Ipilimumab-induced hypophysitis: MR findings

A Clark Level IV melanoma of the left thoracic wall metastasizing in axillary lymph nodes, lungs, and brain was treated with Ipilimumab.14 days after an Ipilimumab cycle the patient came with reduced general condition, severe headache, and polyuria.Laboratory examinations revealed low serum levels of fT4, fT3, TSH, testosterone, and DHEAS.An MR examination of the brain and pituitary gland revealed diffuse enlargement of the hypophysis involving the pituitary stalk (Figure 1c,d).A previous MR scan of the brain, done 4 months before, showed at that time a regular-sized and shaped pituitary gland and pituitary stalk (Figure 1a,b).Therefore, the diagnose was acute secondary hypophysitis.After that, the patient was treated with dexamethasone.An MR control 17 days later demonstrated complete remission with normalization of the size, shape, and position of the pituitary gland and stalk (Figure 1e,f).Also laboratory parameters were normalized.Ipilimumab (MDX-010), a human monoclonal antibody, is used for treatment of metastasizing resp.unresectable melanoma [1].Ipilimumab augments the immune response against tumors by overcoming the suppressive effects of cytotoxic T-lymphocyte antigen 4 expression [2].However, this may lead to immune-related side effects,