Skin nontumor
Dermal collagen and elastic tissue alterations and metabolic disorders
Pretibial myxedema
Last author update: 1 August 2011
Last staff update: 21 February 2024
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PubMed Search: Myxedema [title] skin
Table of Contents
Definition / general | Clinical features | Case reports | Treatment | Microscopic (histologic) description | Positive stains | Negative stains | Additional referencesCite this page: Hamodat M. Pretibial myxedema. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumormyxedema.html. Accessed April 25th, 2024.
Definition / general
- Thick, dry, and waxy skin due to accumulation of mucopolysaccharides in dermis; similar to that in orbital tissues, caused by excess TSH secretion or hypothyroidism
- Often in pretibial skin
- Localized or generalized
- Elephantiasis: extreme disease
Clinical features
- Pink, yellow and waxy plaques and nodules on the anterolateral aspect of leg
- Indurations with prominence of follicles giving rise to peau d’orange appearance and secondary hypertrichosis is occasionally marked
- Asymptomatic or mildly pruritic
Case reports
- 75 year old woman with Graves disease (eScholarship)
Treatment
- Self limiting
Microscopic (histologic) description
- Epidermis is hyperkeratotic with follicular plugging and may be papillomatous and acanthotic
- Dermis shows separation of collagen bundles by large quantities of mucin
- Satellite fibroblasts are evident, but no increase in numbers except in elephantiasis form
Positive stains
- Mucicarmine, Hale colloidal iron, PAS+ diastase resistant
Negative stains
- Direct immunofluorescence is usually negative, although granular deposits of IgM have been identified
Additional references
