesion seems to have been well controlled by medical treatment.

Echocardiographic Assessment of Patients with Pulmonary Tumor Thrombotic Microangiopathy First Diagnosed in the Emergency Department

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal disease that obstructs pulmonary vessels, leading to pulmonary hypertension (PH) and right-sided heart failure causing rapid progressive dyspnea in patients with cancer. This retrospective chart review involved nine patients with PTTM who were first clinically diagnosed in a tertiary emergency department (ED) between January 2015 and June 2021. They underwent laboratory tests, chest radiography, chest computed tomography (CT), and echocardiography. All patients presented with severe and rapidly progressive dyspnea within a few days, a high oxygen demand. The right ventricle (RV): left ventricle ratio was >1 on chest CT, and no life-threatening pulmonary thromboembolism (PTE) was observed. Echocardiographic findings indicated that all patients had moderate-to-severe RV dilatation with a D-shaped LV. The median tricuspid regurgitation maximum velocity was 3.8 m/s, and the median RV systolic pressure was 63 mmHg, indicating severe PH. The median value of tricuspid annular plane systolic excursion was 15 mm, showing a decrease in RV systolic function, and McConnell’s sign was observed in five patients. Two patients immediately underwent chemotherapy and are currently alive. PTTM should be suspected and evaluated using echocardiography in patients with cancer presenting to the ED with acute dyspnea and RV failure without PTE.