Nasal angioleiomyoma in 2 dogs.

This case report describes 2 dogs, an Appenzeller Mountain dog and an Irish Wolfhound, with angioleiomyoma within the nasal cavity. Endoscopic surgical resection resulted in cure in both dogs. Macroscopically and on diagnostic imaging, tumor masses may appear malignant because of local turbinate destruction. This highlights the importance of histological examination before any recommendations are made to owners because tumors of the nasal cavity may be benign and surgery curative.

Metastatic Osteolytic Angioleiomyosarcoma Induced by a Foreign Body in a Kangaroo (Macropus giganteus).

An adult female Eastern Grey kangaroo (Macropus giganteus) was examined for lameness due to a mass located at the right tibiotarsal joint. Radiographs revealed a metal arrowhead-shaped foreign body within the mass alongside a pathologic fracture. Grossly, at necropsy, there was a multilobulated and haemorrhagic mass with intralesional metal fragments, associated osteolysis of the tibiotarsus and pulmonary metastatic nodules. Histologically the neoplasm was composed of plump elongated and fusiform cells that often formed concentrically around small vessels. The pulmonary nodules were composed of similar neoplastic cells, necrosis and haemorrhage. Neoplastic cells were positive immunohistochemically for vimentin and smooth muscle actin. The histological features, immunohistochemical profiles and behaviour of this tumour support a diagnosis of a primary angioleiomyosarcoma with lung metastasis associated with a metal foreign body.

Uterine angioleiomyoma in an African green monkey (Chlorocebus aethiops sabaeus).

BACKGROUND: A uterine neoplasm was observed, as an incidental finding, during post-mortem examination of a 26-year-old female multiparous African green monkey (Chlorocebus aethiops sabaeus). The intramural, expansile, 2 to 3 cm well-demarcated, dark-red, nodular neoplasm was located on the anterior uterine body (corpus) wall. METHODS: The mass was examined by light microscopy and by immunohistochemistry. RESULTS: The mass was confirmed as a cavernous uterine angioleiomyoma (syn. vascular leiomyoma) characterized by abundant intratumoural vasculature lined by Factor VIII-positive endothelial cells and surrounded by smooth muscle actin-positive cell proliferations. CONCLUSION: Angioleiomyoma sharing the characteristics of intramural human cavernous uterine angioleiomyoma should be considered in the differential diagnosis of uterine tumours in non-human primates.

Angioleiomyoma in a conger (Conger conger).

A wild adult male conger Conger conger, captured by a SCUBA diver in the waters of coastal Italy, was sent for laboratory analysis due to the presence of multiple productive ulcerous skin lesions localized in the dorso-lateral body area, caudally to the gill operculum under the dorsal fin. The main mass was sessile, ulcerated and hemorrhaging in appearance and was surrounded by several smaller masses, which originated peripherally from the same mass or were isolated, always with a tendency to ulceration. Histology confirmed that the newly formed tissue originated from derma invading the closer tissues. The tumour consisted of spindle cells, each with an ovoidal nucleus and rarely with evident nucleoli, which were arranged in parallel or storiform patterns and were often surrounding blood-filled spaces discontinuously lined by endothelial cells. Tumour tissue was richly vascularized and no mitoses were seen. The overlying epidermis was ulcerated. Masson's trichrome technique indicated the presence of a small amount of perivascular connective tissue. No excessive glycogen storage, bacteria, virus or fungi were detected by periodic acid-Schiff (PAS)-reaction. Immunohistochemistry showed dot-like or diffuse cytoplasmic positivity against smooth muscle actin and the monoclonal antibody D2-40. CD34 exhibited relevant immunoreactivity at plasma membranes. Growth fraction evaluated using MIB-1 was <1%. Immunoreactions for wide spectrum CK, CK5/6, CK8, CK18, EMA, desmin, myoglobin, S-100, CD20, CD68, GFAP, and NSE were negative. Histopathological and immunohistochemical results supported a diagnosis of angioleiomyoma, a benign tumour of the muscular cellular component of the blood vessels. To our knowledge, this is the first report of such neoplasms in fishes in which monoclonal antibodies work on fish tissues, facilitating a useful immunohistochemical approach for differential diagnosis.

Cutaneous angioleiomyoma in a black-tailed prairie dog (Cynomys iudovicianus).

A 3-year-old male black-tailed prairie dog (Cynomys iudovicianus) was presented with a dome-shaped cutaneous mass over the left femur. Microscopically, the mass was encapsulated and composed of proliferating spindle cells arranged in haphazard, interlacing bundles. There were vascular structures within the mass and some spindle cells had transitioned from the peripheral regions of the vascular wall. Immunohistochemically, the cells expressed vimentin, α-smooth muscle actin, desmin and heavy caldesmon. Based on these findings, the mass was diagnosed as a cutaneous angioleiomyoma. To the best of our knowledge, this is the first case of cutaneous angioleiomyoma in a black-tailed prairie dog.

