Microscopic pulmonary tumoral embolism and subacute cor pulmonale as the first clinical signs of cancer

Pulmonary tumor thrombotic microangiopathy caused by metastatic ovarian high-grade serous carcinoma: a case report and literature review

BACKGROUND

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare entity with poor prognosis, and often diagnosed postmortem. PTTM is resulting from tumor emboli induced activation of coagulation cascade, fibrin clot formation and fibrocellular intimal proliferation in pulmonary microvasculature.

CASE

The patient was a 65-year-old female, with past medical history of ovarian high-grade serous carcinoma, presented with chest pain and shortness of breath. The chest computed tomography (CT) revealed innumerable new lung nodules as well as small hazy and patchy opacities compared to the chest CT 2 months before current presentation. She developed progressive respiratory failure and expired. A lung-restricted autopsy showed diffuse subcentimetric nodules in bilateral lungs grossly. Microscopic examination revealed the lung parenchyma demonstrated numerous tumor emboli consisting of pleomorphic tumor cells with varying degrees of fibrin deposition and fibrocellular intimal proliferation in the pulmonary arterioles, small arteries, and capillaries in the alveolar septa. Immunohistochemistry confirmed the ovarian origin of the tumor cells. The findings were consistent with PTTM secondary to metastasis of ovarian high-grade serous carcinoma. Literature review of PTTM caused by ovarian cancer was conducted.

CONCLUSION

PTTM is a fatal entity with rare association with primary ovarian malignancy. This case study demonstrates the clinicopathological features of PTTM associated with high-grade serous carcinoma, and it will be the second case of PTTM with this association in the literature.

Syncope as the initial presentation of pulmonary embolism in two patients with hepatocellular carcinoma: Two case reports and literature review

RATIONALE

Pulmonary embolism (PE) has diverse clinical manifestations and syncope might be the first or only symptom of PE. Tumor disease usually presents with symptoms associated with the primary site, however, PE may be the first manifestation of occult tumors.

PATIENT CONCERNS

Here, we report 2 patients admitted to our hospital because of syncope. One patient had a chronic hepatitis B history of more than 20 years and the other patient had chronic heavy drinking for many years. Neither patient had been diagnosed with neoplastic disease before admission.

DIAGNOSES

Clinical examinations, including laboratory tests and imaging tests upon admission demonstrated PE resulting in syncope. Furthermore, malignant hepatocellular carcinoma (HCC), inferior vena cava, and right atrium tumor thrombus were diagnosed.

INTERVENTIONS

Thrombolysis and anti-coagulation therapy were performed immediately after the diagnosis of PE. Twenty-seven HCC patients with PE in 27 articles from 1962 to 2020 in the PubMed database were reviewed.

OUTCOMES

The improvement was achieved that no syncope recurred after treatment of PE. The oxygen partial pressure increased and the D-dimer level decreased. The clinical characteristics of 27 HCC patients with PE were summarized and analyzed.

LESSONS

It is important for clinicians to be aware that occult carcinoma might be a reason for patients with PE presenting with syncope. If PE cannot be explained by common causes, such as our patient, and HCC should be highly suspected when inferior vena cava and right atrial mass are found on imaging tests.

[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 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.

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a 'negative autopsy' in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.

An autopsy case of subacute cor pulmonale due to pulmonary tumor cell emboli in a patient with gastric cancer

A 53-year-old woman was admitted to our hospital due to a severe respiratory condition and malnutrition. Radiological and electrophysiological findings suggested the existence of inexplicable cor pulmonale. Although we commenced to determine the causes of her severe condition, she suddenly died 3 days after admission. Postmortem autopsy revealed tumor cell microemboli in the small pulmonary arteries due to gastric cancer. Such a case of cor pulmonale as the first clinical manifestation is exceptionally rare. Occult malignancy should be considered as a differential diagnosis when one encounters a patient with subacutely aggravated respiratory condition and inexplicable cor pulmonale.

Massive pulmonary tumor microembolism from a hepatocellular carcinoma

A 48-year-old patient with known alcohol abuse and long-standing liver cirrhosis presented with spontaneous bacterial peritonitis and subsequent hepato-renal syndrome. Autopsy revealed a large hepatocellular carcinoma of the right liver lobe. Histologically, pulmonary arteries, arterioles, and capillaries were occluded by numerous tumor emboli. Small tumor emboli also covered the endocardium of the right ventricle. A review of the literature shows that macroscopic as well as microscopic pulmonary tumor embolism is often diagnosed in patients with a previously unknown malignancy. Moreover, pulmonary tumor embolism radiologically mimics pneumonia, tuberculosis, or interstitial lung disease. Therefore, an autopsy should be considered in cases of fulminant or massive pulmonary embolism to exclude tumor embolism even when the patients' history is insignificant as to this point, and in cases with known malignant tumors and respiratory symptoms to exclude tumor microembolism.

Acute cor pulmonale due to microscopic tumour embolism as the first manifestation of hepatocellular carcinoma

Microscopic pulmonary tumour embolism is a rare cause of pulmonary hypertension. In most of the reported cases, symptoms develop over several days or weeks in patients previously diagnosed with malignant diseases. In our case, a 41-year-old man with an unremarkable medical history presented with respiratory failure that led to death less than 48 h from the onset of symptoms. Autopsy revealed massive microscopic pulmonary tumour embolism and a multifocal hepatocellular carcinoma. This case report is exceptional because it describes a very rapid clinical progression, and because acute cor pulmonale was the first manifestation of a previously undiagnosed neoplastic disease.