Lacrimal gland pleomorphic adenoma and malignant epithelial tumours: clinical and imaging differences

Aims To investigate the clinical and imaging features of primary and recurrent lacrimal gland pleomorphic adenoma (LGPA), as well as lacrimal gland malignant epithelial tumours (LGMET). Methods Retrospective comparative case series from September 2000 to September 2016 in a single tertiary institution. Medical records of cases with histopathologically proven primary LGPA (PLGPA), recurrent LGPA (RLGPA) and LGMET were reviewed. Results Sixty-four patients with LGPA (55 primary and nine recurrent) and 36 patients with LGMET underwent surgical excision in the study period. There was no significant difference in terms of age, gender or laterality. In terms of symptom duration, that of LGMET (7.1 months) was significantly shorter than PLGPA (23.9 months), which in turn was significantly shorter than RLGPA (127.1 months). Proptosis was the most common presenting symptom among all three groups. On CT, LGMET and RLGPA were significantly more likely to have ill-defined margins (p<0.001) and be heterogeneous (p<0.001) than PLGPA. RLGPAs (56%) were significantly more likely to have calcification than LGMET (34%), which in turn was more likely to have calcification than PLGPA (13%); LGMET (40%) and RLGPA (33%) were significantly more likely to have bony invasion than PLGPA (2.2%). On MRI, LGMETs (55%) were significantly more likely to have a tail or wedge sign indicating infiltration into the posterior orbit than PLGPA (0%) or RLGPA (0%). Conclusion Our study adds important information regarding differentiating clinical and radiological features between malignant and benign epithelial lacrimal gland tumours that would aid in their management.