Anaplastic large cell lymphoma
Anaplastic large-cell lymphoma (ALCL) is an uncommon type of T-cell lymphoma first reported by Stein et al 1) It is characterized by large pleomorphic CD30 (Ki-1)-expressing lymphoid blasts containing horseshoe-shaped nuclei 2).
Classification
Currently, the fourth edition of the WHO classification of tumors of hematopoietic and lymphoid tissues, published in 2008, divides systemic Anaplastic large cell lymphomas into two entities: anaplastic lymphoma kinase (ALK)-positive and ALK-negative.
Outcome
Some cases lack ALK translocation correlated with a more unfavorable prognosis 3).
see also Primary central nervous system ALK-positive anaplastic large cell lymphoma
see also Primary central nervous system ALK-negative anaplastic large cell lymphoma
Case reports
A case of ALCL-ALK(-) that presented as a progressive, enlarged, swollen mass on the scalp after an acute head injury in an 84-year-old man. Neither palpable lymph nodes nor any B symptoms were noted at admission. Brain computed tomography showed a hematoma in the right posterior occipital region of the scalp as the only remarkable finding. Debridement and biopsy were performed. Histologic and immunohistochemical analysis of the specimen revealed an ALCL-ALK(-) of the scalp. The lymphoma was resistant to bendamustine-containing chemotherapies, ultimately leading to the patient's death within 2 months.
This case report highlights the importance of recognizing the possibility of an ALCL presenting as a focal inflammatory swelling mass on the scalp 4).