ALK and non-Hodgkin lymphoma: Malignant tumours - both lymphoid and epithelial - have been reported to present clinically and radiologically as abscesses, leading to significant diagnostic delays. Anaplastic large cell lymphoma (ALCL) is a rare subtype of T cell non-Hodgkin lymphoma (NHL) characterised by CD30 positivity and, in some cases, anaplastic lymphoma kinase (ALK) expression.