Equine conjunctival pseudotumors

Abstract

Five horses presented with unilateral pink, smooth, nonulcerated conjunctival masses with histologic features characteristic of inflammatory pseudotumors, i.e. proliferative inflammatory lesions clinically resembling true neoplasia. Although causes for the inflammatory lesions were not determined, based on the presence histologically of mononuclear (predominantly lymphocytic) inflammatory cell infiltrates and the absence of infectious agents, parasites or foreign bodies, an immune-mediated pathogenesis was suspected. Affected horses ranged from 5 to 8 years of age with no apparent breed or sex predilection. Conjunctival lesions were nodular in two cases and relatively flat and more diffuse in three cases. Third eyelid lesions were present in three cases and two affected eyes had corneal involvement. Based on findings from these five cases, the prognosis for equine conjunctival pseudotumors appears to be good when lesions are treated by partial or complete surgical excision, local administration of anti-inflammatory agents, or a combination of surgery and anti-inflammatory therapy.

Bilateral nodular lymphocytic conjunctivitis in a horse

“…Histopathology of the masses of the horse of this report were similar to the previous report of conjunctival pseudotumor in horses by Moore et al. 1 with characteristic inflammatory cell infiltration and the absence of pathologic agents. Because of the bilateral aspect and the behavior of the lesion, the immune‐mediated pathogenesis suggested previously is supported by our report.…”

“…This horse had bilateral conjunctival masses, with the mass of the left eye located at the dorsal bulbar conjunctiva and the lobulated mass of the right eye located at the basal portion of the third eyelid, with histologic features characteristic of inflammatory lesions. Moore et al 1 . presented five cases of unilateral nonulcerated conjunctival masses with histologic features characteristic of inflammatory pseudotumor.…”

“…Equine conjunctival inflammatory pseudotumor is suspected to have an immune‐mediated pathogenesis 1 and shares some similarities with nodular granulomatous episclerokeratitis (NGE) of dogs. NGE in dogs 38–41 may present as a subconjunctival mass and has been described as a non‐neoplastic disease primarily affecting the cornea, limbus, episclera, and/or nictitans.…”

Inflammatory Myofibroblastic Tumors in Two Dogs

“…13 These are suspected to have an immune-mediated pathogenesis and share some similarities with so-called nodular granulomatous episcleritis (NGE) of dogs. 17 NGE is a nonneoplastic disease primarily affecting the canine limbus and sclera.…”

Renal leiomyosarcoma in a cat

“…13,15 However, neoplasms with a similar histologic appearance have been reported in various species in various locations, but frequently are described as "pseudotumors" or "inflammatory pseudotumors" or some other similar term, so their actual incidence may be underestimated. 2,3,8,9,19,20,23,28,30 None of these cases in veterinary species involved the kidney. Similar varying terminology has been problematic in the human literature with such varied terms as "inflammatory pseudotumor," "pseudosarcomatous myofibroblastic or fibromyxoid lesion," and "plasma cell granuloma" for the same lesion.…”