Baseline 18F-FDG PET and MRI were performed in a patient with IgG4-related hypophysitis, showing a 15-mm hypervascular hypermetabolic lesion with sellar and suprasellar extension. Lack of response after 10 months of first-line corticosteroid therapy was demonstrated on both 18F-FDG PET and MRI. Three months later, after 2 injections of 1 g of rituximab associated with continued corticosteroid therapy, MRI showed substantial shrinkage of the pituitary lesion with minimal residual Gd enhancement, whereas 18F-FDG PET evidenced complete metabolic response. As such, joint 18F-FDG PET and MRI assessment during therapy may have a potential interest for treatment response evaluation in pituitary IgG4-related disease.
From the *Nuclear Medicine Department, Montpellier University Hospital; and
†PhyMedExp, INSERM, CNRS, Montpellier University, Montpellier, France.
Received for publication December 7, 2018; revision accepted January 17, 2019.
Conflicts of interest and sources of funding: none declared.
Correspondence to: Fayçal Ben Bouallègue, MD, PhD, Lapeyronie University Hospital, 371 Av Doyen Giraud, 34090 Montpellier, France. E-mail: email@example.com.