Preoperative ultrasonographic identification of the sentinel lymph node in patients with malignant melanoma

Abstract

BACKGROUND Dissection of the “sentinel lymph node” (SLN) as identified by lymphoscintigraphy is becoming increasingly important in the treatment of patients with malignant melanoma. The purpose of the current study was to determine whether the SLN also could be identified by ultrasound. METHODS Sixty‐seven patients with malignant melanoma (40 females and 27 males, with an average age of 48.8 years) in whom extirpation of the SLN was indicated underwent ultrasonography of the regional lymph nodes prior to preoperative lymphoscintigraphy. The location of the melanoma was the legs in 30 patients, the arms in 14 patients, and the trunk in 23 patients. During regional ultrasonography, the location of the lymph nodes that differed in the cortex/medulla ratio from the surrounding lymph nodes was marked on the skin corresponding to the planes of insonation (M1) when the probe was held vertically to the skin surface. After lymphoscintigraphy using technetium‐99m, the position of a gamma probe at which the highest count rate vertical to the skin surface was recorded also was marked (M2). RESULTS In the inguinal region, the agreement between M1 and M2 was found to be 100% (40 of 40 SLNs) and was 72.5% in the axilla (29 of 40 SLNs). In patients with melanomas located on the leg, the location of M1 and M2 agreed in 97% of cases (36 of 37 lymph nodes in 30 patients); in patients with melanomas located on the arms, the agreement was 76% (13 of 17 lymph nodes in 14 patients) and in patients with melanomas located on the trunk, the agreement was 75% (21 of 28 lymph nodes in 23 patients). The position documented by ultrasound relative to the neighboring structures of the SLN was confirmed intraoperatively in all cases. CONCLUSIONS The results of the current study indicate that the SLN in patients with melanoma located on the limbs, especially the legs, are characterized by a specific sonomorphologic pattern. Preoperative sonography might constitute an important addition to lymphoscintigraphy in the planning of SLN biopsy. Cancer 2003;97:1947–54. © 2003 American Cancer Society. DOI 10.1002/cncr.11261

Ultrasound Examination of Sentinel Nodes in the Initial Assessment of Patients With Primary Cutaneous Melanoma

“…These features have been well described previously. [7][8][9] In a recent study by Kahle et al, 15 a specific asymmetrical cortical thickening phenomenon causing a ''cap''-like sonomorphological pattern to occur on US in the SLNs of melanoma patients was described. The locations of any lymph nodes found to show this cap phenomenon on US were compared with the location of nodes subsequently determined to be the SLNs by lymphoscintigraphy.…”

Influence of sporting activity and smoking on peripheral lymph nodes in patients with melanoma analyzed by high-resolution ultrasound

“…6 The value of HRUS for staging of patients with melanoma as an inexpensive and noninvasive imaging method has been well documented in several studies in the past. [7][8][9][10][11] However, knowledge about sonographic appearance of nontumor affected peripheral LNs is rather marginal. Just a few past publications examined this issue.…”

Sonography for Locoregional Staging and Follow-up of Cutaneous Melanoma

“…At initial melanoma staging, in patients scheduled for SLNB, we do not try to recognize where and which are the sentinel lymph nodes. Kahle et al 30 identified a specific sonographic pattern of sentinel lymph nodes and found a high correlation with lymphoscintigraphic findings, particularly for inguinal sentinel nodes. These authors noted that the sentinel nodes had asymmetric thickening of the cortex (the "cap," making the hyperechoic hilum eccentric) in the longitudinal view, whereas the nonsentinel nodes had a symmetric cortical thickness (ie, centrally located hyperechogenicity).…”