Lichen myxedematosus (LM) is a chronic cutaneous mucinosis that can present as a localized skin lesion or as a generalized systemic disease termed scleromyxedema. The differential diagnosis is determined by a combination of clinical presentation, serological studies, and histopathological examination. Currently, well-established and accepted histopathological features to distinguish localized LM from scleromyxedema have not been elucidated. Our recent publication, together with a retrospective literature review, suggests that the presence of groups of light chain-restricted plasma cells represents a distinct histopathological clue for the diagnosis of localized LM. In this report, we provide two additional cases of localized LM with lambda light chain-restricted plasma cells, together with clinical and histopathological findings that are similar to our previous publication. These cases support our theory that the light chain-restricted plasmacytic microenvironment is primarily attributed to the pathogenesis of localized LM. Therefore, we consider these cases to constitute a clinically and pathologically new variant of localized LM and name it primary localized cutaneous LM with light chain-restricted plasma cells.

Lichen myxedematosus (LM) is an idiopathic cutaneous mucinosis disorder, and monoclonal gammopathy of undetermined significance (MGUS) is a preneoplastic plasma cell disease with a monoclonal increase in globulin. Patients with LM combined with monoclonal gammopathy are normally diagnosed with scleromyxedema. However, we report a case of generalized papules combined with MGUS in a 78-year-old man who was eventually diagnosed with atypical or intermediate forms of LM because it only involved the skin, and the pathological type was not consistent with scleromyxedema. Few cases of atypical or intermediate forms of LM have been reported, so the course of atypical or intermediate forms of LM is unpredictable. We report the diagnosis and treatment of a case of atypical forms of LM to discuss the current understanding of the disease, hoping to provide a reference for clinical research on this disease.

Scleromyxedema is an uncommon and progressive fibromucinous disorder characterized by disseminated papular eruption with histological features of dermal mucin deposition. The skin changes associated with this disease are highly visible and they tend to affect the patient\'s quality of life. We report a case of a 50-year-old male patient that presented a 3-year-old history of disseminated asymptomatic firm papules-associated systemic symptoms. Medical treatment with oral corticosteroid and thalidomide was indicated and surgical treatment on residual facial folds was performed, with an excellent outcome.

Localized lichen myxedematosus (LM) is a rare, idiopathic mucinosis characterized by dermal mucin deposition and variable fibroblast proliferation. Nodular lichen myxedematosus, a clinicopathologic subtype of localized LM, is exceedingly rare in pediatric patients with only three prior cases reported. Understanding of LM in pediatric patients is limited by the rarity of the disease, and diagnosis is complicated by overlapping clinical and histopathologic features. There is no standardized treatment for localized LM and treatment is largely dictated by a patient\'s desire to minimize cosmetic disfigurement. This case series reports two additional patients with juvenile nodular lichen myxedematosus, highlights the limitations of existing diagnostic criteria, and describes successful treatment of one patient with intralesional triamcinolone.

暂无摘要。

Scleromyxedema is regarded as a rare cutaneous mucinosis from a group of lichen myxedematosus characterized by diffuse mucin deposition, sclerosis, and lichenoid eruptions in the absence of thyroid disease. The paper discusses the pathogenesis of the disease and histological changes in tissues. It underlines the need for using histochemical tests to identify acidic and neutral glycosaminoglycans and gives a differential diagnosis of this disease.
Склеромикседема рассматривается как редкий муциноз кожи из группы микседематозного лихена, характеризующийся диффузным отложением муцина, склерозом и лихеноидными высыпаниями при отсутствии патологии щитовидной железы. Обсуждаются вопросы патогенеза заболевания и гистологические изменения в тканях. Подчеркивается необходимость использования гистохимических реакций для выявления кислых и нейтральных гликозаминогликанов. Приведена дифференциальная диагностика этого заболевания.

Lichen myxedematosus is an idiopathic, cutaneous mucinosis with 2 clinicopathologic subsets. There is the generalised papular and sclerodermoid form, more properly termed scleromyxedema, and the localised papular form. We report the first case, to our knowledge, of lichen myxedematosus in association with rheumatoid arthritis as well as a case in association with dermatomyositis. An up-to-date literature review on cutaneous mucinoses and connective tissue diseases, excluding the common association of primary and secondary mucinoses with systemic lupus erythematosus, was also performed.

A 41-year-old man was referred to our outpatient department with a diagnosis of urticaria with angioedema of 3 months duration. On examination, he had generalized coalescent waxy papules and diffuse periorbital swelling. Systemic examination was unremarkable except for limited finger flexion. Serum electrophoresis and thyroid function tests were normal. Histopathological examination showed normal epidermis and intradermal mucin deposition, which was diagnostic of lichen myxedematosus (LM). The patient showed prompt response to melphalan. Here, we report this case of atypical LM because the patient had generalized eruption with normal thyroid function along with the absence of monoclonal gammopathy.

暂无摘要。

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.