Sonographic detection and fine-needle aspiration biopsy of nonpalpable recurrent or metastatic melanoma in subcutaneous tissues.

Subcutaneous or lymph node metastases from melanoma may not be palpable because of their small size, their distance from the skin surface, or their location in an area of fibrosis due to previous surgery or irradiation. High-resolution sonography has been used to detect clinically occult foci of recurrent or metastatic melanoma, whereas real-time, ultrasound-guided, fine-needle aspiration biopsy provided cytologic confirmation. Following excision of cutaneous melanoma, sonographic follow-up of the areas of the surgical scar and lymphatic drainage is recommended whenever residual disease is suspected or when clinical evaluation is limited by postoperative or postradiation changes. Any nonpalpable hypoechoic mass detected in those areas should have a biopsy under real-time sonographic guidance.