Magnetic Resonance Lymphography of Lymphatic Vessels in Upper Extremity With Breast Cancer-Related Lymphedema.

Background: Magnetic resonance lymphangiography (MRL) has been proven to be able to visualize pathological lymphatic networks and accompanying complications through subcutaneous injection of commonly used contrast agents. However, no comprehensive prior studies have previously been reported regarding MRL for the evaluation of upper extremity lymphedema in patients with breast cancer-related lymphedema (BCRL). In this study, we establish a novel MRL protocol to characterize the normal and abnormal characteristics of different clinical stages of BCRL in patients using high-spatial-resolution MRL.

Methods: Fifty females with unilateral upper extremity BCRL underwent MRL. Lymphatic vessel morphology in normal and affected limbs was compared. The appearance, distribution pattern, morphologic characteristics, and maximum transversal diameter of the lymphatic vessels, dermal backflow, and regeneration of lymphatic vessels were analyzed.

Results: Lymph fluid was retained in the subcutis of the affected limbs, and no edema was observed in the subfascial compartment. In stage 1, tortuous and dilated lymphatic vessels exhibited a beaded appearance, and their diameters were larger than those in the contralateral forearm (P < 0.05). In stage 2, the dilated lymphatic vessels exhibited larger diameters. "Dermal backflow" and tiny regenerated lymphatic vessels appeared. The thickened subcutaneous tissue showed a honeycomb pattern induced by soft tissue fibrosis and adipose hypertrophy. In stage 3, disordered and unrecognizable affected lymphatic vessels were observed with many small regenerated lymphatics and confluent dermal backflow; the tissue fibrosis was more serious.

Conclusions: Each stage presents different characteristics, and the deformity degree of the lymphatic network is consistent with the severity of the disease. Magnetic resonance lymphangiography could provide adequate information for clinical staging in patients with BCRL.