Patient description: The patient is a 33-year-old woman complained of fatigue, weight gain and abnormal spotting between menses. No hirsutism or nipple discharge was detected. Her BMI was 34. Her lab results were remarkable for high TSH level (13 mU/L) and low free T4 level (0.2 ng/dl). Her anti-TPO levels were extremely high (120 IU/ml). She was diagnosed with Hashimoto's thyroiditis. Her aunt, brother and mother have the same disease. After starting 250 mcg Levothyroxine per day, her symptoms improved significantly and her periods are normal. She is still overweight with BMI of 31. Her most recent thyroid profile revealed all results except for anti-TPO within the normal range: TSH: 2.35 mU/L Free T4: 2.7 ng/dl Anti-TPO: 75 IU/ml

Clinical trial eligibility criteria: eligible ages (years): 1.0-30.0,  T Acute Lymphoblastic Leukemia T Lymphoblastic Lymphoma T-ALL patients must be enrolled on AALL08B1 prior to treatment and enrollment on AALL0434 Patients must have newly diagnosed T-ALL or T-lineage lymphoblastic lymphoma (T-NHL) stage II-IV; B-lineage lymphoblastic lymphoma will not be eligible for this study; a diagnosis of T-ALL is established when leukemic blasts lack myeloperoxidase or evidence of B-lineage derivation (cluster of differentiation [CD]19/CD22/CD20), and express either surface or cytoplasmic CD3 or two or more of the antigens CD8, CD7, CD5, CD4, CD2 or CD1a; if surface CD3 is expressed on all leukemic cells, additional markers of immaturity, including transmission disequilibrium test (TdT), CD34 or CD99 will be assessed for expression; cases with uncertain expression will receive additional review within the appropriate Children's Oncology Group (COG) reference laboratory T-NHL For T-NHL patients with tissue available for flow cytometry, the criterion for diagnosis should be analogous to T-ALL; for tissue processed by other means (i.e. paraffin blocks), the methodology and for immunophenotypic analysis to establish the diagnosis of T-NHL defined by the submitting institution will be accepted Prior therapy restrictions Patients shall have had no prior cytotoxic chemotherapy with the exception of steroids and/or IT cytarabine IT chemotherapy with cytarabine is allowed prior to registration for patient convenience; this is usually done at the time of the diagnostic bone marrow or venous line placement to avoid a second lumbar puncture; (Note: the CNS status must be determined based on a sample obtained prior to administration of any systemic or intrathecal chemotherapy, except for steroid pretreatment); systemic chemotherapy must begin within 72 hours of this IT therapy Patients diagnosed as having T-NHL or T-ALL with respiratory distress or hyperleukocytosis may require steroids prior to the initiation of additional systemic therapy; they are eligible for AALL0434 and will be stratified, based on the initial complete blood count (CBC); steroid pretreatment may alter the risk group assessment; if the T-ALL patient's clinical status precludes a lumbar puncture within 48 hours of the initiation of steroid therapy, T-ALL patients be classified as low risk and will be Intermediate or high risk based on the results of the day 29 marrow as above; patients with T-NHL who receive steroid pre-treatment will be classified as high risk; the dose and duration of previous steroid therapy should be carefully documented For the management of airway compromise, patients who have received emergent chest irradiation up to 600 cGy will be eligible for this study Patients with a prior seizure disorder requiring anti-convulsant therapy are not eligible to receive nelarabine; in addition, patients with pre-existing grade 2 (or greater) peripheral neurotoxicity, as determined prior to Induction treatment by the treating physician or a neurologist, are not eligible to receive nelarabine; these restrictions in are designed to prevent excessive nelarabine-induced central and peripheral neurotoxicity in at-risk patients; for the purposes of this study, this includes any patient that has received anticonvulsant therapy to prevent/treat seizures in the prior two years  Pregnant or lactating females are ineligible Patients with Down syndrome are ineligible to enroll onto this study For T-NHL patients the following additional apply B-precursor lymphoblastic lymphoma Morphologically unclassifiable lymphoma Absence of both B-cell and T-cell phenotype markers in a case submitted as lymphoblastic lymphoma CNS3-positive or testicular involvement