Endobronchial Hamartoma Misdiagnosed as Pneumonia：A Case ReportLina Peng1, Cuixia Bian1, Ran Gao2, Baowei Sheng11Department of Respiratory and Critical Care Medicine, Jining First People’s Hospital, Jining, Shandong, P.R. China;2Departments of Respiratory Medicine, Jiaxiang People’s Hospital, Jiaxiang, Jining, Shandong, P.R. ChinaCorrespondence: Baowei Sheng (jnrm0726@sina.com)Funding: The authors received no specific funding for this work.Keywords: Endobronchial hamartoma, pulmonary hamartomas, case report, bronchoscopic resection, benign endobronchial tumorABSTRACTEndobronchial hamartoma is a rare benign tumor of the bronchus. We describe a 43-year-old man who has had a cough and fever for two months. Initially, he was misdiagnosed with obstructive pneumonia caused by bronchial sputum thrombus, and repeated treatments with antibiotics and mechanical expectoration were unsuccessful. A bronchoscopy revealed that a mass had completely obstructed the lower lobe of the patient’s left lung. The electrocautery snare technique was employed to fully remove the lesion. Histopathological examination confirmed the diagnosis of hamartoma. This case serves as an important reference for clinical practice to help prevent future misdiagnoses.Introduction With a total incidence rate that ranges from 0.025% to 0.32%, hamartoma is the most prevalent benign tumor [1]. The lung parenchyma is involved in the great majority of pulmonary hamartomas. Roughly 10% of pulmonary hamartomas are bronchial hamartomas, which are extremely uncommon [2]. Clinical signs and symptoms of pulmonary parenchymal hamartoma are frequently subtle. Endobronchial hamartomas can produce respiratory symptoms like coughing, breathing problems, fever, and even hemoptysis because they restrict the airway. Endobronchial hamartoma can be diagnosed using CT scans; however, misdiagnosis is common in clinical practice due to the lack of distinct CT images and specific clinical symptoms associated with bronchial hamartomas. Bronchoscopy is considered the gold standard for diagnosing endobronchial hamartoma. In recent years, various treatment options for endobronchial hamartoma have emerged. In addition to conventional surgical lobectomy, bronchoscopy employs various methods such as cryotherapy, argon plasma coagulation, and electrosurgical snare techniques, which are not only highly effective but also very safe [3]. This article described a case of a middle-aged man who was initially misdiagnosed with obstructive pneumonia due to sputum thrombosis. Despite undergoing repeated treatments over the course of two months, he showed no improvement. It wasn’t until he received bronchoscopic electrosurgical snare that the underlying pathology became clear, and his health began to improve.Case History/ExaminationThe patient is a 43-year-old man with no history of chronic illnesses. He was admitted to the respiratory clinic of our hospital due to a dry cough and fever lasting for two months. Over this period, he experienced recurrent episodes of dry cough and fever, with his body temperature reaching as high as 38.5 ℃. The patient did not report any additional symptoms, such as diarrhea, frequent urination, chest pain, or the common cold. A CT scan conducted at a local hospital revealed obstructive pneumonia and a sputum thrombus in the bronchus of the lower lobe of the left lung.Methods (Differential Diagnosis, Investigations, and Treatment) Based on the patient’s clinical symptoms and the results of the chest CT scan, the local hospital established a preliminary diagnosis of pneumonia and sputum thrombus in the bronchus. For two weeks, patients received mechanically assisted expectoration, antibacterial, and antitussive therapy. Although the patient’s fever and coughing have somewhat subsided, they continue to reoccur. Following admission to our hospital’s respiratory department, a full chest-enhanced CT scan revealed a 1.9 cm × 1.3 cm nodular lesion near the bronchus origin in the left lung’s lower lobe, along with consolidation and atelectasis in the same region (Figure 1). Lung cancer indicators like CEA, CF21-1, NSE, and SCC all show findings that fall within the normal range. We take the patient’s symptoms and imaging findings into consideration when assessing the risk of bronchial masses and foreign bodies. Therefore, a bronchoscopy was done on the patient. During the bronchoscopy, a new organism was discovered that completely blocked the entrance of the left lung’s lower lobe . The organism had a broad base, a smooth surface, and a stalk that was firmly attached to the bronchial opening of the lower lobe. After several treatments using electrocautery snare, a mass approximately 2cm long was successfully removed . There was a significant flow of purulent discharge from the left lung’s lower lobe. Following multiple rounds of aspiration and irrigation, the lumen of the left lung’s lower lobe was cleared (Figure 2).Conclusion and Results (Outcome and Follow-Up) Following the bronchoscopy treatment, the patient’s cough significantly improved and the fever subsided. Pathological examination confirmed that the removed mass was a hamartoma. His follow-up chest CT was evaluated a week after the procedure, it showed that the left lower lung had re-expanded, and the airways in the lower lobe were unobstructed (Figure 3). The patient’s hospital discharge went smoothly, and he is currently undergoing routine chest CT follow-ups at our hospital’s outpatient department. Fortunately, there has been no