RESUMO
Six cases of a distinctive but poorly recognized variant of lymphangiomatosis with predominant or exclusive involvement of the soft tissues of the limb/limb girdle are described. The six patients were male and presented with slowly progressive swelling of the involved limb. The age of onset was at birth (three cases), 3 months (one case), 11 years (one case) and 12 years (one case). Five patients had involvement of the lower extremity and one of the right upper extremity. Three patients had concomitant asymptomatic bone involvement either in the affected limb (two cases) or in distant bones (one case). Only one patient had visceral involvement that was limited to the ipsilateral thorax and was associated with chylothorax. Diagnosis was confirmed in all but one patient by lymphangiography. Treatment consisted principally of surgical reduction with significant clinical improvement. No patient later developed systemic involvement and the clinical course was benign. The bone lesions did not progress in any patient. Histologically, each case was characterised by interconnecting, dilated lymphatic spaces, lined by a single, attenuated layer of endothelial cells, involving the dermis, subcutis, and occasionally, underlying fascia and skeletal muscle with characteristic and extensive "dissection" of collagen and surrounding normal adnexal structures. Despite the absence of red blood cells in the vascular spaces, interstitial hemosiderin deposition was prominent in four cases. As opposed to most cases of lymphangiomatosis, which usually have extensive visceral involvement associated with a very poor prognosis, involvement in this variant is limited almost exclusively to soft tissues of the limb and bone and is associated with good prognosis.
