CT features of primary bone neoplasia of the thoracic wall in dogs.

Primary thoracic wall neoplasia is uncommon in dogs and the prognosis depends on tumor type. The aims of this retrospective, multi-center, observational study were to describe CT features of primary thoracic wall neoplasia in dogs and to test the hypothesis that CT features would differ among tumor types. Dogs with a diagnosis of primary thoracic wall bone neoplasia and thoracic CT study were included. CT findings recorded were as follows: dimensions, location, invasiveness, grade and type of mineral attenuation, periosteal reaction, contrast enhancement, and presence of presumed pulmonary metastases, pleural effusion, and sternal lymphadenopathy. Fifty-eight cases were included (54 ribs and four sternum). Fifty-six were malignant (sarcomas - SARC) and two were benign (chondromas - CHO). Out of the 56 malignant tumors, 41 had histological confirmation of the tumor type: 23 (56%) osteosarcomas (OSA), 10 (24%) chondrosarcomas (CSA), and eight (20%) hemangiosarcomas (HSA). The majority of rib tumors were right-sided (59%) and ventrally located (72%). Malignant masses showed severe invasiveness, mild/moderate contrast enhancement, and different grades of mineral attenuation. Sternal lymphadenopathy was significantly more frequent in dogs with OSA and HSA compared to dogs with CSA (p = 0.004 and p = 0.023). Dogs with HSA showed significantly lower mineral attenuation grades compared to dogs with OSA (p = 0.043). Primary thoracic wall bone neoplasias were more frequently arising from the ribs, with only a few cases of sternal masses. Findings can be used to help prioritize differential diagnoses for CT studies of dogs with thoracic wall neoplasia.

Prolonged survival after craniectomy with skull reconstruction and adjuvant definitive radiation therapy in three dogs with multilobular osteochondrosarcoma.

Multilobular osteochondrosarcoma is an uncommon canine tumor but presents a treatment challenge when arising on the skull. This retrospective case series study aimed to describe outcome of a multimodality treatment approach involving aggressive surgical resection and adjuvant definitive radiation therapy in a group of dogs with multilobular osteochondrosarcoma of the calvarium. Clinical, imaging, treatment, and outcome data were collected from retrospective review of medical records. Three dogs met inclusion criteria. The presenting clinical complaint was the presence of a mass effect of the skull in all three dogs and concurrent neurologic abnormalities in one dog. Advanced imaging revealed aggressive lytic and proliferative tumors arising from the calvarium in all three dogs. All dogs were treated surgically with a modified craniectomy, repaired with a titanium mesh-polymethyl methacrylate bone cement implant or a low prolife titanium mesh plate and followed by adjuvant definitive radiation therapy with 2.5 Gy per fraction for 22 daily fractions. There were no major immediate surgical complications and radiation was well tolerated overall. Neurologic improvement was seen in the patient that presented with neurologic disease. Survival times from surgery were 387, 422, and 730 days and from the time of radiation were 358, 397, and 677 days. Findings in this sample of three dogs supported the use of aggressive therapy with a combination of surgical craniectomy and cranioplasty utilizing a titanium mesh implant and high dose definitive radiation therapy for local control and prolonged survival times in dogs with multilobular osteochondrosarcoma of the skull.

Preserved limb function following subtotal iliopsoas muscle and femoral nerve resection in a dog with low grade intramuscular chondrosarcoma.

A 9-year-old spayed female Labrador retriever dog was diagnosed with a grade 1 chondrosarcoma associated with the right iliopsoas muscle. A computed tomography scan of the patient revealed the mass to begin at the level of L5, continuing to the insertion of the iliopsoas muscle on the femur. Surgery was performed to remove the mass. The femoral nerve was encased within the mass and the nerve was transected and removed, along with the iliopsoas muscle, with minimal intraoperative complications. With regular physiotherapy, the patient was able to independently walk, run, and jump, with mild functional lameness after 6 months.

