A 55-year-old man presented to his general physician with pain and swelling of his right great toe. He repoed he has had this pain for approximately 2 days and it is getting worse. He also stated that he had a similar episode of this 4 years ago, but in the interim, he has been symptom free. He was given something for the prior episode, but does not recall the name. He denied trauma, fever, chills or sweats, and has been afebrile. On physical examination, he was afebrile and his right great toe is swollen at the metatarsophalangeal joint. There was decreased range of motion. X-ray films are unrevealing. He had no other joint involvement. A joint aspiration is performed. Which of the following types of crystals in the joint aspirate would confirm the likely diagnosis?
Negatively-birefringent needle-shaped crystals are classically found in the diagnosis of gout. Positively-birefringent rhomboidal crystals are diagnostic for pseudogout, or calcium pyrophosphate crystal deposition. The other choices are not diagnostic or commonly occurring combinations.
Negatively-birefringent needle-shaped crystals.
Negatively-birefringent oval crystals.
Negatively-birefringent rhomboidal shaped crystals.
Positively-birefringent needle-shaped crystals.