Keywords
carcinoma ex-pleomorphic adenoma - lacrimal gland - skull base - free flap
Case Description
A 47-year-old man with neurofibromatosis type I exhibited a rapidly enlarging right
orbital mass, deteriorating vision, and facial pain. Magnetic resonance imaging (MRI)
identified a 4.0 × 4.1 × 3.5 cm enhancing orbital mass with diffusion restriction,
bone erosion, and intracranial involvement ([Fig. 1A, B]). There was mild pachymeningeal enhancement and minimal T2 FLAIR signal hyperintensity
in the right frontal lobe. Malignant cytological features without further histological
definition were confirmed via fine-needle aspiration.
Fig. 1 Coronal (A) and axial (B) T1-weighted magnetic resonance imaging demonstrating an enhancing, destructive orbital
mass with intracranial extent.
Intervention
Multidisciplinary tumor board discussion led to recommendation of orbital exenteration,
orbitocranial craniotomy, and resection of intracranial disease followed by adjuvant
therapy as indicated by final pathology. Reconstruction involved defect coverage with
a pericranial flap, remnant craniotomy bone flap, synthetic dural matrix and sealant,
and left anterolateral thigh free flap. Initial free flap reconstruction was complicated
by multiple arterial thromboses and immediate flap failure. The decision was then
made to perform a second-stage flap reconstruction with utilization of low-intensity
heparin infusion. Following initial surgery, computed tomography imaging revealed
a small intraparenchymal hemorrhage within the right middle/inferior frontal gyri
with mild surrounding edema without significant mass effect. A subsequent successful
latissimus dorsi free flap reconstruction was performed 48 hours after an initial
surgery.
Outcomes
Postoperative imaging showed no intracranial hemorrhage progression, and the patient
was discharged after an uneventful hospital course on postoperative day 8. Pathology
reported high-grade adenocarcinoma with PLAG1–RP1 fusion, indicative of carcinoma
ex-pleomorphic adenoma (CXPA). Follow-up MRI at 2 months after surgery and 1 year
indicated no recurrence ([Fig. 2A–D]).
Fig. 2 (A, B) Two-month postoperative coronal (A) and axial (B) T1-weighted magnetic resonance imaging (MRI) showing postsurgical changes with generalized
soft tissue enhancement and no evidence of local recurrence or residual tumor. (C, D) One-year postoperative coronal (C) and axial (D) T1-weighted MRI showing residual dural thickening and postsurgical changes without
evidence of local recurrence.
Discussion
This case highlights the locally aggressive nature of lacrimal CXPA, and the surgical
complexities involved in management of lacrimal malignancy. Lacrimal tumors represent
10% of all space-occupying lesions of the orbit.[1] CXPA is the second most common lacrimal gland malignancy, but its overall incidence
is relatively low, comprising 8% of all lacrimal gland epithelial tumors. Histologically,
PLAG–RP1 fusion is a useful specific marker for identifying CXPA, especially those
of salivary gland origin.[2]
[3] Prognosis is relatively favorable with 5-year overall and cancer-specific survival
of 81.9%.[4] Signs and symptoms at presentation typically include rapid eyelid swelling, proptosis,
pain, and vision change.[5] Treatment strategies involve surgical resection and adjuvant therapy as indicated
by pathologic features. A globe-sparing approach is reasonable in early-stage tumors,
but this requires multidisciplinary evaluation and careful consideration of patient-specific
factors. More advanced cases typically require orbital exenteration.[6] Patients who require free tissue transfer may be at significantly increased risk
of flap vessel thrombosis if their defect involves dura and/or brain parenchyma.[7] Despite the potential risks, aggressive surgical management with a multidisciplinary
approach can lead to favorable outcomes in cases of advanced tumors.
Conclusion
This case underscores the importance of a multidisciplinary approach to managing lacrimal
malignancies, particularly those with intracranial extent. Aggressive surgical management
is required for definitive treatment of advanced local disease. Careful reconstructive
planning is necessary for patients with composite skull base defects.
