1. Introduction
Intra-abdominal vascular malformations are rare entities, reported in the literature to have a 1% incidence, with the true incidence likely higher given small asymptomatic lesions.1–3 There are three general types of vascular malformations which are seen in non-solid organs of the abdomen which include venous, lymphatic, arteriovenous, and combinations such as lymphatic-venous malformations.4 Lymphatic malformations (LM) occur during embryonic development as a result of abnormally formed lymphatic vessels and represent the most common form of low-flow, non-solid organ, intra-abdominal vascular malformation.1,4
Intraabdominal lymphatic malformations (ILM) are medically and surgically complex and require a sophisticated, multi-disciplinary approach to treatment. There are no consensus guidelines on the management or prognosis of these lesions. Recent studies have demonstrated that though LM are rare entities, both inpatient charges and resource utilization as well as mortality are on the rise for patients with lymphatic malformations.5 Intraabdominal lymphatic malformations have a known association with other vascular malformations, especially those involving the trunk. Patients with CLOVES syndrome (Congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and scoliosis/skeletal/spinal anomalies syndrome), a PIK3CA related overgrowth syndrome (PROS), frequently manifest with involvement/features on the flanks or abdomen.4,6 Sirolimus therapy has been used to treat PROS and has demonstrated safety and efficacy, though it is accepted that it does not cause shrinkage of the malformations, but rather stabilizes them and reduce symptoms including pain.4,7–10 The purpose of this study was to investigate the natural history and clinical course of this disease process including required and delivered therapies and treatments.