Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan; Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kean, Thailand.
Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan.
Ann Diagn Pathol. 2022 Oct;60:152004. doi: 10.1016/j.anndiagpath.2022.152004. Epub 2022 Jun 30.
Genomic-based ancillary assays including immunohistochemistry (IHC) for BRCA-1 associated protein-1 (BAP1) and methylthioadenosine phosphorylase (MTAP), and fluorescence in situ hybridization (FISH) for CDKN2A are effective for differentiating pleural mesothelioma (PM) from reactive mesothelial proliferations. We previously reported a combination of MTAP and BAP1 IHC effectively distinguishes sarcomatoid PM from fibrous pleuritis (FP). Nevertheless, cases of sarcomatoid PM with desmoplastic features (desmoPM) are encountered where the IHC assessment is unclear.
We evaluated assessment of MTAP IHC, BAP1 IHC, and CDKN2A FISH in 20 desmoPM compared to 24 FP. MTAP and BAP1 IHC could not be assessed in 11 (55 %) and 10 (50 %) cases, respectively, due to loss or faint immunoreactivity of internal positive control cells, while CDKN2A FISH could be evaluated in all cases. The sensitivities for MTAP loss, BAP1 loss, and CDKN2A homozygous deletion in desmoPM were 40 %, 10 %, and 100 %. A combination of MTAP loss and BAP1 loss yielded 45 % of sensitivity.
MTAP IHC is a useful surrogate diagnostic marker in differentiating ordinary sarcomatoid PM from FP, but its effectiveness is limited in desmoPM. CDKN2A FISH is the most effective diagnostic assays with 100 % sensitivity and specificity in discriminating desmoPM from FP in the facilities where the FISH assay is available.
基于基因组的辅助检测，包括 BRCA-1 相关蛋白-1（BAP1）和甲基硫腺苷磷酸化酶（MTAP）的免疫组织化学（IHC）以及 CDKN2A 的荧光原位杂交（FISH），可有效区分胸膜间皮瘤（PM）和反应性间皮增生。我们之前报道过 MTAP 和 BAP1 IHC 的组合可有效区分肉瘤样 PM 和纤维性胸膜炎（FP）。然而，遇到具有促结缔组织增生特征的肉瘤样 PM（desmoPM）时，IHC 评估结果并不明确。
我们评估了 20 例 desmoPM 和 24 例 FP 中 MTAP IHC、BAP1 IHC 和 CDKN2A FISH 的评估情况。由于内部阳性对照细胞的缺失或弱免疫反应，11 例（55%）和 10 例（50%）病例分别无法评估 MTAP 和 BAP1 IHC，而所有病例均可评估 CDKN2A FISH。在 desmoPM 中，MTAP 缺失、BAP1 缺失和 CDKN2A 纯合缺失的敏感性分别为 40%、10%和 100%。MTAP 缺失和 BAP1 缺失的组合可获得 45%的敏感性。
MTAP IHC 是区分普通肉瘤样 PM 和 FP 的有用替代诊断标志物，但在 desmoPM 中其有效性有限。CDKN2A FISH 是最有效的诊断检测方法，在具备 FISH 检测条件的情况下，特异性和敏感性均为 100%，可用于区分 desmoPM 和 FP。
