Extensive Extramedullary Involvement at Presentation in B-Cell Acute Lymphoblastic Leukemia.

Extensive extramedullary involvement as presentation is uncommon in pediatric B-cell acute lymphoblastic leukemia. A 7-year-old boy was diagnosed with painless parotid gland enlargement. He had pancytopenia and significantly raised serum lactate dehydrogenase. Fine-needle aspiration cytology from the parotid was suggestive of lymphoid malignancy. Flow cytometry and bone marrow biopsy suggested B-cell acute lymphoblastic leukemia. 18 F-FDG PET/CT revealed extensive bone marrow disease and the involvement of the spleen, pancreas, kidneys, and the parotid, submandibular, and lacrimal glands. He had negligible physiological brain uptake.