Introduction
Immunotherapy checkpoint inhibition (ICI) has heralded dramatic survival advances in many tumour types and its use is increasingly prevalent throughout oncology. Immune-related adverse events (irAE) are being experienced with variable frequency and wide-ranging organ involvement. To our knowledge we describe the first published case of immunotherapy related epiglottitis.
Case
A 75 year old man with extensive stage small cell lung cancer was initiated on carboplatin, etoposide and atezolizumab. Despite radiological response, after 5 cycles he developed a productive cough, with slowly progressive odynophagia and dysphagia over 4 months associated with weight loss of 10kg. After un-impactful courses of antibiotics and antifungals a gastroscopy noted pharyngitis with thick mucus and mid-section oesophagitis. A bronchoscopy failed due to the enlarged and oedematous epiglottis prompting a panendoscopy with microlaryngoscopy which confirmed a thick, erythematous epiglottis with circumferential thickening around aryepiglottic folds. Multiple epiglottic biopsies revealed a heavily inflamed squamous mucosa with ulceration and a dense, mixed subepithelial inflammatory infiltrate with plasma cells, lymphocytes and neutrophils. No evidence of fungal, viral or dysplastic elements were identified. 50mg of oral prednisolone was commenced and led to a significant improvement in cough, mucous production and oral intake within 2 weeks. Symptoms resolved within 6 weeks. Atezolizumab was not re-challenged due to disease progression and the patient subsequently completed 11 cycles of second-line irinotecan before further progression.
Discussion
It is important to consider immunotherapy toxicity in the context of any unexplained symptomatology given the broad spectrum of irAE as its use becomes increasingly commonplace. For patients receiving immunotherapy with unexplained productive cough, odynophagia or dysphagia, a prompt infectious work-up, multi-disciplinary involvement and endoscopy should be considered. Whilst ICI’s most directly expand cytotoxic T cell activity, their impact on the immune system is complex resulting in variability of diagnostic histological pattern.