Uterine Leiomyoma in a Spayed Poodle Bitch: A Case Report

A 16‐year‐old, spayed, female poodle dog was presented for evaluation of tenesmus, with the ability to attract male dogs and a willingness to mate. The dog had undergone an ovariohysterectomy when it was 7 years old. Haematological and serum biochemistry analyses demonstrated leucocytosis and a mild uraemia. A vaginal smear was predominantly made up of superficial cells, accounting for at least 80% of the cells. Abdominal ultrasonography revealed a heterogeneous multicystic mass at the caudal abdomen and two masses with anechoic areas adjacent to the caudal pole of each kidney. A midline exploratory laparotomy identified a uterine mass and residual ovaries that were surgically excised. Histopathological examination of the mass demonstrated that it was a leiomyoma. The left ovary had a cystic structure and the right ovary had a papillary cystic adenoma. Seven months after the surgery, the owner reported that the dog was clinically normal. To the authors’ knowledge, this is the first reported case of a uterine leiomyoma after an incomplete ovariohysterectomy in the dog.     

Unique cytologic and histologic features of a suspected cutaneous xanthoma in a dog

A 4‐year‐old spayed female American Staffordshire Terrier presented to the U‐Vet Animal Hospital, Werribee, Australia, with a cutaneous mass that had been slowly growing over 12 months. Cytologic evaluation showed cohesive to individualized, vacuolated spindled cells often arranged in a perivascular pattern. The mass was completely excised, and the histopathologic examination demonstrated sheets of vacuolated spindled to round cells expanding the full thickness of the dermis. The cells demonstrated both Iba1 and CD18 antibody binding, leading to an initial interpretation of histiocytic sarcoma. Given the discordance with the clinical presentation, further immunohistochemistry (IHC) was performed. The cells demonstrated strong CD204 antibody binding and did not bind E‐cadherin antibody, consistent with a dermal macrophage origin. Ki‐67 antibody binding was regionally variable from <5% to 25%, with more regions that had low Ki‐67 expression. A fasted serum biochemistry panel revealed hypertriglyceridemia and persistent hypercholesterolemia. Based on clinical, microscopic, biochemical, and IHC results, the final interpretation was an indolent dermal histiocytic proliferation of macrophage origin, with a preference for cutaneous xanthoma or reactive dermal fibrohistiocytoma.     

Olfactory ganglioneuroblastoma in a dog: case report and literature review

A 7-y-old, intact male Alaskan Malamute was presented with a 3-mo history of stertor and epistaxis. Computed tomography of the skull revealed generalized loss of gas throughout both nasal passages with replacement by a soft tissue mass that traversed the cribriform plate. Histopathology revealed neoplastic neuroblast cells arranged in anastomosing cords, as well as separately located aggregates of ganglion cells. Both neoplastic cell populations demonstrated immunoreactivity to MAP-2, TuJ-1, and synaptophysin. Neuroblastic cells additionally exhibited punctate immunoreactivity to MCK and CK8/18. We document here both the positive neural immunohistochemical markers for this neoplasm, as well as propose possible histomorphologic variants.     

Paraneoplastic leukocytosis with mature neutrophilia in a cat with pulmonary squamous cell carcinoma

A 13-year old cat had 3-day duration of vomiting, lethargy, and anorexia. A complete blood count revealed a severe neutrophilia (126.9 x 10(3) cells/microl). Thoracic radiographs demonstrated a large solitary lung mass. A bone marrow aspirate documented myeloid hyperplasia. A left intercostal thoracotomy was performed and left cranial and caudal lung lobectomies were performed in order to remove the mass in its entirety. Histological diagnosis was squamous cell carcinoma of the lung. Following surgery, the severe neutrophilia began to decrease. It was in the normal range approximately 6 weeks postoperatively. The presence of a primary lung tumor combined with a mature neutrophilia with resolution following surgical resection suggests a paraneoplastic syndrome.     

