Patient description: A 17 year old boy complains of vomiting, non-bloody diarrhea, abdominal pain, fever, chills and loss of appetite for the past 3 days. He ate a salad at a restaurant prior to his diarrhea onset. Physical exam was remarkable for pallor, jaundice, and diffuse abdominal tenderness. Lab results were as follows: Hemoglobin: 9.7 g/dL Platelet: 110,000 /cu.mm Creatinine: 3.6 mg/dL blood urea nitrogen (BUN): 73 mg/dL direct bilirubin: 2.4 mg/dL lactate dehydrogenase (LDH): 881 IU/L (normal: 110-265 IU/L) Peripheral blood smear showed a moderate number of schistocytes and helmet cells. Shiga-like toxin-producing E. coli (STEC) stx1/stx2 were found in stools. He has no other underlying disease and he is not on any medications.

Clinical trial eligibility criteria: eligible ages (years): 12.0-999.0,  Anaplastic Large Cell Lymphoma, ALK-Positive CD30-Positive Neoplastic Cells Present Systemic Anaplastic Large Cell Lymphoma Treatment-naive systemic ALK-positive ALCL patients Histologically confirmed diagnosis of cluster of differentiation (CD)30-positive ALCL with documented ALK-positive status Fluorodeoxyglucose (FDG)-avid disease by positron emission tomography (PET) and dimensional measurable disease of at least 1.5 cm as documented by radiographic technique (spiral computed tomography [CT] preferred) Eastern Cooperative Oncology Group (ECOG) performance status =< 3 Absolute neutrophil count (ANC) >= 1500/ul Platelet count >= 75,000/ul (unless documented bone marrow involvement with lymphoma) Hemoglobin (Hgb) >= 8 gr/dL Serum creatinine =< 1.5 x mg/dL and/or calculated creatinine clearance (using Cockcroft-Gault formula) >= 30 mL/min Total bilirubin =< 1.5 x upper limit of normal (ULN), except for patients with Gilbert's syndrome or documented hepatic involvement with lymphoma who may be included if bilirubin =< 3.0 x ULN or direct bilirubin =< 1.5 x ULN Aspartate transaminase (AST) =< 3 x ULN, except with liver involvement by the lymphoma who are only included if AST =< 5 x ULN; alanine transaminase (ALT) < 3.0 x ULN, except with liver involvement by the lymphoma who are only included if AST =< 5 x ULN  Known hypersensitivity to any of the excipients of ceritinib (microcrystalline cellulose, mannitol, crospovidone, colloidal silicon dioxide and magnesium stearate) Known prior history of interstitial pneumonitis, including clinically significant radiation pneumonitis (i.e. affecting activities of daily living or requiring therapeutic intervention) Impaired gastrointestinal (GI) function or GI disease that may significantly alter the absorption of ceritinib (e.g. ulcerative disease, uncontrolled nausea, vomiting, diarrhea, or malabsorption syndrome) or inability to swallow up to five ceritinib capsules daily History of pancreatitis or history of increased amylase or lipase that was due to pancreatitis Other severe, acute, or chronic medical condition including uncontrolled diabetes mellitus or psychiatric condition or laboratory abnormalities that, in the opinion of the investigator, may increase risk associated with study participation or may interfere with the interpretation of study results Major surgery (e.g. intra-abdominal, intra-thoracic or intra-pelvic) within 4 weeks prior to starting study treatment or lack of recovery from side effects of such procedure; video-assisted thoracic surgery (VATS) and mediastinoscopy will not be counted as major surgery and patients can receive study treatment >= 1 week after these procedures History of another primary malignancy that has not been in remission for at least 3 years (the following malignancies are exempt from the 3 year limit: non-melanoma skin cancer, fully-excised melanoma in situ [stage 0], curatively treated, localized prostate cancer, and cervical carcinoma in situ in biopsy or a squamous intraepithelial lesion on Papanicolau [PAP] smear) Known cerebral/meningeal disease Clinically significant, uncontrolled heart disease and/or recent cardiac event (within 6 months), such as: * Unstable angina * Myocardial infarction * History of documented congestive heart failure (New York Heart Association functional classification III-IV) * Uncontrolled hypertension defined by a systolic blood pressure (SBP) >= 160 mm Hg and/or diastolic blood pressure (DBP) >= 100 mm Hg, with or without antihypertensive medication * Ventricular arrhythmias, or supraventricular/nodal arrhythmias not controlled with medications; other cardiac arrhythmias not controlled with medications * Left ventricular ejection fraction < 20% corrected QT (QTcF) > 470 ms using Fridericia's correction on the screening electrocardiogram (ECG) * Initiation or adjustment of antihypertensive medication(s) is allowed prior to screening Any active grade 3 or higher (per the National Cancer Institute [NCI] Common Terminology for Adverse Events [CTCAE], version 4.03) viral, bacterial, or fungal) infection within two weeks prior to the first dose of study treatment