Case report and review of solitary cutaneous focal mucinosis: a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases.

Localized deposition of mucin in the upper dermis is referred to as cutaneous focal mucinosis. Patients with this condition either present with a single skin lesion (solitary cutaneous focal mucinosis) or numerous skin lesions (multiple cutaneous focal mucinosis). A man with solitary cutaneous focal mucinosis is described and the features of this condition are reviewed. Solitary cutaneous focal mucinosis has a slight male predominance and typically presents in adults, ranging in age from 29 years to 60 years, as a nodule or papule that is flesh-colored or white and most commonly located on an extremity or the trunk. Microscopic examination shows deposition of mucin in the upper dermis; the overlying epidermis can be normal, atrophic or hyperplastic. The skin lesion is often removed at the time of biopsy. However, recurrence has not been observed when the mucin deposition is present at the edge of the biopsy or excision specimen. Although the pathogenesis of this condition remains to be established, in contrast to individuals with multiple cutaneous focal mucinosis, solitary cutaneous focal mucinosis is a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases.