Canine orbital rhabdomyosarcoma: a report of 18 cases.

PURPOSE: To describe clinical and pathological features of canine orbital rhabdomyosarcoma (COR). METHODS: Retrospective review of patients with COR from the archives of the Comparative Ocular Pathology Laboratory of Wisconsin and the University of Wisconsin Veterinary Medical Teaching Hospital (1983-2014). RESULTS: Eighteen cases of COR were identified, all diagnosed in an 8-year period (2006-2014). Affected dogs were typically young (range 1-8; median 2 years), and both sexes were equally represented. Common clinical signs included exophthalmos (16/18) with dorsolateral deviation of the globe (10/18) and elevation of the nictitans (12/18). Ultrasonography, performed in nine cases, revealed an orbital mass with mixed echogenicity and posterior globe indentation. Advanced imaging, performed in nine cases, demonstrated a soft tissue mass with variable contrast enhancement and lysis of the orbital bones (5/9). Histologically, all tumors were subclassified as embryonal rhabdomyosarcoma. All neoplasms demonstrated positive immunohistochemical labeling for desmin, and 14/18 were positive for skeletal muscle actin. Follow-up information was available for 15/18 cases. Older dogs, aged 6-8 years, had no clinical signs of recurrence or metastasis 8-13 months postdiagnosis (4/4). Most younger dogs (9/11), aged 1-4 years, were euthanized within 6 months (median 2.5 months) of diagnosis due to recurrence at the surgical site (5/9) and/or metastasis (5/9). CONCLUSIONS: Canine orbital rhabdomyosarcoma is a highly malignant neoplasm in juvenile dogs, but may be amenable to surgical resection in older dogs. This duality in biologic behavior may reflect differences in tissue of origin between juvenile onset tumors and adult onset tumors.

Ten-year follow-up of mammary carcinoma arising in microglandular adenosis treated with breast conservation.

adenosis is a rare proliferative lesion of the breast that may mimic carcinoma grossly and histologically. Although the lesion in its simplest form is benign, it can give rise to carcinoma, which may be found at the time of diagnosis in a minority of cases. Limited follow-up data have indicated no predisposition to develop subsequent carcinoma in patients treated with excisional biopsy for microglandular adenosis when carcinoma was not initially present. Breast conservation has rarely been used in patients with carcinoma arising in microglandular adenosis. We report here the unique 10-year follow-up of a woman who underwent breast conservation treatment for carcinoma that arose in microglandular adenosis.