Lichen myxedematosus: a rare group of cutaneous mucinosis

Abstract: Cutaneous mucinoses are a heterogeneous group of dermatoses in which excess deposition of mucin in the dermis gives the skin a waxy appearance, with papules and plaques that can vary from self-healing mucinosis to even disrupting the normal shape of a patient's face, conferring a leonine facies, or be part of life threatening diseases like scleromyxedema. This review will describe the most recent classification on lichen myxedematosus in the generalized (scleromyxedema) and the localized forms, as well as the different organ systems involved in scleromyxedema, diagnostic workup, current management, and prognosis.

Case for diagnosis. Lichen myxedematosus

Abstract Scleromyxedema or lichen myxedematosus is a rare papular mucinosis of chronic and progressive course and unknown etiology. It is commonly associated with monoclonal gammopathy and may show extracutaneous manifestations, affecting the heart, lung, kidney, and nerves. The diagnosis is based on four criteria: generalized papular and sclerodermoid lesions; mucin deposition, fibroblast proliferation, and fibrosis in the histopathology; monoclonal gammopathy; and no thyroid disorders. This article reports the case of a scleromyxedema patient with a recent history of acute myocardial infarction and monoclonal gammopathy.

Acral papular mucinosis: a new case of this rare entity

Abstract Acral persistent papular mucinosis (APPM) is a rare subtype of localized lichen myxedematosus. It consists of small papules localized exclusively on the back of the hands, wrists and extensor aspects of distal forearms with no other clinical or laboratory manifestations. The lesions tend to persist and may increase slowly in number. Histologically, hematoxylin-eosin and Alcian blue staining demonstrate mucin accumulation in the upper reticular dermis with separation of collagen fibers as a result of hyaluronic acid deposition. Treatment is rarely necessary due to the absence of symptoms. We present a 27-year-old healthy woman with asymptomatic papules on her upper extremities, which adequately meet clinical and pathological criteria of acral papular mucinosis.

Scleromyxedema: clinical diagnosis and autopsy findings

Abstract Scleromyxedema is a rare chronic cutaneous mucinosis of unknown etiology. It is characterized by papular eruption and scleroderma with microscopic evidence of mucin deposition, fibroblast proliferation, and fibrosis. Most patients with scleromyxedema have monoclonal gammopathy and systemic manifestations resulting in significant morbidity and mortality. Several types of treatment have been reported with partial or inconsistent responses. Despite showing unpredictable evolution, systemic consequences of scleromyxedema and treatment side effects may result in death. We describe a rare case of a patient with scleromyxedema without paraproteinemia with systemic involvement that evolved to death despite treatment with cyclophosphamide.

Mucinose papulosa associada ao hipotireoidismo / Papular mucinosis associated with hypothyroidism

A mucinose papulosa ou líquen mixedematoso é doença idiopática, manifestada por pápulas, nódulos ou placas por depósito de mucina na derme, na ausência de doença tireoidiana. Apresentamos um caso atípico, com lesões exuberantes em placas, associado ao hipotireoidismo subclínico. Nas mucinoses cutâneas há quantidade anormal de mucina na pele. Tradicionalmente as classificações consideram critério diagnóstico para mucinose papulosa a ausência de doença tireoidiana. Poucos casos associados ao hipotireoidismo são descritos e, assim como o nosso, constituem líquen mixedematoso atípico, sugerindo que a presença de doença tireoidiana não deva ser critério de exclusão para essa doença.

Papular mucinosis or lichen myxedematosus is an idiopathic disorder characterized by papules, nodules or plaques caused by mucin deposition in the dermis, in the absence of thyroid disease. The present report describes an atypical case with exuberant lesions in the form of plaques, associated with subclinical hypothyroidism. In cutaneous mucinosis, there is an abnormal quantity of mucin in the dermis. In traditional classifications of papular mucinosis, an absence of thyroid disease constitutes a diagnostic criterion. A few cases of the disease have been reported in association with hypothyroidism constituting, as in the present case, atypical lichen myxedematosus. It is therefore suggested that the presence of thyroid disease should not be considered an exclusion criterion for the diagnosis of this condition.