ABSTRACT. A 13-year-old castrated male Labrador retriever dog presented with a mass caudal to the first molar of his left mandible. Although the tumor was excised, a recurrent tumor was detected one month later and resected. Both tumors displayed invasive growth and were composed of neoplastic proliferation arranged in irregular lobules, nests and cords continuous with mucosal epithelium. The most prominent feature of the tumors was the presence of many proliferating spindle cells admixed with palisading basal-like cells, acanthocytes and stellate cells. In immunohistochemical examinations, the spindle cells were found to be positive for vimentin; cytokeratin AE1/AE3, 5/6, 14 and 19; and p63. The other neoplastic cells were positive for all of these markers shown above except vimentin. Based on these findings, the tumors were diagnosed as spindle cell ameloblastic carcinoma. Except for canine acanthomatous ameloblastoma, odontogenic neoplasms are uncommon in domestic animals [3]. Ameloblastoma originates from the odontogenic epithelium with no known metastasis [6]. In human, ameloblastic carcinoma represents ameloblastoma-like features, cellular atypia and morphological malignancy without metastasis [2]. Only two cases of ameloblastic carcinomas have been reported in domestic animals [4,9]. In addition, the spindle cell variant of ameloblastic carcinoma is rare in humans [8,11]. The present report describes a canine case of spindle cell ameloblastic carcinoma.A 13-year-old castrated male Labrador retriever dog with a mass caudal to the first molar of his left mandible was presented to an animal hospital (Fig. 1). This dog had suffered from mitral insufficiency and had been medicated with an angiotensin-converting enzyme inhibitor for about 6 years. A radiographic examination did not detect any pulmonary metastasis. Although the tumor was excised, a recurred mass was found without metastasis one month later and resected. He deceased about two months later after the second operation. The cause of death was unknown, because necropsy was not performed. The shape of the bone around the mass was obscure on radiographic examination. Both of the first (5 × 1.7 × 1 cm) and second masses (4.2 × 1.5 × 2.5 cm) displayed a friable surface and a white mildly firm interior. These tissues, fixed in 10% buffered formalin, were routinely processed and embedded in paraffin wax. The tissue sections (3 µm) were stained with hematoxylin and eosin (HE). Immunohistochemical (IHC) examinations were performed using the streptavidin-biotin peroxidase method with commercial kits (Nichirei Corp., Tokyo, Japan). The primary antibodies employed in these examinations are as follows: cytokeratin (CK) AE1/AE3 (Nichirei, Tokyo, Japan; prediluted), CK 5/6 (Clone D5/16 B4; Chemincon, Temecula, CA, U.S.A.; prediluted), CK 14 (Clone LL002; Thermo Scientific, Runcorn, U.K.; diluted 1 in 20), CK 19 (Clone BA17; Thermo Scientific; diluted 1 in 150), p63 (Clone 4A4; Thermo Scientific; diluted 1 in 200) and vimentin (Clone V9; Nichirei; prediluted).Micros...

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An 11-year-old castrated male rabbit presented with a subcutaneous mass in the right hind limb. The mass comprised solid and myxoid areas. Solid areas were characterized by a storiform or interlacing pattern of spindle cells, strap cells, multinucleated giant cells and round cells with eccentrically located nuclei, whereas the myxoid areas were composed predominantly of elongated fusiform cells with hyperchromatic nuclei embedded in Alcian Blue-positive myxoid stroma. Immunohistochemically, tumor cells in both areas were positive for desmin and vimentin. Ultrastructurally, the tumor cells in the solid areas had abundant myofilaments with electron dense Z-band structures. Based on these pathological findings, this case was diagnosed as rhabdomyosarcoma in a rabbit.

We examined calcium channel blockers (CCBs) and angiotensin receptor II blockers in low-risk hypertensives to evaluate renal, vascular function and left ventricular mass (LVM) from the viewpoint of salt intake (SI). Low-risk hypertensives who had not met blood pressure (BP) goals with CCB were administered telmisaltan. Office and home BP, urinary albumin excretion (uAE), brachial ankle pulse wave velocity (baPWV) and LVM were significantly reduced. uAE and baPWV correlated with SI. It is therefore necessary to evaluate the organ-protecting effects from the viewpoint of SI. In low-risk hypertensives, telmisartan with CCB improves renal, vascular function and LVM.

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