Abstract
Purpose: :
Orbital Mucosa-associated lymphoid tissue (MALT) lymphomas occur with increasing frequency. Standardized echography (SE) is a useful tool for the differential diagnosis of orbital tumors. Up to now, a differentiation of lymphomas from other so called low reflective orbital tumors like sarcoma and idiopathic orbital inflammation was not possible. The aim was to reevaluate the discriminative power of SE focusing on MALT-lymphomas.
Methods: :
Retrospective analysis identified 50 patients with orbital tumors with low reflectivity in SE. Lesions were precisely measured and echographic criteria were analysed. Results were compared to histological assessment of biopsy samples performed by a reference pathologist.
Results: :
Biopsy diagnosed 37 orbital lymphomas, 33 of which fulfilled the criteria of MALT-lymphomas. In 11 cases an inflammatory pseudotumor (IOI) and in two cases a rhabdomyosarcoma was identified. The retrospective analysis revealed a statistically higher intralesional reflectivity of MALT-lymphomas compared to IOI. MALT-lymphomas exhibited a specific echographic pattern with higher septa signals intermingled with very low reflective sections.
Conclusions: :
MALT-lymphomas are most frequent in orbital lesions with low internal reflectivity. Their echographic appearance is rather specific. They might be differentiated from other malignant lymphomas and from benign lesions like IOI by SE.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • orbit • tumors