Pathology Notes

Practice questions answers Lymphoid neoplasms IV   © Jun Wang, MD, PhD   1. D. This case is characterized by a rapid growing lymphoid lesion composed of small to medium sized round lymphocytes. Large cells with pale cytoplasm are scattered among these lymphocytes, forming a starry sky appearance. The expressions of CD10, CD19 and CD20, but not ALK, CD3, CD5, CD23, CD30, CD56 and cytokeratin are consistent with a B-cell lymphoma. Proliferative index by Ki67 100% is characteristic for Burkitt lymphoma , commonly with c-myc mutation. ALK is abnormal in anaplastic large cell lymphoma . BRAF mutation can be seen in hairy cell leukemia , melanocytic nevus and melanoma . IGH-CCND1 is a result of t(11;14)(q13;q32) in mantle cell lymphoma . MYD88 mutation can be seen in lymphoplasmacytic lymphoma . 2. A. EBV is associated with various lymphomas, including classical Hodgkin lymphoma , extranodal T/NK cell lymphoma , Burkitt lymphoma and primary effusion lymphoma . H. pylori can

Practice questions Lymphoid neoplasms IV © Jun Wang, MD, PhD   1. Use this case and image for the next three questions. A 9-year-old boy presents to the clinic with a rapidly growing mass on his left face for the last 3 weeks. He has had intermittent night sweat, fatigue and a 9-lb weight loss during this period. Physical examination reveals a 7 cm poorly circumscribed firm mass on the left mandible. No other abnormality is noted. His CBC reveals a hemoglobin of 10.5 g/dL (11-13.5 g/dL). His WBC and platelet counts are within normal range. Peripheral blood smear reveals no significant morphological abnormalities of the blood cells. An image of his biopsy is shown. (Image credit: Ed Uthman, MD., CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons) These cells are positive for CD10, CD19 and CD20, but negative for ALK, CD3, CD5, CD23, CD30, CD56 and cytokeratin. Proliferative index by Ki67 is approximately 100%. What gene is most likely abn