Maxillary central giant cell granuloma in a dog

A young labrador dog had a rapidly enlarging osteolytic lesion of the left maxillary bone. The histological diagnosis was central giant cell granuloma. This is a benign, non-neoplastic lesion that has some radiographic and histological similarities to malignant bone tumours of this region. The importance of biopsy in making the diagnosis is emphasised because surgical treatment of central giant cell granuloma by resection or curettage usually resolves these lesions.     

Peripheral giant cell granuloma in a cat

A gingival mass excised from a cat was determined to be a peripheral giant cell granuloma. Characteristic histologic features were large numbers of multinucleated giant cells intermixed with mononuclear mesenchymal cells in a loose fibrovascular stroma. The lesion recurred twice, indicating that these non-neoplastic growths may be locally invasive.     

Granulomatous giant cell submandibular sialadenitis in a dog

A 4-month-old dog was presented with a progressive swelling of the submandibular area. The history, course, cytological, and sialographic findings were consistent with an aseptic pyogranulomatous sialadenitis with concurrent duct blockage. This rare entity, responsive to medical treatment, appears to be similar to the granulomatous giant cell sialadenitis of humans.     

Osteoclast-like giant cell tumour arising from the kidney in a dog

In this study, a case of osteoclast-like giant cell tumour arising from the kidney is reported in an eight-year-old female Anatolian Shepherd dog. Macroscopically, the tumorous mass covered the hilus of the left kidney. It was 26 x 22 x 12 cm in size and 3700 g in weight. Metastatic tumorous nodules, 0.5-2.0 cm in diameter, were found on the abdominal side of the diaphragm and in the lungs. Microscopically, numerous large osteoclast-like multinucleated giant cells and spindle-spheroidal-shaped cells were seen. Osteoblastic differentiation and osteoid matrix were noted in a few areas at the periphery of the tumour, near the connective tissue septa. The stroma of the tumour tissue was vascular, oedematous and loose. By immunoperoxidase staining, tumour cells showed immunoreactivity for vimentin but not for keratin and desmin, indicating that the tumour had mesenchymal origin. This is the first report in the literature on a malignant osteoclast-like giant cell tumour arising from a visceral organ in animals.     

Cholesterol granuloma of the maxilla in a dog

A case of cholesterol granuloma of the maxilla is described in a 13-year-old dog presented because of a long history of facial swelling, irritation and epiphora. Plain and contrast radiography indicated an intramaxillary mass with overlying bone destruction unrelated to the nasolacrimal duct. The lesion was excised and all clinical signs resolved.     

Aural cholesterol granuloma in a dog

A five-year-old female Irish setter was referred for surgery for a left-sided aural mass. The dog was generally well, but had signs of left-sided otalgia for one week. Biopsy identified the lesion as a cholesterol granuloma. The mass was removed three weeks later by a total canal ablation/lateral bulla osteotomy. The dog recovered from surgery without any complications. Ten months later, there was no evidence of recurrence. The purpose of this paper is to report the clinical and histopathological findings of this unusual form of granuloma which has not previously been reported in the canine ear.     

Parosteal osteosarcoma of the mandible in a dog

A mandibular parosteal osteosarcoma was diagnosed in a 7-year-old Collie with prolapse of the third eyelid. Diagnosis was made by histologic evaluation of a mass removed by surgical excision. The dog was euthanatized because of local recurrence of the tumor, with metastasis to the lungs. Parosteal osteosarcomas are rarely reported in dogs and usually involve long bones in human beings.     

Eosinophilic granuloma of the nasal skin in a dog

A recurrent mass removed surgically from the dorsocaudal aspect of the planum nasale in a 12-year-old dog was identified histologically as eosinophilic granuloma. The dog was treated orally with prednisone for 15 days, and the granuloma has not recurred.     

A giant parovarian cyst in a dog with a granulosa cell tumor

A 13-year old intact female poodle showed persistent signs of estrus. Ultrasonographically, a large cystic mass containing echogenic fluid with a thin wall was observed, and it was 8 cm in diameter. The cystic mass was located at the mesovarium between the left ovary and uterine horn, and it was identified as a giant parovarian cyst. A right ovarian mass was histologically diagnosed as a granulosa cell tumor. Persistent estrogen hormone secretion by the granulosa cell tumor was thought to cause a rapid increase in the size of the parovarian cyst. This rare cystic mass originated from the genital system and was differentiated from the uterus.     

Multilobular tumor of the mandible in a Pekingese dog

Multilobular tumor of bone detected in a 2.5-year-old male Pekingese dog is reported. Grossly, the neoplasm consisted of multiple, variably sized, gritty, grayish-white to yellow nodules separated by thick collagenous septa. Histologically, these nodules contained multiple lobules of irregularly shaped and sized islands of well-differentiated osteoid and cartilage, separated by anastomosing fibrovascular septa. Chondrocytes and osteocytes were observed in the lacunae and in more osseous islands in the lobule, respectively. These lobules were surrounded by mesenchymal spindle cells. Mitotic figures were not evident. The neoplastic pattern was consistent with that of a multilobular bone tumor. Diagnosis was based on gross and light microscopic findings. The cause of this neoplasm was not determined.     