Spontaneous Adenosquamous Carcinoma with Rapid Growth and EMT-like Changes in the Mammary Gland of a Young Adult Female BALB/c Mouse

This study histopathologically and immunohistochemically investigated a spontaneously occurring single mass subcutaneously located in the left lower abdomen of a female BALB/cAJcl−nu/+ mouse at 10 weeks of age. The mass was about 20 × 15 × 10 mm in size after formalin fixation; nevertheless, it was not detected by clinical observations at 9 weeks of age. H&E staining revealed the tumor origin was epithelial and probably arose from the mammary gland, and the tumor cells demonstrated a squamous, acinar or polyhedral/basal pattern. A cell kinetics analysis revealed that many of the tumor cells of the squamous, acinar or polyhedral/basal component were positive for PCNA and cyclin D1, although there were a few of TUNEL-positive tumor cells in all of the components. An epithelial/mesenchymal analysis demonstrated that most of the tumor cells of the squamous and acinar components contained keratin and E-cadherin; however, most of the tumor cells of the polyhedral/basal component were less or very weakly positive for these markers. The tumor cells of the squamous component were negative for vimentin and SMA; however, many of the tumor cells of the polyhedral/basal component exhibited vimentin. In addition, expression of SMA was confirmed in some tumor cells of the acinar and basal components. Based on the microscopic and immunohistochemical characterizations, the tumor was diagnosed to be adenosquamous carcinoma that originated from the mammary gland with rapid growth, and the tumor cells demonstrated epithelial-mesenchymal transition-like changes.     

Chondrosarcoma Associated With the Appendicular Skeleton of 2 Domestic Ferrets

A 5-year-old male neutered ferret (Mustela putorius) and a 2-year-old male neutered ferret were evaluated for fast growing immobile swellings involving the left hock and the right scapula, respectively. In both cases, serum chemistry was unremarkable and a complete blood count demonstrated mild anemia. In case 1, radiographic evaluation demonstrated increased soft tissue density in the region of the distal tibia and fibular tarsal bone. A fine-needle aspirate demonstrated atypical mesenchymal cells, and an incisional biopsy revealed irregular partly mineralized proliferations of cartilage consistent with chondrosarcoma. Computed tomography was performed, demonstrating attachment of the mass to the distolateral tibial epiphysis. A limb-sparing surgery was performed; however, 5 months following resection local reoccurrence was noted. At 18 months, the ferret underwent a left hind limb amputation. No sign of metastatic disease was reported at 27 months. In case 2, radiographic evaluation demonstrated a poorly organized mineralized soft tissue mass extending from the right acromion to the area surrounding the neck of the scapula. Microscopic evaluation of an incisional biopsy revealed a chondrosarcoma. A forequarter amputation was performed. The ferret died 4 years later with no evidence of local recurrence or the development of metastatic disease. These 2 cases represent the first reports of chondrosarcoma in the appendicular skeleton of 2 ferrets. Based on these 2 cases, local recurrence may be expected unless adequate surgical margins are achieved. The metastatic potential of chondrosarcoma in this species appears to be low.     

Primary pulmonary artery leiomyosarcoma in an adult dog

A 7-year-old neutered female English Setter presented with syncope, anemia, and weight loss. Clinical examination revealed a systolic murmur and echocardiography demonstrated a mass on the pulmonic valve. Postmortem examination confirmed the presence of a pulmonic valve mass that extended along the pulmonary trunk and into the left pulmonary artery. Multiple pale nodules were observed in the right lung. Microscopic examinations of the pulmonary artery mass and the lung nodules revealed a pleomorphic population of spindle cells often arranged in broad bands containing strap-like nuclei and eosinophilic cytoplasm devoid of cross striations. The neoplastic cells expressed vimentin and alpha-smooth muscle actin but did not express desmin, CD31, factor VIII, or S100. The presentation, histological features, immunocytochemical profiles, and behavior of this tumor were indicative of a primary pulmonary artery leiomyosarcoma with lung metastasis.     

