Giant Epiglottic Inclusion Cyst

Abstract

Epiglottic inclusion cysts are extremely rare benign laryngeal lesions. A 41-year-old woman suffered from persistent pharyngeal foreign body sensation for one year. Laryngoscopy detected a giant epiglottic cyst, and contrast-enhanced cervical CT showed the typical pedunculated 'apple sign'. Under fiber optic intubation, complete resection was performed by suspension laryngoscopic coblation. Histopathology verified epiglottic inclusion cyst. Pathognomonic apple sign significantly contributes to precise preoperative diagnosis and individualized surgical planning. Transoral plasma resection provides a safe, effective and low recurrence therapeutic option for this rare laryngeal disease.

Significance Statement

Epiglottic inclusion cysts belong to extremely rare laryngeal lesions. This study verifies that the typical apple sign on contrast-enhanced CT acts as a central imaging hallmark for its clinical diagnosis and treatment. Transoral plasma resection performed under suspension laryngoscopy obtains satisfactory clinical outcomes. Our results offer credible imaging references and safe minimally invasive surgical protocols for the standardized management of rare cystic pharyngolaryngeal lesions.

A 41-year-old woman patient presented to the Department of Otorhinolaryngology with a persistent history of foreign body sensation of the pharynx for one year. She reported mild intermittent pharyngeal pain and occasional brief episodes of choking, without manifest dyspnea, fever, chills, cough, sputum production, or dysphagia. Oral intake remained unaffected. The patient had a long-standing dietary habit of eating irritating fried and spicy foods. She denied any history of pharyngolaryngeal trauma or surgery, tobacco or alcohol use, and had no positive family history of similar laryngeal lesions.Flexible fiberoptic laryngoscopy demonstrated a large smooth-surfaced cystic mass with superficial telangiectasis located on the laryngeal surface of the epiglottis. The lesion completely obscured the visualization of the glottis (Figure 1A). The preoperative laboratory examinations, including complete blood count and liver and renal function panels, were all within normal ranges. Serological screening for HIV and syphilis yielded negative results. Contrast-enhanced computed tomography (CT) of the neck revealed a well-circumscribed round isodense lesion measuring approximately 1.4 cm in diameter within the epiglottic region (Figure 1B). The mass was pedunculated and appeared from the left epiglottic margin, exhibiting a characteristic apple-shaped morphological appearance without contrast enhancement. Cervical lymphadenopathy was not identified.

Figure 1.

(A) A large smooth cystic mass with superficial telangiectasis was observed on the laryngeal surface of the epiglottis, which fully blocked the view of the glottis. (B) Axial contrast-enhanced computed tomography (CT) images show that the lesion was attached to the left epiglottic wall, presenting a pedunculated, apple-like morphology, with no enhancement on contrast-enhanced scanning, corresponding to the characteristic “apple sign” (arrows). (C) Histopathology (hematoxylin and eosin staining, ×10) shows fibrous tissue hyperplasia in the cyst wall, lined with simple cuboidal epithelium on the luminal surface, accompanied by squamous metaplasia in some epithelial cells.

After induction of intravenous general anesthesia, fiberoptic guided endotracheal intubation was performed safely. Suspension laryngoscopy confirmed a large epiglottic cyst severely obstructing the distal laryngeal inlet. The cyst wall was incised using a laryngeal microscalpel, leading to immediate decompression after the evacuation of abundant milky white cystic fluid. The entire lesion was radically resected at its pedunculated base using low-temperature radiofrequency plasma ablation.Histopathological examination with hematoxylin-eosin staining showed fibrous proliferation of the cyst wall. The inner cavity was predominantly lined with a simple cuboidal epithelium with focal squamous metaplastic changes (Figure 1C). The final pathological diagnosis was consistent with an epiglottic inclusion cyst. Postoperatively, systematic anti-inflammatory and supportive symptomatic management was administered. A one-month follow-up endoscopy revealed complete mucosal healing at the surgical site, with substantial resolution of all preoperative symptoms.

Inclusion cysts typically arise from congenital developmental defects or traumatic epidermal implantation within subcutaneous soft tissues. These lesions occur most frequently in the head, face, neck, and trunk regions and may occasionally affect the mucosal surfaces of the tongue, lip, and buccal cavity.^1,2 Isolated epiglottic inclusion cysts are extremely rare in clinical practice. In the present case, chronic stimulation from long-term intake of spicy and fried diet was considered a potential contributing factor.

Contrast-enhanced CT serves as a valuable preoperative modality to evaluate the basal attachment of the cyst, the vascularity, and the eradication of suspicious malignant features. The pathognomonic ‘apple sign’ imaging feature accurately delineates the size of the lesion, assesses the compromise of the lower airways, and guides individualized intubation strategies and surgical planning. ³ To avoid emergent tracheotomy, minimize operative trauma, and reduce the risk of catastrophic cyst rupture and asphyxia during blind intubation, ¹ fiberoptic-guided endotracheal intubation under intravenous anesthesia was successfully applied in this patient.^3,4

Complete en bloc resection of both the cyst content and the epithelial lining represents the definitive treatment associated with a negligible risk of recurrence. ¹ The patient and her legal guardians gave their informed written consent for the publication of all relevant clinical data, endoscopic images, and radiological materials.