Department of Pathology and Dermatopathology, Southern California Permanente Medical Group, Kaiser Permanente Anaheim/Irvine Medical Center, Anaheim, California, USA.
Kaiser Permanente Los Angeles Medical Center, Los Angeles, California, USA.
J Cutan Pathol. 2022 Aug;49(8):709-716. doi: 10.1111/cup.14245. Epub 2022 May 24.
Spitzoid melanocytic neoplasms are well known to be diagnostically challenging. Immunohistochemistry (IHC) and molecular approaches have been used as ancillary diagnostic tests. Herein, we investigate the use of PRAME IHC for the assessment of spitzoid melanocytic neoplasms.
Ten Spitz nevi, 14 atypical Spitz tumors, and 11 spitzoid melanomas were retrieved, and PRAME IHC was scored on a scale of 1-4 (in % quartiles). Intensity of staining was categorized as weak or strong. Cases with no staining received a score of 0. Positive lymph nodes from three spitzoid melanomas were also analyzed.
Spitz nevi, atypical Spitz tumors, and spitzoid melanomas had mean PRAME IHC scores of 1.20, 0.93, and 3.36, respectively. The percentage of cases with a score 3 or higher for each category of spitzoid neoplasms are as follows: Spitz nevus (20%), atypical Spitz tumor (0%), and spitzoid melanoma (82%). Among the spitzoid melanomas, three cases had positive sentinel lymph nodes, which showed PRAME score of 2, 4, and 4 in the metastatic deposits.
Previous reports revealed PRAME IHC as useful tool to distinguish benign from malignant melanocytic lesions. The results presented here are concordant with the prior studies, but expand the application of this marker to Spitz nevi/tumors and spitzoid melanomas. The present findings suggest the potential diagnostic utility of PRAME IHC in the assessment of spitzoid melanocytic lesions, particularly in distinguishing spitzoid melanomas from Spitz nevi and atypical Spitz tumors.
Spitz 样黑色素细胞肿瘤的诊断极具挑战性，因此常借助免疫组化（IHC）和分子检测等辅助诊断方法。本文旨在研究 PRAME IHC 在评估 Spitz 样黑色素细胞肿瘤中的应用。
选取 10 例 Spitz 痣、14 例非典型 Spitz 肿瘤和 11 例 Spitz 样黑色素瘤，按 1-4 分（按四分位数%）进行 PRAME IHC 评分；染色强度分为弱阳性和强阳性，无染色记 0 分。分析 3 例 Spitz 样黑色素瘤阳性淋巴结的 PRAME 表达。
Spitz 痣、非典型 Spitz 肿瘤和 Spitz 样黑色素瘤的 PRAME IHC 评分均值分别为 1.20、0.93 和 3.36；每个 Spitz 样肿瘤类别的 3 分或 4 分病例比例如下：Spitz 痣（20%）、非典型 Spitz 肿瘤（0%）和 Spitz 样黑色素瘤（82%）。在 Spitz 样黑色素瘤中，3 例前哨淋巴结转移灶的 PRAME 评分为 2、4 和 4。
既往报道表明 PRAME IHC 有助于区分良性和恶性黑色素细胞病变。本文结果与既往研究一致，同时将该标志物的应用扩展到 Spitz 痣/肿瘤和 Spitz 样黑色素瘤。本研究提示 PRAME IHC 对评估 Spitz 样黑色素细胞病变具有潜在的诊断价值，特别是在鉴别 Spitz 样黑色素瘤与 Spitz 痣和非典型 Spitz 肿瘤方面。