recurrence of the hamartoma.DiscussionIn clinical practice, benign endobronchial tumors are incredibly uncommon. About 39% of benign endobronchial tumors are hamartomas (11/28) [4]. Hamartomas in histological pathology frequently exhibit a combination of several different components. Typically, endobronchial hamartomas show fibroblasts, fat, and cartilage [5]. The detection rate of rare endobronchial hamartomas has grown recently due to the ongoing advancements in bronchoscopy, and doctors must pay close attention to their diagnosis and treatment.Pneumonia symptoms, such as fever, coughing, and dyspnea, can often be caused by endobronchial hamartomas. These lesions typically present as space-occupying masses in the soft tissues of the bronchi on imaging studies and can lead to atelectasis [6]. On CT scans, these lesions usually appear spherical or nearly circular, with calcifications resembling popcorn and fat density [7]. In this case, the patient is experiencing a chronic cough and fever. The CT scan of the lesion in the left lower lung’s bronchus did not show the typical signs of hamartomas, such as fat density or popcorn-like calcification. Instead, the scan indicated that sputum was obstructing the left lower lung’s bronchus. Initially, this condition was misdiagnosed as pneumonia and bronchial sputum thrombus. After more than two months of unsatisfactory treatment, a thorough bronchoscopy examination confirmed the diagnosis.This case highlights two important insights: First, when encountering similar cases in clinical practice, we should consider rare disorders like bronchial hamartoma to avoid missed or incorrect diagnoses. Second, despite the associated risks, bronchoscopy should be performed proactively and discussed thoroughly with patients.Both surgical and endoscopic procedures are used to treat endobronchial hamartomas. Abdel Hady [8] et al. compared the advantages and disadvantages of surgical resection versus bronchoscopic resection for these tumors. Their findings showed that bronchoscopic resection had favorable outcomes with fewer complications and eliminated the need for lung resection. As a result, endoscopic treatment is considered the preferred approach for endobronchial hamartomas. According to Song et al., the treatment outcomes were favorable, and there were no treatment-related complications, such as major hemoptysis, airway perforation, or hypoxia, among the 13 patients with endobronchial hamartomas who were treated using bronchoscopic intervention [3]. Several methods, including cryosurgery [9], laser and microwave ablation [10], and electrocautery snare [11] under bronchoscopy, can be used to remove airway tumors. In conclusion, depending on the lesion’s location, size, and shape, we can select the best endoscopic treatment option. In this case, the microscopic findings of the patient reveal a smooth, pedunculated tumor that completely obstructed the lower lobe of the left lung. The use of an endoscopic electrocautery snare was appropriate for this situation. There were no visible bleeding issues, and after several treatments with the endoscopic electrocautery snare, the lesion was fully removed. A follow-up CT scan showed that the airway was unobstructed, atelectasis had significantly improved, and the patient’s symptoms had markedly lessened. According to the patient’s follow-up, there has been no recurrence of the tumor. These results support previous research, confirming that bronchoscopy is a safe and effective treatment option for managing endobronchial hamartoma, with a favorable prognosis.Conclusion The clinical incidence of endobronchial hamartoma is quite low, and its clinical symptoms and imaging findings are often nonspecific. This can lead to misdiagnosis and missed diagnoses in clinical practice. However, early diagnosis and prompt treatment can significantly enhance the prognosis. This case serves as an important reference for the diagnosis and management of endobronchial hamartoma.Author ContributionsLina Peng: investigation, writing-original draft. Cuixia Bian: supervision, writing-review and editing. Ran Gao: collect resources, writing-original draft. Baowei Sheng: data curation, writing-review and editing.AcknowledgmentsThe authors are grateful to the patient and his family for their valuable support in the preparation of this manuscript.ConsentWritten consent from the patient was taken.Conflicts of InterestThe authors declare no conflicts of interest.Data Availability StatementData sharing is not applicable to this article as no datasets were generated or analyzed during the current study.References1. Abu Omar M, Abu Ghanimeh M, Tylski E, et al. Endobronchial hamartoma: a rare disease with more common presentation. 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Endobronchial chondroid hamartoma of left main bronchus and its bronchoscopic management.Lung India . 2023;40(3):282-284. doi:10.4103/lungindia.lungindia_547_22Figure 1: Chest-enhanced CT scan revealing a 1.9 cm × 1.3 cm nodular lesion causing consolidation and atelectasis of the left lower lobe. (1a) Lung window. (1b) Mediastinal window. Figure 2: Bronchoscopy electrocautery snare treatment. (2a) A smooth mass completely blocking the lower lobe of the left lung. (2b) Electrocautery snare treatment. (3c) The unobstructed lower lobe of the left lung after treatment. (3d) The removed mass. Figure 3: The follow-up chest CT showing the airways unobstructed and the left lower lung re-expanded. (3a) Lung window. (3b) Mediastinal window.