An uncommon etiological factor for aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with cerebrospinal fluid rhinorrhea: a case report

(2021) 21:254 Cao et al. BMC Pulm Med https://doi.org/10.1186/s12890-021-01620-5 Open Access CASE REPORT An uncommon etiological factor for aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with cerebrospinal fluid rhinorrhea: a case report Jiayu Cao1†, Wei Liu2†, Li Wang1, Yujuan Yang1, Yu Zhang1* and Xicheng Song1 Abstract Background: Aspiration pneumonitis is an inflammatory disease of the lungs which is difficult to diagnose accurately. Large-volume aspiration of oropharyngeal or gastric contents is essential for the development of aspiration pneumonitis. The role of cerebrospinal fluid (CSF) rhinorrhea is often underestimated as a rare etiological factor for aspiration in the diagnosis process of aspiration pneumonitis. Case presentation: We present a case of a patient with 4 weeks of right-sided watery rhinorrhea accompanied by intermittent postnasal drip and dry cough as the main symptoms. Combined with clinical symptoms, imaging examination of the sinuses, and laboratory examination of nasal secretions, she was initially diagnosed as spontaneous sphenoid sinus meningoencephalocele with CSF rhinorrhea, and intraoperative endoscopic findings and postoperative pathology also confirmed this diagnosis. Her chest computed tomography showed multiple flocculent ground glass density shadows in both lungs on admission. The patient underwent endoscopic resection of meningoencephalocele and repair of skull base defect after she was ruled out of viral pneumonitis. Symptoms of rhinorrhea and dry cough disappeared, and pneumonitis was improved 1 week after surgery and cured 2 months after surgery. Persistent CSF rhinorrhea caused by spontaneous sphenoid sinus meningoencephalocele was eventually found to be a major etiology for aspiration pneumonitis although the absence of typical symptoms and well-defined risk factors for aspiration, such as dysphagia, impaired cough reflex and reflux diseases. Conclusions: We report a rare case of aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with CSF rhinorrhea, which can bring more attention and understanding to the uncommon etiology for aspiration, so as to make more accurate diagnosis of the disease and early surgical treatment. Keywords: Aspiration pneumonitis, Meningoencephalocele, Sphenoid sinus, Etiology, Postnasal drip *Correspondence: † Jiayu Cao and Wei Liu contributed equally to this paper. 1 Department of Otolaryngology‑Head and Neck Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai 264000, China Full list of author information is available at the end of the article Background Aspiration pneumonitis is an infectious disease of the lungs caused by large-volume aspiration of oropharyngeal or upper gastrointestinal contents, which is more likely to occur in patients with risk factors such as impaired swallowing, consciousness, and cough reflex, © The Author(s) 2021. 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The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Cao et al. BMC Pulm Med (2021) 21:254 etc. [1]. However, aspiration pneumonitis is sometimes difficult to diagnose in the first place due to atypical clinical features and uncertain etiology. We described such a case of aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with cerebrospinal fluid (CSF) rhinorrhea. Case presentation A 62-year-old female presented with 4 weeks of rightsided watery rhinorrhea. She reported spontaneous clear, salty nasal drainage without a history of trauma. Two weeks later, she developed a frequent dry cough caused by postnasal drip and gradually worsened especially when lying down, which prevented her from falling asleep. The patient underwent nasal cavity examination and computed tomography (CT) scan of sinuses after visiting department of otolaryngology, and we found a continuous flow of clear fluid to posterior pharyngeal wall (Fig. 1a) and sinus CT showed the lesion tissue extending from the right middle cranial fossa into sphenoid sinus through a local bone defect in the lateral wall of the right sphenoid sinus (Fig. 1b). Combined with measurement of glucose level in nasal secretions (4.4 mmol/L), the patient was initially diagnosed with spontaneous sphenoid sinus meningoencephalocele accompanied by CSF rhinorrhea, and she was admitted to department of otolaryngology -head and neck surgery on June 29, 2020. Chest computed tomography (CT) scan was performed and showed multiple flocculent ground glass density shadows in both lungs after consultation with a respiratory physician, which could not be ruled out as viral pneumonitis. The patient had no epidemiological history related to coronavirus disease 2019 Page 2 of 5 (COVID-19). COVID-19 was ruled out after the results of both oropharyngeal swabs and serum IgM/IgG for COVID-19 were negative. Meanwhile, test results of TORCH (TOX, RV, CMV, HSV), EB virus nucleic acid, and nine respiratory pathogens were all negative and the possibility of the patient suffering from viral pneumonitis was excluded. Meanwhile, she underwent a pulmonary function test that showed normal pulmonary ventilation, and the serum allergen-specific IgE test showed no seasonal allergy. Therefore, we considered preliminarily that pulmonary inflammation might result from chronic aspiration of CSF. The patient underwent endoscopic resection of meningoencephalocele and repair of skull base defect on July 10, 2020. We found a 4 * 5 mm2 bone defect in the lateral wall of the right sphenoid sinus (Fig. 2a), and a free mucosal flap of nasal floor was used to repair the defect. The patient’s dry cough disappeared on the first day after surgery. Pathological diagnosis revealed the resected lesion was brain tissue. Nasal endoscopy showed that the repaired area of the skull base defect healed well 2 months after surgery (Fig. 2b). Compared to preoperative imaging (Fig. 3a), pneumonitis seemed to be still in progressive stage with characteristics of the consolid (...truncated)