[Blast-like tumor tissue in cervical lymph node with expression of placental alkaline phosphatase]. / Blastäres Tumorgewebe in Halslymphknoten mit Expression plazentaalkalischer Phosphatase.

ABSTRACT

We report a case of ALK1-positive anaplastic large cell lymphoma with expression of placental alkaline phosphatase (PLAP) in many tumor cells. Initially, due to the positivity of tumor cells for CD30 and PLAP, lymph node metastasis of a germ cell neoplasm was discussed. Anaplastic large cell lymphomas of T­cell lineage form a group of rare non-Hodgkin lymphomas with heterogeneous morphological and immunohistochemical appearance. They may imitate other neoplasms, such as large cell B­cell lymphomas, metastasis of a carcinoma, melanoma, embryonal carcinoma or seminoma, rhabdomyosarcoma and inflammatory myofibroblastic tumor. Only an extended immunohistochemistry panel leads to an accurate diagnosis.