Hypertrophic osteopathy associated with hepatocellular carcinoma in a dog

A 9-year-old spayed female dog diagnosed with hepatocellular carcinoma and hypertrophic osteopathy was negative for additional lesions on computed tomography of the thorax and abdomen. Resection of the affected liver lobe resulted in resolution of clinical signs. This is the first case of hypertrophic osteopathy secondary to hepatocellular carcinoma.     

Hypertrophic osteopathy associated with pulmonary adenosquamous carcinoma in a dog

A six-year-old intact female Maltese dog weighing 3.8 kg presented with a history of mild lameness and swelling on both forelimbs. Radiographic and computed tomographic views revealed an extensive periosteal reaction in all four limbs and a large round mass on the right middle lung lobe. A total lobectomy was performed and pulmonary adenosquamous carcinoma was histologically confirmed. A diagnosis of hypertrophic osteopathy (HO) secondary to a lung tumor was made. Periosteal proliferation decreased significantly after surgery; however, there was evidence of dyspnea, mass recurrence, and periosteal reaction three months post-operatively. This is the first case report of pulmonary adenosquamous carcinoma with HO in a dog in which we describe clinical, imaging, surgical, and histological findings.     

Hypertrophic osteopathy associated with pulmonary Eikenella corrodens infection in a dog

CASE DESCRIPTION: A 4-year-old English Pointer was examined because of chronic, progressive signs of pulmonary disease and failure to respond to medical treatment. CLINICAL FINDINGS: At examination, radiography of the thorax revealed increased pulmonary opacity and air bronchograms in the right caudal lung lobe, and radiography of the forelimbs revealed periosteal bone production typical of hypertrophic osteopathy. Attempts to isolate a causative organism included bacterial culture of bronchoalveolar lavage fluid and a lung tissue specimen obtained via fine-needle aspiration. Despite a cytologic diagnosis of septic suppurative inflammation in the lavage fluid, those specimens did not yield bacterial growth. However, a biopsy specimen obtained during a lung lobectomy procedure yielded growth of Eikenella corrodens. TREATMENT AND OUTCOME: Despite successful surgical removal of the consolidated lung lobe and initiation of antimicrobial treatment, the dog died 6 days after surgery. CLINICAL RELEVANCE: The authors are not aware of reports of pulmonary infection with E. corrodens in animals. Infection with the organism is rare, but it is possible that infections are underreported given that the organism is difficult to culture and biopsy may be necessary to obtain enough tissue to yield a diagnosis.     

Hypertrophic osteopathy associated with renal pelvis transitional cell carcinoma in a dog

A 6-year-old male, Belgian shepherd dog was presented with lethargy, oliguria, hematuria, and reluctance to move. The dog developed hypertrophic osteopathy secondary to renal pelvis transitional cell carcinoma. A nephrectomy was performed and after a year, the dog was completely asymptomatic, and no evidence of metastatic disease was present.     

Hypertrophic osteopathy associated with infective endocarditis in an adult boxer dog

A 20-month-old, entire male boxer dog was presented with lethargy and intermittent shifting limb lameness. Diagnostic tests revealed aortic valve vegetations suggestive of infective endocarditis causing severe aortic outflow obstruction, and hypertrophic osteopathy of all four limbs. The dog was treated symptomatically and euthanased four days later. The association of infective endocarditis and hypertrophic osteopathy has been poorly documented in the veterinary literature. The pathogenesis of hypertrophic osteopathy is unknown; however, four theories have been put forth to explain this disease: pulmonary shunting, vagal nerve stimulation, humoral substances produced by neoplastic cells and megakaryocyte/platelet clump hypothesis.     

Hypertrophic osteopathy associated with a bronchial foreign body and lobar pneumonia in a dog

Hypertrophic osteopathy was diagnosed in a dog with a bronchial foreign body and lobar pneumonia. Hypertrophic osteopathy is generally associated with primary or secondary neoplasms of the lungs and rarely associated with nonneoplastic thoracic lesions. The foreign body and affected lung lobe were removed by pneumonectomy, resulting in recovery of the dog and resolution of the hypertrophic osteopathy lesions.     

Hypertrophic osteopathy in a dog with a chronic lung abscess

A 2-year-old dog was examined because of gradual lameness of all 4 limbs and weight loss. Hypertrophic osteopathy was diagnosed. Radiography revealed a mass in the caudal lobe of the right lung. At necropsy, the mass was determined to be a chronic abscess. Corynebacterium pyogenes was cultured from the lesion. Although hypertrophic osteopathy in dogs is commonly associated with a thoracic lesion, most often neoplastic, the chronic lung abscess in this dog might have been formed as a result of a paralaryngeal abscess that was treated 3 months before the onset of the lameness.     

Hypertrophic osteopathy associated with disseminated metastases of renal cell carcinoma in the dog: a case report

A 6-year-old, mixed breed, intact male dog showed signs of left carpal joint swelling and weakness of the forelimbs one month before presentation. The symptoms gradually progressed to bilateral carpal and tarsal joint swelling and tetraparalysis. There were a number of radiographically identified lytic-proliferative bone lesions noted on the axial skeleton. Hypertrophic osteopathy of the metacarpi and all distal long bones was also evident. Because of the deteriorating quality of life and guarded prognosis, the patient was euthanized and a complete necropsy was performed. Renal cell carcinoma, with metastasis to the lung, thoracic vertebrae, ribs, and the right adrenal gland, was diagnosed. To our knowledge, renal cell carcinoma with bone metastases and hypertrophic osteopathy has not been reported in dogs.     

Hypertrophic osteopathy in a pony with a pituitary adenoma

Hypertrophic osteopathy was diagnosed in a pony that had no antemortem or postmortem evidence of an intrathoracic lesion. With a history of hirsutism in an aged pony, a pituitary adenoma was suspected, and evaluation of plasma cortisol and insulin values and their response to thyrotropin-releasing hormone supported the diagnosis.     

Hypercalcaemia associated with a retroperitoneal apocrine gland adenocarcinoma in a dog

A seven-year-old, entire female golden retriever was presented with a history of polyuria/polydipsia and progressive dysuria. Clinical examination, radiography and ultrasonography demonstrated urinary retention due to a large soft tissue mass in the retroperitoneal space. Laboratory findings revealed paraneoplastic hypercalcaemia. Fine-needle aspiration cytology of the mass suggested an epithelial tumour, resembling an apocrine gland carcinoma of the anal sac. Following euthanasia and necropsy, the histopathological diagnosis of the retroperitoneal mass was apocrine gland adenocarcinoma. Despite ante- and postmortem examination, no perineal or anal sac tumour was found. The retroperitoneal tumour in this case could be a very large lymph node metastasis from an occult primary apocrine carcinoma of the anal sacs, or it could represent the first case of an ectopic apocrine gland carcinoma of the retroperitoneal space in a dog.     

Hypertrophic osteopathy in three horses and a pony.

Hypertrophic osteopathy was diagnosed in 3 horses and in a pony, ranging in age from 8 to 21 years. There were 2 females, 1 sexually intact male, and 1 gelding. In 3 animals, hypertrophic osteopathy was associated with pulmonary abscesses, bronchogenic squamous cell carcinoma, and ovarian granulosa-cell tumor, respectively, and resulted in death or euthanasia. Duration of the condition ranged from 1 to 4 months. In 1 horse, hypertrophic osteopathy was believed to be secondary to pregnancy, and resolved following uncomplicated delivery of a live foal.     

Hypertrophic osteopathy secondary to pulmonary sarcoma in a cat

A case of hypertrophic osteopathy secondary to a pulmonary spindle cell sarcoma is described. The 9‐year‐old male cat presented with a 1‐month history of decreased appetite, decreased activity and progressive lameness with swelling and pain of all four limbs. Thoracic radiographs showed a soft tissue opaque mass in the left caudal lung lobe. Radiographs of all limbs showed extensive periosteal new bone formation of uniform opacity demonstrating a ‘palisading’ pattern. The lung mass was removed at exploratory thoracotomy; histopathological examination diagnosed a low‐grade spindle cell sarcoma. Prior to surgery, the cat had a non‐specific conjunctivitis that resolved spontaneously following lobectomy raising the possibility of a paraneoplastic association. The lameness also resolved; six months after surgery, the periosteal palisading of new bone on the long bones had remodelled, and there was no evidence of pulmonary metastases.