Myotonic dystrophy (DM) is an autosomal dominant disease of variable penetrance. Myotonic dystrophy types 1 (DM1) and 2 (DM2) result from a mutation in a gene on chromosomes 19 and 3, respectively. DM is the most frequent muscle dystrophy in adults. Muscle weakness and myotonia may be associated with eye, cardiovascular, neural, gastrointestinal, endocrine, metabolic, and skin abnormalities. Although skin involvement usually consists of multiple pilomatricomas, basal cell carcinomas have also been described. A 42-year-old woman presented with DM1 and multiple, nodular, pigmented, basal cell carcinomas on the face (Fig. 1). Histologic examination of four biopsy specimens revealed lobular, cord-like, pigmented, basal cell lesions with trichoepithelioma-like features (Fig. 2). She had suffered from muscle pain, hypotonia, and weakness since the age of 34 years. DM was clinically diagnosed in 1996 and confirmed in 2003 as DM1, when a genetic study showed 600–700 repeats of the CTG trinucleotide. Nodular, pigmented, basal cell carcinomas Basal cell carcinoma with trichoepithelioma-like features (hematoxylin and eosin stain, ×125) The patient had also suffered from diffuse alopecia and psoriasis vulgaris during the past 10 years, from irritable colon syndrome since childhood, and from endometriosis. Her 6-year-old daughter had DM1 (730–750 CTG repeats). Routine laboratory tests, electrocardiograms, and eye examinations were normal. An electromyogram was consistent with DM. Basal cell carcinomas responded to topical treatment with 5% imiquimod three times a week for 12 weeks. The mutation leading to DM1 is an expansion of the CTG trinucleotide repeat in the DMPK gene (chromosomal locus 19q13.3).1 The 3q abnormality initially detected in DM2 patients2 is an expansion of the CCTG tetranucleotide in intron 1 of the ZNF9 gene (chromosomal locus 3q21.3).3 Both DM types are clinically similar and cause myotonia, muscle dystrophy, cataracts, diabetes, testicular or ovarian failure, cardiac conduction disturbances, gastrointestinal dysfunction, neuropsychiatric symptoms, skin lesions, and hypogammaglobulinemia. DM2 is similar to adult-onset DM1; DM2, however, produces predominantly proximal muscle weakness, whilst DM1 usually affects the distal muscles. The most significant difference is the absence of severe congenital DM2.3 As both DM1 and DM2 are clinically similar, it has been suggested that the genetic defect may express itself via the RNA, and the increased number of CTG and CCTG repeats may affect certain protein synthesis mechanisms.3 In 1965, Cantwell and Reed4 reported an association of pilomatricomas with DM. These lesions may be the most common skin manifestations in DM patients, particularly in multiple and familial cases. To our knowledge, only four articles have described basal cell carcinomas associated with DM.5-8 Because these cases, as well as our patient, developed multiple basal cell carcinomas at a relatively young age, suggesting a syndrome-like disorder, and because recent publications9, 10 have linked 19q defects to a higher risk of basal cell carcinoma, this rather uncommon skin manifestation may be a significant finding in DM1 patients.