Congenital smooth muscle hamartoma

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Congenital smooth muscle hamartoma

Congenital smooth muscle hamartoma (CSMH) is a rare cutaneous hamartomatous lesion most often located on the lumbosacral area or proximal limbs (but rarely on atypical areas such as scalp eyelid or foot) and characterized by a disorganized proliferation of smooth muscle fibres of arrector pili presenting usually as a localized skin-colored or hyperpigmented plaque (up to 10 cm in diameter) with prominent vellus hairs (most common classic form) or less commonly by multiple skin-colored papules that can coalesce to form irregularly shaped plaques. With time hyperpigmentation and vellus hairs usually diminish and neither malignant transformation nor associated systemic involvement has been reported.

Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview.

Reference: Access aggregated data from Orphanet at Orphadata.

Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http: // Data version September 2023.

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Congenital smooth muscle hamartoma?

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