Congenital smooth muscle hamartoma is typically a skin colored or lightly pigmented patch or plaque with hypertrichosis.
[1]: 627 [2] Congenital smooth muscle hamartoma was originally reported in 1969 by Sourreil et al.[3] Although the clinical presentation of congenital smooth muscle hamartoma varies, it typically takes the form of an irregularly shaped, skin-colored, or slightly hyperpigmented patch or plaque on the trunk or extremities that is accompanied by noticeable vellus hairs.
[7] Rarely do diffuse forms of congenital smooth cell hamartoma cause the skin to fold.
It has been observed that CD34-positive dermal dendritic cells are an inherent component of smooth muscle hamartomas.
[6] Furthermore, to distinguish clearly between skin cancers of myofibroblastic or fibroblastic origin and spindled smooth muscle cell soft tissue tumors, the cytoskeletal protein h-caldesmon has been employed as a smooth muscle cell-specific marker.