Neonatal Consultations: Vascular Lumps, Bumps, and Tumors in the Neonate

Lymphatic Malformation

A lymphatic malformation (LM) is a congenital malformation of lymphatic vessels and may be further differentiated into microcystic, macrocystic, or mixed types depending on the size of the channels. An LM may present at birth or later and persists over time. Superficial microcystic LMs, synonymous with the term lymphangioma circumscriptum, characteristically appear as a group of clear and violaceous hemorrhagic vesicles on the skin. Deeper LMs appear as a tense or spongy, flesh-colored nodule or mass. Involvement of the head and neck is common. Complications frequently occur in LMs. Cutaneous LMs may ooze or bleed. Infection and hemorrhage into cysts may occur, which will cause acute pain, redness, swelling, and induration. Cervicofacial lesions may result in respiratory distress. Thus, the majority of LMs require treatment, though asymptomatic lesions may be observed in the neonate. An ultrasound will demonstrate a low-flow lesion, and magnetic resonance imaging is the diagnostic modality of choice for diagnosis and definition of extent.

KHE and Tufted Angioma

Kaposiform hemangioendothelioma is a rare, locally aggressive, vascular tumor that is frequently associated with a potentially life-threatening coagulopathy, Kasabach-Merritt phenomenon. Tufted angiomas are now understood to belong on a spectrum with KHEs, which usually present in the neonatal period or infancy as firm, red-violaceous plaques, nodules, or large tumors. Infiltration into nerve, muscle, and bone may occur. The firm/hard nature and deep violaceous appearance generally are initial clues that it is not an IH. Kasabach-Merritt phenomenon manifests as thrombocytopenia as well as low fibrinogen and elevated D-dimer levels. Thrombocytopenia is generally profound in Kasabach-Merritt phenomenon and results from platelet trapping within the vascular tumor. Given these potential complications, KHEs generally require immediate medical attention, and various treatment protocols including prednisone, vincristine, and sirolimus are utilized for complicated cases.⁵ The diagnosis may require biopsy to distinguish it from malignant tumors, particularly sarcomas.

Malignant Tumors

Various malignancies, including congenital leukemia, neuroblastoma, Langerhans cell histiocytosis, infantile fibrosarcoma, and rhabdomyosarcoma, rarely may present as cutaneous nodules or masses in a neonate mimicking hemangiomas or other vascular lesions (Figure 2). Neonates may present with multiple bluish papules and nodules resembling a blueberry muffin baby; multiple violaceous-red nodules; or a single red-violaceous, highly vascular–appearing mass mimicking hemangiomas. Malignant tumors may display vascularity on imaging, and thus the presence of vascular flow on ultrasound should not dissuade one from the possibility of a malignancy if other clinical features are atypical or unusual for a hemangioma. When a neonatal malignancy is suspected, a large punch biopsy or incisional biopsy is required for workup.

Final Thoughts

Although IHs are the most common vascular nodules in neonates and young infants, other conditions such as VMs, LMs, CHs, KHEs, and malignancy may occur less commonly. Identifying features that would be considered atypical for IH is crucial to recognize these less common possibilities.