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).