A case of pseudolymphoma of the lacrimal gland and a clinicopathologic study of inflammatory pseudotumor of the orbit

The case of a 55-year-old female with pseudolymphoma of the right lacrimal gland is reported. The patient complained of exophthalmos of the right eye for three years. Clinical examination revealed 6 mm forward protrusion and marked downward displacement of the right globe. A hard tumor was palpable in the supero-temporal quadrant of the right orbit. The motion of the right eye was limited to the upper and outer sides. Right visual acuity was decreased because of the retinal folds of the posterior pole. Ultrasonography was carried out in A- and B-mode, and both suggested a mass lesion in the right lacrimal gland region. CT scans also detected a mass shadow demonstrating contrast enhancement with contrast medium. 67Ga scintigram revealed increased uptake in the right lacrimal gland region; sup(99m)Tc scintigram also detected increased uptake in the supero-temporal region of the right orbit. Based on these clinical findings, the tumor was removed, with clinical diagnosis of tumor of the right lacrimal gland. A histopathological diagnosis established the lesion as a pseudolymphoma because the tumor consisted of lymphoid tissue characterized by uniform proliferation of lymphocytes, formation of lymph follicles with germinal centers, dense fibrosis and vascular formation. The right lacrimal gland was practically replaced by this lymphoid tissue, only a few glandular elements remaining peripherally. Histopathological features showed no malignancy. The classification of orbital inflammatory pseudotumor and differential diagnosis of lymphoid pseudotumor of the orbit are discussed. (author)