Spinelli M, Khorshad J, Viola P
Cellular Pathology Department, Worcester Royal Hospital, Worcester, UK.
North West London Pathology, Molecular Department, Hammersmith Hospital, London, UK.
Pathologica. 2019 Jun;111(2):58-61. doi: 10.32074/1591-951X-12-19.
The 2011 WHO Classification for lung adenocarcinoma enlightened the need for a wise use of immunohistochemistry to preserve tissue for both diagnosis and molecular studies. The current recommendation is to use a panel comprising TTF1 and p40 to classify tumors with no clear squamous or glandular differentiation as many studies have showed the higher specificity of p40 over p63 as marker of squamous differentiation. However, the co-expression of both markers opens a new scenario with subsequent classification and potentially treatment issues.
We report a case of a non-small lung cell carcinoma (NSCLC) with coexistent expression of TTF1 and p40 in the same tumour cells. To our knowledge, this peculiar immunohistochemical profile is very rare, and thus a review of the clinical and molecular features including molecular variances of the tumour was performed. Review of the pertinent literature was also carried out.
Two additional articles describing unusual cases of NSCLC with coexistent expression of TTF1 and p40 were found and compared to our case. Interestingly, they all carried out aberrant mutation in TP53 oncogene and were of advance stage.
The positivity for both "squamous" and "adenocarcinomatous" markers and mutations of TP53 could be the expression of a not fully recognized variant of NSCLC with possible implications for classification, diagnosis and therapy.
2011年世界卫生组织（WHO）的肺腺癌分类法表明，有必要明智地使用免疫组化技术，以便为诊断和分子研究保留组织。目前的建议是使用由甲状腺转录因子1（TTF1）和p40组成的一组指标，来对没有明确鳞状或腺性分化的肿瘤进行分类，因为许多研究表明，作为鳞状分化标志物，p40比p63具有更高的特异性。然而，这两种标志物的共表达开启了一个新的局面，随之而来的是分类以及潜在的治疗问题。
我们报告了一例非小细胞肺癌（NSCLC），同一肿瘤细胞中同时存在TTF1和p40的表达。据我们所知，这种特殊的免疫组化特征非常罕见，因此我们对该肿瘤的临床和分子特征，包括分子变异进行了回顾。我们还对相关文献进行了综述。
我们发现另外两篇文章描述了NSCLC的不寻常病例，其中TTF1和p40同时表达，并与我们的病例进行了比较。有趣的是，它们都在TP53癌基因中发生了异常突变，且都处于晚期。
“鳞状”和“腺癌”标志物均呈阳性以及TP53突变，可能是一种尚未被充分认识的NSCLC变异型的表现，这可能对分类、诊断和治疗产生影响。
