A study of 14 patients with focal mucinosis revealed the usual clinical features—a solitary, asymptomatic, flesh-colored to white papule or nodule. The pathologic changes consisted of fibroblastic proliferation in the corium, an increased production of hyaluronic acid by these fibroblasts and an associated decrease or absence of reticulum and collagen formation. Hyaluronic acid accumulates between the collagen fibers, eventually replaces most of the collagen, and occasionally results in formation of small cystic spaces. The pathogenesis of focal mucinosis is similar to that of myxoid cysts of the fingers and toes, and minor variations may be related to the anatomical differences of the involved sites. Similarities to and differences from other cutaneous mucinoses and myxomas are discussed. The lesions did not recur after simple surgical excision, and this appears to be the treatment of choice.
JOHNSON WC, HELWIG EB. Cutaneous Focal MucinosisA Clinicopathological and Histochemical Study. Arch Dermatol. 1966;93(1):13-20. doi:10.1001/archderm.1966.01600190019003