Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 18.0-70.0,  Primary Mediastinal B-cell Lymphoma Diffuse, Large B-cell Lymphoma Diffuse Large B-Cell Lymphoma Transformed From Follicular Lymphoma Mantle Cell Patient must have a cluster of differentiation 19 (CD19)-expressing B-cell lymphoma. Patients with diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, and diffuse large B-cell lymphoma transformed from follicular lymphoma must have measurable disease after at least two prior chemotherapy regimens one of which must have contained doxorubicin and rituximab. 2. Confirmation of diagnosis of B-cell malignancy and positivity for CD19 confirmed by the Laboratory of Pathology of the National Cancer Institute (NCI). The choice of whether to use flow cytometry or immunohistochemistry will be determined by what is the most easily available tissue sample in each patient. Immunohistochemistry will be used for lymph node biopsies, flow cytometry will be used for peripheral blood, fine needle aspirates and bone marrow samples. 3. Patients must have indications for treatment for their B-cell malignancy at the time of enrollment on this trial. 4. Greater than or equal to 18 years of age and less than or equal to age 70. 5. Willing to sign a durable power of attorney. 6. Able to understand and sign the Informed Consent Document. 7. Clinical performance status of Eastern Cooperative Oncology Group (ECOG) 0 or 1. 8. Life expectancy of greater than three months. 9. Patients of both genders must be willing to practice birth control from the time of enrollment on this study and for four months after treatment. 10. Women of child bearing potential must have a negative pregnancy test because of the potentially dangerous effects of the treatment on the fetus. 11. Serology Seronegative for human immunodeficiency virus (HIV) antibody. (The experimental treatment being evaluated in this protocol depends on an intact immune system. Patients who are HIV seropositive can have decreased immune -competence and thus be less responsive to the experimental treatment and more susceptible to its toxicities.) Seronegative for hepatitis B antigen and hepatitis C antibody unless antigen negative. If hepatitis C antibody test is positive. Then patients must be tested for the presence of antigen by reverse transcription-polymerase chain reaction (RT-PCR) and be hepatitis C virus ribonucleic acid (HCV RNA) negative. 12. Hematology Absolute neutrophil count greater than or equal to 1000/mm^3 without the support of filgrastim Platelet count greater than or equal to 50,000/mm^3 Hemoglobin greater than 8.0 g/dl Lymphocyte count less than or equal to 4,000/ mm^3 13. Chemistry Serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) less or equal to 5 times the upper limit of normal Serum creatinine less than or equal to 1.6 mg/dl Total bilirubin less than or equal to 1.5 mg/dl, except in patients with Gilbert's Syndrome who must have a total bilirubin less than 3.0 mg/dl 14. More than three weeks must have elapsed since any prior systemic therapy at the time the patient receives the preparative regimen, and patient toxicities must have recovered to a grade 1 or less (except for toxicities such as alopecia or vitiligo). 15. Normal cardiac ejection fraction and no evidence of pericardial effusion as determined by an echocardiogram  Patients that require urgent therapy due to tumor mass effects such as bowel obstruction or blood vessel compression. 2. Patients that have active hemolytic anemia. 3. Patients with active brain metastases, or with a history of any central nervous system (CNS) metastases or cerebrospinal fluid malignant cells. Note: patients who are asymptomatic but are found to have malignant cells in the cerebrospinal fluid (CSF) on lumbar puncture prior to treatment will be considered eligible. 4. Women of child-bearing potential who are pregnant or breastfeeding because of the potentially dangerous effects of the treatment on the fetus or infant. 5. Active systemic infections, coagulation disorders or other major medical illnesses of the cardiovascular, respiratory or immune system, myocardial infarction, cardiac arrhythmias, obstructive or restrictive pulmonary disease. 6. Any form of primary immunodeficiency (such as Severe Combined Immunodeficiency Disease). 7. Concurrent opportunistic infections (The experimental treatment being evaluated in this protocol depends on an intact immune system. Patients who have decreased immune competence may be less responsive to the experimental treatment and more susceptible to its toxicities). 8. Concurrent systemic steroid therapy. 9. History of severe immediate hypersensitivity reaction to any of the agents used in this study. 10. History of allogeneic stem cell transplantation 11. Patients with cardiac atrial or cardiac ventricular lymphoma involvement. Screening Evaluation: Within 4 weeks prior to starting the chemotherapy regimen: 1. Complete history and physical examination, including, weight and vital signs, noting in detail the exact size and location of any lesions that exist. (Note: patient history may be obtained within 8 weeks.) 2. Chest x-ray 3. Electrocardiography (EKG) 4. Baseline computed tomography (CT) of the chest, abdomen and pelvis, positron emission tomography (PET) scan, and brain magnetic resonance imaging (MRI) to evaluate the status of disease. Additional scans and x-rays may be performed if clinically indicated based on patient signs and symptoms. 5. HIV antibody titer and Hepatitis B surface antigen (HbsAG) determination, and anti HCV, (Note: May be performed within 3 months of the chemotherapy start date). 6. Anti cytomegalovirus (CMV) antibody titer, herpes simplex virus (HSV) serology, and Epstein-Barr virus (EBV) panel (Note: patients who are known to be positive for any of the above do not need to be retested; may be performed within 3 months of chemotherapy start date) 7. Patients with a left ventricular ejection fraction (LVEF) of less than or equal to 55% will not proceed to treatment (Note: may be performed within 8 weeks of treatment). 8. Cluster of differentiation 19 (CD19) staining of malignant cells by immunohistochemistry or flow cytometry (testing is permitted to be conducted at any time prior to this point). 9. All patients must have a T cells, B cells, and natural killer cells (TBNK) for Peripheral blood cluster of differentiation 3 (CD3) count and CD19#. 10. Patients with a history of leptomeningeal disease, or signs/symptoms suggestive of leptomeningeal involvement, or with symptoms of central nervous system malignancy such as new onset severe headaches, neck stiffness, or any focal neurologic findings on physical exam will have lumbar puncture for examination of cerebral spinal fluid. 11. Patients may undergo lumbar puncture (LP) for flow cytometry of the CSF in order to assess the presence of CD19 positive lymphocytes for potential correlation with neurologic toxicity. Patients who have no neurologic symptoms at the time of LP will be eligible for enrollment regardless of the results of the flow cytometry. Within 14 days prior to starting the chemotherapy regimen: 12. Chem 20: (Sodium (Na), Potassium (K), Chloride (Cl), Total carbon dioxide (CO2) (bicarbonate), Creatinine, Glucose, Urea nitrogen (BUN), Albumin, Calcium total, Magnesium total (Mg), Inorganic Phosphorus, Alkaline Phosphatase, ALT/glutamic pyruvic transaminase (GPT), AST/glutamic oxaloacetic (GOT), Total Bilirubin, Direct Bilirubin, lactate hydrogenase (LD), Total Protein, Total creatine kinase (CK), Uric Acid) 13. Thyroid panel 14. Complete blood count (CBC) with differential and platelet count 15. Prothrombin time (PT)/partial thromboplastin time (PTT) 16. Urinalysis and culture, if indicated Within 7 days prior to starting the chemotherapy regimen: 17. Beta-human chorionic gonadotropin (βHCG) pregnancy test (serum or urine) on all women of child-bearing potential 18. ECOG performance status of 0 or 1