Background:
Prior to any imaging, when there is a question of type of malformation, screening labs are often obtained to help guide the clinician. In this case, a CBC, coagulation testing, d-dimer, and fibrinogen are our institution’s standard screen. This cohort of tests helps rule out a vascular tumor which can be associated with KMP. Additionally, d-dimer can be used to help distinguish between malformation types, with LMs typically having normal d-dimer levels while VMs often have varying degrees of elevation (42).
LMs can present at birth, early childhood, or adolescence, and are most commonly located in the head and neck area. On exam, they are soft masses with often normal overlying skin, but can exhibit a bluish hue, or have associated lymphatic vesicles or blebs (11). LMs can be associated with other syndromes such as KTS or congenital lipomatosis overgrowth, vascular malformations, epidermal nevi and scoliosis/skeletal/spinal anomalies (CLOVES) (56). The majority of LMs are due to somatic mutations in the phosphatidylinositol-4,5-biphosphonate 3-kinase catalytic subunit alpha (PIK3CA) gene (57). This gain of function mutation leads to a constitutively active PI3K/AKT/mTOR pathway, resulting in increased cell proliferation, survival and angiogenesis (56).There is a wide spectrum of clinical symptoms secondary to LMs, ranging from asymptomatic lesions to those that cause significant complications. Given their propensity for involvement of the head and neck area, functional impairment of the airway, feeding, or speech issues may arise in addition to cosmetic concerns (58). Increased pain and swelling can be associated with bacterial or viral infection, inflammation, trauma, or intra-lesional bleeding (59).