Mycobacterium tuberculosis infection of a tophaceous pseudogout nodule.

Musculoskeletal infections are uncommon complications of monosodium urate and calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, and frequently involve gram positive and negative organisms. Tumoral calcinosis (tophaceous pseudogout) is a rare manifestation of CPPD deposition disease. We describe a highly unusual case of an infection by Mycobacterium tuberculosis (TB) of a tophaceous pseudogout nodule in a patient with endstage renal disease.