Orbital dermoid cysts: clinicopathologic correlations, classification, and management. The 1997 Josephine E. Schueler Lecture.

The dermoid cyst is one of the most common space-occupying orbital lesions, but there has been no large series that details the clinical, pathologic, and therapeutic aspects of this condition. Furthermore, despite the various presentations and types of dermoid cysts, there is no clinically applicable classification of these lesions. We performed a retrospective histopathologic study of 197 consecutive orbital and periorbital dermoid cysts excised at Wills Eye Hospital during a 32-year period, correlated the histopathologic findings with the recorded clinical and radiographic observations, and devised a clinically applicable classification of orbital dermoid cysts. The mean age at excision was 17 years (range, 5 months to 85 years), and the most frequent clinical finding was a painless subcutaneous mass, present in 89% of cases. In 72% of patients, the mass was located in the superotemporal orbital region and produced no abnormalities of vision or intraocular pressure. Computed tomography and magnetic resonance imaging, performed mainly in the more recent cases, disclosed a characteristic round to ovoid cystic lesion with a well-defined lining. Histopathologically, 165 of the cysts (84%) were lined by keratinizing, stratified squamous epithelium. Ten (5%) were lined by nonkeratinizing epithelium resembling conjunctival epithelium. Hair shafts were present in the wall or lumen of the cyst in 195 (99%) of specimens, sebaceous glands in 148 (75%), and sweat glands in 39 (20%); inflammation was present in 75 cases (38%). Based on these personal observations and a review of the literature, a classification of orbital dermoid cysts is proposed that we believe will provide guidance for the ophthalmologist in the management of these lesions.

Occult prostatic carcinoma metastatic to the medial canthal area. Diagnosis by immunohistochemistry.

A 91-year-old man developed a mass in the right medial canthal and lacrimal sac region, which was found histopathologically to be a poorly differentiated neoplasm. The results of a complete systemic evaluation, including urologic consultation, rectal examination, bone scan, and determination of serum acid phosphatase level, were normal. In spite of the negative evaluation for prostatic carcinoma, immunohistochemical studies using immunoperoxidase stains for prostatic-specific antigen demonstrated that the lacrimal sac tumor was metastatic carcinoma from an occult primary neoplasm in the prostate gland. The presence of tumor in the prostate gland was then confirmed by a needle biopsy. Modern immunohistochemical techniques are particularly valuable in the diagnosis of selected ophthalmic tumors in which the diagnosis cannot be determined by routine diagnostic techniques.

Cryotherapy enhances intravitreal dispersion of viable retinal pigment epithelial cells.

Proliferative vitreoretinopathy (PVR) is the most common cause of failure in retinal reattachment surgery. Giant retinal tears are associated with a particularly high incidence of PVR. It involves the formation of cellular membranes that contract and cause traction retinal detachments. Retinal pigment epithelial (RPE) cells are a major component of these cellular membranes. Displacement of viable RPE cells from their normal position into the vitreous cavity is necessary for membrane formation to occur. This study demonstrates that cryotherapy, but not diathermy, enhances intravitreal dispersion of viable RPE cells in bovine eyes in vitro. This suggests that in some circumstances, excessive cryotherapy may play an exacerbating role in the initiation of PVR.