Dermal mucinosis as a sign of venous insufficiency

Dermal mucinoses are a heterogeneous group of disorders characterized by abnormal deposition of dermal mucin, an amorphous substance composed of hyaluronic acid and sulfated glycosaminoglycans. We describe two cases of dermal mucinosis in the setting of chronic venous insufficiency. Both patients presented with painful, edematous lower extremity plaques. Biopsies of all lesions showed striking dermal mucin deposition, a slight increase in small blood vessel density, slightly thickened vessel walls and no inflammation. Neither patient showed laboratory or clinical findings consistent with a secondary mucinosis such as thyroid dysfunction, lupus erythematosus, dermatomyositis, scleroderma, granuloma annulare, graft‐vs.‐host disease or mucin deposition post‐ultraviolet or photochemotherapy treatment. Both patients were diagnosed with localized cutaneous mucinosis secondary to venous insufficiency. The clinicopathological features of this entity are described, and a pathogenic mechanism is proposed. Pugashetti R, Zedek DC, Seiverling EV, Rajendran P. Berger T. Dermal mucinosis as a sign of venous insufficiency.     

Chronic obesity lymphoedematous mucinosis: three cases of pretibial mucinosis in obese patients with pitting oedema

Pretibial mucin deposition on the shins is known as pretibial myxoedema. We report three patients with pretibial mucinosis without thyroid disease. The patients were characterized clinically by morbid obesity and bilateral lower extremity pitting oedema with gradual and painless onset, and that did not involve the feet and ankles. Vesicles, semitranslucent papules or a woody plaque were found on the shins. Histologically, patients showed characteristic features of epidermal atrophy with effacement of the rete ridge pattern, separation of collagen bundles associated with oedema with stellate to linear fibroblasts, upward-running increased capillary and small vessels with haemosiderin deposition, and mucin deposition at the superficial papillary dermis and around the vessels. We propose that the present cases of 'chronic obesity lymphoedematous mucinosis' belong to the clinical entity of pretibial mucinosis.     

Obesity-associated lymphoedematous mucinosis

Background: Mucin deposition on the shins is considered as an indicator of pretibial myxoedema, which is typically seen in patients with Graves' disease.
Objective: The purpose of this study was to report the clinical and histopathological features of a group of patients with pretibial mucinosis in the absence of thyroid disease.
Methods: Five patients are included in this series and studied both clinically and histologically and compared with similar cases in the literature.
Results: All patients were middle aged or elderly. Four patients were women. They were characterized clinically by morbid obesity and bilateral lower extremity pitting oedema sparing the feet. Semitranslucent papules and/or nodules and sometimes vesicles were found on the shins. Characteristic histological features include (i) hyperorthokeratosis with epidermal atrophy and effacement of the rete ridge pattern, (ii) oedema in the papillary and upper part of the reticular dermis with mucin deposition stained positively with alcian blue and colloidal iron, (iii) angioplasia in the upper part of dermis with upward-running, increased and thickened capillary vessels and (iv) variable fibrosis in the reticular dermis with separation of collagen bundles and increased stellate or linear fibroblasts. A hypocaloric diet was given in two cases, and an important weight loss was observed, which was accompanied by a marked improvement of the pretibial mucinosis.
Conclusions: Pretibial mucinosis is a histological feature associated with morbid obesity and lymphoedematous features of the legs that should be distinguished from true pretibial myxoedema. The term of 'obesity-associated lymphoedematous mucinosis' seems to be appropriate for this condition.     

Cutaneous mucinoses: microscopic criteria for diagnosis

The clinical aspects and the histologic features of cutaneous mucinoses have been reviewed and their classification updated. Cutaneous mucinoses are divided into distinctive (primary) cutaneous mucinoses in which the mucin deposit is the main histologic feature resulting in clinically distinctive lesions, and disorders associated with histologic mucin deposition as an additional finding (secondary mucinoses). The former are further divided into degenerative-inflammatory mucinoses, which may be either dermal or follicular, and into neoplastic-hamartomatous mucinoses.Histopathologic diagnosis is particularly difficult for dermal mucinoses and requires clinicopathologic correlation. Three histologic clues, namely the pattern of mucin distribution (diffuse or focal), the level of mucin deposit in the dermis and some additional findings may help diagnosis. Follicular mucinoses have the easiest pattern to recognize histologically, but the distinction between Pinkus' follicular mucinosis and follicular mucinosis with mycosis fungoides is very difficult.Lastly, neoplastic-hamartomatous cutaneous mucinoses include mucinous nevus, a benign hamartoma, and myxoma, which is a benign tumor to be differentiated from reactive cutaneous focal mucinosis.     

Pretibial mucinosis in a patient without Graves disease

Although an uncommon location, cutaneous mucinoses may present in the pretibial area in distinct clinical circumstances. The terms pretibial myxedema and pretibial mucinosis often are used interchangeably, but pretibial myxedema should be regarded as a type of pretibial mucinosis. We present a case of cutaneous mucinosis localized to the pretibial area of a patient without Graves disease.     

