Rare Nasal Swelling and Ulceration as Immune-Related Adverse Event from Atezolizumab in SCLC

Overview

A 56-year-old male with extensive-stage small cell lung cancer developed rare immune-related cutaneous adverse events characterized by nasal swelling and ulceration after treatment with atezolizumab. Discontinuation of atezolizumab and administration of glucocorticoids led to significant improvement and near-complete resolution of symptoms.

Background

Atezolizumab, a PD-L1 immune checkpoint inhibitor, is widely used in treating various malignancies including small cell lung cancer (SCLC). While immune-related adverse events (irAEs) are common with immune checkpoint inhibitors, cutaneous irAEs manifesting as nasal ulceration and swelling are extremely rare. Recognizing such rare ircAEs is critical to avoid misdiagnosis and inappropriate management.

Data Highlights

The patient was diagnosed with extensive-stage SCLC in February 2023 and received multiple lines of treatment including atezolizumab combined with chemotherapy and anlotinib. Nasal swelling and ulceration developed in April 2025 after prolonged atezolizumab exposure. Histopathology showed lymphocytic infiltration without evidence of infection or metastasis. After discontinuing atezolizumab and initiating intravenous dexamethasone, nasal lesions improved significantly over two months, with near-complete resolution by December 2025.

Key Findings

• The patient developed nasal swelling, ulceration, and scabbing during maintenance atezolizumab therapy combined with anlotinib.
• Infectious causes and autoimmune diseases were ruled out by negative microbiological tests and antibody profiles.
• Histopathology revealed diffuse lymphocytic infiltration predominantly of CD8+ T cells, with no evidence of metastatic carcinoma or vasculitis.
• Discontinuation of atezolizumab and glucocorticoid treatment led to marked clinical improvement and eventual resolution of nasal lesions.
• No similar cases of nasal ulceration as an ircAE from atezolizumab were found in the literature, highlighting the rarity of this presentation.

Clinical Implications

Clinicians should be aware that immune checkpoint inhibitors like atezolizumab can cause rare cutaneous irAEs such as nasal swelling and ulceration. Early recognition and differentiation from infection, metastasis, or autoimmune disease are essential. Prompt discontinuation of immunotherapy and initiation of glucocorticoids can lead to resolution of symptoms and prevent unnecessary treatments.

Conclusion

This case underscores a unique and rare immune-related cutaneous adverse event involving nasal ulceration caused by atezolizumab in a patient with SCLC. Awareness of such presentations is important for timely diagnosis and effective management.

References

1. Atezolizumab Mechanism and irAEs -- Clinical Context
2. Case Report Qingdao Municipal Hospital 2025 -- Nasal Swelling and Ulceration Following Atezolizumab