A few other eyelid conditions can mimic the symptoms similar to those observed with eyelid tumors. It is important to exclude these conditions before establishing a conclusive diagnosis.
- Hordeolum (stye). Styes represent bacterial infections or inflammation of the eyelid margin glands. They can appear as either a single abscess or multiple abscesses with swelling along the eyelid margins.
- Chalazion. A chalazion is the retention and accumulation of material within one of the glands of the eyelid. Chalazia typically appear as smooth white, yellow or tan nodules along the inside rim of the eyelid margins. They may remain quiet and non-painful with little to no change in appearance, they may eventually decrease in size, or they may induce inflammation and increase in size.
- Allergic blepharitis (inflammation of the eyelids). Ocular exposure to a contact allergen can result in a rapid onset of symptoms that include eyelid (conjunctival) swelling and redness. The eyelid condition may also be associated with a generalized allergic reaction of the body. This is most often seen after insect bites, drug reactions and as a post-vaccination reaction.
- Autoimmune skin diseases. Certain autoimmune skin diseases can manifest as eyelid inflammation, swelling and ulceration. These include pemphigus foliaceus, pemphigus vulgaris, and pemphigus erythematosus. These diseases commonly affect the skin of the face, lips, nose pads, ears and eyelids.
- Bacterial blepharitis. Inflammation of the eyelids is often caused by Staphylococcus and Streptococcus spp. of bacteria infecting the meibomian glands located within the eyelid margin. Abscesses form nodules along the eyelid margin. The infections can be long-standing and recurrent in nature. In puppies, this condition can be quite severe and cause considerable facial and eyelid swelling.
- Parasitic blepharitis. Both demodectic and sarcoptic mange can involve the eyelids in dogs. In young dogs, the infection is commonly isolated to the face and eyelids. Typically these mites cause crusty, hairless lesions on the eyelids rather than nodule formation.
- Mycotic (fungal) blepharitis. Ringworm can cause inflammation of the eyelids, but usually cause hairless and crusty lesions rather than the development of nodules or masses.
- Cuterebra larvae. The Cuterebra fly may lay its eggs along the eyelid margin. After the eggs hatch, a large larval worm begins to grow under the skin and a slow growing mass may develop around it. The mass always has a small hole in the surface of the skin through which the larva breathes.
- Granulomatous inflammation. Certain immune-mediated inflammations of the eyelids of dogs may form nodules that appear very similar to eyelid tumors. These include two rather unusual diseases: nodular granulomatous episcleritis and periadnexal multinodular granulomatous dermatitis. Both of these conditions may be accompanied by nodules in other locations, such as within the eye or skin.
Diagnostic tests are performed to determine the cause for the eyelid nodule/swelling, verify that the lesion is of a specific tumor type, define the degree of local invasion of the tumor, and determine if the eyelid tumor will spread. The following tests are often recommended:
- Complete medical history and physical examination including palpation of regional lymph nodes for evidence of enlargement and auscultation of the chest. Historically, it is important to ascertain the duration of the eyelid lesion, the occurrence of any prior tumors (anywhere in the body), and any accompanying physical symptoms of disease.
- Complete ophthalmic examination includes close examination of the eyelids, cornea, conjunctiva, and front chamber of the eye. This examination helps to delineate the boundaries and local extent of the eyelid tumor. The conjunctiva and cornea are examined for evidence of irritation caused by the eyelid tumor.
- Fluorescein staining of the cornea is performed to assess the presence of corneal erosions and ulcerations.
- Bacterial culture of secretions from the eye may be done to determine the presence and type of bacteria.
- Fungal culture and microscopic examination of skin scrapings from around the eyelid are done to assess for the presence of ringworm and parasitic mites.
- Fine needle aspirate of the eyelid tumor for cytology (complete cell analysis) can, in some cases, help to classify the type of tumor. Because cells are difficult to retrieve in some tumors, this test may be inconclusive.
- Tissue biopsy of the eyelid tumor provides the best means to establish a definitive diagnosis of the tumor type.
- Complete blood count and serum biochemistry are done to evaluate organ functions and to search for evidence of infection or certain types of malignant cancers such as lymphosarcoma.
- Cytology of cell aspirates from enlarged regional lymph nodes may be considered
to assess for the presence of tumor metastasis.
- Thoracic (chest) and abdominal radiographs are performed to determine the presence and extent of tumors that are suspected to have spread from somewhere else in the body.
Treatment In-depth for Dogs with Eyelid Tumors
With respect to treatment eyelid tumors may be divided into two types, those that can be managed with medicines and those that require surgery. Most eyelid tumors in dogs require surgery, and the surgery may be followed by the application of certain topical medications.