Restrictive orbital myofibroblastic sarcoma in a cat – Cross‐sectional imaging (MRI&CT) appearance, treatment, and outcome

Abstract

Case Description A 16-year-old spayed female cat evaluated for lagophthalmos and chronic exposure keratitis in both eyes. Clinical Findings Ophthalmic examination revealed upper and lower eyelid entropion of the left eye (OS) and markedly decreased retropulsion, restricted eye movement, marked episcleral congestion, and severe keratitis of both eyes (OU). Magnetic resonance imaging of both orbits revealed extensive, irregular, contrast-enhancing tissue without evidence of osteolysis considered compatible with diffuse inflammatory tissue. Feline herpesvirus DNA was not detected in conjunctival samples. Treatment and Outcome Partial temporary tarsorrhaphies were placed OU and the cat was treated with topically administered erythromycin ointment OU, orally administered famciclovir and prednisolone, and sublingually administered buprenorphine. Little improvement was noted after 2 weeks. Six weeks after presentation, a left exenteration was performed and histopathology was consistent with idiopathic sclerosing orbital pseudotumor (ISOP). Ten weeks after presentation, the patient presented for weight loss and jaw pain. Computed tomography demonstrated disease progression in the right orbit and the patient was euthanized. Histopathology of the decalcified skull revealed an aggressive and highly infiltrative mass involving the right orbit with extension to the maxilla, hard palate, nasal cavity and gingiva most consistent with feline restrictive orbital myofibroblastic sarcoma (FROMS). Clinical Relevance Clinical data from this patient support the reclassification of ISOP as FROMS. MRI and CT may provide supportive evidence for FROMS but histopathology is necessary for definitive diagnosis. Aggressive and early surgical treatment, including bilateral exenteration, with adjunctive radiotherapy and/or chemotherapy should be considered for patients with FROMS.

Idiopathic sclerosing orbital inflammation mimicking a malignant spindle cell tumor in a dog

“…Descriptions of orbital pseudotumor in the veterinary literature, however, include only one prosimian primate and a lacrimal pseudotumor in a bull terrier 26, 27. Feline lesions originally recorded as orbital pseudotumor have since been reclassified as feline restrictive orbital myofibroblastic sarcoma (FROMS) owing to their highly aggressive nature, resulting in bilateral exenteration and/or euthanasia in all reported cases 1, 3, 28, 29. However, a few early reports in this species did describe a relatively extended survival time alongside immunosuppressive treatment 13, suggesting one or more of the following: (1) that a less aggressive subtype exists, (2) that patient‐derived factors modify disease progression and/or therapeutic response, or (3) that FROMS and feline IOI are two separate disease entities.…”

“…Whilst IOI is rare beyond human medicine, our findings highlight the need to consider this diagnosis in dogs presenting with recalcitrant ophthalmic signs associated with a retrobulbar mass. Given their proximity to the brain, and propensity for local invasion and contralateral emergence, early referral for these lesions is warranted, even though a standard‐of‐care therapy is not clear 1, 28, 29. Advanced imaging instituted promptly may capture early changes in the contralateral orbit (for bilateral presentations) before clinical signs emerge, and immunomodulatory therapy (with or without surgery) may improve patient welfare.…”

Orbital invasive squamous cell carcinoma with adnexal involvement clinically mimicking feline restrictive orbital myofibroblastic sarcoma: 19 cases (1990‐2016)

“…Middle-aged to older patients comprised the population of identified cases, with a median of 12 years of age (range [8][9][10][11][12][13][14][15][16][17][18][19]. A majority of the population were spayed females (n = 11) and the remaining were neutered males (n = 8).…”

“…Reported medical therapies, all palliative at best, consist of one or more of the following: topical lubricants, topical anti-inflammatories, topical antibiotics, oral antivirals, oral anti-inflammatories, and oral antibiotics. [12][13][14][15] Radiation therapy has also been described in one case but with no improvement of clinical signs. 13 Adnexal procedures reported include a temporary tarsorrhaphy to reduce exposure keratitis and a Hotz-Celsus surgery.…”

“…13,14 Ultimately, enucleation, exenteration, or euthanasia was performed in all cases reported. [12][13][14][15] Despite all known attempted therapeutic intervention options, eventual progression to involve the surrounding orbital and facial tissues, including the lips, oral, and nasal cavities, and even the contralateral eye, resulting in disease incompatible with reasonable comfort and quality of life, over a period of weeks to months is expected. 5,12,14 Histologically, FROMS appears as a highly infiltrative population of bland spindle cells with moderate collagen deposition and low mitotic index.…”