A 42-year-old fair-skinned woman requests a full body examination. Her medical history is negative for skin cancer, genodermatoses, and thyroid disease. She underwent lumpectomy for breast cancer 3 years earlier. On examination, scattered nevi and a flesh-colored nodule are noted on her upper back. The lesion is asymptomatic, and the patient is unsure how long it has been present.
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Histopathology revealed homogeneous deposits of mucin within the dermis, which is diagnostic for focal mucinosis. Cutaneous mucinoses are a varied group of connective tissue disorders characterized by accumulation of mucin within the skin or hair follicles.1 They are classified as primary mucinosis or secondary to an associated disease such as malignancy or thyroid disorder. Cutaneous mucinoses may be further subdivided by pattern of distribution: focal, follicular, or diffuse. Females aged 11 to 40 years have the highest prevalence of focal mucinosis,2 which usually presents clinically as either a firm papule or a waxy nodule that may occur anywhere on the body, including the oral mucosa.
The etiology of mucinosis is unknown. It has been hypothesized that fibroblast stimulation mediated by an immune response is the cause of mucin deposition in the more generalized variants of mucinosis,3 and several cases of focal mucinosis have been linked to trauma.4 Surgical excision is the treatment of choice for localized lesions.
Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.
- Truhan AP, Roenigk HH Jr. The cutaneous mucinoses. J Am Acad Dermatol. 1986;14:1-18.
- Cohen PR, Rabinowitz AD, Ruszkowski AM, DeLeo VA. Reticular erythematous mucinosis syndrome: review of the world literature and report of the syndrome in a prepubertal child. Pediatr Dermatol. 1990;7:1-10.
- Rongioletti F, Rebora A. Cutaneous mucinoses: microscopic criteria for diagnosis. Am J Dermatopathol. 2001;23:257-267.
- Kempf W, von Stumberg B, Denisjuk N, Bode B, Rongioletti F. Trauma-induced cutaneous focal mucinosis of the mammary areola: an unusual presentation. Dermatopathology (Basel). 2014;1:24-28.