Pretibial mucinosis in an euthyroid patient

A case of exuberant pretibial mucinosis in a patient with normal thyroid function is reported. A review of literature on possible etiologies other than thyroid disease for the accumulation of mucin in the pretibial area is presented. In the patient described, it is possible that vascular insufficiency is involved. However, this is not the only factor responsible for the accumulation of mucin, since there are still unidentified causes and many patients with vascular diseases do not develop similar injuries.     

Lichen myxedematosus: a rare group of cutaneous mucinosis

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.     

Cutaneous mucinosis associated with thyroid dysfunction

An unusual case of pruritic, papular cutaneous mucinosis in conjunction with hypothyroidism is described. Resolution of this disorder followed thyroid hormone supplementation. The various cutaneous mucinoses and the pathogenesis of mucin deposition are reviewed.     

Cutaneous mucinosis associated with dermatomyositis and nephrogenic fibrosing dermopathy: fibroblast hyaluronan synthesis and the effect of patient serum

BACKGROUND: Dermal mucin is an amorphous gelatinous substance composed primarily of hyaluronan (HA) and sulphated glycosaminoglycans (GAGs). In primary cutaneous mucinosis, accumulation of mucin is a characteristic feature of lichen myxoedematosus, scleromyxoedema and reticular erythematous mucinosis. Secondary mucinoses are disorders where mucin deposition is an additional finding, and deposition is associated with lupus erythematosus, dermatomyositis, scleroderma and granuloma annulare. The underlying cause of the abnormal mucin deposition is unknown. An increasing number of cases of a fibromucinous scleromyxoedema-like disorder associated with renal dysfunction, recently termed nephrogenic fibrosing dermopathy (NFD), is being reported. OBJECTIVES: To examine the synthesis of sulphated GAGs and HA by fibroblasts derived from uninvolved and involved skin of a patient with dermatomyositis and two patients with NFD, and the effect of patient serum. METHODS: GAGs were quantified by a radiometric assay and HA was determined by an enzyme-linked HA-binding protein assay. RESULTS: We found that fibroblasts derived from active lesions of NFD synthesize elevated levels of GAGs, and in particular HA, compared with normal controls, while serum from the patient with dermatomyositis and the two patients with NFD stimulates GAG synthesis, including HA synthesis, by both control and patient fibroblasts. CONCLUSIONS: Fibroblasts from patients with active NFD are either activated to synthesize elevated levels of HA or contain another cell type, possibly derived from circulating fibrocytes. In both disorders, there is additionally a serum-derived factor that stimulates production of sulphated GAGs and HA by fibroblasts.     

Cutaneous focal mucinosis: a case report

Cutaneous or dermal mucinoses are a heterogeneous group of connective tissue disorders in which there is an accumulation of mucin in the skin or within the hair follicle. They have a number of different morphologic presentations and can often be confused with other diseases. We report a 12-year-old Chinese girl with a 1-year history of a well-defined, hypopigmented plaque on her chin, consistent with cutaneous focal mucinosis, a rare condition in children.     

Acral persistent papular mucinosis

The case is reported of a 56-year-old man with an unusual papular eruption on the forearms with deposition of mucin in the dermis. The clinical and histopathological features were consistent with acral persistent papular mucinosis, a recently described focal type of cutaneous mucinosis.     

Acral persistent papular mucinosis

Cutaneous mucinoses, also called lichen myxoedematosus, are a group of diseases characterized by mucin deposit on the skin. They may be associated to systemic diseases (scleromyxedema) or be primary ones (papular mucinosis, localized lichen myxoedematous), although they share common findings (intermediate or atypical forms) in some cases. Acral persistent papular mucinosis (APPM) is a type of papular mucinosis that is located exclusively on the back of the hands and in the distal zone of the forearms and is not associated to any systemic disease. We present the case of a 52-year-old healthy woman who had skin lesions on the back of her hands and whose histological study confirmed an APPM.     

The cutaneous mucinoses

The cutaneous mucinoses are a group of connective tissue disorders characterized by the deposition of mucin, either focally or diffusely, in the interstices of the dermis. The diseases may be a primary (metabolic) or secondary (catabolic) process. Systemic abnormalities are seen with most of these disorders. This review discusses the primary mucinoses in which the predominant dermal mucin is hyaluronic acid. Current therapy and proposed mechanisms for the mucinoses are considered.     

Nevoid follicular mucinosis: a new type of hair follicle nevus

Follicular mucinosis represents a term for a histopathologic reaction pattern in follicular epithelium. It is a characteristic of alopecia mucinosa. However, it may also occur in a variety of unrelated conditions. Epidermal nevi are considered to be hamartomatous disorders and they can show a predominant component of non‐organoid (keratinocytes) and/or organoid nevi. All the cases of epidermal nevi described with mucin deposits until now are reported as mucinous nevus or mucinous eccrine nevus; in the first type of disorder, diffuse mucin deposition is only seen in the papillary dermis, and in the second type, the mucin is found around the proliferation of eccrine structures. We believe this is the first reported case of epidermal nevus along Blaschko's lines exhibiting typical microscopic findings of mucinosis exclusively distributed inside the follicular epithelia.     

