A 7-year-old neutered female Doberman pinscher was presented with a palpebral nodule on the haired eyelid of the left eye. The nodule was removed surgically. Microscopically, the nodule was consistent with eyelid melanocytoma. The tumour was characterized by the presence of numerous lacunar and slit-like spaces filled by erythrocytes and interspersed throughout the neoplastic melanocytes. Immunohistochemically, these spaces were lined by cells expressing PNL2 and factor VIII, but the cells were negative for CD31. These findings were consistent with neoplastic melanocytes without endothelial cell participation. This feature was interpreted as 'vasculogenic mimicry', a mechanism of tumour angiogenesis that is well-recognized in human melanomas, but has not yet been reported in melanomas in animals.
Most canine tumors of the eyelid are tumors generally encountered in the skin. They are most commonly of epithelial origin and benign. In this report, we describe the cases of two sibling Czech wolfdogs presented, one year apart, with a subcutaneous mass involving the left eyelid. Both lesions were histologically consistent with a diagnosis of subcutaneous fibrosarcoma. Immunohistochemical analyses of the tumors revealed a mild positivity for vimentin and negativity for GFAP, desmin, αSMA, myoglobin, S100, PNL2 and calponin, excluding all differential diagnosis (i.e. peripheral nerve sheath tumor, melanoma, perivascular sarcoma, myofibroblastic sarcoma, rhabdomyosarcoma). To the best of authors’ knowledge, this is the first report of canine eyelid fibrosarcoma. Since this rare tumor has been observed in two full siblings, we could speculate the existence of some genetic predisposition to sarcoma, however the present data did not allow any definite conclusion on the etiopathogenesis or genetic basis of these tumors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.