The authors reviewed their experience with 524 secondary orbital tumor
cases diagnosed histopathologically during 1963-1993. Secondary tumor
s constituted 48.0% of all orbital biopsies during the same period. Th
ere were 186 (35.5%) cases with eyelid tumors, 146 (27.9%) cases with
intraocular tumors, 137 (26.1%) cases with conjunctival tumors, 26 (5.
0%) cases with nasopharyngeal tumors, 22 (4.2%) cases with sinus carci
nomas, 3 (0.6%) cases with intracranial meningiomas, 3 (0,6%) cases wi
th esthesioneuroblastomas, and 1 (0.2%) case with chordoma. The three
most frequent tumors making secondary orbital invasion were basal cell
eyelid carcinoma (129 cases; 24.6%), squamous cell conjunctival carci
noma (125 cases; 23.8%), and retinoblastoma (123 cases; 23.5%). Squamo
us cell carcinoma, from various sites of origin, was the most frequent
histopathologic tumor variant, accounting for 215 (41.0%) cases. Exen
teration was performed on 334 (63.7%) of 524 cases with secondary orbi
tal invasion. The ignorance of many lid and conjunctival lesions until
the advanced stages, which could otherwise be easily treatable, cause
d blindness and life-threatening complications under our conditions. O
rbital invasion from ocular retinoblastoma and uveal malignant melanom
a led to a markedly poor prognosis, again related to the late presenta
tion of many patients. Lack of health consciousness, inadequate primar
y surgery, and/or insufficient follow-up were the main reasons for sec
ondary orbital invasion in many tumor cases.