Association of Remitting Seronegative Symmetrical Synovitis with Pitting Edema, Polymyalgia Rheumatica, and Adenocarcinoma of the Prostate

BACKGROUND Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare condition that occurs in elderly individuals. It can present alone or in association with various rheumatic or malignant diseases. CASE REPORT An 83-year-old man presented with anemia, hyper-sedimentation, and pitting edema of the back of the hands. The patient complained of pain and stiffness of the shoulder and hip girdles, especially in the morning. He was previously diagnosed with adenocarcinoma of the prostate. After 3 years of watchful waiting, treatment with goserelin, a gonadotropin releasing hormone agonist, was started, when PSA had increased to 67.9 µg/l. About 1 year before the cancer treatment, the patient also presented with sore and swollen hands, compatible with RS3PE, which remitted after a few months of prostatic cancer treatment. Thorough laboratory evaluation was performed upon admission to the Rheumatology Department and he was referred for FDG PET/CT on suspicion of metastases of the previously diagnosed prostatic cancer. PET/CT imaging revealed increased FDG uptake in the soft tissues around the shoulders and hips, but no evidence of bone metastasis or other malignant findings. A diagnosis of polymyalgia rheumatica (PMR) together with RS3PE syndrome was made and treatment with prednisolone 15 mg/d was started, which resulted in rapid resolution of the symptoms. CONCLUSIONS Presence of RS3PE in relation with PMR and prostatic cancer in our patient suggests a common trigger factor. To the best of our knowledge, this is the first report of a case of RS3PE that presented twice with 2 different diagnoses in the same patient.