The purpose of this study is to evaluate the efficacy of preoperative 5-ALA oral administration and subsequently intraoperative tumor bed phototherapy with red light laser, as an adjuvant therapy on the 3 years rate of local tumor recurrence in patients with desmoid tumors. To evaluate the Safety of 5-ALA administration. 5 years local recurrence rate.

Inclusion Criteria:

1. Patient has a resectable histologically confirmed desmoid tumor.
2. Previously treated (by chemotherapy, irradiation or surgery) patients are eligible.
3. Age > 18 years
4. Signed informed consent prior to patient recruitment. -

Exclusion Criteria:

1. Hepatic enzymes or bilirubin > 2X upper limit of normal.
2. Serum creatinine > 2.5 x upper limit of normal.
3. Suspected /documented metastatic disease.
4. Active or uncontrolled infections.
5. Active second malignant disease (excluding non-melanoma skin cancer, or in situ cervix or breast carcinoma) < 2 years prior to the study.
6. Use of other investigational agents < 30 days prior to the study.
7. Patients who are mentally or physically unable to comply with all aspects of the study.
8. Any serious medical condition, including the presence of laboratory abnormalities, which places the subject at an unacceptable risk if he or she participates in this study or confounds the experimental ability to interpret data from the study.
9. Pregnant or lactating females.
10. Known intolerance or allergy to 5-ALA
11. Suspicious or documented acute or chronic porphyria