Distal extremity metastases from prostate cancer in a patient with rheumatoid arthritis.

A 71-year-old male patient with longstanding seropositive RA presented for the continuation of therapy with rituximab and MTX. He appeared significantly compromised compared with his usual state of health. He reported increased fatigue, weight loss and bone pain. Laboratory investigations revealed normochromic normocytic anaemia, leucocytopenia, elevated AP and gamma glutamyltransferase, CRP and prostate-specific antigen of 277.4 μg/l. Additional imaging tests and consultations were initiated. The work-up revealed prostate cancer with osseous metastases, and treatment with antiandrogenic therapy was initiated. Despite a decline of prostate-specific antigen, the pain of the wrists and fingers persisted. Ultrasound revealed increased power Doppler activity at the wrist level. Radiographs of the hands performed before (Fig. 1A) the cancer diagnosis showed changes typical of RA, with a carpal predominance; radiographs 1.5 years later showed osseous metastases to the hands (Fig. 1B) and feet (not shown). Distal extremity metastases are very rare but have been reported in lung, skin, bladder, breast and prostate cancer [1, 2]. Osseous metastases to the hand and feet have, to the best of the author's knowledge, not been reported in RA with prostate cancer.

. 1

Conventional radiographs of the right hand

Before (A) and after (B) the diagnosis of metastatic prostate cancer 1.5 years apart. (A) Typical changes of RA are observed, with a predominance of the wrist with ankylosis. (B) Osteoblastic metastases to the distal extremity in a patchy and diffuse distribution. There is an overall decreased bone density.

Funding: No specific funding was received from any funding bodies in the public, commercial or not-for-profit sectors to carry out the work described in this manuscript.

Disclosure statement: The author has declared no conflicts of interest.