Abstract
Purpose :
Metastatic orbital tumors are rare and account for 3% of orbital lesions. It can be the initial manifestation of a systemic metastatic disease, and accurate pathological diagnosis is crucial. The objective of this study is to report 10 orbital metastases and to further understand these histopathological and immunohistochemical (IHC) characteristics.
Methods :
From 8018 cases reviewed, 203 orbital lesions including 28 malignant tumors were collected at the MUHC-McGill University Ocular Pathology & Translational Research Laboratory from 2006 to 2020. Among the malignant tumors, 11 cases were metastatic. Ten of the metastatic cases were selected based on complete clinical history and available slides.
Results :
Of the 10 patients with metastatic orbital tumors, 6 were women and 4 were men. The mean age was 68 years (range 52-83). Pathological examination revealed 70% (7/10) of carcinomas: metastatic breast carcinoma (3/10); adenocarcinoma consistent with metastasis of a prior cutaneous carcinoma (2/10) prostatic carcinoma (1/10); poorly differentiated carcinoma with a past history of skin squamous cell carcinoma (SCC) (1/10). The other three cases were plasmacytoma (2/10) and mucosal melanoma (1/10). All cases of breast carcinoma were positive for Estrogen Receptors (ER). Prostatic carcinoma was confirmed by PSA and NKX3.1. The two adenocarcinomas of the skin showed IHC findings which cannot exclude the possibility of breast origin: one case was 70-year-old female mucinous carcinoma, positive for ER, CK7, GATA3; the other was 53-year-old male signet-ring adenocarcinoma, positive for CK7, CK20, GATA3, BRST2. In both cases, no breast primary lesion was found, and the prior skin lesions showed similar morphology and IHC profile. Poorly differentiated carcinoma with a past skin SCC was positive for CK7 and negative for CK20, p40. The findings are consistent with metastasis from skin. In plasmacytoma, monoclonality was confirmed by light chain restriction with kappa and lambda. Melanoma was positive for HMB45 and Melan A.
Conclusions :
The use of a panel of immunohistochemical markers is crucial for the final diagnosis of orbital metastasis. The histopathological and immunohistochemical findings may be inconclusive particularly in cases of cutaneous carcinoma. Careful interpretation and clinicopathological correlation are essential for final diagnosis.
This is a 2021 ARVO Annual Meeting abstract.