Treatment of a malignant pheochromocytoma in a dog using 131I metaiodobenzylguanidine.

A 12 yr old castrated male Yorkshire terrier was presented with a history of an inoperable pheochromocytoma. Physical examination revealed a large, midabdominal mass. Neurologic examination was normal at presentation. An abdominal computed tomography scan revealed a 215 cm(3) mass in the region of the right kidney. Forty-eight hours after IV injection of 370 megabecquerels (MBq, equivalent to10 millicuries [mCi]) of metaiodobenzylguanidine labeled with radioactive iodine ([(131)I]MIBG), standard planar scintigraphy was performed. A diffuse area of moderate uptake was noted in the midabdominal region. The dog experienced stable disease for 1.5 mo after injection based on a follow-up computed tomography (CT) scan; however, 5 mo after injection, repeat CT imaging revealed progression of the tumor, and a second IV injection of 370 MBq (10 mCi) of [(131)I]MIBG was administered. The dog died 3 wk after the second injection as a result of gastrointestinal blood loss that was believed to be caused by compression-induced bowel ischemia by the mass. A full necropsy was not performed, but the mass was removed for histologic evaluation, which confirmed the diagnosis of pheochromocytoma. This report is the first to document the treatment of canine pheochromocytoma using [(131)I]MIBG.

Digital spot mammography using an add-on upright unit: diagnostic application in daily practice.

INTRODUCTION: To present the use of digital spot mammography (DSM) in a diagnostic practice. METHODS AND PATIENTS: Digital spot images of 779 women requiring a spot compression or a spot magnification view were collected. The digital images were acquired on a digital spot upright unit using a 61 mm x 61 mm field of view. Lesions reported included masses, calcifications, and areas of distortions. RESULTS: 1065 lesions required additional views with DSM. Lesions reported included masses (n = 113), masses and microcalcifications (n = 53), spiculated masses (n = 34), architectural distortions (n = 16), and microcalcifications (n = 849). DSMs were considered to be adequate in 97.7% of patients. Unsatisfactory exams resulted from difficulties encountered in targeting the area of interest at the beginning of our experience. CONCLUSION: DSM, most commonly used to perform interventional procedures, can also be used in a diagnostic practice taking advantage of post-processing of images not available with conventional spot compression and magnification.

Water transport in the kidney and nephrogenic diabetes insipidus.

Nephrogenic diabetes insipidus is caused by an inability of the kidney to concentrate urine despite adequate concentration of vasopressin in blood and is characterized by polyuria, polydipsia, and hyposthenuria in the presence of plasma hyperosmolality. Nephrogenic diabetes insipidus is the result of defects in water homeostasis in the kidney. Nephrogenic diabetes insipidus occurs when the kidneys cannot or do not respond to vasopressin. There are 2 categories of nephrogenic diabetes insipidus. Congenital nephrogenic diabetes insipidus is a rare, inherited, irreversible cause of polyuria and polydipsia in humans that is even rarer in animals. Acquired nephrogenic diabetes insipidus is more common and is often secondary to illness or medication that interferes with the action of vasopressin in the renal tubules. Unlike congenital nephrogenic diabetes insipidus, acquired or secondary nephrogenic diabetes insipidus is often reversible with correction of the associated or causative problem.

Gastrointestinal leiomyosarcoma in 14 dogs.

A retrospective review over a 5-year period was performed to identify clinical characteristic features and survival in 14 dogs with intestinal leiomyosarcoma after surgery. Anemia, hypoglycemia, polyuria, and polydipsia were identified as common clinical signs in these dogs. Dogs that survived the immediate postoperative period had a median survival of 21.3 months, (range 0.1-72.5 months). The 1- and 2-year survival rates were 75 and 66%, respectively. Dogs with intestinal leiomyosarcoma that survive the immediate postoperative period can experience long-term survival after surgical excision. Furthermore, dogs with histologically documented metastasis at the time of surgery also appear to have a long survival, with a mean survival of 21.7 months (range 4.2-41.5 months).

Evaluation of sensitivity and specificity of cytologic examination: 269 cases (1999-2000).

OBJECTIVE: To determine sensitivity and specificity of cytologic examination used in a clinical setting. DESIGN: Retrospective study. ANIMALS: 216 dogs, 44 cats, 4 horses, 2 ferrets, 1 llama, 1 rat, and 1 mouse. PROCEDURE: Records were reviewed of cases in which a cytologic diagnosis was followed by a surgical biopsy or postmortem examination within 3 days with subsequent histopathologic diagnosis. Diagnoses were compared for agreement at various levels, including complete agreement, partial agreement, no agreement, or no comparison possible because of insufficient or incorrect cytologic specimen. Levels of agreement were compared for different categories of lesions, including neoplastic, inflammatory, dysplastic-hyperplastic-other, and normal tissue. Additionally, levels of agreement for neoplastic lesions were categorized with regard to cell type, degree of malignancy, and location. Sensitivity and specificity of cytologic examination were calculated. RESULTS: At the level of general agreement (complete and partial agreement), the sensitivity of cytologic examination ranged from 33.3 to 66.1%, depending on the location of the lesion. Cytologic examination was most accurate when used to diagnose cutaneous and subcutaneous lesions and least accurate for diagnosis of liver lesions. Cytologic examination was most effective in diagnosis of neoplastic disease and least effective in diagnosis of dysplastic or hyperplastic conditions. CONCLUSIONS AND CLINICAL RELEVANCE: Cytologic examination is a valuable diagnostic tool, although our results indicated lower accuracy than previously reported. False-negative results (missing a diagnosis) were far more common than false-positive results (categorizing a healthy animal as diseased): therefore, if the clinical index of suspicion is high, cytologic examination should be repeated or another technique should be selected to rule out the suspected condition.