Inclusion Criteria:

- Patients with basal cell carcinoma (BCC)

- Patients ineligible for curative locoregional treatment and have either progressed
on, did not tolerate, unwilling to try or ineligible for investigational smoothened
antagonist such as vismodegib (GDC 0449), XL 139 (BMS 833923), IPI- 926, LDE225 and
PF-04449913

- Life expectancy estimate > 3 months

- Performance status Eastern Cooperative Oncology Group (ECOG) 0-2

- Absolute neutrophil count >= 1,500/mcL

- Platelets >= 100,000/mcL

- Total bilirubin within normal institutional limits

- Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase
[SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT])
=< 2.5 x institutional upper limit of normal

- Creatinine within normal institutional limits

- Corrected QT interval (QTC) by 12 lead electrocardiogram (EKG) < 450 msecs

- Serum potassium within normal limits

- Magnesium within normal limits

- Calcium within normal limits

- Include the following: ability to understand and the willingness to sign a written
informed consent document

- Patients must have evaluable tumor and be potentially eligible for pre and post ATO
tumor biopsy

Exclusion Criteria:

- Concurrent use of other Investigational agents is prohibited

- Patients with cardiac arrhythmias are excluded

- Patients receiving potassium wasting diuretics or amphotericin, while not excluded,
must be noted to have theoretically increased arrhythmia risks with ATO

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, recurrent seizure history or psychiatric illness/social situations that
would limit compliance with study requirements

- Pregnant women and breastfeeding women are excluded from this study