Cutaneous Focal Mucinosis Presenting as a Vesicle / 대한피부과학회지

ABSTRACT

Cutaneous focal mucinosis is a rare disease which usually manifests itself as a single asymptomatic papule or nodule, but vesicular presentation has only rarely been reported. This condition is one of many mucinoses, including localized lichen myxedematosus, acral persistent papular mucinosis, alopecia mucinosa, follieular mucinosis, and myxoid cysts which present with localized cutaneous lesions. We report a rare vesicular form of cutaneous focal mucinosis in a 42-year-old caucasian male who showed a slowly growing, 0.5 cm-sized, asymptomatic vesicle of one-week duration on his right knee. A histopathological examination revealed a localized accumulation of amorphous basophilic material which was positive on colloidal iron staining at pH 2.5. However, it was negative at pH 0.4 in an alcian blue stain, and negative on colloidal iron staining after treatment with hyaluronidase. The amorphous material was judged to be hyaluronic acid from the results of the above special stains. Proliferation of fibroblasts was also observed. Electron microscopy showed well-develuped endoplasmic reticulum and secretory vesicles in the fibroblasts. The lesion could not be completely removed even after two succesive wide excisions.