Evaluation of the Upper Limb Lymphatic System: A Prospective Lymphoscintigraphic Study in Melanoma Patients and Healthy Controls

Background: Current research on the upper limb lymphatic system mainly studies breast cancer patients with unilateral lymphedema. Without preoperative lymphoscintigraphy, the contralateral limb is used as a control, assuming that it is functionally intact. Few lymphoscintigraphic studies investigate patients before any axillary surgery. The purpose of this study was to evaluate, through lymphoscintigraphy, the preoperative condition of the upper limb lymphatic system in melanoma patients and healthy controls. Methods: Two groups were studied: the study group (16 patients with trunk/upper limb melanoma candidates for axillary sentinel lymph node biopsy) and the control group (10 healthy volunteers). All subjects underwent upper limb lymphoscintigraphy. Lymphoscintigraphic images were classified into three patterns based on the tracer appearance time in the axillary nodes. Type I, 20 minutes; type II, 60 minutes; and type III, 120 minutes. Statistical analysis was used to assess the relationship between lymphoscintigraphic patterns and clinical variables and to compare patterns of distribution. Results: Lymphoscintigraphic patterns were asymmetric in 37.5 percent (study group) and 50 percent (control group). Type III was the most common pattern. There was no significant association between lymphoscintigraphic patterns and considered clinical variables. There was no significant difference in the lymphoscintigraphic pattern distribution of the two groups (p = 0.870). Conclusion: The authors' findings show wide differences and an often "slow" tracer appearance time in patients with intact lymphatic system, questioning the use of contralateral limb as control and transportation time greater than 30 minutes as criteria for identification of lymphatic alterations. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.