Blaheta H J, Schittek B, Breuninger H, Garbe C
Department of Dermatology, Eberhard-Karls-University, Tübingen, Germany.
Recent Results Cancer Res. 2001;158:137-46. doi: 10.1007/978-3-642-59537-0_14.
The technique of sentinel lymph node (SLN) biopsy has been demonstrated to be highly predictive for the detection of melanoma micrometastases in the regional lymph node basin. Therefore, the SLN was proposed to accurately reflect the lymph node status of patients with primary cutaneous melanoma. As the regional lymph node status is one of the most powerful predictors of survival in patients with primary melanoma, the histopathologic assessment is critically important for accurate staging. In approximately 20% (ranging from 9% to 42%) of patients with primary melanoma, the SLN was found to be tumor-positive by histopathology or immunohistochemistry. However, the true incidence of metastatic melanoma cells in (sentinel) lymph nodes is underestimated by histopathologic examination. Recently, the method of reverse transcription-polymerase chain reaction (RT-PCR) for tyrosinase mRNA has been used as a molecular marker for the presence of melanoma cells. Tyrosinase RT-PCR was demonstrated to significantly increase the detection of melanoma cells in SLNs as compared to histopathology. All lymph nodes positive by histopathology were shown to express tyrosinase by RT-PCR. Furthermore, tyrosinase transcripts were also detected in 36-52% of stage I and II melanoma patients with SLNs negative by histopathology. Importantly, the recurrence rate was significantly higher in patients with histologically negative SLNs who were found to be positive by RT-PCR than in patients with negative results by both techniques. These findings indicate that RT-PCR status of the SLN is more sensitive for detection of minimal melanoma disease than histopathology. Therefore, the RT-PCR status of the SLN may be suitable to improve melanoma staging and may serve as a prognostic factor in patients with primary cutaneous melanoma.
前哨淋巴结（SLN）活检技术已被证明对检测区域淋巴结区域内的黑色素瘤微转移具有高度预测性。因此，有人提出前哨淋巴结能准确反映原发性皮肤黑色素瘤患者的淋巴结状态。由于区域淋巴结状态是原发性黑色素瘤患者生存的最有力预测指标之一，组织病理学评估对于准确分期至关重要。在大约20%（范围从9%到42%）的原发性黑色素瘤患者中，通过组织病理学或免疫组织化学发现前哨淋巴结为肿瘤阳性。然而，组织病理学检查低估了（前哨）淋巴结中转移性黑色素瘤细胞的真实发生率。最近，用于检测酪氨酸酶mRNA的逆转录-聚合酶链反应（RT-PCR）方法已被用作黑色素瘤细胞存在的分子标志物。与组织病理学相比，酪氨酸酶RT-PCR被证明能显著提高前哨淋巴结中黑色素瘤细胞的检测率。所有组织病理学阳性的淋巴结经RT-PCR检测均显示表达酪氨酸酶。此外，在36%至52%的组织病理学检查前哨淋巴结阴性的I期和II期黑色素瘤患者中也检测到了酪氨酸酶转录本。重要的是，RT-PCR检测为阳性而组织学检查前哨淋巴结阴性的患者的复发率明显高于两种技术检测结果均为阴性的患者。这些发现表明，前哨淋巴结的RT-PCR状态在检测微小黑色素瘤疾病方面比组织病理学更敏感。因此，前哨淋巴结的RT-PCR状态可能适合于改善黑色素瘤分期，并可作为原发性皮肤黑色素瘤患者的一个预后因素。
