[Pulmonary tumor thrombotic microangiopathy]

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.

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.

A case of severe cancer-related pulmonary hypertension; An unexpected resolution

Pulmonary hypertension (PH) in cancer patients can be caused by several mechanisms. It can be a direct cancer effect through pulmonary tumor thrombotic microangiopathy, pulmonary tumor emboli, extrinsic compression, intravascular tumors, or a secondary consequence of therapy, including chemotherapy agents, radiation, and stem cell transplantation. We present the first case of complete resolution of cancer-related PH.