Oesophageal angioleiomyosarcoma in a cat.

A female spayed domestic longhair cat aged 3 years and 9 months was referred for investigation of regurgitation and weight loss of 2 months' duration. Thoracic radiographs revealed a soft tissue mass within the cranial mediastinum causing focal oesophageal dilation. Computed tomography confirmed a contrast-enhancing mass located cranial to the heart base, possibly originating from the oesophagus. Exploratory thoracotomy revealed an intramural soft tissue mass within the ventral oesophageal wall. Surgical excision of the mass and reconstruction of the oesophagus around an oesophageal tube was performed successfully. Histopathological examination of the mass was compatible with a spindle cell tumour with a prominent vasoformative component. Immunohistochemistry was positive for α-smooth muscle actin and von Willebrand factor protein, and negative for CD117/c-kit protein. Both histopathological and immunohistochemical findings confirmed the diagnosis of an angioleiomyosarcoma. The cat was clinically well 6 months postoperatively. To our knowledge, this is the first report of an oesophageal angioleiomyosarcoma in a cat.

Claudin-5-positive angioleiomyoma in the uterus of a degu (Octodon degus ).

A 5-year-old female degu (Octodon degus ) showed the clinical sign of metrorrhagia. During ovariohysterectomy a circumscribed tumoural lesion was found in the right uterine horn. The histopathological diagnosis of this soft tissue mass was primary benign cavernous angioleiomyoma of the uterus. During immunohistochemical analysis the neoplastic endothelial cells of this mixed mesenchymal tumour showed strong membrane positivity for the endothelial marker claudin-5 but were negative for CD31 (another endothelial marker). The endothelial cells of the internal positive control tissues such as intact peritumoural vessels were positive for claudin-5 but negative for the CD31 endothelial marker. As it has been described also in other species, it seems that claudin-5 is a better endothelial marker than CD31 for the detection of normal and neoplastic endothelial cells in different tissues of degus.

Cardiac angioleiomyoma in 44 cattle in Japan (1982-2009).

A retrospective study was performed on primary cardiac tumors found in 44 cattle during meat inspection in Japan, using histology, immunohistochemistry, and electron microscopy. The age of affected cattle ranged from 10 to 129 months; 82% were less than 3 years old. In 38 hearts, the tumor was solitary; the remaining 6 hearts had multiple masses. All tumors were subendocardial and involved the papillary muscles and/or cardiac valves. Two histologic patterns were recognized; both included giant cells. Pattern 1 was characterized by interlacing fascicles of spindle-shaped cells; pattern 2 resembled cavernous hemangioma. The 2 patterns coexisted and were linked by transitional zones. Given the immunohistochemical reactivity and ultrastructure, the spindle-shaped cells were identified as smooth muscle cells and the giant cells as endothelial cells. Single cell and multicellular angiogenesis by giant cells was observed. The tumors were classified as cardiac angioleiomyoma. Subendocardial multipotential mesenchymal cells, persistent tissue of the endocardial cushion, or valvular interstitial cells were suspected as the origin.

Splenic angioleiomyoma in an owl monkey (Aotus nancymae).

BACKGROUND: An adult male owl monkey (Aotus nancymae) underwent a splenectomy. When the spleen was removed, a small, nodular mass slightly bulging over the splenic surface was noted. METHODS: The mass was examined by light and transmission electron microscopy and by immunohistochemistry. RESULTS: On light microscopy, the mass was well-circumscribed, non-encapsulated, and composed of haphazardly arranged smooth muscle bundles admixed with numerous small capillary-like structures containing blood. Immunohistochemical (IHC) staining revealed the tumor was strongly positive for smooth muscle actin yielding vascular smooth muscle bundles, and for Factor VIII, staining endothelial cells within the smooth muscle bundles. Transmission electron microscopy (TEM) showed a large portion of the cells to be atypical appearing smooth muscle and a few cells had structures resembling Weibel-Palade bodies indicating endothelial cells. CONCLUSIONS: Based on cell morphology, by light and TEM, and IHC a final diagnosis of splenic angioleiomyoma was made. This is, to our knowledge, the first report of an angioleiomyoma in a non-human primate.

Angioleiomyoma of the nasopharynx in a dog.

A polypoid angioleiomyoma was surgically removed from the nasopharynx of a 1-year-old, male golden retriever. The polypoid mass recurred 4 months later and was again excised. There was no sign of regrowth 13 months postoperatively. This is, apparently, the first reported angioleiomyoma occurring in the dog.