Asymptomatic Presentation of Mediastinal Actinomycosis in a Pediatric Patient with Acute Lymphoblastic Leukemia

We report a nine year old male with Philadelphia positive Precursor B Acute Lymphoblastic Leukemia who was diagnosed with mediastinal actinomycosis following failed central line placement. The patient had a normal chest X-Ray at diagnosis, had a good response to initial chemotherapy, but subsequently developed a widened mediastinum with vascular compression. The differential diagnosis for this included infection, leukemia relapse, a second malignancy and vascular and congenital abnormalities. Actinomycosis is associated with hematogenous spread and invasion of neighbouring structures, and should be considered in the differential diagnosis of any child with a mediastinal mass.