Management of isolated recurrence of extramedullary myeloid tumor at a single site
A 9-year-old male child presented with fever, weakness, and easy fatiguability for 1 month. There was no history of cough, chest pain, and bleeding manifestations. Family history was insignificant and there was no other significant past medical history. Physical examination was significant for pallor, bilateral subcentrimetric cervical, axillary and inguinal lymphadenopathy, and hepatomegaly. Investigations revealed hemoglobin of 8.6 gm%, leukocyte count 22.40 × 109/L and platelet count of 78 × 109/L. Peripheral blood examination showed 84% myeloblasts which were myeloperoxidase (MPO) positive. Bone marrow was hypercellular with 58% blasts that showed auer rods and were MPO positive. On flow cytometry, the blasts were positive for CD 13, CD 33, CD117, CD34, CD38, CD15, and CD19 and negative for CD11b and CD64. Fluorescent in situ hybridization (FISH) analysis of the bone marrow revealed the presence of t (8,21) translocation. The patient was classified as having good-risk AML and was treated with standard 3+7 induction with daunorubicin 60 mg/m2 iv push for 3 days and cytarabine 100 mg/m2 continuous 24-h infusion for 7 days. Day 10 marrow was dilute with no excess of blasts, suggestive of good response to therapy. Marrow examination done on day 30, after the recovery of counts, was in morphologic and cytogenetic remission. He was planned for consolidation with three cycles of cyatrabine at 18 g/m2. Following the 1st consolidation, he was detected to have a single hard 1 cm × 2 cm right cervical lymph node. Excisional biopsy of the lymph node revealed the presence of extramedullary myeloid tumor / granulocytic sarcoma. Cytogenetic evaluation showed the presence of translocation t (8, 21) in the aspirate from the lymph node. Imaging failed to reveal any other sites of lymphadenopathy. Bone marrow continued to be in morphological and cytogenetic remission by FISH. He was treated with salvage chemotherapy with two cycles continuous infusion cytarabine (500 mg/m2), Day 1-5, along with cladribine (9 mg/m2) Day 2-6.[] Following two cycles, patient continued to be in both clinical and hematological remission. Though allogenic stem cell transplant was considered as an option, the patient did not have a HLA-matched sibling and matched unrelated transplant was not financially feasible. Further consolidation was given with one cycle of mitoxantrone 8 mg/m2 for 1 day, cytarabine 75 mg/m2 for 5 days and etoposide 75 mg/m2 for 5 days. Maintenance was with six cycles of oral 6-TG 40 mg/m2 for 21 days of 28 days, oral etoposide 50 mg/m2 for 21 days of 28 days, and oral sodium valproate 500 mg twice daily. Following the oral maintenance, the patient was treated with external beam radiotherapy to the right hemi-neck at a dose of 25.2 Gy in 14 fractions. Presently, the child is disease-free and is doing well 18 months post-diagnosis of relapse and 6 months of completing chemotherapy.