Pediatric Precursor B-cell Lymphoblastic Lymphoma Presenting with Extensive Skeletal Lesions
A 3-year-old girl presented with right knee pain and swelling of 3 months duration. She had a fracture of the left femoral diaphysis 6 weeks prior to presentation. There was no history of any constitutional symptoms. Radiograph revealed expansile lytic lesion at the right supracondylar region and multiple lytic areas in the diaphyseal and metaphyseal regions of both femora and tibia []. She had been treated with antibiotics for suspected osteomyelitis. In view of non-response to antibiotics, possibility of malignancy was considered. Biopsy revealed a small round cell tumor. When she presented to us, she had mild pallor, but no icterus, rash, hemorrhagic manifestations, edema, lymphadenopathy or organomegaly. Her investigations revealed hemoglobin 105 gm/L, white blood cell count 7.4 × 109/L, platelet count 445 × 109/L, neutrophils 52%, lymphocytes 33%, monocytes 5% and bands 10%. Peripheral smear examination did not reveal blasts. Serum uric acid level was 350 μmol/L and lactate dehydrogenase level was 368 U/L. Urinary vanillylmandelic acid was not increased. Bone scan revealed foci of patchy radiotracer concentration in the proximal shaft of the bilateral tibia, distal shaft of the bilateral femur, proximal shaft and head of the right femur and proximal shaft of the left femur. Increased radiotracer concentration was seen in the right superior pubic ramus. Computerized tomography scan revealed multiple, well-defined expansile lytic lesions of varying sizes without sclerotic rim involving the bilateral femoral heads and femoral shafts, bilateral iliac blades, bilateral ischial tuberosity, right ilio-pubic ramus, vertebral body of D9 vertebrae, bilateral scapulae, bilateral humeral head and humeral shafts. Multiple hypodense focal lesions were seen in both the kidneys, the largest measuring 15 × 16 mm in size in the right lower pole [; panel A]. A hypodense, poorly enhancing lesion measuring 3.1 cm × 3.0 cm × 2.2 cm was seen in the left adnexal region [; panel B]. Bone marrow aspiration revealed occasional abnormal cells. Bilateral bone marrow biopsy could not reveal any abnormal cells.\nRight supracondylar biopsy review from an apex oncology institute revealed a high-grade hematolymphoid malignancy with blastic morphology. On immunohistochemistry, tumor cells were positive for leucocyte common antigen, CD79a, CD10 and terminal deoxynucleotidyl transferase, while being negative for CD20, CD3, CD5, c-kit and desmin, suggestive of precursor B-cell lymphoblastic lymphoma. Unfortunately, the parents refused treatment for socioeconomic reasons. The rate of refusal of treatment is about 20% in our unit.