Myxoid cysts were first described in 1883 by Hyde as synovial lesions of the skin.1 Known by many different names (the synonyms reflect the different opinions as to their etiology and pathogenesis), they are considered one of the most common pseudotumors of the nail apparatus, occur in a variety of clinical forms, and have a wide range of treatments.2 Clinically, they appear as a 3–10 mm skin-colored to dome-shaped papules on the proximal nail fold of the fingers (occasionally on the toes) on people between the ages of 40–70 years, and more commonly in women than in men.3 Mostly the lesions are solitary, but in some cases more than one digit is affected, and rarely two lesions can be found on the same finger (Figure 14.1).2 They are often asymptomatic, but they sometimes can be painful and cause a reduction in motility, as well as weakness and deformity in the nails.4 Some authors claim that “myxoid pseudocyst” would be a more appropriate name, since histological examination shows that an epithelial lining does not surround the collection of mucinous fluid.