Aberrant TTF1 expression in anaplastic large cell lymphoma

The study demonstrated for the first time the possibility of aberrant expression of TTF1 by anaplastic large cell lymphoma cells. In one case, intense expression of TTF1 was observed in 100% of tumor cells, in the rest - in no more than 15%. Moreover, expression was observed both in cases of using clone SP141 and clone SPT24. In our opinion, the identified aberrant expression of TTF1 in anaplastic large cell lymphoma, may cause an error in the morphological diagnosis of the metastatic process and requires additional attention from the pathologist.