Myotonic dystrophy and lipoma: a new association

Diastolic heart dysfunction is correlated with CTG repeat length in myotonic dystrophy type 1

The aims of this study were to investigate the correlations of tri-nucleotide (CTG) repeat length with detailed echocardiography (ECHO) parameters that represent myocardial function and to find a relationship between heart function and CTG repeat length in adult-onset myotonic dystrophy type 1 (DM1). In this study, clinical data for patients with DM1, including age, onset age, CTG repeat length, Medical Research Council sum score (MRCSS), and 6-min walking test (6MWT), were recorded. In addition, ECHO parameters and cardiac conduction abnormalities were evaluated. Among the cardiac parameters, the EA ratio and left ventricular end-diastolic dimension (LVEDD) were significantly correlated with the CTG repeat length (p < 0.05). Interventricular septal thickness at end-diastole was also significantly correlated with the 6MWT in a multivariate linear regression model (p < 0.05). In conclusion, motor function (MRCSS and 6MWT) and CTG repeat length significantly correlated with LV diastolic dysfunction in patients with DM1. More emphasis should be given to diastolic dysfunction, which is currently under-recognized, when evaluating patients with DM1 with no abnormalities in routine electrocardiography studies. Lastly, well-designed and longitudinal studies are warranted to characterize and understand the pathophysiology of diastolic dysfunction in DM1.

Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma Developed in a Patient with Progressive Muscular Dystrophy: A Case Report and Review of the Literature

BACKGROUND

Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLS) is an intermediate or locally aggressive form of adipocytic soft tissue sarcoma. Muscular dystrophy (MD) is characterized by progressive muscle atrophy and its replacement by adipose and fibrous tissue. Recently, some authors have reported that MD genes are related to neoplastic formation, but there have been no detailed clinical reports of ALT associated with MD.

CASE PRESENTATION

A 73-year-old woman with a diagnosis of limb-girdle MD visited our department for recurrence of a huge tumor in her left thigh. She had undergone resection of a lipoma at the same site more than 20 years earlier. Imaging studies revealed a lipomatous tumor in her left thigh. We performed marginal resection including the adjacent muscles. Histological diagnosis was atypical lipomatous tumor. The postoperative course was uneventful, with no recurrence at 36 months of follow-up.

CONCLUSION

We encountered a huge atypical tumor in a patient with MD. This is the first detailed report to describe an association between ALT and MD. We hypothesize that degenerative changes occurring in adipose tissue during muscle atrophy can cause lipomatous neoplasms and moreover that the mutation of MD-related genes may lead to the proliferation of tumor cells or to malignancy.