Fonction préservée des membres après une résection partielle du muscle ilio-psoas et du nerf fémoral chez un chien atteint d'un chondrosarcome intramusculaire de faible grade. Une chienne Labrador retriever stérilisée âgée de 9 ans a été diagnostiquée avec un chondrosarcome de grade 1 associé au muscle ilio-psoas droit. Une tomodensitométrie de la patiente a révélé une masse commençant au niveau de L5 et se poursuivant vers l'insertion de l'ilio-psoas sur le fémur. Une chirurgie a été réalisée pour enlever la masse. Le nerf fémoral était enveloppé par la masse et le nerf a été coupé et enlevé, ainsi que le muscle ilio-psoas, avec des complications peropératoires minimes. Grâce à de la physiothérapie régulière, après 6 mois le patient était capable de marcher, courir et sauter de façon indépendante, avec une légère boiterie fonctionnelle.(Traduit par Isabelle Vallières).

Presumed post-traumatic ocular chondrosarcoma with intrathoracic metastases in a cat.

An indoor-only, 5-year-old, spayed female domestic shorthair cat presented for an ophthalmic examination of the left eye. An intraocular tumor with secondary glaucoma and blindness was diagnosed; the globe was enucleated and sent for histopathological examination. Gross examination revealed a solid white mass filling the entire vitreous space and replacing the iris and ciliary body. The lens and retina appeared to be similarly replaced by the neoplasm. Histological examination revealed a complete loss of the internal ocular structures, with a ruptured capsule as the only remnant of the lens within an extensive malignant mesenchymal neoplastic cell proliferation. The cells were polygonal, with well-defined cytoplasmic borders and abundant weakly basophilic cytoplasm, embedded within the islands of chondroid matrix. No neoplastic invasion of the sclera was apparent. The animal died 6 months after the enucleation due to respiratory distress. Gross examination revealed numerous firm, white to tan nodular masses with smooth to mildly irregular surfaces dispersed throughout the parietal pleura, thoracic surface of the diaphragm, tracheobronchial and mediastinal lymph nodes, pericardium, and lungs. On cross-section, the neoplastic nodules were solid and variably translucent, resembling hyaline cartilage. Histologically, these nodules were similar to the neoplasm identified earlier in the left globe. Metastasis of post-traumatic ocular chondrosarcoma has not yet been described in cats. This is therefore believed to be the first report of metastases of this type of neoplasm in cats. This case adds to the limited set of data on the outcome of this type of tumor.

Chondroblastic osteosarcoma of the middle ear in a guinea pig (Cavia porcellus).

A 3-year-old intact female guinea pig (Cavia porcellus) was presented for acute anorexia. Medical and surgical treatments for cystitis and ovarian cysts, respectively, did not prevent continuous weight loss. Computed tomography and histopathological analysis revealed a chondroblastic osteosarcoma of the right middle ear, which has not been reported in this species.

Ostéosarcome chondroblastique de l'oreille moyenne chez un cobaye(Cavia porcellus). Un cobaye (Cavia porcellus) femelle de 3 ans a été présentée pour une anorexie d'apparition aiguë. Malgré la prise en charge médicale et chirurgicale d'une cystite et de kystes ovariens, l'individu continuait de perdre du poids. L'examen tomodensitométrique et l'analyse histologique ont mis en évidence un ostéosarcome chondroblastique de l'oreille moyenne, ce qui n'a jamais été rapporté dans cette espèce.(Traduit par Dre Ophélie Cojean).

Osteocalcin and Osteonectin Expression in Canine Osteosarcoma.

