Upper eyelid tumour

Purpose To describe the clinical and histologic features of a rare eyelid tumour. Methods A 56‐year‐old male patient presented with a nodular subcutaneous tumour in his right upper eyelid close to the eye brow. The lesion had been present for 2 years; there was no pain or inflammation but a slow increase in size. No other significant ocular abnormality was noted, and the patient's general health was good without any medication. On MRI, the tumour presented as a circumscribed non‐infiltrating pseudocystic mass, 20mm in diameter in size and located in the subcutis. Results Histopathology showed a loose myxoid stroma with low cellularity and occasional small blood vessels. A distinct capsule or pseudocapsule was not identified. Near the periphery some fat lobules were seen. The mucoid ground substance stained lightly with Alcian blue. The tumour cells were sparsely distributed throughout the tumour without any particular pattern; most appeared spindle‐shaped with an inconspicuous nucleus and no mitotic figures. Several mast cells were identified. Together with immunohistochemical findings (CD34+, SMA‐, Desmin‐), the diagnosis of myxoid spindle cell lipoma was made. Conclusion To our knowledge, no tumour has been documented in the literature that was histologically really similar to the one present in our patient. There was only very little normal adipose tissue, and a floret‐like nuclear pattern typical for pleomorphic lipoma (but also seen occasionally in normal orbital fat) was not observed. Even though the distinction from other lesions might in some cases be somewhat academic the differential diagnosis includes herniated orbital fat, other lipoma variants such as myolipoma and the hitherto mentioned pleomorphic lipoma, other myxoid tumours, and obiously malignant lesions such as (especially myxoid) liposarcoma.