Radiological imaging features of the salivary glands in xerostomia induced by an immune checkpoint inhibitor

Abstract

The clinical features of xerostomia induced by immune checkpoint inhibitors (ICI) are similar to those of Sjögren’s syndrome (SS), whereas the immunohistological and serological features are known to differ from those of SS. However, the radiologic imaging features of salivary glands are not yet well known. We report a case of a 56-year-old male patient diagnosed with ICI-induced xerostomia. The patient underwent various imaging examinations to investigate the condition of the salivary glands, which indicated the following: (1) less specific findings on contrast-enhanced computed tomography, (2) mixed with intermediate and low signal intensity on both T1-weighted and fat-suppressed T2-weighted magnetic resonance imaging and poor “salt and pepper” appearance on magnetic resonance sialography, and (3) multiple ovoid hypoechoic areas with hyperechoic bands without acute sialadenitis on ultrasound. These radiologic imaging findings suggested remarkable lymphocyte infiltration, which could be a characteristic of ICI-induced xerostomia.

Oral Immune-Related Adverse Events – Current Concepts and their Management

“…hypothesized that xerostomia associated with ICI therapy is caused by damage to the salivary acini due to lymphocytic infiltration induced by ICI therapy. [ 32 ] Warner et al . also reported diffuse T-lymphocytic infiltration in minor salivary glands in cases of ICI-induced xerostomia.…”