Lymphangiomas are benign lesions but are associated with high morbidity when they become very large, occur in critical locations, or when surgically removed, develop secondary wound infections. Almost all lesions require surgical treatment. Complete excision is curative; however, relapses must be anticipated with incomplete excision. We report the case of a patient with a long history of massive cavernous lymphangioma of the breast and thoracic wall extending into the axilla in whom complete excision was not possible.