A deposit of crystalline uric acid and other substances at the surface of joints or in skin or cartilage, typically as a feature of gout.
- ‘Definite diagnosis can be made by demonstration of the presence of monosodium urate crystals within synovial leukocytes or in material derived from tophi under polarizing microscopy.’
- ‘Four years later, he obtained uric acid from a gouty tophus.’
- ‘Joint damage in hyperuricemia causes classical attacks of gout but tophi may also develop in cartilage, tendons and other tissues.’
- ‘Crystal deposits may also build up under the skin around the joints and behind the ears, causing small lumps known as tophi and, in a few cases, in the kidneys.’
- ‘Only a minority of patients with hyperuricemia develops tophi and gouty arthritis.’
- ‘Less commonly, a septic arthritis of the knee or the big toe can occur in association with gout, particularly when a tophus has ulcerated and become secondarily infected.’
- ‘Chalky deposits called tophi may appear under the skin around joints and in the cartilage of the ears.’
- ‘Patients with long-standing gout may have tophi over the olecranon prominence, first metatarsal joints, or pinnae.’
- ‘If histopathology of a tophus or synovial biopsy suggests gout, fine-needle aspiration may be an alternative for crystal identification and subsequent definitive diagnosis.’
- ‘The slides stained with HE and our method were examined with a light microscope for the presence of urate crystals and diagnostic histologic features of gouty tophus.’
- ‘Diagnosis is by removing fluid from an affected joint or tophus and identifying urate crystals under a polarized-light microscope.’
- ‘One swallow does not make a summer, but one tophus makes gout and one crescent malaria.’
Early 17th century: from Latin, denoting loose porous stones of various kinds.
We take a look at several popular, though confusing, punctuation marks.