Introduction: Anaplastic Large Cell Lymphoma (ALCL) is a rare distinct subset of T-cell non-Hodgkin lymphomas (T-cell NHL). Anaplastic Lymphoma Kinase (ALK) positive ALCL patients are generally associated with younger age and have a better prognosis. While Central Nervous System (CNS) involvement in T-cell NHL is rare and has a dismal prognosis. There was no report about ALK + ALCL and CNS vasculitis.
Case presentation: A 17-year-old boy who was diagnosed ALK + ALCL and underwent six courses of systemic chemotherapy presented as severe CNS vasculitis in the beginning, but eventually he was diagnosed CNS metastasis of ALCL by the presence of cranial nerve palsy, the demonstration of lesions on MRI and PET-CT, and Flow cytometry detection of tumor cells in Cerebrospinal Fluid (CSF).
Conclusion: We first present a case of CNS metastasis of systemic ALK + ALCL accompanied with CNS vasculitis. When an ALK + ALCL patient had CNS symptoms while imaging revealed CNS vasculitis, we need to be vigilant that the patient may have CNS involvement.