RESUMEN
BACKGROUND: Anaplastic large cell lymphoma (ALCL) is a malignant non-Hodgkin lymphoma, typically associated with anaplastic lymphoma kinase (ALK) expression. In some cases, lack of ALK translocation correlated with a more unfavorable prognosis. CASE DESCRIPTION: We describe a case of ALK(-) ALCL that manifested 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 on admission. Brain computed tomography showed a hematoma in the right posterior occipital region of the scalp as the only remarkable finding. Débridement and biopsy were performed. Histologic and immunohistochemical analysis of the specimen revealed an ALK(-) ALCL of the scalp. The lymphoma was resistant to bendamustine-containing chemotherapies, ultimately leading to the patient's death within 2 months. CONCLUSIONS: This case report highlights the importance of recognizing the possibility of an ALCL manifesting as a focal inflammatory swelling mass on the scalp.