Pulmonary tumour microembolism clinically mimicking alveolitis

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.

Fatal Microscopic Pulmonary Tumor Thromboemboli: Unusual Presentation of Occult Cervical Carcinoma. Two Case Reports and Review of the Literature

Cor pulmonale (right heart failure) due to microscopic pulmonary tumor emboli (MPTE) can arise from a variety of malignancies including breast, lung, and liver and carries significant morbidity and mortality. Tumor cell aggregates spread hematogenously to the lungs and occlude small pulmonary vessels leading to pulmonary hypertension through either a mechanical process or inducing vascular remodeling as a downstream result of interactions between the embolus and the vessel wall. Its presentation includes unexplained dyspnea, hypoxemia, tachycardia, pulmonary hypertension, right heart failure, and in some cases sudden death. The symptoms may suggest the more common entity of pulmonary thromboembolism, particularly in the setting of previously known metastatic cancer; however, computed tomography scans may appear normal and ventilation-perfusion scans which are the preferable diagnostic modality are not always ordered. In most cases of MPTE, the presentation reflects metastasis of an already known and advanced tumor, but, in rare cases, it may be the primary manifestation of an occult malignancy. We present here 2 unique cases of MPTE in women with occult cervical cancer. In both cases, the malignancy was discovered and diagnosed at autopsy. Microscopic pulmonary tumor emboli can be easily overlooked, and therefore, forensic pathologists and other death investigators should be aware of it and trained to at least consider the possibility in appropriate situations. Thorough microscopic examination of apparently normal tissues may be necessary, particularly in cases of unexplained right heart failure and sudden death, even if the decedent has few or no identifiable risk factors for cancer.

Neoplastic embolization to systemic and pulmonary arteries

OBJECTIVE

Arterial neoplastic emboli are uncommon, accounting for <1% of thromboemboli in the current literature. Nonetheless, this event may be associated with significant morbidity and mortality. Herein, we report a series of 11 cases of arterial neoplastic emboli from a single tertiary care center along with a comprehensive review of the literature to date. The aim of this study was to document the incidence, clinical presentations, and complications of arterial neoplastic emboli as well as to highlight the importance of routine histologic examination of thrombectomy specimens.

METHODS

Pathology archives from a single tertiary care institution were queried to identify cases of surgically resected arterial emboli containing neoplasm (1998-2014). Histopathology was reviewed for confirmation of diagnosis. Patient demographics and oncologic history were abstracted from the medical record. Comprehensive literature review documented 332 patients in 275 reports (1930-2016).

RESULTS

Eleven patients (six men) with a median age of 63 years (interquartile range, 42-71 years) were identified through institutional archives. Embolism was the primary form of diagnosis in seven (64%) cases. Cardiac involvement (primary or metastasis) was present in more than half of the cohort. Comprehensive literature review revealed that pulmonary primaries were the most common anatomic origin of arterial neoplastic emboli, followed by gastrointestinal neoplasia. Cardiac involvement was present in 18% of patients, and sentinel identification of neoplasia occurred in 30% of cases. Postmortem evaluation was the primary means of diagnosis in 27%.

CONCLUSIONS

This study highlights the importance of routine histopathologic evaluation of embolectomy specimens in patients with and without documented neoplasia.

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.