Histiocytic sarcoma in the tarsus of a cat

A 12-year-old Persian cat was examined for a firm swelling of the right tarsal region and enlargement of the corresponding right popliteal lymph node. Cytologic evaluation demonstrated a population of malignant cells consistent with large cell lymphoma. Necropsy revealed a multi-lobulated subcutaneous mass involving the tarsus with some extension into adjacent deep muscular tissue. Histologically, the mass was composed of round cells with eosinophilic cytoplasm and pleomorphic anisokaryotic nuclei. Evidence of articular and nodal infiltration by these cells was observed. Differential diagnoses included synovial sarcoma and histiocytic sarcoma. Neoplastic cells were negative for cytokeratin, CD79a, and CD3 and positive for CD18, vimentin, lysozyme, and alpha-1-antitrypsin, most consistent with a diagnosis of histiocytic sarcoma. This is the first report of a histiocytic sarcoma involving a joint of a cat. The final diagnosis was based on the light microscopic appearance in combination with the immunohistochemical stains.     

Lingual haemangiosarcoma in a crossbred dog

An eight-year-old, male neutered, crossbred dog was presented for investigation of a lingual mass of four months duration. Oral examination revealed a 7 cm × 5 cm soft, fluctuant mass at the caudal aspect of the tongue. Ultrasound examination of the mass demonstrated mixed echogenicity, with cavitations containing hypoechoic and anechoic regions. Lingual haemangiosarcoma was diagnosed on histopathological examination of multiple biopsy samples, with confirmation of the vascular endothelial origin of tumour cells by positive immunolabelling for factor VIII-related antigen.     

Cutaneous melanoma in a red-footed tortoise (Chelonoidis carbonaria)

There are few clinical reports of melanomas in reptiles. A 10-year-old male red-footed tortoise (Chelonoidis carbonaria) was referred to the Veterinary Hospital presenting with an ulcerated mass in the lateral aspect of the left pelvic limb. Radiographs demonstrated swelling and increased soft tissue density overlying the femur, tibia, and fibula, without bone involvement. Fine-needle aspiration cytology revealed innumerable round cells, with a defined cytoplasm filled with fine brown-black granules (melanin), which were considered well-differentiated melanocytes, suggesting a case of cutaneous melanoma. The mass was surgically removed. It was encapsulated and had an abundant blood supply. Histopathological examination revealed a well demarcated and encapsulated neoplastic proliferation of mesenchymal cells, with high cellularity and moderate fibrous stroma. Lymphangiectasia in the dermis adjacent to the tumor was also observed. Immunohistochemistry confirmed the diagnosis, with cells staining positive for Melan-A antibody being observed in neoplastic proliferation, adjacent dermis, inside lymphatic vessels, and invading the delimiting tumor's capsule. There was no evidence of local or systemic recurrence of the neoplasm over 500 days after removal. Chelonians can be affected by cutaneous melanomas. Surgical removal in this case was curative.     

Vaginal Neurofibroma in a Hysterectomized Poodle Dog

A 15‐year‐old, spayed, female poodle dog was presented for evaluation of a mass of tissue prolapsed from the vulva. The dog had been hysterectomized when it was 5 years old. A vaginal mass had been removed approximately 10 months before presentation. Haematological and serum biochemistry analyses demonstrated mild leucocytosis and glycaemia. A vaginal smear was predominantly made up of parabasal cells and intermediate cells with no neoplastic cells. Thoracal and abdominal radiographic findings were unremarkable. The ovaries could not be identified using abdominal ultrasonography. A midline exploratory laparotomy identified both ovaries that were surgically excised. The vaginal mass was also removed following an episiotomy procedure. Histopathological examination of the mass demonstrated that it was a neurofibroma. Both ovaries had cystic changes. Four months after the surgery, the owner reported that the dog was clinically normal. To the authors’ knowledge, this is the first reported case of a vaginal neurofibroma after an incomplete ovariohysterectomy in the dog.     

Lymphosarcoma with leukemic blood profile in a Savannah monitor lizard (Varanus exanthematicus).

