Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a tumor predisposition syndrome caused by germline fumarate hydratase (FH) mutations and characterized by uterine and cutaneous leiomyomas and renal cell cancer. Currently, there is no generally approved method to differentiate FH-deficient uterine leiomyomas from other leiomyomas. Here, we analyzed 3 antibodies (S-(2-succino)-cysteine [2SC], aldo-keto reductase family 1, member B10 [AKR1B10], and FH) as potential biomarkers. The study consisted of 2 sample series. The first series included 155 formalin-fixed paraffin-embedded uterine leiomyomas, of which 90 were from HLRCC patients and 65 were sporadic. The second series included 1590 unselected fresh frozen leiomyomas. Twenty-seven tumors were from known HLRCC patients, while the FH status for the remaining 1563 tumors has been determined by copy number analysis and Sanger sequencing revealing 45 tumors with monoallelic (n=33) or biallelic (n=12) FH loss. Altogether 197 samples were included in immunohistochemical analyses: all 155 samples from series 1 and 42 available corresponding formalin-fixed paraffin-embedded samples from series 2 (15 tumors with monoallelic and 7 with biallelic FH loss, 20 with no FH deletion). Results show that 2SC performed best with 100% sensitivity and specificity. Scoring was straightforward with unambiguously positive or negative results. AKR1B10 identified most tumors accurately with 100% sensitivity and 99% specificity. FH was 100% specific but showed slightly reduced 91% sensitivity. Both FH and AKR1B10 displayed also intermediate staining intensities. We suggest that when patient’s medical history and/or histopathologic tumor characteristics indicate potential FH-deficiency, the tumor’s FH status is determined by 2SC staining. When aberrant staining is observed, the patient can be directed to genetic counseling and mutation screening.

遗传性平滑肌瘤病和肾细胞癌（HLRCC）是一种由种系富马酸水合酶（FH）突变引起的肿瘤易感综合征，以子宫和皮肤平滑肌瘤和肾细胞癌为特征。目前，尚无普遍认可的方法来区分 FH 缺陷型子宫肌瘤与其他子宫肌瘤。在这里，我们分析了 3 种抗体（S-(2-琥珀基)-半胱氨酸 [ 2SC ]、醛酮还原酶家族 1、成员 B10 [AKR1B10] 和 FH）作为潜在的生物标志物。该研究由 2 个样本系列组成。第一个系列包括 155 例福尔马林固定石蜡包埋子宫肌瘤，其中 90 例来自 HLRCC 患者，65 例为散发性子宫肌瘤。第二个系列包括 1590 个未经选择的新鲜冷冻平滑肌瘤。27 个肿瘤来自已知的 HLRCC 患者，而其余 1563 个肿瘤的FH状态已通过拷贝数分析和 Sanger 测序确定，显示 45 个肿瘤具有单等位基因 (n=33) 或双等位基因 (n=12) FH丢失。免疫组织化学分析中总共包括 197 个样本：系列 1 中的所有 155 个样本和系列 2 中的 42 个可用的相应福尔马林固定石蜡包埋样本（15 个肿瘤具有单等位基因 FH 缺失，7 个肿瘤具有双等位基因 FH 缺失，20 个肿瘤无FH缺失）。结果显示2SC表现最佳，灵敏度和特异性均为 100%。评分很简单，有明确的阳性或阴性结果。AKR1B10 能够准确识别大多数肿瘤，灵敏度为 100%，特异性为 99%。FH 具有 100% 特异性，但敏感性略有下降（91%）。FH 和 AKR1B10 也显示出中等染色强度。我们建议，当患者的病史和/或组织病理学肿瘤特征表明潜在的 FH 缺陷时，通过2SC染色确定肿瘤的 FH 状态。当观察到异常染色时，可以指导患者进行遗传咨询和突变筛查。