Elevated carcinoembryonic antigen and bronchial obstruction caused by a rotten vegetable leaf mimic lung cancer: A case report

Abstract Background Tracheobronchial foreign body aspiration is a potentially risky medical event, while the condition often requires early detection and rapid intervention to improve respiratory symptoms and prevent major morbidity. Notably, foreign bodies may not be identified and they are likely to be mistaken for neoplastic lesions. However, CEA, as one of tumor markers, presents to be available for assisting in lung cancer diagnosis, especially for non–small‐cell lung cancer, while the specificity of CEA is not high. Methods Here, we described a case of bronchial opening obstruction with elevated carcinoembryonic antigen (CEA) that was firstly misdiagnosed as lung cancer and proved as foreign body aspiration in the upper lobe bronchus of right lung by bronchoscopy. Results Carcinoembryonic antigen level increased. CT scan demonstrated a cavitation accompanied by multiple small nodular shadows appeared in the right upper lobe field. Bronchoscopy suggested right upper lobe bronchus was blocked by a brown smooth organism with plenty of purulent materials, which was proved as a rotten vegetable leaf. Conclusions Elevated CEA and bronchial obstruction are not typical manifestations of lung cancer. Bronchoscopy is crucial for making a reliable diagnosis.

Methods: Here, we described a case of bronchial opening obstruction with elevated carcinoembryonic antigen (CEA) that was firstly misdiagnosed as lung cancer and proved as foreign body aspiration in the upper lobe bronchus of right lung by bronchoscopy.
Results: Carcinoembryonic antigen level increased. CT scan demonstrated a cavitation accompanied by multiple small nodular shadows appeared in the right upper lobe field. Bronchoscopy suggested right upper lobe bronchus was blocked by a brown smooth organism with plenty of purulent materials, which was proved as a rotten vegetable leaf.
Conclusions: Elevated CEA and bronchial obstruction are not typical manifestations of lung cancer. Bronchoscopy is crucial for making a reliable diagnosis.

K E Y W O R D S
bronchoscopy, carcinoembryonic antigen, foreign body aspiration, lung cancer Here, we present an adult case of bronchial opening obstruction in right upper lobe caused by a rotten vegetable leaf that was firstly misdiagnosed as lung cancer, which proved as foreign body aspiration in the upper lobe bronchus of right lung by bronchoscopy. The aim of this report was to provide clues that may facilitate a reliable diagnosis.

| C A S E REP ORT
In this article, we report an adult case with repeated pulmonary infection within a month firstly misdiagnosed as lung cancer, which confirmed as foreign body aspiration in the right upper lobe bronchus by bronchoscopy. In the absence of obvious incentives, the patient, a 57-year-old man, suffered from recurrent cough, yellow sputum, and occasional hemoptysis accompanied by fever for a month. He presented a history of smoking more than 40 years (about 20 cigarettes per day) with heavy alcohol intake. He received anti-inflammatory treatment without significant relief.
When he was transferred to our hospital for further treatment and admitted in our department, he received laboratory tests and chest CT scan. The physical examination was normal and there was no obvious abnormality in blood routine, while there was an obvious rise in CEA level (17.11 μg/L, normal value <5.0 μg/L). The chest CT scan revealed a cavitation accompanied by multiple small nodular shadows appeared in the right upper lobe field, the right upper lobe bronchus was in poor patency, and multiple mediastinal lymphadenopathies were pointed out during the observation period ( Figure 1A-B). Considering clinical manifestations combined elevated CEA and radiographic findings, lung cancer was highly suspected. Therefore, rigid bronchoscopy was arranged to identify the property of lesion. Bronchoscopy suggested plenty of purulent materials in the bronchial wall of right upper lobe bronchus, of which the opening was completely blocked ( Figure 1C-D). We used biopsy forceps to remove purulent secretion; then, we saw a brown smooth organism completely blocked the right upper lobe bronchus. We repeatedly clamped the new organism, but no tumor cells were seen under rapid on-site evaluation (ROSE). So, we used carbon dioxide instead to freeze the foreign body. Eventually, the new organism was removed and the right upper lobe bronchus was unobstructed; then, we found the new organism was a rotten vegetable leaf ( Figure 1E-F). Hence, the definitive diagnosis was foreign body aspiration in the right upper lobe bronchus. We repeatedly asked the patient whether he ever had choking cough, while he had no history. After the operation, the patient pulmonary infection was under control and CEA level was normal after 2 weeks later (3.10 μg/L).

| D ISCUSS I ON
FB aspiration in adults, accounting for 25% of accidental aspiration cases, while the events mainly occurs in children. Symptoms of adult FB inhalation typically present with a sudden chocking and recurrent cough. 3,4 Due to non-specific symptoms, initial occurrence usually goes unnoticed in elderly patient with altered state of awareness and misdiagnosed other chronic respiratory illnesses, such as COPD and asthma. 4 When the diagnosis was delayed, it may cause severe harms to respiratory passageways, such as suffocation or death. 5 Therefore, the condition often requires early detection and rapid intervention to improve respiratory symptoms and prevent major morbidity.
F I G U R E 1 A-B, Chest CT scan revealed a cavitation accompanied by multiple small nodular shadows appeared in the right upper lobe, the right upper lobe bronchus was in poor patency, and multiple mediastinal lymphadenopathies were seen. C-D, Bronchoscopy suggested plenty of purulent materials in the bronchial wall of right upper lobe bronchus, of which the opening was completely blocked by the new organism. E, The new organism was discovered to be a rotten vegetable leaf. F, The new organism was clamped, and there were only scattered hyperchromatic cells with small nuclei but no tumor cells seen under rapid on-site evaluation (ROSE).
The pathogenesis of the events with aspects varies, including aspiration, ingestion, and purposeful insertion. 6 Owing to the ver- Bronchoscopy designed initially as a safe and efficient tool to assist in removing foreign body. 8 During bronchoscopy, a foreign body perhaps can be seen directly, or appears as tissue reaction characterized by granulation tissue, endobronchial stenosis, and edema. In Sometimes, the FBs could be detected on chest radiographs or CT scans, which usually provide a proper evaluation of the specific shape and location of foreign matter, 9 or reveal indirect signs, including non-dissolving pneumonia, localized bronchiectasis, and atelectasis, especially airway obstruction. 7 Occasionally, on the image studies, lung cancer is poorly differentiated from benign lung disease with nodular shadows. 9 In this case, the patient had no clear history of aspiration; combined with elevated CEA and unsatisfactory therapeutic effects, we highly suspected the cavitation with nodular shadows as neoplastic lesions and linked it to lung cancer. 10,11 However, rigid bronchoscopy was arranged to discover the new organism to be a rotten vegetable leaf completely blocked the right upper lobe bronchus finally. Accordingly, foreign matter may not be identified and they are likely to be mistaken for neoplastic lesions in imaging. 12,13 As a result, identification of FB aspiration should be raised the profile and included in the differential diagnosis, especially for the elderly without a history of inhalation.

| CON CLUS ION
When a patient has repetitive respiratory symptoms combined abnormal changes on laboratory examinations and imaging, physicians should attach importance to if those changes are secondary to possible factors of tracheobronchial stenosis, especially guard against foreign body obstruction and tumor. Bronchoscopy is crucial for making a reliable diagnosis and treatment method.

ACK N OWLED G M ENTS
We thank other members of the Department of Respiratory

Medicine of North China University of Science and Technology
Affiliated Hospital for their critical comments.