Department of Thoracic Surgery, Guy's and St Thomas' Hospitals NHS Foundation Trust, London, UK.
Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, Manchester, UK.
J Clin Pathol. 2024 Jan 18;77(2):125-127. doi: 10.1136/jcp-2022-208655.
Micronodular thymoma with lymphoid stroma is a rare subtype of thymoma with characteristic clinical and pathological features. Some of the features, such as indolent nature, principally spindle morphology and no significant association to myasthenia gravis, are shared with type A and AB thymoma, which is closely linked to mutation. However, not much is known regarding the molecular genetics of this thymoma subtype. In this study, the mutation status was investigated in 16 cases of micronodular thymoma.
16 micronodular thymomas were retrieved and the GTF2I mutation was tested by Sanger sequencing. The clinicopathological findings were documented.
GTF2I c.1271T>A p.(Leu424His) mutation within exon 15 was detected in 14 out of 16 tumours (87.5%). Two patients died of other causes while all others remained alive with no evidence of recurrence during the follow-up period ranging from 19 to 188 months (median: 100 months).
GTF2I mutation status and presence of spindle cell morphology may indicate that type A and AB thymoma, and micronodular thymoma represent a group biologically distinct from type B thymomas, which generally lack this mutation.
淋巴间质微结节性胸腺瘤是一种罕见的胸腺瘤亚型，具有特征性的临床和病理特征。其某些特征，如惰性性质、主要梭形形态和与重症肌无力无显著关联，与 A 型和 AB 型胸腺瘤相似，而后者与 突变密切相关。然而，对于这种胸腺瘤亚型的分子遗传学知之甚少。本研究调查了 16 例微结节性胸腺瘤的 突变状态。
检索了 16 例微结节性胸腺瘤，并通过 Sanger 测序检测 GTF2I 突变。记录了临床病理发现。
在 16 个肿瘤中的 14 个（87.5%）检测到 GTF2I 外显子 15 内的 c.1271T>A（p.Leu424His）突变。两名患者因其他原因死亡，而其余患者在随访期间均存活，无复发证据，随访时间从 19 至 188 个月不等（中位数：100 个月）。
GTF2I 突变状态和梭形细胞形态的存在可能表明 A 型和 AB 型胸腺瘤以及微结节性胸腺瘤代表了一组与通常缺乏这种突变的 B 型胸腺瘤在生物学上不同的群体。
