A cyst is a smooth, dome-shaped nodule containing keratin, whereas calcinosis cutis lesions are hard, irregular, and may extrude chalky white calcium.
These are yellowish papules that appear suddenly in the context of hyperlipidemia, a different color and metabolic association than the stony-hard lesions of calcinosis.
Tophi are also deposits, but they are composed of uric acid crystals, often found over joints, and are associated with a history of gout.
These are tiny, superficial, white keratin cysts, much smaller and less hard than the subcutaneous, rock-like nodules of calcinosis cutis.
A neurofibroma is a soft, fleshy, skin-colored papule that can often be invaginated into the skin with pressure (the "buttonhole" sign), unlike the hard nature of calcinosis.
These are multiple cysts containing oily, yellowish fluid, and are softer and more cystic on palpation than the hard deposits of calcinosis.
These are small, benign sweat duct tumors, typically appearing as flat-topped papules around the eyes, a different location and softer consistency.
These are lipid-filled papules or nodules with a characteristic yellowish color, unlike the whitish, stony-hard deposits of calcinosis cutis.
