Self-healing Cutaneous Mucinosis in Adulthood: The Adult Counterpart of the Juvenile Variant of the Disease?

Self healing cutaneous mucinosis (SHCM) is an idiopathic localized cutaneous mucinosis mainly described in children and characterized clinically by an acute onset of papules and nodules that exhibit a spontaneous resolution in a period ranging from weeks to few months. Histologically, a diffuse mucin deposition in the dermis and/or hypodermis associated with a proliferation of spindleshaped cells and some large epithelioid gangliocyte-like mononuclear cells is usually observed. An uncommon adult variant of SHCM has also been reported; however, the clinicopathological features described in these patients are extremely heterogeneous and differ significantly from the juvenile variant of the disease, often showing exclusively dermal involvement. We report a case of a 37-year-old female patient with multiple asymptomatic nodules located on the legs and arrns that resolved spontaneously in a period of 2 years, showing the typical subcutaneous features of the juvenile variant of SI ICM at the histological examination (ie, mucinous areas associated with dense bands of fibrosis containing arborizing thin-walled vessels, spindle-shaped fibroblasts, and some gangliocytelike cells). To the best of our knowledge, this is the first report of SHCM showing the classic pattern of deep-seated subcutaneous involvement of the disease in an adult patient. We also review the cases of adult-onset SHCM reported in the literature.