BACKGROUND: Few histologic studies describe the histopathologic aspects of scleromyxedema.
OBJECTIVE: We sought to describe the histopathologic and immunohistochemical features of scleromyxedema in a large series of patients.
METHODS: We studied all the cases with scleromyxedema diagnosed between 2000 and 2014 at participating centers. Sections with hematoxylin-eosin and special stains were examined. Immunohistochemistry for CD3, CD4, CD8, CD20, CD68, and factor XIIIa was performed in 10 cases.
RESULTS: A total of 44 skin biopsy specimens from 34 patients were reviewed. Two different histopathologic patterns were observed: the classic microscopic triad (dermal mucin deposition, fibroblast proliferation, fibrosis) was identified in 34 specimens, whereas an interstitial granuloma annulare-like pattern was found in 10 specimens. A superficial perivascular infiltrate with T lymphocytes was found in all specimens whereas an interstitial proliferation of CD68(+) epithelioid cells was identified in the 10 specimens with an interstitial granuloma annulare-like pattern. Elastic fibers were largely lost, explaining the redundant folds of the disease.
CONCLUSIONS: This was a retrospective study.
CONCLUSIONS: Scleromyxedema shows 2 histopathologic patterns, including the classic type with the microscopic triad of mucin, fibroblast proliferation and fibrosis, and an interstitial granuloma annulare-like pattern. Recognition of these histologic presentations expands the spectrum of scleromyxedema and highlights the difficulty in diagnosing this disabling condition in the absence of a clinicopathological correlation.

BACKGROUND: Cutis laxa-like features were observed in a subset of patients with scleromyxedema. Given this observation, clinical and histopathologic features of scleromyxedema were reviewed in correlation with elastic tissue staining.
METHODS: We retrospectively reviewed clinical records and histopathologic features from patients with scleromyxedema seen at our institution from 1992 through 2013. We also evaluated available skin biopsies with an elastin stain and assessed whether dermal elastin fibers were diminished in density or were fragmented (or both).
RESULTS: Nineteen patients with scleromyxedema and 34 skin biopsies were identified. Alcian blue (mucin) stain was used to grade mucin deposition as weakly positive (24%), positive (44%) and markedly positive (32%). Eight patients (42%) had clinical findings of cutis laxa, which were often observed in conjunction with areas of papular eruption or induration. Elastic tissue fibers were normal in 9 of 34 skin specimens (26%), 18 of 34 specimens (53%) had diminished elastic fiber density and 7 of 34 (21%) had markedly decreased density. The elastic tissue was fragmented in 25 specimens (74%).
CONCLUSIONS: A cutis laxa-like clinical presentation and decreased elastic tissue density on skin biopsy were consistent findings. Dermatologists and dermatopathologists should be aware of these previously unreported clinical and histopathologic findings.