Osteosarcoma (OSA) is a malignant heterogeneous primary bone tumor responsible for up to 90% of all primary bone tumors in dogs. In this study, osteocalcin (OC) and osteonectin (ON) immunoreactivity was evaluated in 23 canine OSAs, 4 chondrosarcomas, 4 fibrosarcomas, 2 hemangiosarcomas, and 4 histiocytic sarcomas. The effects of three different decalcification agents (ethylenediaminetetraetic acid [EDTA], formic acid and hydrochloric acid [HCl]) on the immunoreactivity for OC and ON was also assessed. Immunoreactivity to OC was present in 19/23 (83%) cases of OSA and all cases of chondrosarcoma. In three OSAs the extracellular matrix showed immunoreactivity to OC. None of the fibrosarcomas, histiocytic sarcomas or hemangiosarcomas showed immunoreactivity to OC. The sensitivity and specificity for OC in canine OSA in this study was 83% and 71% respectively. For ON, 100% of both OSAs (23/23) and non-OSAs (14/14) showed cytoplasmic immunoreactivity to this antibody, giving a sensitivity of 100% but a complete lack of specificity. There were no significant differences in immunoreactivity for OC and ON between the different decalcification agents used. In conclusion, OC showed high sensitivity for identifying OSA but it failed to distinguish between OSA and chondrosarcoma, and the osteoid produced by neoplastic cells in most cases did not show immunoreactivity to OC. These factors may limit the practical utility of OC in the diagnosis of OSA in dogs when chondrosarcoma is a differential diagnosis. ON showed no specificity in detecting OSA and has little practical application for the diagnosis of OSA in dogs.

Cartilaginous Tumors of the Larynx and Trachea in the Dog: Literature Review and 10 Additional Cases (1995-2014).

Cartilaginous tumors of the larynx and trachea are uncommon in the dog. The authors describe 10 cases diagnosed between 1995 and 2014 and review 16 cases in the literature. Seven of our cases were tracheal and 3 were laryngeal. Two of the laryngeal tumors were chondromas, which have not been previously reported in this site. The third laryngeal tumor was a myxochondroma. Of the 7 tracheal tumors, 6 arose from the ventral tracheal wall, including 2 that were extraluminal. Tracheal tumor types included chondrosarcoma (n = 3), chondroma (n = 2), and osteochondroma (n = 2). All of the laryngeal tumors and 5 of 7 of the tracheal tumors occurred in adult dogs (aged 5-11 years). The 2 tracheal osteochondromas were in young dogs (3-4 months) and were intrathoracic, while the remaining tracheal tumors were cervical. Surgical excision had a good outcome in most cases. Combining our 10 cases with the 16 previously reported cases showed that 6 (27%) of the affected dogs were Arctic breeds (Alaskan Malamute or Siberian Husky) suggesting a predisposition in this type of dog.

Description of the Anatomy, Surgical Technique, and Outcome of Hemipelvectomy in 4 Dogs and 5 Cats.

OBJECTIVE: To provide (1) a comprehensive description of hemipelvectomy; and (2) report clinical application and outcome of hemipelvectomy in dogs and cats. STUDY DESIGN: Descriptive report and retrospective case series. ANIMALS: Dogs (n = 4) and 5 cats. METHODS: Cadaveric dissection was performed for imaging purposes using 4 mixed breed dogs euthanatized for reasons unrelated to this study. Medical records (2005-2012) were reviewed for dogs and cats that had hemipelvectomy. Data collected included signalment, body weight, body condition score, clinical presentation, diagnostic imaging findings, location and extent of tumor, definitive diagnosis, use of adjuvant therapy, ability to ambulate postoperatively, complications, and survival. RESULTS: The most common indication for hemipelvectomy in cats was injection site sarcoma (ISS) and in dogs, osteosarcoma or peripheral nerve sheath tumor (PNST). Complete tumor excision was achieved in 6 (67%) cases. Incomplete excision occurred in 2 dogs with lumbosacral PNST and 1 cat having a 2nd surgery for ISS. Complications included intraoperative hemorrhage (n = 2), postoperative soft tissue infection (2), and discharge from the incision site (1). All but 1 animal were ambulatory at the time of discharge. Hospitalization ranged from 1-10 days (median, 4 days). Survival after surgery was individually assessed. CONCLUSION: With in-depth anatomic familiarity, hemipelvectomy can be successful for excision of neoplastic lesions of the proximal aspect of the pelvic limb, with only minor complications.

Ischiectomy With Limb Preservation for a Dog With Ischial Chondrosarcoma: Case Report and Surgical Technique.

