Orbital dermoid cysts are benign which are typically found at the junction of sutures, most commonly at the fronto-zygomatic suture. Large deep orbital dermoid cysts can cause pressure effects on the muscles and optic nerve, leading to diplopia and loss of vision.

The most common eyelid tumor is called basal cell carcinoma. This tumor can grow around the eye but rarely spreads to other parts of the body. Other types of common eyelid cancers include squamous carcinoma, sebaceous carcinoma and malignant melanoma. The most common orbital malignancy is "orbital lymphoma". This tumor can be diagnosed by biopsy with histopathologic and immunohistochemical analysis. Most patients with orbital lymphoma can be offered chemotherapy or radiation therapy.

Glandular and epithelial neoplasm is a grouping of tumors arising from the glands and epithelium.

An example is adenoma.

Hidrocystoma (also known as cystadenoma, a Moll's gland cyst, and a sudoriferous cyst) is an adenoma of the sweat glands.

Hidrocystomas are cysts of sweat ducts, usually on the eyelids. They are not tumours (a similar-sounding lesion called hidroadenoma is a benign tumour).

There are three types of "sweat" glands: True sweat glands or eccrine glands;

sebaceous glands, which have an oily secretion around hair follicles; and apocrine glands which have more oily product than eccrine glands and are found on the face, armpit, and groin.

Hidrocystomas usually arise from apocrine glands. They are also called Cysts of Moll or sudoriferous cysts. There may be a type of hidroadenoma that arises from eccrine glands, but these are uncommon.

Other related conditions on the eyelids include chalazion ( a granulomatous reaction to sebaceous glands on the eyelid), lacrimal duct cysts (cysts related to tear ducts) and nasolacrimal duct cysts (the nasolacrimal duct drains tears into the nose via a punctum on the lower eyelid).

Conjunctival concretions are generally asymptomatic. Common symptoms include eye discomfort, eye irritation, and foreign body sensation. Sometimes, the larger, harder or multiple concretions make the rubbing off of the superficial layers of the conjunctiva or eyelids to cause conjunctival abrasion, especially prominent when upon blinking. In severe cases, dysfunction or inflammation of the Meibomian (Meibomianitis, an inflammation of the tarsal glands) glands may occur.

Ectropion is a medical condition in which the lower eyelid turns outwards. It is one of the notable aspects of newborns exhibiting congenital Harlequin-type ichthyosis, but ectropion can occur due to any weakening of tissue of the lower eyelid. The condition can be repaired surgically. Ectropion is also found in dogs as a genetic disorder in certain breeds.

Cementoblastoma usually occurs in people under the age of 25, particularly males. It usually involves the permanent mandibular molars or premolars. The involved tooth usually has a vital pulp. It is attached to the tooth root and may cause its resorption, may involve the pulp canal, grows slowly, tends to expand the overlying cortical plates, and, except for the enlargement produced, is usually asymptomatic. This involves the buccal and lingual aspects of the alveolar ridges. But may be associated with diffuse pain and tooth mobility, but the tooth is still vital.

Since a cementoblastoma is a benign neoplasm, it grossly forms a mass of cementum-like tissue as an irregular or round mass attached to the roots of a tooth, usually the permanent mandibular first molar.

Sebaceous carcinoma is an uncommon and aggressive malignant cutaneous tumor. Most are typically about 10 mm in size at presentation. This neoplasm is thought to arise from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. Because the periocular region is rich in this type of gland, this region is a common site of origin. The cause of these lesions are, in the vast majority of cases, unknown. Occasional cases may be associated with Muir-Torre syndrome.

This type of cancer usually has a poor prognosis because of a high rate of metastasis.

Ectropion in dogs usually involves the lower eyelid. Often the condition has no symptoms, but tearing and conjunctivitis may be seen. Breeds associated with ectropion include the Cocker Spaniel, the Saint Bernard, the Bloodhound, the Clumber Spaniel, and the Basset Hound. It can also result from trauma or nerve damage. Treatment (surgery) is recommended only if there is chronic conjunctivitis or if there is corneal damage. A small part of the affected lid is removed and then the lid is sewn back together.

Complications of blepharochalasis may include conjunctival hyperemia (excessive blood flow through the moist tissues of the orbit), chemosis, entropion, ectropion, and ptosis.

A cementoblastoma in a radiograph appears as a well-defined, markedly radiopaque mass, with a radiolucent peripheral line, which overlies and obliterates the tooth root. it is described as having a rounded or sunburst appearance. There is usually apparent external resorption of the root where the tumor and the root join. Severe hypercementosis and chronic focal sclerosing osteomyelitis are lesions to consider in the differential diagnosis of this lesion.

Blepharochalasis results from recurrent bouts of painless eyelid swelling, each lasting for several days. This is thought to be a form of localized angioedema, or rapid accumulation of fluid in the tissues. Recurrent episodes lead to thin and atrophic skin. Damage to the levator palpebrae superioris muscle causes ptosis, or drooping of the eyelid, when the muscle can no longer hold the eyelid up.

Pancreatic serous cystadenoma, also known as serous cystadenoma of the pancreas and serous microcystic adenoma, a benign tumour of pancreas. It is usually found in the head of the pancreas, and may be associated with von Hippel-Lindau syndrome.

