desmoplastic melanoma


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desmoplastic melanoma

An uncommon melanoma (2% of all melanomas) that may not be recognised as such initially, and thus is often diagnosed at a higher stage. It is usually associated with lentigo maligna, or less commonly with acral melanoma and other melanomas.

Demographics
Male:female ratio, 2:1; more common in head and neck.

Clinical findings
Innocuous clinical presentation in the form of indurated discoid papule, plaque or nodule. Pigmentation is often absent, but lentiginous discolouration adjacent to the nodule may be seen.

DiffDx
Basal cell carcinoma, squamous cell carcinoma, DFSP, dermatofibroma, cysts, indurated scar-like plaques.
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MELANOMA

desmoplastic melanoma

A rare type of malignant melanoma in which the typical melanotic pigmentation may be absent. It often occurs on the head or neck. Microscopically, the tumor cells are spindle-shaped. Local recurrences after surgical excision are common, as are metastases, esp. to the lungs.
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See also: melanoma
References in periodicals archive ?
Desmoplastic melanoma has thus far been almost exclusively found in the oral cavity, while conventional mucosal melanoma more commonly arises in the nasal cavities.
We believe that immunohistochemistry is indispensable to identifying desmoplastic melanoma markers--S-100 in particular, (17) but also gpl00, vimentin, (11) and desmin.
The only previously reported case of nasal mucosal desmoplastic melanoma caused obstructive symptoms; it also recurred and eventually led to the patient's death 20 months after diagnosis.
Histologic Clues to the Diagnosis of Desmoplastic Melanoma Mitotic figures Cytologic atypia Lymphocytic aggregates Intraepidermal melanocytic proliferation Mucinous stroma Perineural invasion Table 3.
Histopathologic characteristics, recurrence patterns, and survival of 129 patients with desmoplastic melanoma.
Expression of basic fibroblast growth factor in desmoplastic melanoma.
In 2 cases, FISH was performed to confirm a suspected but histologically challenging diagnosis of nonsarcomatoid desmoplastic melanoma.
Fluorescence in situ hybridization as an ancillary method for the distinction of desmoplastic melanomas from sclerosing melanocytic nevi.
Another marker typically expressed in desmoplastic melanoma and not in scars is p75.
S100-positive spindle cells in scars: a diagnostic pitfall in the re-excision of desmoplastic melanoma.
Low-grade desmoplastic melanoma can easily be misdiagnosed as sclerosing BN, especially in a small biopsy specimen interpreted without awareness of the clinical context.
37,38) Other entities to be considered in histologic differential diagnosis of hypomelanotic/amelanotic BN are scar, neurofibroma, perineurioma, and desmoplastic melanoma.