Acral Ichthyosiform Mucinosis in Association with Sjögren's Syndrome: A Peculiar Form of Pretibial Myxedema?

Two Japanese women developed well-dermarcated ichthyosiform plaques on the lateral aspect of their lower legs. Deposition of mucin was demonstrated throughout the papillary dermis, unlike the site of mucin deposition seen in pretibial myxedema. Their thyroid function was normal. The condition of both women was complicated by Sjögren's syndrome. One of them who presented with positive anti-microsomal and anti-thyroglobulin antibodies had goiter, suggesting that her malady was also complicated by Hashimoto's thyroiditis. Their skin manifestations differed from those described in cutaneous mucinosis including pretibial myxedema, specifically with regard to the well-demarcated ichthyosiform appearance, the mucin deposition in the papillary dermis, and the association with Sjögren's syndrome. To the best of our knowledge, our cases may thus be considered to be a previously undescribed form of cutaneous mucinosis associated with Sjögren's syndrome.     

Discrete papular dermal mucinosis with Hashimoto thyroiditis: a case report

The cutaneous focal mucinoses are a group of connective tissue disorders characterized by deposition of mucin found either focally or diffusely in the dermis. A 47-year-old woman presented with asymptomatic flesh-colored papules on the neck, inguinal area, intergluteal area, vulvar area, and extremities of 5 months' duration. There was no history of preceding trauma or insect bites. The patient had undergone a subtotal thyroidectomy 21 years prior but had not used any thyroid medication before she was referred to our clinic. Thyroid ultrasonography was consistent with Hashimoto thyroiditis. During dermatologic examination, flesh-colored, well-defined, smooth papules that measured approximately 1.5 x 1 cm in size on the genital region, fingers, face, and scalp were seen. Histopathologic examination of a lesional biopsy revealed no abnormalities in the epidermis. Alcian blue staining showed that abundant deposits of dermal mucin had replaced collagen in the dermis.     

Macroscopic and microscopic mucinosis in chronic sclerodermoid graft-versus-host disease

Secondary cutaneous mucinosis is a well-recognized feature of connective tissue diseases such as lupus erythematosus and dermatomyositis. We report the first three cases of dermal mucinosis in association with severe chronic cutaneous graft-versus-host disease of the sclerodermoid variety. One patient had clinical changes due to abundant mucin accumulation within the papillary dermis (mucinoma). In the other two patients histological examination revealed extensive deposits of mucin predominantly within the reticular dermis. The microscopic appearances were striking, with numerous vacuolated spaces interspersed between collagen bundles. We speculate that this appearance is the result of ground substance becoming trapped within grossly sclerodermoid connective tissue.     

Acral persistent papular mucinosis

Acral persistent papular mucinosis is a rare subtype of localized lichen myxedematosus. For half a century, this disease has endured a controversial and constantly evolving classification. We describe a patient who presented with discrete, flesh-colored papules on the hands, wrists, and forearms in a distribution consistent with acral persistent papular mucinosis. Histology was also constant with this disease, showing a well-circumscribed deposition of mucin in the upper and mid dermis that spared a small grenz zone. The changing nomenclature and diagnostic requirements of acral persistent papular mucinosis that have allowed it to remain a topic of debate are examined through a comprehensive review of the literature. All reported cases are reviewed.     

毛囊黏蛋白病

报告1例毛囊黏蛋白病。患者男,33岁。全身泛发红斑伴瘙痒13年余,加重近半年,并出现眉毛脱落。皮损组织病理检查示：真皮毛囊周围炎性细胞浸润。阿新蓝染色阳性,毛囊内可见黏蛋白沉积。诊断为毛囊黏蛋白病。     

Morphea-like cutaneous mucinosis

A whitish, indurated, oval plaque, lasting for 1.5 year, was observed in the right paraumbilical skin of a middle-aged man in otherwise good health. No erythema was present or referred. Histological examination revealed massive deposits of a globular, slightly basophilic, amorphous substance in the dermis, accompanied by a slight perivascular mononuclear cell infiltrate and scattered mast cells. Special staining with Alcian blue at pH 2.5 confirmed the intense deposition of mucin involving the entire dermis. sparing epidermis, adnexa and perivascular areas. No abnormal laboratory results indicating lupus erythematosus or thyroid dysfunction were present. Morphea was excluded on clinical and histological grounds. A plaque-like form of cutaneous mucinosis was diagnosed. Plaque-like mucinosis and reticular erythematous mucinosis (REM) syndrome are currently considered to be the same disease, although some authors noted a different response lo treatment. Clinical presentation of our case was unusual: no erythema preceded or accompanied the plaque growth, which had a whitish, indurated, morphea-like appearance from the beginning but with preservation of hair follicles, quite different from archetypical REM syndrome based on clinical grounds.