Efficacy of diagnostic ultrasonography of lipomas, epidermal cysts, and ganglions

Objective: To determine the efficacy of ultrasonography for the diagnosis of subcutaneous benign lesions. Design: Retrospective study. Setting: Tokyo Kousei-Nenkin Hospital, Tokyo, Japan. Patients: The study included 183 patients with subcutaneous benign lesions who underwent ultrasonography and then received a pathologic diagnosis after surgery. Main Outcome Measures: The study evaluated the number of cases in which the preoperative diagnosis after ultrasonography or just after palpation agreed with the pathologic diagnosis. Results: Ultrasonography significantly increased the preoperative diagnostic yield of subcutaneous benign lesions (after palpation, 29%; after ultrasonography, 46%; P<.001). The sensitivity for the diagnosis of lipoma (after palpation, 54.8%; after ultrasonography, 88.1%; P<.01) and the specificity for the diagnosis of epidermal cyst (after palpation, 93.5%; after ultrasonography, 99.3%; P<.05) significantly increased after ultrasonography. The sensitivity for the diagnosis of epidermal cyst and ganglion also tended to increase after ultrasonography. Conclusion: The study results suggest that ultrasonography is useful for the preoperative examination of subcutaneous benign lesions.