A 6-mo-old male Savannah monitor lizard (Varanus exanthematicus) was presented for lethargy and anorexia of 7 days duration. Physical examination revealed a slightly raised subcutaneous mass (1 cm diameter) in the left scapular area. Fine-needle aspiration cytology of the mass revealed a population of immature, pleomorphic lymphoid cells consistent with lymphosarcoma. A hemogram indicated marked leukocytosis (465,000 cells/microl) characterized by extreme lymphocytosis and many circulating lymphoid blast cells. The lizard was euthanized at the owner's request. Necropsy revealed severe hepatomegaly and multiple raised, ulcerated mural masses in the gastrointestinal tract. There were many raised, poorly demarcated tan foci in all the parenchymal organs. Histopathologic examination confirmed infiltration of all parenchymal organs by neoplastic lymphoid cells. Transmission electron microscopic examination failed to identify viruses within the neoplastic cells. A literature review revealed few reports of squamate leukemia and lymphosarcoma and none in Savannah monitor lizards.     

Unilateral external and internal ophthalmoplegia caused by intracranial meningioma in a dog

Unilateral internal and external ophthalmoplegia caused by an intracranial meningioma occurred in a 15-year-old Belgian Sheepdog. The dog initially presented with ventro-lateral strabismus of the left eye, and ptosis of the left upper eyelid. Anisocoria was present with the left pupil fixed and dilated. Both eyes were visual. Neuro-ophthalmic evaluation revealed a lesion located in the left oculomotor nerve. Pharmacological testing with dilute pilocarpine (0.1% in artificial tears) revealed evidence of parasympathetic denervation of the left eye. Further evaluation via magnetic resonance imaging (MRI) revealed a well-defined mass to the left of midline and lateral to the sella turcica. An attempt was made to excise/debulk the mass due to worsening conditions and the dog died the following day. Necropsy revealed a mass of randomly arranged bundles and streams of spindle cells. Immunohistochemistry demonstrated a strong avidity for vimentin and a negative response for S-100 protein. These findings suggest a diagnosis of meningioma.     

Ganglioneuroma in the urinary bladder of a dog

An 11-year-old male Labrador retriever presented with chronic oliguria. Ultrasonography findings revealed a protruding mass at the neck of the urinary bladder. A cystotomy was performed, and the mass was removed by ligation with surgical sutures. Histopathological examination revealed conspicuous foci with a variable number of ganglion cells in the tumor and abundant interwoven bundles of schwannian cells with fine fibers. The ganglion cells were positive for neuron-specific enolase and neurofilament. The schwannian cells were positive for vimentin, S-100 protein, and glial fibrillary acidic protein. Thus, according to the classification of tumor with neuronal cell differentiation, the urinary tumor was diagnosed as a ganglioneuroma.     

Paratracheal air cyst in a foal

A 1-day-old American Paint Horse was presented for a large air-filled mass along the ventral aspect of the neck. Bronchoscopy and oesophagoscopy revealed no sign of communication with the trachea or oesophagus. Radiographs and a computed tomography scan of the neck identified a communicating tract between the lumen of the cystic mass and mid-trachea. The foal was systemically healthy at this initial presentation, and delayed removal of the cyst was recommended to allow further maturation of the foal prior to undergoing general anaesthesia. Upon discharge, the cyst continued to grow in size and became more fluid than air-filled requiring repeat centesis and draining. The foal was then re-presented at 3 weeks of age for surgical removal. In surgery, direct communication with the trachea was identified and ligated. Histopathology demonstrated that the cyst lining was composed of squamous epithelium with goblet cells and occasional ciliated cells. The location, morphological features and congenital presentation of the mass were consistent with a paratracheal air cyst (PAC). Surgical resection resulted in excellent functional and cosmetic outcome. Although not previously reported in horses, PAC should be included in the differential diagnosis of an air-filled ventral neck mass in equine neonates. Complete surgical excision may result in a successful outcome.     

