Imaging Findings:
In suspicion of oro-pharyngeal malignancy, the patient underwent CE MRI of neck which showed a homogenously enhancing well circumscribed lobulated T1 hypointensity and T2 hyper intensity lesion measuring 4.0 x 2.8 x 2.0cm involving the right side of the oropharynx and tonsil(Fig 1). The lesion was causing partial effacement of the right side of vallecula, without midline extension of the lesion noted. No extension of the lesion beyond the confinement of oropharynx seen. Diffusion restriction noted with ADC value of 0.4 x 10^-3mm2/sec on b value of 800. Patient was counselled about the possibility of malignant lesion and was advised for biopsy to rule out malignancy. Punch biopsy was done and histopathology followed by immunochemistry and Interphase fluorescence in situ hybridization (FISH) confirmed it as case of Burkitt Lymphoma.
Microscopic Findings showed multiple fragments of tissue, partially lined by non-keratinized stratified squamous epithelium. Sub epithelium showed infiltration by monotonous population of atypical lymphoid cells. Those atypical lymphoid cells were intermediate to large in size with round to ovoid with coarse chromatin, irregular nuclear membrane, scant cytoplasm. Cytoplasm was scant in amount. Immunohistochemistry showed atypical lymphoid cells which were diffusely positive for CD45, CD20, PAX-5, CD10, BCL6 (weak), MUM-1, c-MYC (45%), while they are negative for CK (AE1/AE3), CD3, BCL2, Cyclin-D1, CD21 and CD34. Ki67 proliferation index is approximately 90%.
Thoracic abdominal and pelvic CT scans did not show any distant extension of the disease. Bone marrow aspiration and biopsy showed normocellular marrow. The complete blood count was unremarkable. Human immunodeficiency virus (HIV) serology was negative. Serology testing was positive for anti‑Epstein–Barr virus IgG.