Page 1328 - Clinical Small Animal Internal Medicine

1266 Section 11 Oncologic Disease

chondrosarcoma. The cell of origin in the three subtypes
VetBooks.ir is unclear, although damage to the lens and chronic
uveitis are common historical complaints.
Most eyes are blind from the preceding trauma or
chronic inflammation, and the most common presenting
signs are white, tan, or pink mass filling the anterior
chamber and distortion of the globe. Extension beyond
the sclera or into the optic nerve may be seen ultrasono-
graphically and are poor prognostic indicators. Growth
along the optic nerve into the chiasm and brain, invasion
of regional lymph nodes, and distant metastasis have
been reported. Early enucleation of suspicious globes
with removal of as much of the optic nerve as possible is
recommended, although it is unclear if this prolongs
survival.

History and Clinical Signs
Common presentations of intraocular tumors include
a visible mass involving intraocular tissues, sclera or
Figure 138.4 Canine iridociliary epithelial tumor. There is a occasionally the orbit, as well as glaucoma, hyphema,
nonpigmented, vascular ciliary body adenoma filling the posterior or anterior uveitis. Intraocular neoplasia should
chamber and pushing the inferior iris forward. Source: Courtesy of always be considered in animals with hyphema, glau-
University of Wisconsin‐Madison Comparative Ophthalmology coma, or both when there is no history of trauma or
Service Collection.
coagulopathy. Small masses frequently have no
clinical signs. Pigmentation is not a reliable indicator
Clinical signs include a retroiridal mass that may displace of tumor type.
the iris or lens and in advanced cases, secondary glau-
coma, intraocular hemorrhage, and ocular pain. Diagnosis
Tumors that invade the sclera are typically classified as
adenocarcinomas and have anaplastic features, but Usually, the clinical or ultrasonographic appearance (if the
metastasis is uncommon and occurs late in the course of media are opaque) is strongly suggestive of intraocular neo-
the disease, if at all. However, a few cases of truly malig- plasia. It may be difficult to differentiate organizing blood
nant pleomorphic adenocarcinomas with fatal metasta- clots from neoplastic mass lesions and more invasive diag-
sis have been reported in dogs. Dogs affected with this nostic procedures may be required. Because most anterior
rare form usually have long‐standing ocular disease that uveal brown or black masses are cystic and not neoplastic,
was initially thought to be inflammatory or traumatic in transillumination or ultrasonography should be attempted
origin. before resorting to more invasive procedures. Uveal cysts
Due to the possibility of malignancy, early enucleation typically are spherical, may be attached to the ciliary body
of ciliary body tumors has been recommended, although or free‐floating in the anterior chamber, and allow bright
benign adenomas may remain static for years. This light to pass through them (see Figure 138.2a). Once sus-
makes enucleation controversial for small tumors unas- pected, most primary canine intraocular tumors that are
sociated with secondary ocular disease. Local intraocu- not blinding nor causing discomfort are observed for
lar resection or laser photoablation in an effort to progression, although occasionally FNA (with its risks of
preserve vision and ocular comfort has been described. inflammation, infection, and hemorrhage), intraocular
resection, or enucleation are used for diagnostic purposes.
Feline Ocular Posttraumatic Sarcoma It is also important to rule out metastasis from another
A unique entity in cats, sarcomas following ocular primary site (e.g., oral cavity or nailbed) to the eye, or from
trauma are second only to melanomas in frequency as a the eye to other organs (especially lungs and liver).
primary feline ocular tumor. Most cats are middle‐aged
to older and the latency period following ocular trauma Therapy
to tumor development averages six to seven years. There
are three morphologic subtypes: spindle cell sarcoma Because the risk of metastasis is low and the ability of
(the most common), round cell, and osteosarcoma/ enucleation to prevent metastasis in the few malignant