In contrast to some of the other cyst-forming tumors of the pancreas (such as the intraductal papillary mucinous neoplasm and the mucinous cystic neoplasm), serous cystic neoplasms are almost always entirely benign. There are some exceptions; rare case reports have described isolated malignant serous cystadenocarcinomas. In addition, serous cystic neoplasms slowly grow, and if they grow large enough they can press on adjacent organs and cause symptoms.

The most common sites for melanotic tumors are on the under-side of the tail near the base, on the prepuce, around the mouth or in the skin over the parotid gland (near the base of the ear). Tumors will initially begin as single, small raised areas that may multiply or coalesce into multi-lobed masses (a process called melanomatosis) over time. Horses under 2-years-old can be born with or acquire benign melanotic tumors (called melanocytomas), but these tumors are often located on the legs or trunk, not beneath the tail as in older animals.

Chronic conjunctivitis (e.g. trachoma) and aging factor are two causes of conjunctival concretion, which will make the conjunctiva cellular degeneration to produce an epithelial inclusion cyst, filled with epithelial cells and keratin debris. After calcification, the conjunctival cyst hardens and forms a conjunctival concretion. Congenital conjunctival concretion condition is also more common.

Pathologists classify serous cystic neoplasms into two broad groups. Those that are benign, that have not spread to other organs, are designated "serous cystadenoma". Serous cystadenomas can be further sub-typed into microcystic, oligocystic (or macrocystic), solid, mixed serous-endocrine neoplasm, and VHL-associated serous cystic neoplasm. This latter classification scheme is useful because it highlights the range of appearances and the clinical associations of these neoplasms. Serous cystic neoplasms that have spread ("metastasized") to another organ are considered malignant and are designated "serous cystadenocarcinoma".

The appearance and number of sarcoids can vary, with some horses having single or multiple lesions, usually on the head, legs, ventrum and genitalia or around a wound. The distribution pattern suggests that flies are an important factor in the formation of sarcoids. Sarcoids may resemble warts (verrucous form), small nodules (nodular form), oval hairless or scaly plaques (occult form) or very rarely, large ulcerated masses (fibroblastic form). The occult form usually presents on skin around the mouth, eyes or neck, while nodular and verrucous sarcoids are common on the groin, penile sheath or face. Fibroblastic sarcoids have a predilection for the legs, groin, eyelid and sites of previous injury. Multiple forms may also be present on an individual horse (mixed form). Histologically, sarcoids are composed of fibroblasts (collagen producing cells) that invade and proliferate within the dermis and sometimes the subcutaneous tissue but do not readily metastasize to other organs. Surgical biopsy can definitively diagnose sarcoids, but there is a significant risk of making sarcoids worse. Therefore, diagnosis based solely on clinical signs, fine-needle aspiration or complete excisional biopsy are safer choices.

Lid lag is the static situation in which the upper eyelid is higher than normal with the globe in downgaze. It is most often a sign of thyroid eye disease, but may also occur with cicatricial changes to the eyelid or congenital ptosis. Lid lag differs from Von Graefe's sign in that the latter is a dynamic process.It can also be the manifestaition of chemosis (swelling (or edema) of the conjunctiva)

Well-differentiated and moderately differentiated sebaceous carcinoma tend to exhibit vacuolization within the cytoplasm of the tumor cells. Histology may mimic basal cell carcinoma.

Symptoms of entropion include:

- Redness and pain around the eye

- Sensitivity to light and wind

- Sagging skin around the eye

- Epiphora

- Decreased vision, especially if the cornea is damaged

In addition to small palpebral fissures, features include epicanthus inversus (fold curving in the mediolateral direction, inferior to the inner canthus), low nasal bridge, ptosis of the eyelids and telecanthus.

Dermatochalasis is caused by a loss of elasticity in the connective tissue supporting the structure of the front portion of the eyelid. Normally, in Caucasians, the orbicularis muscle and overlying skin form a crease near the tarsal border. In dermatochalasis, the excess tissues hangs down, over the front edge of the eyelid. The excess tissue can sometimes obstruct the visual field, especially the superior visual field. In severe cases, it may obstruct as much as 50 percent of the superior visual field.

An muscle tissue neoplasm is a neoplasm derived from muscle.

An example is myoma.

Squamous-cell thyroid carcinoma (SCTC) is rare malignant neoplasm of thyroid gland which shows tumor cells with distinct squamous differentiation. The incidence of SCTC is less than 1% out of thyroid malignancies.

Squamous epithelial cells are not found in normal thyroid, thus the origin of SCTC is not clear. However, it might be a derived from the embryonic remnants such as thyroglossal duct or branchial clefts. Often SCTC is diagnosed in one of the thyroid lobes, but not in the pyramidal lobe. Another possible way of SCTC development can be through the squamous metaplasia of cells. However, that theory is also controversial, since the Hashimoto's thyroiditis and chronic lymphocytic thyroiditis (neoplasms to be showed squamous metaplasia) are not associated with SCTC. Primary STCT is usually diagnosed in both lobes of thyroid gland. The histopathology of STCT shows a squamous differentiation of tumor cells.