A case report and literature review incidental pulmonary embolism: prevalence, risk factors, diagnosis, and treatment strategies

Abstract

Incidental pulmonary embolism (IPE) is defined as pulmonary embolism (PE) found through imaging studies in patients who are not suspected clinically. The incidental diagnosis of PE has been increasing lately due to the introduction of multi-detector CT scan, which gives better visualization of pulmonary arteries.
However, there is still limited information about clinical significance of IPE. The case report aims to highlight the prevalence, potential factors, diagnosis, and treatment strategies of IPE. A case of a 60-year-old male was reported with a history of smoking but no significant medical comorbidities, who presented with a persistent dry cough and mild chest discomfort that had lasted for a month. A coronary CT angiography incidentally revealed a left-sided contrast void in the left pulmonary artery suggested of pulmonary artery embolism. Physical examinationshowed stable vital signs withouth respiratory distress. Laboratory tests were normal except for elevated D-dimer level (1.7). Pulmonary CTA confirmed a complete embolism in the left main pulmonary artery extending to the segmental branches. The patient was treated with LMWH (enoxaparin
sodium) 2x 60mg/0.6mL subcutaneously. Bronchoscopy showed stenosis in segment B6 of the left lower lobe and a smooth-surfaced, non-bleeding nodule. The PET scan revealed an irregular, hypermetabolic atelectatic lesion in segment B6, suspicious for malignancy, without lymph node involvement or distant metastasis. Cytology and histopathology did not indicate malignancy. After 5 days, LMWH was switched to rivaroxaban 20mg once daily PO. The patient was discharged in a stable condition. IPE is more frequently detected in cancer
patients. Other potential factors associated with IPE are similar to symptomatic PE, including immobilization, surgery or trauma, and prior VTE. The diagnosis of IPE is difficult due to the lack of typical symptoms, hence termed “silent PE”. Despite rising incidence, optimal treatment strategies are not wellestablished. Current guidelines recommend managing IPE similarly to symptomatic PE because of a comparable prognosis.