Cao et al. BMC Pulm Med (2021) 21:254 https://doi.org/10.1186/s12890-021-01620-5 CASE REPORT Open Access An uncommon etiological factor for aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with cerebrospinal fuid rhinorrhea: a case report Jiayu Cao1†, Wei Liu2†, Li Wang1, Yujuan Yang1, Yu Zhang1* and Xicheng Song1 Abstract Background: Aspiration pneumonitis is an infammatory disease of the lungs which is difcult to diagnose accu- rately. Large-volume aspiration of oropharyngeal or gastric contents is essential for the development of aspiration pneumonitis. The role of cerebrospinal fuid (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 exami- nation of the sinuses, and laboratory examination of nasal secretions, she was initially diagnosed as spontaneous sphenoid sinus meningoencephalocele with CSF rhinorrhea, and intraoperative endoscopic fndings and postopera- tive pathology also confrmed this diagnosis. Her chest computed tomography showed multiple focculent ground glass density shadows in both lungs on admission. The patient underwent endoscopic resection of meningoenceph- alocele 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-defned risk factors for aspira- tion, such as dysphagia, impaired cough refex and refux diseases. Conclusions: We report a rare case of aspiration pneumonitis caused by spontaneous sphenoid sinus meningoen- cephalocele 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 Background Aspiration pneumonitis is an infectious disease of the *Correspondence: [email protected] lungs caused by large-volume aspiration of oropharyn- †Jiayu Cao and Wei Liu contributed equally to this paper. geal or upper gastrointestinal contents, which is more 1 Department of Otolaryngology-Head and Neck Surgery, Yantai likely to occur in patients with risk factors such as Yuhuangding Hospital, Qingdao University, Yantai 264000, China Full list of author information is available at the end of the article impaired swallowing, consciousness, and cough refex, © The Author(s) 2021. 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The Creative Commons Public Domain Dedication waiver (http:// creat iveco mmons. org/ publi cdoma in/ 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 Page 2 of 5 etc. [1]. However, aspiration pneumonitis is sometimes (COVID-19). COVID-19 was ruled out after the results difcult to diagnose in the frst place due to atypical clini- of both oropharyngeal swabs and serum IgM/IgG for cal features and uncertain etiology. We described such a COVID-19 were negative. Meanwhile, test results of case of aspiration pneumonitis caused by spontaneous TORCH (TOX, RV, CMV, HSV), EB virus nucleic acid, sphenoid sinus meningoencephalocele with cerebrospi- and nine respiratory pathogens were all negative and nal fuid (CSF) rhinorrhea. the possibility of the patient sufering from viral pneu- monitis was excluded. Meanwhile, she underwent a Case presentation pulmonary function test that showed normal pulmo- A 62-year-old female presented with 4 weeks of right- nary ventilation, and the serum allergen-specifc IgE sided watery rhinorrhea. She reported spontaneous test showed no seasonal allergy. Terefore, we consid- clear, salty nasal drainage without a history of trauma. ered preliminarily that pulmonary infammation might Two weeks later, she developed a frequent dry cough result from chronic aspiration of CSF. Te patient caused by postnasal drip and gradually worsened espe- underwent endoscopic resection of meningoencepha- cially when lying down, which prevented her from falling locele and repair of skull base defect on July 10, 2020. asleep. Te patient underwent nasal cavity examination We found a 4 * 5 mm2 bone defect in the lateral wall of and computed tomography (CT) scan of sinuses after vis- the right sphenoid sinus (Fig. 2a), and a free mucosal iting department of otolaryngology, and we found a con- fap of nasal foor was used to repair the defect. Te tinuous fow of clear fuid to posterior pharyngeal wall patient’s dry cough disappeared on the frst day after (Fig. 1a) and sinus CT showed the lesion tissue extending surgery. Pathological diagnosis revealed the resected from the right middle cranial fossa into sphenoid sinus lesion was brain tissue. Nasal endoscopy showed that through a local bone defect in the lateral wall of the right the repaired area of the skull base defect healed well sphenoid sinus (Fig. 1b). Combined with measurement of 2 months after surgery (Fig. 2b). Compared to preoper- glucose level in nasal secretions (4.4 mmol/L), the patient ative imaging (Fig. 3a), pneumonitis seemed to be still was initially diagnosed with spontaneous sphenoid sinus in progressive stage with characteristics of the consoli- meningoencephalocele accompanied by CSF rhinorrhea, dation lesion with a mini cavity in the right lung 1 week and she was admitted to department of otolaryngology after surgery although parts of multiple focculent -head and neck surgery on June 29, 2020. ground glass density shadows were gone (Fig. 3b). Te Chest computed tomography (CT) scan was per- lesion disappeared completely 2 months after surgery formed and showed multiple focculent ground glass (Fig. 3c). Infection-related infammatory indexes, such density shadows in both lungs after consultation with as c-reactive protein (CRP), white blood cells (WBC), a respiratory physician, which could not be ruled and neutrophils were completely improved 1 week after out as viral pneumonitis. Te patient had no epide- surgery (Fig. 4). miological history related to coronavirus disease 2019 Fig. 1 Preoperative endoscopy image and sinus computed tomography (CT) scan. a Preoperative endoscopy image. The blue arrow indicates the persistent fow of cerebrospinal fuid (CSF) backwards into the right posterior nostril. b Sinus CT scan. The black arrow indicates the place of lesion tissue protruding into right sphenoid sinus Cao et al. BMC Pulm Med (2021) 21:254 Page 3 of 5 Fig. 2 Endoscopy images. a Intraoperative endoscopy image. The blue arrow points to the lesion tissue and skull base defect in the lateral wall of the right sphenoid sinus. b Endoscopy image 2 months after surgery. The black arrow indicates repaired area of the skull base defect Fig. 3 Chest CT images. a Preoperative chest CT image. b Chest CT image 1 week after surgery. c Chest CT image 2 months after surgery Fig. 4 Changes of infection-related infammatory indexes such as white blood cells (WBC), neutrophils and c-reactive protein (CRP) after surgery Discussion and conclusions compared to those with non-aspiration pneumonitis [4]. Aspiration pneumonitis accounts for 5–24% of com- Terefore, it is very important to fnd out relevant etio- munity-acquired pneumonitis and about 5–15% of hos- logical factors for aspiration in time for early diagnosis pitalized pneumonitis [2, 3]. A meta-analysis showed and treatment of aspiration pneumonitis. that in-hospital and 30-day mortality was signifcantly Te patient was not initially diagnosed with aspira- increased in patients with aspiration pneumonitis tion pneumonitis. One of the main reasons was similar Cao et al. BMC Pulm Med (2021) 21:254 Page 4 of 5 clinical symptoms and chest CT imaging features with Although uncommon, spontaneous sphenoid sinus viral pneumonitis. Runny nose and dry cough, as com- meningoencephalocele with CSF rhinorrhea is an etio- mon symptoms of respiratory tract infection, did not logical factor for macroaspiration. Timely endoscopic cause enough attention of the patient at the begin- lesion resection and repair of skull base defect can efec- ning. Most of the imaging fndings of viral pneumoni- tively avoid large-volume aspiration and make aspiration tis, including COVID-19, are manifested as multiple