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Metabolic disorders and reticulohistiocytic proliferative disorders
Published in Rashmi Sarkar, Anupam Das, Sumit Sethi, Concise Dermatology, 2021
Cutaneous mucinoses are a class of disorders characterized by the deposition of mucin in the skin. They are primarily divided into two groups: (i) primary cutaneous mucinoses, in which mucin deposition is the main histopathological feature; and (ii) secondary mucinoses, in which mucin deposition is secondary only an additional finding. A classification of cutaneous mucinoses is given in Table 16.4. Lichen myxoedematosus/scleromyxedema is a prototype of idiopathic cutaneous mucinoses and is discussed next.
Other infiltrative conditions
Published in Aimilios Lallas, Enzo Errichetti, Dimitrios Ioannides, Dermoscopy in General Dermatology, 2018
Enzo Errichetti, Aimilios Lallas
Cutaneous mucinoses are a heterogeneous group of disorders that are characterized by an abnormal mucin deposition in the skin.42 Notably, mucin is a jell-like amorphous mixture of acid glycosaminoglycans and is able to absorb 1000 times its own weight in water, thereby making dermal connective tissue significantly edematous when it excessively accumulates.42 Even though mucin may be seen on hematoxylin and eosin stains as a light blue stained material between collagen bundles, it is usually highlighted by using special stains, such as Alcian blue at pH 2.5, colloidal iron, and toluidine blue at pH 4.0.42 Cutaneous mucinoses are divided into two groups, viz. primary (idiopathic) cutaneous mucinoses (in which the mucin deposit is the main histological feature resulting in clinically distinctive lesions) and secondary mucinoses (in which histological mucin deposition is only an additional finding and secondary phenomenon).42 The former group, which is the object of this subchapter, is further divided into dermal and follicular mucinoses, both of them including various subtypes (see Table 11.2).42
Animal Models Of Connective Tissue Diseases
Published in Marcos Rojkind, Connective Tissue in Health and Disease, 2017
Gerald Α. Hegreberg, Lynetta J. Freeman
The primary cutaneous mucinoses are a heterogeneous group of diseases in which a mucinous material accumulates as solitary or multiple, elevated (papular), cutaneous lesions located on the face, trunk, or extremities.139,140 Several clinical variations of the cutaneous mucinoses have been identified, including both generalized and localized forms. The generalized forms include generalized myxedema and a circumscribed or pretibial myxedema form. Both of these generalized forms are commonly associated with altered thyroid metabolism. The myxedema associated with hypothyroidism usually results in a diffuse edema of the skin. Circumscribed or pretibial myxedema is almost always associated with exophthalmic goiter with an associated thyrotoxicosis. Papular mucinosis is a third form of generalized cutaneous mucinosis. The cause of papular mucinosis is unknown, and there is no evidence of an endocrine imbalance, i.e., thyroid disease, in this form. Investigators have reported a monoclonal immunoglobulin in the serum of affected patients, and there is evidence that a serum factor stimulates mucin production in papular mucinosis.141
Nodular localized primary cutaneous amyloidosis and primary Sjögren’s syndrome
Published in Scandinavian Journal of Rheumatology, 2020
K Davies, A Collins, FG Charlton, W-F Ng
Owing to the nature of the skin lesion, a biopsy was taken. Histology revealed extensive stromal deposition of eosinophilic material which stained positively with Congo Red and was ‘apple green’ under polarized light, consistent with amyloidosis (Figure 2). There was no evidence of mucinosis or immunoglobulin G4 disease. She was referred to the National Amyloidosis Centre at the Royal Free Hospital (London, UK) for review, and immunohistochemical staining for serum amyloid A (SAA) protein and kappa and lambda immunoglobulin light chains was negative. A diagnosis of nodular localized primary cutaneous amyloidosis (NLPCA) was made. She was reviewed by the Royal Free Hospital. No immediate treatment was required but surgical intervention remained an option in the future. At the most recent review, the patient reported that the lesion has slightly grown in size (Figure 1).
Isolated intraosseous extra-gnathic orbital myxoma: a clinicopathologic case report
Published in Orbit, 2019
Fairooz P. Manjandavida, Shaifali Chahar, Brijal Dave
In our case, the tumor upon excision and gross examination was diagnosed as myxoid liposarcoma due to the presence of vascularity and bony invasion. Histopathology in combination with IHC helped in the definitive diagnosis. Angiomyxoma predominantly affects the pelvic-perineal region, and histopathologically it shows an abundance of small blood vessels. Also, angiomyxoma occurring in orbit is an extremely rare entity. Literature review reveals only four reported cases of angiomyxoma of the orbit.1,22 Myxoid liposarcoma must contain lipoblasts and complex arborizing or plexiform vascular patterns. Myxofibrosarcoma shows storiform cellular patterns and mixture of plump and spindle cells, infiltrative periphery and sends out long tentacles with frequent positive margins. Benign focal mucinosis contains fibroblastic-appearing cells embedded in a mucinous stroma. Myxolipoma is characterized by mature adipocytes and spindle cells in the myxoid stroma. IHC may be helpful in some cases. Myxomas are immunoreactive to Vimentin, CD34 (50%), SMA (10%), and factor XIIIa. It is negative for Desmin and S100. These markers differentiate myxomas from other varieties mimicking myxoma. In our case, IHC was positive for Vimentin and SMA and negative for S-100.
Advances in understanding and treatment of scleromyxedema
Published in Expert Opinion on Orphan Drugs, 2018
Laura Atzori, Caterina Ferreli, Franco Rongioletti
Scleromyxedema is a rare diffuse/generalized form of primary cutaneous mucinosis of unknown etiology, usually associated with monoclonal gammopathy and systemic complications, but characteristically not related to thyroid diseases [1–4]. In the past, the terms ‘scleromyxedema’, ‘papular mucinosis’, and ‘lichen myxedematosus’ were indiscriminately used as synonyms; however, only the former is a generalized disease, with a completely different prognostic burden in respect to the other localized forms of mucinosis [5]. To avoid further confusion, at least three out of four criteria define the diagnosis of scleromyxedema: (1) generalized papular and sclerodermoid manifestations, (2) evidence of monoclonal gammopathy, (3) typical microscopic findings, and (4) absence of thyroid disease.