Enhanced cutaneous lymphatic network in the forearms of women with postmastectomy oedema

Postmastectomy oedema (PMO) of the arm is a common aftermath of axillary ly mphatic damage during treatment for breast cancer. The aim of the present s tudy was to quantify the forearm dermal lymphatic capillaries in order to d etermine whether they exhibit adaptive responses to PMO. Both forearms were examined by fluorescence microlymphography in 16 patients with oedema foll owing treatment for breast cancer (mean swelling 25 +/- 4%) and 19 patients treated for breast cancer but without oedema. Delineated lymphatic network s were analysed stereologically. The main findings were: (1) lymphatic dens ity at any specified distance from the injection site was greater in the sw ollen arm than the control arm (p < 0.01, t test); (2) taking into account the increased skin area, the total length of lymphatic capillaries in a 1-c m annulus of skin was 676 +/- 56 cm (swollen), compared with 385 +/- 30 cm (control) (p < 0.001, t test); (3) fluorescent marker was transported over a greater distance before draining deep in the swollen arm (2.74 +/- 0.33 c m) than in the control arm (1.59 +/- 0.24 cm) (p = 0.02); (4) there was no evidence of lymphatic dilatation in the swollen arm, and (5) in breast canc er patients without swelling, the arm on the side of radiotherapy/surgery ( otherwise referred to as the unswollen arm) showed none of the above change s, indicating that the changes are linked to the oedema rather than being u niversal responses to breast cancer or its treatment. It is concluded that microlymphatic changes occur in the swollen arm, namely a local superficial rerouting of lymph drainage and either lymphangiogenesis and/or increased recruitment of dormant lymphatic vessels. Since blood capillary angiogenesi s occurs in the swollen arms, and lymphangiogenesis occurs in experimental lymphoedema, there is a precedent for proposing lymphangiogenesis in PMO. A n increased number of functional vessels would help to maintain the ratio o f local tissue drainage capacity to filtration capacity. Copyright (C) 2000 S. Karger AG, Basel.