OBJECTIVE: To describe the surgical technique for ischiectomy in the dog and to report the procedure in a case. STUDY DESIGN: Case report. ANIMAL: An 11-year-old spayed female mixed breed dog with chondrosarcoma of the ischium. METHODS: The dog presented for hindlimb lameness and evaluation after a radiographic finding of a lytic lesion confined to the left ischium. Following staging and confirmation of stage 1 disease, an ischiectomy with preservation of the hindlimb was performed. RESULTS: The dog recovered from surgery and was initially moderately lame on the hindlimb. Over time, the dog regained satisfactory hindlimb use and was alive >500 days postoperative with no evidence of local recurrence or metastatic disease. CONCLUSIONS: Ischiectomy with hindlimb preservation is a technically straight-forward procedure and in this case, resulted in good hindlimb function postoperatively. The procedure should be considered for the treatment of dogs with bone tumors confined to the ischium.

Hemipelvectomy: outcome in 84 dogs and 16 cats. A veterinary society of surgical oncology retrospective study.

OBJECTIVE: To report clinical findings, perioperative complications and long-term outcome in dogs and cats that had hemipelvectomy surgery for treatment of neoplasia. STUDY DESIGN: Multi-institutional retrospective case series. ANIMALS: Dogs (n = 84) and cats (16). METHODS: Medical records (January 2000 to December 2009) of dogs and cats that had hemipelvectomy at participating institutions were reviewed. Postoperative progress and current status of the patient at the time of the study was determined by either medical record review, or via telephone contact with the referring veterinarian or owner. RESULTS: Complications were infrequent and usually minor. Hemorrhage was the main intraoperative complication; 2 dogs required blood transfusion. One dog developed an incisional hernia. In dogs, hemangiosarcoma had the worst prognosis with a median survival time (MST) of 179 days. MST for chondrosarcoma (1232 days), osteosarcoma (533 days), and soft tissue sarcoma (373 days) were not statistically different. Median disease-free interval (DFI) for local recurrence of all tumor types was 257 days. Cats had 75% survival at 1 year, which was significantly longer than dogs. CONCLUSIONS: Survival times for most tumor types can be good, but surgical margins should be carefully evaluated to ensure complete tumor removal. Adjuvant therapies may be advisable particularly for dogs to reduce rates of local recurrence or distant metastasis.

Nasal clear cell chondrosarcoma in a dog.

An intranasal tumour was diagnosed in a 5-year-old male neutered crossbreed dog following a 6-8 week history of intermittent epistaxis and nasal discharge. Computed tomography identified a mass in the right nasal cavity. Histologically, the mass was composed of sheets and indistinct clusters of predominantly clear or vacuolated round to polygonal cells; periodic acid-Schiff staining revealed glycogen granules within some tumour cells. Immunohistochemical labelling revealed that the tumour cells were immunopositive for vimentin and S100 and negative for pancytokeratin, Melan-A and PNL2, supporting a diagnosis of a clear cell variant of chondrosarcoma (CCC). Although the dog was treated with meloxicam, the owners opted for euthanasia 9 days after presentation. Considering that there is only one other reported case of a suspected CCC in a dog, also in the nasal cavity, this could represent a species-specific predilection site of this rare canine neoplasm.

Clinical outcome of 42 dogs with scapular tumors treated by scapulectomy: a Veterinary Society of Surgical Oncology (VSSO) retrospective study (1995-2010).

OBJECTIVE: To report signalment, clinical signs, preoperative staging tests, histologic diagnosis, surgical, and oncologic outcomes including postoperative limb use, in dogs with scapular tumors treated by scapulectomy. STUDY DESIGN: Retrospective case series ANIMALS: Dogs (n = 42) with scapular tumors. METHODS: Medical records (1995-2010) from 6 hospitals were searched for dogs with scapular tumors treated by scapulectomy. Data retrieved were: signalment, weight, percentage of scapula removed, histologic diagnosis, postoperative limb use, adjunctive therapy, disease free interval (DFI), and survival time (ST). Individual variables were modeled with a Cox proportional hazard model accounting for censoring to determine risk factors for decreased DFI and ST. For categorical variables, Kaplan-Meier survival plots as well as mean and median survival times (MSTs) were calculated. RESULTS: Subtotal scapulectomy was performed in 18 dogs (42.9%). Osteosarcoma (OSA) was diagnosed in 27 dogs (64.3%). Limb use was evaluated immediately after surgery in 41 dogs. Information on limb use at other times (1, 2, 3, and >3 months) postoperatively was also available for some dogs and was good to excellent overall. Only adjunctive chemotherapy had a positive significant effect on DFI (P = .00011) and ST (P = .0003). CONCLUSION: Canine scapular tumors can be treated effectively by scapulectomy and limb use is fair to excellent for most dogs. OSA was the most common scapular tumor. Overall prognosis for scapular OSA is similar to appendicular OSA at other sites and use of adjunctive chemotherapy prolonged the overall DFI and MST.

