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. Often, it is located in the lumbosacral region.[4]
Congenital smooth muscle hamartoma most likely arises from an abnormal development that occurs during mesodermal maturation, primarily in the arrector pili muscle.[5] It is hypothesized that hypertrichosis results from the CD34 + dermal dendritic cells in the hamartoma stimulating the bulge's epithelial cells.[6]
There have been reports of familial cases recently, which raise the possibility of a genetic susceptibility.[7]
Rarely do diffuse forms of congenital smooth cell hamartoma cause the skin to fold.[5] It may indicate systemic involvement and is described as a symptom of the Michelin tire infant syndrome.[8]
Histologically, the main characteristics of CSMH include reticular dermal smooth muscle hyperplasia with differently orientated, clearly defined bundles of smooth muscle[9][10] that may extend into subcutaneous adipose tissue. Hair follicles and smooth muscle proliferation are frequently tightly related.[11] Increased epidermal pigment is a sign of hyperpigmentation.[9][10] Immunohistochemical methods have recently clarified a few CSMH markers. 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.[12]
^ abKoizumi; Kodama; Tsuji; Matsumura; Nabeshima; Ohkawara (1999). "CD34-positive dendritic cells are an intrinsic part of smooth muscle hamartoma". British Journal of Dermatology. 140 (1). Oxford University Press (OUP): 172–174. doi:10.1046/j.1365-2133.1999.02633.x. ISSN0007-0963. PMID10215795. S2CID28839250.
^García-Gavín, Juan; Pérez-Pérez, Lidia; Allegue, Francisco; Pérez-Pedrosa, Alberto; Ortíz-Rey, Jose Antonio; Zulaica, Ánder (2012-05-01). "Multiple congenital familial smooth muscle hamartoma in two siblings". Dermatology Online Journal. 18 (5). doi:10.5070/D39N52G204. ISSN1087-2108.
^Janicke, Elise C.; Nazareth, Michael R.; Rothman, Ilene L. (2014-01-03). "Generalized Smooth Muscle Hamartoma with Multiple Congenital Anomalies without the "Michelin Tire Baby" Phenotype". Pediatric Dermatology. 31 (6). Wiley: 731–733. doi:10.1111/pde.12280. ISSN0736-8046. PMID24383769. S2CID39284436.
^ abTruhan, A. P. (1985-09-01). "Hypertrichotic skin-colored patches in an infant. Congenital smooth-muscle hamartoma (CSMH)". Archives of Dermatology. 121 (9). American Medical Association (AMA): 1997, 1200–1. doi:10.1001/archderm.121.9.1997. ISSN0003-987X. PMID4037849.
^Huffman, D W; Mallory, S B (June 1989). "Congenital smooth muscle hamartoma". American Family Physician. 39 (6): 117–120. PMID2729037.
^D'Addario, Stephen F.; Morgan, Michael; Talley, Lori; Smoller, Bruce R. (2002-07-25). "h-Caldesmon as a specific marker of smooth muscle cell differentiation in some soft tissue tumors of the skin". Journal of Cutaneous Pathology. 29 (7). Wiley: 426–429. doi:10.1034/j.1600-0560.2002.290707.x. ISSN0303-6987. PMID12139638. S2CID22091736.
Schmidt, Christopher S; Bentz, Michael L (2005). "Congenital Smooth Muscle Hamartoma: The Importance of Differentiation From Melanocytic Nevi". Journal of Craniofacial Surgery. 16 (5). Ovid Technologies (Wolters Kluwer Health): 926–929. doi:10.1097/01.scs.0000181049.99071.23. ISSN1049-2275. PMID16192884.
