Glutsch Valerie, Wobser Marion, Schilling Bastian, Gesierich Anja, Goebeler Matthias, Kneitz Hermann
Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, 97080 Würzburg, Germany.
Dermatopathology (Basel). 2022 May 2;9(2):148-157. doi: 10.3390/dermatopathology9020019.
Rhabdoid melanoma is a rare variant of malignant melanoma with characteristic cytomorphologic features. Due to the potential loss of conventional melanocytic markers, histopathologic diagnosis is often challenging. We hypothesize that immunostaining for (PRAME) might have the potential to uncover the melanocytic origin of these dedifferentiated tumors.
Four cases of rhabdoid primary melanomas were assessed by immunohistochemistry for expression of PRAME and conventional melanocytic markers. Immunohistochemical expression patterns were analyzed in the rhabdoid primaries and, if available, associated metastases.
All four cases of rhabdoid primary melanomas showed a strong nuclear positivity for PRAME, while the expression of conventional melanocytic markers S100, MART-1, SOX-10 and HMB-45 was variable between the analyzed cases.
In summary, we report four cases of rhabdoid primary melanoma with high to intermediate expression of PRAME despite the partial and variable loss of other melanocytic markers. Hence, PRAME might facilitate the recognition of this highly aggressive entity to avoid misdiagnosis due to histopathologic pitfalls.
横纹肌样黑色素瘤是恶性黑色素瘤的一种罕见变体，具有特征性的细胞形态学特征。由于传统黑素细胞标志物可能缺失，组织病理学诊断往往具有挑战性。我们推测，PRAME免疫染色可能有潜力揭示这些去分化肿瘤的黑素细胞起源。
通过免疫组织化学评估4例横纹肌样原发性黑色素瘤中PRAME和传统黑素细胞标志物的表达。分析横纹肌样原发性肿瘤以及（若有）相关转移灶中的免疫组织化学表达模式。
4例横纹肌样原发性黑色素瘤均显示PRAME强核阳性，而分析的病例中传统黑素细胞标志物S100、MART-1、SOX-10和HMB-45的表达各不相同。
总之，我们报告了4例横纹肌样原发性黑色素瘤，尽管其他黑素细胞标志物部分缺失且存在差异，但PRAME表达为高到中度。因此，PRAME可能有助于识别这种高度侵袭性的实体，避免因组织病理学陷阱导致的误诊。
