A cutaneous myxoma, or superficial angiomyxoma, consists of a multilobulated myxoid mass containing stellate or spindled

fibroblasts A fibroblast is a type of biological cell typically with a spindle shape that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibrobla ...

with pools of

mucin Mucins () are a family of high molecular weight, heavily glycosylated proteins ( glycoconjugates) produced by epithelial tissues in most animals. Mucins' key characteristic is their ability to form gels; therefore they are a key component in ...

forming cleft-like spaces. There is often a proliferation of blood vessels and an inflammatory infiltrate. Staining is positive for

vimentin Vimentin is a structural protein that in humans is encoded by the ''VIM'' gene. Its name comes from the Latin ''vimentum'' which refers to an array of flexible rods. Vimentin is a Intermediate filament#Type III, type III intermediate filamen ...

, negative for

cytokeratin Cytokeratins are keratin proteins found in the intracytoplasmic cytoskeleton of epithelial tissue. They are an important component of intermediate filaments, which help cells resist mechanical stress. Expression of these cytokeratins within ep ...

and

desmin Desmin is a protein that in humans is encoded by the ''DES'' gene. Desmin is a muscle-specific, type III intermediate filament that integrates the sarcolemma, Z disk, and nuclear membrane in sarcomeres and regulates sarcomere architecture. ...

, and variable for

CD34 CD34 is a transmembrane phosphoglycoprotein protein encoded by the CD34 gene in humans, mice, rats and other species. CD34 derives its name from the cluster of differentiation protocol that identifies cell surface antigens. CD34 was first desc ...

, Factor VIIIa, SMA, MSA and S-100. Clinically, it may present as solitary or multiple flesh-colored nodules on the face, trunk, or extremities. It may occur as part of the

Carney complex Carney complex and its subsets LAMB syndrome and NAME syndrome are autosomal dominant conditions comprising myxomas of the heart and skin, hyperpigmentation of the skin ( lentiginosis), and endocrine overactivity. It is distinct from Carney triad ...

, and is sometimes the first sign. Local recurrence is common. Cutaneous myxoma is diagnosed based on histopathological features. The differential diagnosis for cutaneous myxoma include

alopecia areata Alopecia areata (AA), also known as spot baldness, is a condition in which hair loss, hair is lost from some or all areas of the body. It often results in a few Baldness, bald spots on the scalp, each about the size of a coin. Psychological st ...

, verrucous

hamartoma A hamartoma is a mostly benign, local malformation of cells that resembles a neoplasm of local tissue but is usually due to an overgrowth of multiple aberrant cells, with a basis in a systemic genetic condition, rather than a growth descended fr ...

cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubb ...

fibroma Fibromas are benign tumors that are composed of fibrous or connective tissue. They can grow in all organs, arising from mesenchyme tissue. The term "fibroblastic" or "fibromatous" is used to describe tumors of the fibrous connective tissue. Wh ...

glioma A glioma is a type of primary tumor that starts in the glial cells of the brain or spinal cord. They are malignant but some are extremely slow to develop. Gliomas comprise about 30% of all brain and central nervous system tumors and 80% of ...

hemangioma A hemangioma or haemangioma is a usually benign vascular tumor derived from blood vessel cell types. The most common form, seen in infants, is an infantile hemangioma, known colloquially as a "strawberry mark", most commonly presenting on the sk ...

lipoma A lipoma is a benign tumor made of adipose tissue, fat tissue. They are generally soft to the touch, movable, and painless. They usually occur just under the skin, but occasionally may be deeper. Most are less than in size. Common locations inc ...

scar A scar (or scar tissue) is an area of fibrosis, fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other Organ (anatomy), organs, and biological tissue, t ...

, and

nevus sebaceous Nevus sebaceus or sebaceous nevus (the first term is its Latin name, the second term is its name in English; also known as an "organoid nevus"James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatolog ...

. Treatment involves complete surgical excision.

Signs and symptoms

Cutaneous myxoma appears as a little, slowly expanding dermal or subcutaneous lump that typically affects adults' heads and necks. Alopecic lesions have been reported, characterized by hair tufts overlaying the lesion or even

hypertrichosis Hypertrichosis (sometimes known as werewolf syndrome) is an abnormal amount of hair growth over the body. The two distinct types of hypertrichosis are generalized hypertrichosis, which occurs over the entire body, and localized hypertrichosis, w ...

. Although usually painless, some people have reported experiencing discomfort or tenderness. A pedunculated lesion was reported.

Causes

Cutaneous myxoma may occur in isolation or in association with syndromes such as

nevi The Infrastructure Investment and Jobs Act (IIJA), also known as the Bipartisan Infrastructure Law (BIL),H.R. 3684 is a United States federal statute enacted by the 117th United States Congress and signed into law by President Joe Biden on Nove ...

, atrial myxoma, myxoid neurofibromas, and ephelides (NAME) syndrome,

, and lentigines, atrial myxoma, mucocutaneous myxomas, and blue nevi (LAMB) syndrome.

Diagnosis

A thin arborizing vascular network, a large myxoid stroma, mild to moderate cellularity with spindled to

stellate cells Stellate cells are neurons in the central nervous system, named for their star-like shape formed by dendritic processes radiating from the cell body. These cells play significant roles in various brain functions, including inhibition in the cer ...

with little or mild

atypia Atypia (from Greek language, Greek, ''a'' + ''typos'', without type; a condition of being irregular or nonstandard) is a histopathology, histopathologic term for a structural abnormality in a Cell (biology), cell, i.e. it is used to describe atypi ...

, and the lack of nuclear pleomorphism or mitotic activity are among the histologic markers that are consistently present in cutaneous myxoma.

Alopecia areata Alopecia areata (AA), also known as spot baldness, is a condition in which hair loss, hair is lost from some or all areas of the body. It often results in a few Baldness, bald spots on the scalp, each about the size of a coin. Psychological st ...

, verrucous

, and

are only a few of the many conditions included in the extensive clinical differential diagnosis.

Treatment

The main treatment for cutaneous myxoma is complete surgical excision.

References

External links

VisualDx

Myxoma syndrome
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DermNet DermNet is a worldwide clinical resource website about dermatology and skin conditions. Its co-founder and former editor-in-chief is dermatologist and Adjunct Associate Professor Amanda Oakley. The website was launched in 1996 under the umbrella ...

{{Soft tissue tumors and sarcomas Dermal and subcutaneous growths