Hemangiosarcoma of the third eyelid in a cat

A case of hemangiosarcoma of the third eyelid in a 15-year-old Domestic Short-haired cat is reported. A small red mass protruding from the anterior surface of the third eyelid in the left eye was present. Only mild bilateral conjunctivitis and nuclear sclerosis were revealed on initial ophthalmic examination. After anti-inflammatory treatment, surgery and cryotherapy were performed. On histopathologic examination the mass was located just beneath the conjunctival epithelium, suggesting that the conjunctiva was the tissue of origin. The tumor showed high cellularity and was composed of pleomorphic spindle and polygonal cells arranged in interlacing bundles and solid sheets. The presence of slit-like spaces between tumor cells containing erythrocytes demonstrated the vascular differentiation. Mitotic activity was moderate, but atypical mitoses were detected. The surgical area healed uneventfully and after 7 months there was no recurrence. To the authors' knowledge, this is the first report of conjunctival hemangiosarcoma of the third eyelid in a cat.     

Ectopic cervical thymic carcinoma in a dog

A 10-year-old male German shepherd dog was referred for evaluation of a cranial cervical mass causing progressively worsening respiratory distress. A fine-needle aspirate of the mass was obtained and the cytology results were compatible with a carcinoma. The dog underwent chemotherapy without clinical improvement and was ultimately euthanased because of clinical deterioration. At post-mortem examination, an irregular multi-lobated mass in the cranial cervical region was observed causing ventro-lateral tracheal deviation. Histopathology and immunohistochemistry revealed a mixed population of CD3 lymphocytes and macrophages in an exuberant fibrous stroma, associated with dispersed cytokeratin-positive epithelial cells with marked eosinophilic cytoplasm. Some of the epithelial cells were arranged in concentric clusters that were interpreted as Hassall's corpuscles. Histopathological examination of the thyroid gland revealed several neoplastic emboli composed of epithelial cells similar to those observed in the cervical mass. To the authors' knowledge, this is the first report of an ectopic cervical thymic carcinoma in a dog.     

Traumatic subcutaneous translocation of the spleen in an Old English sheepdog

A 14-month-old entire male Old English sheepdog was presented with a slowly enlarging subcutaneous soft tissue swelling caudal to the last rib. Radiographic and ultrasonographic Investigations demonstrated a soft tissue mass closely adherent to the body wall, with a coarse hypoechoic pattern. Surgical exploration revealed a mass with the gross appearance of splenic tissue. The mass was adhered to a healed paracostal abdominal tear. Histological examination confirmed the resected tissue to be normal spleen.     

Thyroid c-cell carcinoma in an African pygmy hedgehog (Atelerix albiventris).

A 3-yr-old African pygmy hedgehog (Atelerix albiventris) was submitted with dysphagia, weight loss, and tetraparesis. A palpable mass was found on the ventral neck. Histologic examination revealed replacement of the thyroid gland by a highly cellular, expansile, and infiltrative mass composed of lobules of polygonal cells separated by fine fibrovascular septa. Examination of ultrathin sections revealed tumor cells with few to many dense-core neuroendocrine granules, approximately 100-200 nm in diameter, and stromal amyloid. Immunohistochemical stains were positive for neuron-specific enolase. Only rare cells had positive immunohistochemical staining for calcitonin. Findings are consistent with a neuroendocrine tumor of C-cell origin. This is the first report of a C-cell carcinoma in a hedgehog.     

Detection of squamous cell carcinoma of presumed pancreatic origin and its metastasis in a spotted seal (Phoca largha) using ultrasonography and computed tomography

A 21-year-old female spotted seal (Phoca largha), with a swollen abdomen, had a five-month history of anorexia and vomiting. Ultrasonography revealed an extended mass with central necrotic foci in the right cranial abdomen. Computed tomography revealed an abdominal mass with a low-density central lumen and a pulmonary nodular lesion. Cytology of an abdominal specimen collected through fine-needle aspiration indicated a malignant tumor with round, atypical cells with large nuclei. Three days after diagnosis, necropsy revealed a 10-cm large, solid, whitish mass in the pancreatic parenchyma and multiple small nodules in the liver, spleen, mesentery, lungs, and mediastinal lymph nodes. Histopathological analysis showed prolific neoplastic cells with marked atypia and occasional keratinization. Immunohistochemistry revealed that the neoplastic cells were positive for cytokeratin AE1/AE3 antibody. Thus, the seal was diagnosed with squamous cell carcinoma, of presumed pancreatic origin, which had metastasized to multiple organs.