Rapid and intense onset of granulation tissue formation following walnut aspiration: a case report

Abstract

Foreign body aspiration can affect individuals of all ages and lead to symptoms such as dyspnea, coughing, and wheezing. Complications may arise from the physical and chemical properties of the aspirated material as well as the duration of retention. This case study reports the early bronchoscopic and pathological findings of a 38-year-old male patient who aspirated walnuts. The patient underwent flexible bronchoscopy 14 h after aspiration, and a piece of walnut was successfully removed from the intermediate bronchus. During the procedure, the bronchial mucosa appeared extremely irregular and yellowish-green in color. Follow-up bronchoscopy one month later revealed regression of the previously observed granulation tissue. This case highlights the importance of early intervention in foreign body aspiration cases, especially with substances that can rapidly and intensely react with mucous membranes such as walnuts.

Background

Foreign body (FB) aspiration is a potentially life-threatening condition that can occur in people of all ages. It is characterized by the aspiration of foreign objects into the respiratory tract and often causes symptoms such as coughing and shortness of breath due to the mechanical effects of the object in the early stages. [1, 2] Prolonged retention of aspirated material in bronchi can lead to the development of complications such as granulation tissue formation, atelectasis, and postobstructive pneumonia due to mechanical obstruction and superimposed infection. The chemical properties of aspirated material can accelerate the development of the expected complications. [3, 4] Early removal of aspirated material via bronchoscopy, even in the absence of symptoms, can halt the progression of damage and reduce the likelihood of complications. In this case report, we present the bronchoscopic and pathological findings of a 38-year-old male patient who developed intense granulation tissue in the bronchus 14 h after walnut aspiration.

Case presentation

A 38-year-old male patient presented to the hospital with complaints of the aspiration of walnuts while eating approximately 11 h prior, followed by dyspnea and chest pressure. He had no history of medical illness or known allergies to walnuts. The patient’s vital signs were stable and localized inspiratory rhonchi were heard under the scapula on the right. The laboratory values and chest X-ray results revealed no abnormalities. Thoracic CT, performed at another hospital prior to admission, was also unremarkable (see Supplementary Figures for the images). On the 14th hour of aspiration, flexible bronchoscopy was performed under conscious sedation via a therapeutic bronchoscope with a 2.8 mm working channel and an alligator jaw grasping forceps, successfully removing a single walnut piece, measuring approximately 7 × 5 × 3 mm, from the intermediate bronchus (Fig. 1). During the procedure, the intermediate bronchial mucosa appeared extremely irregular and yellowish-green in color (Fig. 2). As it was unclear whether the observed changes represented a preexisting endobronchial lesion, mucosal biopsy and lavage were performed. Pathological evaluation revealed “diffuse histiocytes and eosinophil leukocytes, with negative evidence of malignancy”. Lavage was negative for acid-fast bacilli, and cultures showed no growth. Following the procedure, the patient’s symptoms improved. One month later, a repeat flexible bronchoscopy revealed regression of the previously observed granulation tissue, with mild erythema remaining in the affected areas (Fig. 3).

Fig. 1

Walnut pieces extracted with a bronchoscope

Fig. 2

Bronchoscopic appearance of the intermediate bronchus at the 14th hour

Fig. 3

Bronchoscopic appearance of the intermediate bronchus one month later

Discussion

FB aspiration can occur at any age, although it is most common in early childhood and at an advanced age. The items most frequently aspirated are food items such as nuts, chicken bones, and food particles and inorganic materials such as teeth and plastic. The most common symptoms are acute onset cough, dyspnea, stridor, and wheezing. [1, 2] These early mechanical effects can lead to complications such as granulation tissue formation, airway stenosis, atelectasis, pneumonia, and bleeding if the foreign body remains for a long time, depending on the mechanical and chemical properties of the aspirated material. [5, 6] The results of one study revealed that the incidence of granulation tissue formation was 22.7% in patients whose foreign body was removed within three days, but this rate significantly increased to 89.7% in patients whose foreign body was removed after one month or longer [6]. The breakdown products released during the decomposition and decay of organic materials can cause further damage. Yang et al. reported that plastic foreign bodies take months or even years to cause complications, whereas plant-based foreign bodies such as peanuts and walnuts can lead to complications if they are left in place for more than 24 h [7].

Walnuts are common foods that can elicit allergic reactions worldwide [4]. They contain fatty acids, proteins, and carbohydrates, which can cause allergic and nonallergic reactions [4, 8, 9]. A walnut that remains in the bronchus for a long time may cause early granulation tissue formation due to its chemical composition, leading to complications such as airway stenosis, atelectasis, and pneumonia. Mehta et al. observed this condition in three patients with obstructive granulation tissue and airway stenosis as a long-term complication following areca nut aspiration, attributing it to the chemical irritant nature of the nut. They also emphasized that delayed removal of foreign bodies can lead to complications such as airway stenosis that may require intervention [10].

In our patient, granulation tissue formation was detected as early as 14 h after aspiration. This finding highlights that granulation tissue formation in walnut aspiration begins within the first hours, earlier than previously thought, emphasizing the importance of prompt intervention. To reduce the risk of complications, removing the walnut as soon as possible in cases of walnut aspiration is recommended.

FBs can be visible or invisible on radiological exams, depending on their physical and chemical properties. Normal imaging results are obtained in 20% of FB aspirations, so FBs cannot be excluded on the basis of imaging alone [1, 2]. While computed tomography (CT) can be instrumental in locating and identifying foreign bodies, particularly in cases without a clear aspiration history, we recommend avoiding CT as the first-line diagnostic tool in young patients due to radiation concerns unless absolutely necessary.

Although rigid bronchoscopy is accepted as the gold standard for removing FBs, more than 90% of FBs can be successfully removed with flexible bronchoscopy in adults [2]. In cases with a high risk of complications, such as walnut aspiration, and when the time required for rigid bronchoscopy may be prolonged, flexible bronchoscopy may be the primary option to reduce complications.

Conclusion

In this case report, we present a patient who developed granulation tissue formation on the bronchial wall in a much shorter time than expected. To the best of our knowledge, no studies in the literature have reported such early onset of granulation tissue formation. This case highlights the importance of prompt removal of foreign bodies in cases of foreign body aspiration, regardless of the degree of obstruction and respiratory distress caused by the foreign body. This is particularly crucial in cases of aspiration of objects such as walnuts, which have the potential to cause chemical and allergic reactions. Our findings suggest that even a short duration of foreign body presence in the bronchus can lead to early granulation tissue formation and future complications such as atelectasis and pneumonia. Since radiological examinations such as X-ray and CT cannot definitively rule out foreign body aspiration, bronchoscopy should be considered in cases of suspicion.