Prospective Evaluation of Hypoxia in Primary Melanoma

Inclusion Criteria: 1. Must be willing and able to provide written informed consent for the study. 2. Must have histologically confirmed melanoma for which a Sentinel Lymph Node Biopsy (SLNB) is indicated per the treating physician. 3. Cutaneous or mucosal melanoma is permitted. 4. Female patients of childbearing potential must have a negative urine or serum pregnancy test within 7 days from the time of pimonidazole administration. 1. Female subjects of childbearing potential must not be pregnant or breastfeeding. Female subjects will be considered of non-reproductive potential if they: 1. are postmenopausal (defined as at least 12 months with no menses without an alternative medical cause; in women \< 45 years of age a high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a post-menopausal state in women not using hormonal contraception or hormonal replacement therapy. In the absence of 12 months of amenorrhea, a single FSH measurement is insufficient. 2. have had a hysterectomy and/or bilateral oophorectomy, bilateral salpingectomy or bilateral tubal ligation/occlusion, at least 6 weeks prior to screening. 3. have a congenital or acquired condition that prevents childbearing. 2. Female and male subjects of reproductive potential must agree to avoid becoming pregnant or impregnating a partner, respectively, while receiving study drug and 1 week after the dose of study drug for females and 2 weeks for males by complying with one of the following: 1. practice abstinence from heterosexual activity 2. use (or have their partner use) acceptable contraception during heterosexual activity. 5. Adequate hematologic function: white blood cells (WBC) ≥ 2,500/μL, platelet count ≥ 100,000/μL, hemoglobin ≥ 8.0 g/dL 6. Adequate renal function: serum creatinine ≤ 2.0 mg/dL 7. Adequate hepatic function: serum alkaline phosphatase, bilirubin, and ALT ≤ twice the institutional upper limit of normal Exclusion Criteria: 1. Subjects with known chronic immunosuppression (such as biologic agents like infliximab, mycophenolate, methotrexate, prednisone \> 20 mg daily). 2. Severe septicemia or severe infection in the 4 weeks prior to study entry. 3. History of previous neuropathy from chemotherapy or other causes not related to cancer. 4. Pregnant subjects or breastfeeding subjects. (Note: A pregnancy test will be administered within 7 days prior to the administration of pimonidazole to female subjects of childbearing potential enrolled in the study.) 5. Subjects with (ECOG) Performance scale of 4 - subjects unable to perform self-care. 6. Subjects who have received an investigational new drug 6 half-lives or two weeks prior to enrollment in this study, whichever is shorter.