Primary ocular chondrosarcoma in a discus (Symphisodon aequifasciatus).

An adult discus (Symphisodon aequifasciatus) with a history of buphthalmia and anorexia was referred, from an aquarium, for clinical examination. Surgery was performed to enucleate the eye and obtain a definitive diagnosis. Macroscopic examination revealed a yellowish mass that affected the eye. Histologic examination of the mass revealed a poorly demarcated, high cellular infiltrative mesenchymal neoplasm composed of ovoidal-spindloid cells with elongated nuclei and with scant cytoplasm arranged in a solid pattern. Throughout the tumor, there were scattered foci of cartilaginous differentiation that stained deeply with alcian blue and stained metachromatically with toluidine blue. The neoplastic cells were immunolabeled to varying degrees by antibodies against vimentin and SOX-9. Based on morphologic, histochemical, and immunohistochemical characteristics, the tumor was diagnosed as a chondrosarcoma.

Multi-organ metastases of primary chondrosarcoma of the mammary gland of a spayed Toy Poodle.

We report the clinical and histopathological findings associated with multi-organ metastases of primary mammary chondrosarcoma in a 12-year-old spayed female Toy Poodle. At post-mortem examination, multifocal, sharply demarcated, grey-white to bright brown, round nodules of variable size were randomly distributed in the lungs, myocardium, liver, pancreas, spleen, intestinal tract and kidneys. Histologically, immature cartilage structures and primitive mesenchymal cells were seen in these organs. Neoplastic cells located in the cartilaginous basophilic extracellular matrix had cytoplasmic vacuolation and round vesicular nuclei and were stained with Safranin O and Alcian blue. To the best of our knowledge, this is the first report of a multi-organ metastatic chondrosarcoma that originated in the mammary gland of a dog.

Synovial osteochondromatosis with malignant transformation to chondrosarcoma in a dog.

A 4.5-year-old intact male Labrador Retriever dog had a 1-month history of right forelimb lameness with painful swelling of the elbow. The radiographic findings of increased synovial mass with mineralized opacities and the gross and histologic findings in the synovial biopsy specimens were consistent with a diagnosis of primary (idiopathic) synovial osteochondromatosis. Twenty months after initial presentation, based on progression of clinical signs and radiographic evidence of marked bone lysis in the distal aspect of the humerus and proximal aspects of the radius and ulna, the affected leg was amputated. The histologic diagnosis was chondrosarcoma with fibroblastic differentiation and bone lysis. The chondrosarcoma was interpreted as malignant transformation of primary synovial osteochondromatosis.

Primary bone tumors in birds: a review and description of two new cases.

Primary bone tumors are only occasionally reported in avian species. This paper presents the cases of an osteosarcoma in a 6-yr-old free-range chicken and a chondrosarcoma in a 3-yr-old barred Plymouth Rock chicken. The well-differentiated, moderately productive osteoblastic osteosarcoma arose from the synsacral vertebrae and had metastasized to the liver. The chondrosarcoma was well differentiated and firmly attached to the left side of the keel. There was no evidence of metastasis.

Stereotactic radiotherapy (10 Gy X 3) for canine nonlymphomatous intranasal tumors is associated with prolonged survival and minimal risk of severe radiotoxicity.

