Clinical and histologcal features of benign fibrous histiocytoma of the corneosclera
H. Agostini1, C. Auw-Hädrich1, R. Sundmacher2, H. Witschel1
Benign fibrous histiocytoma is the most common mesenchymal tumor of the orbit. Rarely the tumor affects the anterior sclera or even the choroid. We report about the clinical and histological findings in three patients with a benign fibrous histiocytoma of the corneosclera.
Patients: (1) A 9-year-old boy developed a round, clearly defined tumor of the limbus corneae within several weeks. It grew to a size of about 10mm3. The reddish-yellow tissue was moderately vascularized. (2) A 29-year-old man noticed a reddish tumor close to his cornea. Within a year it increased in volume to about 120 mm3 and showed signs of inflammation. (3) A 53-year-old-woman complained of foreign-body-sensation in one eye. Eight weeks before, she had observed a little tumor next to the cornea. Its volume was about 30 mm3. It appeared well vascularized and was firmly attached to the sclera. The patients were otherwise healthy.
Results: The tumors were surgically removed in all three cases. The histological examination showed a mixed subepithelial inflammation with histiocytes, multinuclear giant cells, lymphocytes, plasma cells, single neutrophilic and eosinophilic granulocytes. Macrophages were characterized by immunohistochemistry. The ratio of fibroblastic to histiocytic cells varied from sample to sample. The storiform pattern of the fibroblasts which is typical for fibrous histiocytoma of the orbit, was a prominent feature in the tumors of the two older patients. The reddish appearence was due to an increased density of blood vessels.
Conclusions: Benign fibrous histiocytoma is a rare tumor of the corneosclera. It can grow significantly within weeks. Patients can be affected regardless of age which is also true for the orbital histiocytoma. Since malignant variants have been reported, it is advisable to remove the tumor surgically.
1Univ.-Augenklinik Freiburg, Killianstr. 5, D - 79110 Freiburg