MR imaging findings for differentiating cutaneous malignant melanoma from squamous cell carcinoma.

This study aimed to assess the efficacy of using MR imaging findings for differentiating cutaneous malignant melanoma (cMM) from cutaneous squamous cell carcinoma (cSCC). Preoperative MR images of patients with histopathologically proven primary cMM and primary cSCC were retrospectively reviewed and compared between the two pathologies. A total of 16 patients with primary cMM (7 men and 9 women; age range, 45-97 years; median age, 75 years) and 49 with primary cSCC (37 men and 12 women; age range, 46-90 years; median age, 76 years) were enrolled in this study. Intratumoral T1 hyperintensity compared to that of the dermis was more frequently observed in cMM than in cSCC (50 % vs. 4 %; p < 0.01). Superficial depression (51 % vs. 19 %; p < 0.05), superficial irregular margins (55 % vs. 25 %; p <  0.05), and reticular or linear T2 hyperintensity (27 % vs. 0 %; p <  0.05) were more frequently observed in cSCC than in cMM, respectively. cMM predominantly exhibited intratumoral T1 hyperintensity, whereas cSCC predominantly exhibited superficial depression, superficial irregular margins, reticular or linear T2 hyperintensity.