OBJECTIVE: To describe oncologic outcomes following administration of a uniform stereotactic radiotherapy protocol (SRT; 10 Gy X 3) for canine intranasal tumors and to identify whether any clinical or dosimetric factors were predictive of event-free or overall survival time (EFST or OST). ANIMALS: 129 dogs. PROCEDURES: In this single-institution retrospective study, the medical records database was searched for canine nonlymphomatous intranasal tumors treated with 10 Gy X 3 SRT between August 2013 and November 2020. Findings regarding adverse effects and outcomes were analyzed overall, for dogs grouped on the basis of life stage (mature adult, senior, or end of life), and for treatment-related or tumor-related variables to identify potential predictors of outcome. RESULTS: After SRT, most dogs clinically improved with minimal acute radiotoxicity. The median EFST was 237 days; median OST was 542 days. Receipt of other tumor-directed therapies before or after SRT was associated with improved EFST in senior dogs (hazard ratio [HR], 0.416) and improved OST in mature adult (HR, 0.241) and senior dogs (HR, 0.348). In senior dogs, administration of higher near-minimum radiation doses was associated with improved EFST (HR, 0.686) and OST (HR, 0.743). In senior dogs, chondrosarcoma was associated with shorter OST (HR, 7.232), and in dogs at end of life, having a squamous cell or transitional carcinoma was associated with worse EFST (HR, 6.462). CLINICAL RELEVANCE: This SRT protocol results in improved quality of life and prolonged OST for dogs of all life stages. Radiation protocol optimization or use of multimodal therapy may further improve outcomes.

Tracheal chondrosarcoma in a blue tegu (Salvator merianae).

An 8-year-and-1-month-old female blue tegu (Salvator merianae) was brought to a clinician with severe cough. The patient died 11 days later despite supportive care, and necropsy was performed by a clinician. The lumen of the distal trachea was almost completely occluded by a milk-white, hard mass measuring 1 cm in diameter. Histopathologically, the mass comprised spindle-shaped to polygonal cells arranged in a loose sheet with abundant production of basophilic cartilaginous matrix, consistent with chondrosarcoma. Reports of tracheal neoplasms in reptiles are limited, and to the best of our knowledge this represents the first pathological documentation of tracheal chondrosarcoma in a reptile.

Novel radical pelvectomy technique to treat chondrosarcoma in a large-breed dog.

Surgical management of chondrosarcoma with hemipelvectomy is well described, but there have been no reports on extensive excision involving bilateral pubis and unilateral ischium. This report describes a novel pelvectomy technique for the treatment of chondrosarcoma in a large-breed dog. A 12-year-old Labrador Retriever presented for tenesmus due to a large, intra-pelvic mass which was confirmed on computed tomography (CT). Surgery involved removal of the entire left ischium and both pubic bones with preservation of both hind limbs. Histopathology confirmed the diagnosis of a high-grade chondrosarcoma with tumour-free margins of less than 3 mm. The dog recovered well following surgery and regained ambulation within 9 days. Four months postoperatively, the dog had no ongoing pain or tenesmus and only a mild gait abnormality in the left hind limb. Pelvectomy involving the entire pubis and unilateral ischium was well tolerated in a large-breed dog. This technique may offer a novel surgical option to treat neoplasia previously considered too extensive for complete excision.

Chondrosarcoma in the humerus of a goat.

The clinical, radiographical and histo-pathological findings of a chondrosarcoma in the humerus of a goat are discussed. An 11-year-old female Saanen goat was admitted for evaluation of chronic, progressive left forelimb lameness. Clinical examination revealed signs of pain in the shoulder region. Radiographs of the scapulohumeral joint showed a large lytic lesion of the proximal third of the humerus with cortical destruction, intralesional calcification and marked periosteal reactions. Differential diagnoses included aggressive bone lesions as seen with osteomyelitis or a primary bone tumour, such as osteosarcoma, chondrosarcoma or fibrosarcoma. The goat was euthanatized for humane reasons because of the poor prognosis. On the basis of the histopathological findings, the lesion was diagnosed as grade II chondrosarcoma. The tumour had already spread to the lungs and the left prescapular lymph node at the time of diagnosis.