Lymphangiomas are vascular malformations with a fragile endothelial and lymphatic component, often presenting with cystic structures [5,7]. They can occur in various locations, but orbital involvement is rare, representing only about 2% of orbital tumors. These lesions are benign, but can have severe functional and aesthetic consequences.

According to the International Orbital Society [2], orbital lymphangiomas are classified as Type 1 (low-flow, with no connection to the vascular system) malformations. Lesions with vascular connections are classified as Type 2.

Clinically, orbital lymphangiomas usually present with progressive exophthalmos (axial or non-axial), often associated with dystopia, limited ocular motility, and tissue infiltration, depending on tumor location.

In some cases, onset is acute, with sudden exophthalmos and decreased visual acuity caused by compressive intra-cystic hemorrhage [3,4].

In our case, the evolution was insidious, later complicated by acute hemorrhage and exophthalmos. Imaging plays a crucial role in diagnosis, assessment of severity, and treatment planning [2,6]:

• Doppler ultrasound: first-line, detects slow-flow cystic
• CT scan: widely available, useful for evaluating tumor extent and its relationship with orbital and facial bones—especially relevant for surgical planning.
• MRI (T1, T2, FLAIR sequences): gold standard, typically shows a heterogeneous, multilobulated lesion with cystic and hemorrhagic MRI also allows precise evaluation of orbital and periorbital extension, involvement of adjacent structures, and detection of other lesions in the face and neck.

In our case, the lesion was purely orbital with slight infiltration of the left upper eyelid.

Management of orbital lymphangioma is difficult, influenced by:

• the young age of most patients,
• the need to preserve visual acuity and prevent

Treatment strategies include:

1. Conservative (medical) therapy:
Sirolimus is currently the most effective systemic treatment. It inhibits the mTOR pathway, exerting anti-lymphangiogenic activity. Wiegand et al. analyzed 28 studies including 105 children (newborn to 17 years) treated with sirolimus for head and neck lymphatic malformations: 91% responded, with treatment durations ranging from 6 months to 4 years. Reported side effects include neutropenia, infections, and hyperlipidemia [1,3].

2. Surgical management:
Challenging because lesions are unencapsulated. Often limited to partial excision or debulking to reduce mass effect, particularly when optic neuropathy is suspected. Intraoperative bleeding is a major risk, but may be minimized using diathermy, CO₂ laser, or fibrin glue injection into cystic components (Boulos et al.) [2].

3. Non-surgical interventional therapy (sclerotherapy)
Agents used include:

• OK-432 (Picibanil)
• Sodium tetradecyl sulfate (5%)
• Sodium morrhuate, Bleomycin A5

These are injected perilesionally to reduce tumor volume, either as definitive treatment or to facilitate subsequent surgery; Patel et al. reported a series of three cases of facial and orbital lymphangiomas successfully treated with sclerotherapy [2].

In our case, the patient was treated conservatively with sirolimus (0.05 mg/kg twice daily) for one year, with no adverse effects reported so far. The decision for medical therapy was taken after a multidisciplinary consultation involving pediatric surgery, neurosurgery, and pediatric oncology. Given the relatively small tumor size, absence of additional lesions, and delicate intra-conal location, surgery or sclerotherapy carried significant risks of ocular or facial ischemia and were therefore avoided.