Endotracheal sialolipoma: a case report

SESSION TITLE: The Path to the Final Diagnosis SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/11/2023 09:40 am - 10:25 am INTRODUCTION: Sialolipomas are an exceedingly rare cause of tracheobronchial obstruction with only three cases identified in the literature to date. We report an unusual case of a 60-year-old male with an endotracheal sialolipoma. The rarity of such cases and the lack of understanding regarding the aetiopathogenesis of sialolipomas warrants reporting when possible. CASE PRESENTATION: A 60-year-old male with a history of hypertension, dyslipidemia, morbid obesity, and insulin-dependent type 2 diabetes mellitus with vascular complications underwent a screening colonoscopy and was found to have a transverse colon adenocarcinoma. Cancer staging was completed. Computed tomography (CT) scan of the chest revealed a fat density nodule, centered along the left lateral wall of the midthoracic trachea resulting in narrowing of the tracheal lumen (Figure 1). No pathologically enlarged mediastinal or hilar lymph nodes were noted. The patient was subsequently referred to the pulmonary service for further investigation of his endotracheal polyp.On presentation, he was without shortness of breath, cough, wheezing or stridor. There was no change in his symptoms with a change in position. Physical examination showed no relevant findings. The patient is a former smoker (120 pack-year smoking history), quitting in 2008.A fiberoptic bronchoscopy was performed, revealing a large endotracheal tumor 8 centimeters below the vocal cords. The tumor appeared pedunculated, obstructing nearly 60% of the airway, occupying mostly the left lateral wall of the trachea (Figure 2). An electrocautery snare was used to excise the tumor and a cryoprobe was used to provide hemostasis at the base of the tumor.Gross examination showed a 2.0 x 1.3 x 1.0 cm tan-pink polypoid structure. Bisection revealed a yellow lobulated cut surface. A final diagnosis of benign sialolipoma was given. DISCUSSION: Lipomas are the most common benign neoplasms of the human body; however, their presentation in visceral tissue is quite uncommon. Sialolipomas are a distinct variant of theses tumors, which are exceedingly rare, with multiple hypotheses for its aetiopathogenesis [1]. There are only three documented instances of endobronchial sialolipomas (Table 3). We presented a case of an incidental endotracheal sialolipoma. Diagnosis of tracheobronchial tumors is challenging given the fact they are not readily recognized from various other etiologies of airway obstruction, often leading to misdiagnosis. CT imaging functions as an appropriate precursor to determine expected technical difficulties of bronchoscopy such as extraluminal extension [2]. Bronchoscopic resection serves as the first line treatment for these benign airway tumors. Though these tumors are benign, recurrence is possible with malignant transformation; therefore, periodic bronchoscopy is recommended to evaluate the resection stump [3]. CONCLUSIONS: Sialolipomas are an extremely rare cause of tracheal obstruction. Detection can be achieved with CT imaging; however, diagnosis of these rare tumors requires resection and histopathological review. Early recognition and intervention help to avoid its otherwise insidious presentation. Mainstay treatment involves bronchoscopic resection; however, indications for surgical resection must also be reviewed. REFERENCE #1: [1] Nagao T, Sugano I, Ishida Y, et al. Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma. Histopathology. 2001;38(1):30-36. doi:10.1046/j.1365-2559.2001.01054.x REFERENCE #2: [2] Nassiri AH, Dutau H, Breen D, et al. A multicenter retrospective study investigating the role of interventional bronchoscopic techniques in the management of endobronchial lipomas. Respiration. 2008;75(1):79-84. doi:10.1159/000109709 REFERENCE #3: [3] Kajiwara N, Kakihana M, Usuda J, Ohira T, Kawate N, Ikeda N. Interventional management for benign airway tumors in relation to location, size, character and morphology. J Thorac Dis. 2011;3(4):221-230. doi:10.3978/j.issn.2072-1439.2011.04.06 DISCLOSURES: No relevant relationships by Vatche Israbian No relevant relationships by Ankur Sinha No relevant relationships by Sivaprakash Sivaji