USMLE paper 2 | In-depth Exam Questions and Correct Answers | Graded A+| New document!

Bone Marrow failure due to hematopoietic stem cell deficiency Causes: -Autoimmune -Infections (Parvo B-19, EBV) -Drugs (Carbamazepine, Chloramphenicol, Sulfonamides) -Exposure to radiation or toxins (benzene, solvents) Pancytopenia: -Anemia (fatigue, weak, pallor) -Thrombocytopenia (mucosal bleeding, easy bruising, petechiae) -Leukopenia (recurrent infections) BIOPSY: Hypocellular bone marrow with fat and stromal cells - Answer infant with pallor, fatigue, easy bruising/bleeding, petechiae, fever. Bone marrow biopsy showing hypocellularity with decrease in all cell lines and fatty infiltration of the marrow. acute lymphoblastic leukemia Most common childhood cancer 2-5 yo M>F bone pain due to leukemic infiltration of the bone marrow and typically affects long bones (femur, tibia). At night the dull pain more noticeable, during the day limp or refuse to walk. Pallor due to anemia, bruising due to thrombocytopenia, fever, hepatosplenomegaly. Dx: Bone marrow evaluation >25% lymphoblasts is diagnostic of leukemia Tx: Multidrug Chemotherapy - Answer splenomegaly, lymphadenopathy, limp. bruising, Petechiae, and mucosal bleeding (IMPAIRED PLATELET PRODUCTION) Pancytopenia Bone pain bone marrow showing infiltrative blasts. Iron deficiency anemia HIGH TIBC and HIGH Transferrin - Answer Total Iron Binding Capacity directly measures the iron bound by transferrin and indirectly measures transferrin levels acquired aplastic anemia Reduced mesenteric perfusion from congenital heart disease and/or HTN risk for intestinal ischemia and infarction. Tx: Bowel rest, parenteral nutrition, broad spec antibiotics, +/- surgery - Answer newborn (premature, hypotension, congenital heart defect) with temperature instability, feeding intolerance, abdominal distention, bloody stools. Bilious emesis. Xray: Air within the bowel wall (Pneumatosis Intestinalis) Chronic Lymphocytic Leukemia (CLL) - Answer elderly with Lymphadenopathy, hepatosplenomegaly, extreme fatigue. Severe lymphocytosis and smudge cells on peripheral smear. Chronic Myeloid Leukemia (CML) - Answer peripheral blood smear shows variety of neutrophil precursor cells (promyelocytes, myelocytes) Hairy Cell Leukemia Clonal B-Cell Neoplasm Middle age/older adults BRAF mutation Dx: Peripheral smear "Hairy" leukocyte cells, Bone Marrow Biopsy with flow cytometry Tx: Chemotherapy for moderate to severe disease. Normal life expectancy. - Answer splenomegaly, pancytopenia Hodgkin's lymphoma B-cell neoplasm with Reed Sternberg Cells Mediastinal mass or painless, enlarged lymph nodes. - Answer painless lymphadenopathy and night sweats and fever setting of normal peripheral blood smear Age 65 or Hysterectomy PLUS No hx of cervical intraepithelial neoplasia 2 or higher (If does continue for 20 years after detection) AND 3 consecutive negative Pap tests OR 2 consecutive negative co testing results - Answer When to STOP Pap Testing Without HPV co testing every 3 years starting at 21yo At 30 yo Pap test with HPV co-testing done and repeated every 5 years if (-) Pap testing ends at age 65 - Answer Pap testing FOLATE Cause megaloblastic anemia - Answer Alcohol abuse is the most common cause of which nutritional deficiency?