“Tophus” is the pathognomonic lesion of which of the following condition:
Tophi are pathognomonic of gout. They are formed by large aggregations of urate crystals. The urate crystals are surrounded by
a. Macrophages
b. Lymphocytes
c. Large foreign body giant cells

They are seen in them.

a. Articular cartilages of joints *
b. Periarticular ligaments*
c. Tendons and soft tissues*
d. Achilles tendon*
e. Earlobes*

Also, remember these very important points related to Gout-
Hyperuricemia is present in approximately 5% of individuals. Most of them are asymptomatic with regard to their hyperuricemia and are at no clinical risk.
The most recognized complication of Hyperuricemia is Gouty arthritis. The higher the serum level of urate the more likely an individual is to develop Gout.
Acute attack of gout occurs without any precipitating cause or may occur following rapid fluctuations in serum urate levels.
Most common joint involved in Gout is Big toe (First metatarsophalangeal)
Diagnosis of Gout- - By observing monosodium urate crystals in polarized light. These are needle-shaped* and strongly negative birefringent crystal
Multiple myeloma
Cystinosis
Gout
Eales disease