Cytologic findings from a benign giant cell tumor of the tendon sheath in a dog

A 6‐year‐old male neutered Australian Shepherd dog was presented for evaluation of a subcutaneous mass on the plantar aspect of the proximal left metatarsus. Fine‐needle aspirate smears contained numerous plump spindle cells and large multinucleated cells amongst a considerable amount of pink extracellular matrix. Histopathologic diagnosis of the tissue obtained during initial biopsy and eventual surgical cytoreduction of the mass was a benign giant cell tumor of the tendon sheath (GCTTS). Immunohistochemically, the synovioblastic neoplastic cells were diffusely strongly positive for vimentin and S‐100, were multifocally moderately positive for cytokeratin AE1/3, and were negative for CD18, muscle‐specific actin (MSA), and melanoma‐associated antigen (mutated) 1 (MUM‐1). The dog recovered from surgery and underwent definitive radiation therapy to treat the local residual disease. Eight months later, the mass had not recurred. The diagnosis of GCTTS in this case supports previously published reports describing GCTTS as a relevant disease entity in dogs, and provides the first documentation of cytologic findings with this tumor. Further investigation is needed to correlate pathologic features with clinical behavior and response to therapy in dogs.     

Multilobular tumor of bone in the mandible of a dog

An 8-year-old Siberian husky dog was presented for a mass involving the rostral mandible. Intraoral radiographs demonstrated diffusely irregular bone and displacement of all mandibular incisor teeth. The mass was diagnosed as a grade I multilobular tumor of bone based on incisional biopsy. A bilateral rostral mandibulectomy was performed with tumor negative margins. Oral examination at 14-months following surgery indicated normal healing with minimal side effects and no evidence of tumor recurrence.     

Extensive bilateral odontogenic cysts in the mandible of a dog

A 5-year-old female neutered Boxer dog was diagnosed with extensive odontogenic cysts that affected the left and right mandibles. Rostral mandibular swelling was detectable clinically, and bilateral cystic mandibular lesions were identified radiographically. The dog's owners elected for euthanasia. A full postmortem was performed. Cystic cavities were confirmed in the body of each mandible, extending from the incisor teeth to the mid premolar region. Incisor, canine, and premolar tooth roots indented each cavity. Histologic examination of the cystic cavities reflected an inner lining of attenuated stratified squamous epithelium overlying a fibrous layer infiltrated by a mixed, predominantly mononuclear, inflammatory infiltrate.     

Osteosarcoma of the mandible in a dog: A case report

The radiographic and histological features of a boney tumour occurring in a 6-year-old Boxer dog are described. The relationship of the different tissues involved is discussed.     

Cutaneous sterile pyogranuloma/granuloma syndrome in a dog

A case of canine cutaneous sterile pyogranuloma/granuloma syndrome (SPGS) with generalized asymmetrical alopecia and plaques is described. Results from histopathologic examination were suggestive of SPGS and failed to demonstrate any etiological agent. A systematic approach on how to definitively rule out infectious skin diseases is discussed.     

Adult Dirofilaria repens in a subcutaneous granuloma on the chest of a dog

A 10-year-old, 9 kg, intact male crossbred dog was treated for nasal mites with milbemycin oxime using a dose of 1 mg/kg bodyweight orally, three times at 10-day intervals. One month after the initiation of this treatment a subcutaneous nodule developed on the sternum of the dog. The nodule was removed and found to contain a single, 82 mm long, thread-like nematode. Several exotic parasites were suspected as possibilities because the dog had been imported to Norway from South Africa. Microfilariae were not detected in the blood and heartworm antigen tests were negative. The worm was identified morphologically as an adult, female Dirofilaria repens. This is the first report of D repens from Norway. The case is of interest because of the differential diagnostic problem it posed and because infestation was recognised following treatment of another parasitic condition with a broad-spectrum, antiparasitic drug. In addition, the case provides a reminder of the necessity to be aware of geographical differences in disease occurrence which can produce unexpected disease in non-endemic areas as a consequence of increased international travel with pets.     

Sperm granuloma in the dog: Complication of vasectomy

This report presents a case of bilateral sperma-tocoele-sperm granuloma in the dog caused by an improperly performed vasectomy.     

Sperm granuloma and sperm agglutination in a dog with asthenozoospermia

A mongrel dog, aged 2 years, was found to have only a small number of sperm, immobilization of all sperm, and many sperm agglutinations in its ejaculates, and scrotal palpation revealed a small nodule in the left cauda epididymis. Addition of the dog's seminal plasma or serum to the semen of 2 normal dogs caused immobilization and agglutination of their sperm. Histological examination showed that the nodule was a sperm granuloma. Many lymphocytes were seen in the stroma around the sperm granuloma. Anti-sperm antibodies are presumed to be present in the semen and serum of the asthenozoospermic dog.