de la Espriella J, Grossin M, Marinho E, Belaïch S
Service de Dermatologie, Hôpital Bichat, Paris.
Ann Dermatol Venereol. 1993;120(12):879-83.
Smooth muscle hamartoma is an uncommon cutaneous dysembryoplasia usually diagnosed in infancy. Among the 61 cases published since 1923, 56 were congenital and 3 appeared in young adults. We report a case in which the lesions started at the age of 15 years as a papular plaque in the right mammary region of a young woman. A review of the literature showed that the usual clinical presentation is a frequently pigmented plaque made of often follicular papules and measuring 1 to 10 centimeters on average. Excessive hairiness is the most frequent sign, being observed in more than two-thirds of the cases, and Darier's pseudo-sign is present in about 53 p. 100 of the patients. The disease is electively located on the lumbar region, the back and the root of the limbs. In 3 cases the lesions were generalized and the patients looked like fatty "Michelin-Tire Babies". The course of the disease is always favourable, and associated pathologies remain exceptional: urticaria pigmentosa and psychomotor retardation have been reported in two cases of the generalized form. Histology is characterized by the presence of numerous smooth muscle fibres disseminated in the dermis and diversely oriented, sometimes in contact with hair follicles which retain their normal morphology. The differential clinical diagnosis is with naevocytic naevus, café-au-lait spots, mastocytosis and connective tissue hamartoma. Belatedly revealed forms of the disease must be distinguished from Becker's hamartoma, but it must be known that in certain cases the classification is so difficult that some authors have suggested that smooth muscle hamartoma and Becker's hamartoma are only two poles of a single spectrum of dysembryoplastic lesions involving to varying degrees the epidermic and hair structures. Finally, the distinction between the localized forms of late onset smooth muscle hamartoma and multiple leiomyomas "en plaques" remains difficult both anatomico-clinically and nosologically.
平滑肌瘤性错构瘤是一种罕见的皮肤发育异常，通常在婴儿期被诊断。自1923年以来发表的61例病例中，56例为先天性，3例出现在年轻人中。我们报告一例，病变于15岁时在一名年轻女性的右乳区开始为丘疹性斑块。文献回顾显示，其常见临床表现通常是一个常有色素沉着的斑块，由毛囊丘疹组成，平均大小为1至10厘米。多毛是最常见的体征，超过三分之二的病例可见，约53%的患者存在 Darier 假体征。该病好发于腰部、背部和肢体根部。3例病变为全身性，患者看起来像脂肪型“米其林轮胎宝宝”。该病病程总是良性的，相关病变仍然罕见：泛发型的两例病例曾报告有色素性荨麻疹和精神运动发育迟缓。组织学特征是真皮内有大量散在分布、方向各异的平滑肌纤维，有时与保持正常形态的毛囊接触。临床鉴别诊断包括黑素细胞痣、咖啡斑、肥大细胞增多症和结缔组织错构瘤。迟发性病例必须与贝克尔错构瘤相鉴别，但必须知道，在某些情况下分类非常困难，以至于一些作者认为平滑肌瘤性错构瘤和贝克尔错构瘤只是涉及表皮和毛发结构程度不同的单一发育异常性病变谱的两个极端。最后，晚发性平滑肌瘤性错构瘤的局限性形式与多发性“斑块状”平滑肌瘤在解剖临床和分类学上的区分仍然困难。
