Multiple cutaneous focal mucinosis

Cutaneous focal mucinosis (see cutaneous focal mucinosis, overview below) is a skin disease characterized by the presence of localized deposits of mucin in the dermis. Cutaneous focal mucinosis may present as a single skin lesion (solitary cutaneous focal mucinosis) but may also present with numerous skin lesions (multiple cutaneous focal mucinosis) and is then associated with systemic disease (Kuo KL et al. 2017).

S.a.u. solitary cutaneous focal mucinosis.

In 2016, it was proposed that the terms

• solitary cutaneous focal mucinosis

and

• multiple cutaneous focal mucinosis

to separate solitary cutaneous focal mucinosis from multiple cutaneous focal mucinosis, as the latter is often associated with systemic disease (Kuo KL et al. 2017).

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Multiple cutaneous focal mucinosis is a dermatosis with multiple skin lesions. These are defined by the presence of mucin, a hyaluronic acid complex, in the dermis. The lesions typically present as asymptomatic papules or nodules on the extremities or trunk. Multiple cutaneous focal mucinosis may be idiopathic but may also occur in association with systemic diseases. Associated systemic diseases include Birt-Hogg-Dubé syndrome (Lindor NM et al 2001), systemic scleroderma, scleromyxedema, systemic lupus erythematosus (Wang N et al 2017/nodularcutaneous lupus mucinosis), and thyroid disease(hypothyroidism/Jakubovic HR et al 1982??). This should be noted in this diagnosis (Truhan AP et al.1986; Rongioletti F et al. 2001;Chen HH et al. 2004; Cohen PR et al. 2020).

Adults aged 29 to 60

Extremities, trunk

Clinically, cutaneous focal mucinoses typically present as asymptomatic flesh-colored but also reddish, soft to soft-elastic, flat papules but also nodules (Schneider BV et al. 1991).

The predominant pathologic feature of cutaneous focal mucinosis is unencapsulated mucin, a hyaluronic acid complex, in the upper dermis. It can be visualized as mild basophilic staining on sections stained with hematoxylin and eosin. Although the diagnosis can be made on sections stained with hematoxylin and eosin, stains that detect mucin (such as alcian blue, colloidal iron, and toluidine blue) can be helpful in confirming the diagnosis.

1. Biondo G et al (2019) Clinical, dermoscopic, and histologic aspects of two cases of cutaneous focal mucinosis. An Bras Dermatol 94:334-336.
2. Chen HH et al (2004) A solitary soft fibroma-like polypoid mucinosis: report of an unusual case. Dermatol Surg 30:450-451.
3. Cohen PR et al (2020) Case report and review of solitary cutaneous focal mucinosis: a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases. Dermatol Online J 26:13030/qt33m815p3.
4. Erickson CP et al (2020) Case report and review of solitary cutaneous focal mucinosis: a unique primary cutaneous mucinosis unrelated to mucinosis-associated systemic diseases. Dermatol Online J 26
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6. Jakubovic HR et al (1982) Multiple cutaneous focal mucinoses with hypothyroidism. Ann Intern Med 96:56-58.
7. Johnson WC et al (1966) Cutaneous focal mucinosis. A clinicopathological and histochemical study. Johnson WC, Helwig EB. Arch Dermatol 93:13-20.
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9. Lindor NM et al (2001) Birt-Hogg-Dube syndrome: an autosomal dominant disorder with predisposition to cancers of the kidney, fibrofolliculomas, and focal cutaneous mucinosis. Int J Dermatol 40:653-656.
10. Rongioletti F et al (2001) Cutaneous mucinoses: microscopic criteria for diagnosis. Am J Dermatopathol. 23:257-267.
11. Truhan AP et al (1986) The cutaneous mucinoses. J Am Acad Dermatol14:1-8.
12. Schneider BV et al (1991) Nodular cutaneous mucinosis--an unusual multiple type of euthyroid focal mucinosis. Dermatologica 183:73-76.
13. Verma G et al (2018) Trauma-induced focal nodular mucinoses: a rare entity. Indian Dermatol Online J 9:50-52.

14. Wang N et al (2017) A case report of atypical nodular cutaneous lupus mucinosis. Medicine (Baltimore) 96:e8391.